JP7560345B2 - Dicing Tape - Google Patents

Description

The present invention relates to a dicing tape that can be used in the manufacturing process of a semiconductor device.

Conventionally, in the manufacture of semiconductor devices, a dicing tape or a dicing die bond film in which the dicing tape and die bond film are integrated may be used to separate a semiconductor wafer into semiconductor chips by a dicing process. Dicing tape has an adhesive layer provided on a base film, and is used to place a semiconductor wafer on the adhesive layer and fix and hold the separated semiconductor chips during dicing of the semiconductor wafer so that they do not scatter. The semiconductor chips are then peeled off from the adhesive layer of the dicing tape and attached to an adherend such as a lead frame, wiring board, or another semiconductor chip via a separately prepared adhesive or adhesive film.

A dicing die bond film is a die bond film (hereinafter sometimes referred to as "adhesive film" or "adhesive layer") that is removably provided on the adhesive layer of a dicing tape. In the manufacture of semiconductor devices, a semiconductor wafer is attached and placed on the die bond film of the dicing die bond film, and the semiconductor wafer is diced together with the die bond film to obtain individual semiconductor chips with adhesive film. The semiconductor chip is then peeled (picked up) together with the die bond film from the adhesive layer of the dicing tape as a semiconductor chip with die bond film, and the semiconductor chip is fixed to an adherend such as a lead frame, wiring board, or another semiconductor chip via the die bond film.

The above-mentioned dicing die bond film is preferably used from the viewpoint of improving productivity, but in recent years, methods for obtaining semiconductor chips with die bond film using dicing die bond film have been proposed, such as (1) a DBG (Dicing Before Grinding) method and (2) a Stealth Dicing (registered trademark) method, which are said to be able to suppress chipping when dividing thin semiconductor wafers into individual chips, instead of the conventional full-cut cutting method using a dicing blade that rotates at high speed.

In the DBG method (1) above, first, a dicing blade is used to form a dividing groove of a predetermined depth on the surface of the semiconductor wafer without completely cutting the semiconductor wafer, and then the back grinding is performed by appropriately adjusting the amount of grinding to obtain a divided body of a semiconductor wafer containing multiple semiconductor chips or a semiconductor wafer that can be diced into multiple semiconductor chips. Then, the divided body of the semiconductor wafer or the semiconductor wafer that can be diced into the semiconductor chips is attached to a dicing die bond film, and the dicing tape is expanded (hereinafter sometimes referred to as "cool expand") at a low temperature (for example, from -30°C to 0°C), so that the die bond film embrittled at low temperature is cut along the dividing groove into sizes corresponding to the individual semiconductor chips, or is cut together with the semiconductor wafer. Finally, the dicing tape is peeled off from the adhesive layer of the dicing tape by picking up, and individual semiconductor chips with the die bond film can be obtained.

In the stealth dicing method of (2) above, first, a semiconductor wafer is attached to a dicing die bond film, and a laser beam is irradiated inside the semiconductor wafer to selectively form a modified region (modified layer) while forming a dicing line. Then, the dicing tape is cool expanded to cause a crack to develop vertically from the modified region on the semiconductor wafer, and the semiconductor wafer is individually broken along the dicing line together with the die bond film embrittled at low temperature. Finally, the semiconductor chips with the die bond film are picked up and peeled off from the adhesive layer of the dicing tape to obtain individual semiconductor chips.
In the DBG method described above in (1), instead of forming a dividing (fracturing) groove on the surface of the semiconductor wafer with a dicing blade, a modified region can be selectively provided inside the semiconductor wafer by stealth dicing to obtain a semiconductor wafer that can be diced into individual pieces. This is a method called SDBG (Stealth Dicing Before Griding).

In the above pick-up process, after the semiconductor wafer with the die bond film is cut, the dicing tape is expanded at around room temperature (hereinafter sometimes referred to as "room temperature expansion") to widen the gap between adjacent individual semiconductor chips with the die bond film (hereinafter sometimes referred to as "kerf width"), and the outer peripheral portion of the dicing tape (the portion to which the semiconductor wafer is not attached) is thermally shrunk to fix the gap between the individual semiconductor chips (kerf width) while keeping it wide, so that the cut individual semiconductor chips with the die bond film can be peeled off from the adhesive layer of the dicing tape and picked up.

In recent years, as semiconductor wafers have become thinner, chip cracks have become more likely to occur during wire bonding in the multi-layer stacking process of semiconductor chips, and as a solution to this problem, a wire-embedded die bond film that also functions as a spacer has been proposed. Wire-embedded die bond films require the wires to be embedded without gaps during die bonding, and tend to be thicker and more fluid (low melt viscosity at high temperatures) than the conventional general-purpose die bond films mentioned above. Therefore, when such wire-embedded die bond films are laminated on conventional dicing tapes and used to manufacture semiconductor chips, the following problems arise:

In other words, in the above-mentioned cool expansion process, a cutting force (external stress) is applied from the cool-expanded dicing tape to the die bond film or semiconductor wafer with die bond film that is in close contact with the dicing tape. In conventional dicing tapes, where the tensile stress at low temperatures is not sufficiently large, the tensile stress is not large enough to provide a sufficient margin as an external stress sufficient to sufficiently cut the semiconductor wafer with the wire-embedded die bond film, and some of the intended cutting locations of the semiconductor wafer with the wire-embedded die bond film may not be cut. In addition, the spacing between the semiconductor chips (kerf width) may not be widened sufficiently, causing redeposition of the cut thick die bond films and collisions between the semiconductor chips, which may induce pick-up errors in the pick-up process.

Furthermore, in the semiconductor chip with the die bond film on the adhesive layer of the dicing tape that has been through the expanding process, the edge portion of the die bond film may partially peel off from the adhesive layer of the dicing tape. The more multi-layered the wiring circuit formed in advance on the semiconductor chip surface is, the more likely the semiconductor chip is to warp, partly due to the difference in thermal expansion coefficient between the wiring circuit and the semiconductor chip material, and the above partial peeling is likely to be promoted. If this partial peeling (hereinafter sometimes referred to as "floating") occurs to a large extent, it may cause the semiconductor chip with the die bond film to unintentionally fall off the dicing tape in a subsequent cleaning process, or may cause a pickup error due to the positional deviation of the semiconductor chip or the following phenomenon in a subsequent pick-up process. In particular, when the adhesive layer of the dicing tape is composed of an active energy ray (e.g., ultraviolet ray) curable adhesive composition, the adhesive layer is cured by irradiating ultraviolet rays to reduce the adhesive strength of the adhesive layer before picking up the semiconductor chip with the die bond film from the dicing tape. However, if the edge portion of the semiconductor chip with the die bond film is largely peeled off from the adhesive layer of the dicing tape, the adhesive layer in the peeled portion may come into contact with oxygen in the air, and the adhesive layer may not be sufficiently cured even when irradiated with ultraviolet rays. In such a case, since the adhesive strength of the adhesive layer is not sufficiently reduced, in the pick-up process, when the dicing tape is pushed up from the underside with a push-up jig with a large area of the push-up portion and a suction collet is brought into contact with the top of the semiconductor chip to pick up the semiconductor chip located on the jig, the edge portion of the semiconductor chip with the die bond film re-adheres to the insufficiently cured adhesive layer, and the phenomenon that the semiconductor chip with the die bond film cannot be picked up from the adhesive layer of the dicing tape is likely to occur.

Therefore, while vigorous research is being conducted into the control of the balance between cleavability and fluidity and the improvement of reliability for die bond films, there is a strong demand for dicing tapes that can be cleaved well together with the semiconductor wafer by expanding, are less likely to peel partially from the adhesive layer of the die bond film, and ultimately achieve good pick-up properties, even when using thicker die bond films with high fluidity such as wire-embedded die bond films as well as conventional die bond films.

As a conventional technique for preventing the above-mentioned breakage problems during expansion and partial peeling after expansion, Patent Document 1 discloses a dicing tape that has a laminated structure including a substrate and an adhesive layer, with the aim of preventing the die bond film on the dicing tape from lifting or peeling off during the expansion process, and that can exhibit a tensile stress in the range of 15 to 32 MPa at at least a portion of the strain value in the range of 5 to 30% in a tensile test under specific conditions.

On the other hand, when handling dicing tape, the dicing tape may be attached to the die bond film under heating conditions, and the dicing die bond film may be attached to the semiconductor wafer under heating conditions. Furthermore, when precutting into a dicing die bond film, the dicing tape may be locally heated to peel off and remove excess dicing tape without cutting. If the dicing tape has low heat resistance, it may stick to the work table (die) and become difficult to peel off. In addition, if the dicing tape is deformed by heat, such as warping or warping, the thinned semiconductor wafer may be deformed. For this reason, the dicing tape is required to have good breakability of the semiconductor wafer with the die bond film described above, good adhesion to the die bond film up to the pick-up process, good pick-up ability, and heat resistance.

As a conventional technique for improving the heat resistance, Patent Document 2 discloses a dicing film substrate that has excellent heat resistance and a good balance between severability (breakability) and expandability, and includes at least one layer of a resin composition that contains 30 parts by mass or more and 95 parts by mass or less of at least one resin (A) selected from the group consisting of ethylene-unsaturated carboxylic acid copolymers and ionomers of the ethylene-unsaturated carboxylic acid copolymers, 5 parts by mass or more and less than 40 parts by mass of at least one resin (B) selected from the group consisting of polyamides and polyurethanes, and 0 parts by mass or more and 30 parts by mass or less of an antistatic agent (C) other than the polyamide (wherein the total of resin (A), resin (B), and antistatic agent (C) is 100 parts by mass).

JP 2019-16787 A JP 2017-98369 A

Regarding the dicing tape in Patent Document 1, the examples show that a semiconductor wafer division body is attached to a dicing die bond film formed by laminating a dicing tape capable of exhibiting specific tensile stress characteristics and a 10 μm-thick die bond film mainly made of acrylic resin, and the die bond film is then cool expanded, thereby showing that the die bond film is successfully divided (fractured). However, in the die bond film after fracturing, the area where the dicing tape is lifted from the adhesive layer may be about 20%, so there is still room for improvement. In addition, there is no mention of the fracturing property of a thick, highly fluid wire-embedded die bond film, the pick-up property of a semiconductor chip, or the heat resistance of the dicing tape, and these points are unclear. At least, the polyvinyl chloride substrate as the dicing tape shown in the examples does not have sufficient heat resistance.

In addition, with regard to the dicing film substrate in Patent Document 2, the examples state that the dicing film substrate containing at least one layer made of a specific resin composition has excellent heat resistance and an excellent balance between the ability to sever (break) semiconductor wafers and expandability, and that its use as a dicing film allows the dicing process and the subsequent expansion process during semiconductor manufacturing to be carried out smoothly, making it possible to manufacture semiconductors without tape residue or deformation. However, there is no recognition of issues such as the breakability of die bond films, including wire-embedded types, or cool expansion, or the occurrence of partial peeling (lifting) of the die bond film from the adhesive layer of the dicing tape, and these points, including the pick-up ability of semiconductor chips, are unclear.

As described above, when the dicing tape of the conventional technology is laminated with a highly fluid and thick die bond film such as a wire-embedded die bond film and used as a dicing die bond film in the semiconductor chip manufacturing process, it cannot be said to be fully satisfactory from many standpoints, such as the cleavability of the semiconductor wafer with the die bond film during cool expansion, the prevention of partial peeling (lifting) of the die bond film from the adhesive layer after expansion, and the pick-up ability and heat resistance of the semiconductor chip, and there is still room for improvement.

The present invention was made in consideration of the above problems and circumstances, and aims to provide a dicing tape that, even when used as a dicing tape for semiconductor manufacturing processes by laminating a die bond film that has high fluidity and is thick, such as a wire-embedded die bond film, (1) has excellent heat resistance, (2) allows a semiconductor wafer with a die bond film to be satisfactorily cleaved by cool expansion, and allows a sufficient kerf width to be secured by room temperature expansion, and (3) sufficiently prevents partial peeling (lifting) of the die bond film after cleavage from the adhesive layer of the dicing tape, allowing for good pick-up of each cleaved semiconductor chip with a die bond film.

As a result of intensive research conducted by the inventors to solve the above problems with the above objective in mind, they discovered that the above problems can be solved by (1) using, as the base film of the dicing tape, a resin film having a predetermined tensile stress property value, which is composed of a resin containing a resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer and a polyamide resin (B) in a specific mass ratio, and (2) using, as the adhesive composition, an active energy ray-curable adhesive composition containing, as a main component, an acrylic adhesive polymer having a hydroxyl value within a specific range, and having a residual hydroxyl group concentration and an active energy ray-reactive carbon-carbon double bond concentration within a specific range, and thus completing the present invention.

That is, the dicing tape of the present invention has the following features:
A pressure-sensitive adhesive layer including an active energy ray-curable pressure-sensitive adhesive composition and disposed on the base film,
(1) The base film contains a resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer and a polyamide resin (B),
the base film is composed of a resin composition in which the mass ratio (A):(B) of the resin (A) to the resin (B) in the entire base film is in the range of 72:28 to 95:5;
the stress at 5% elongation at −15° C. is in the range of 15.5 MPa or more and 28.5 MPa or less when the base film is stretched in either the MD direction (the machine direction during the production of the base film) or the TD direction (the direction perpendicular to the MD direction);
(2) The active energy ray-curable pressure-sensitive adhesive composition comprises an acrylic pressure-sensitive adhesive polymer having an active energy ray-reactive carbon-carbon double bond and a hydroxyl group, a photopolymerization initiator, and a polyisocyanate-based crosslinking agent that crosslinks with the hydroxyl group;
The acrylic adhesive polymer has a main chain glass transition temperature (Tg) in the range of −65° C. or more and −50° C. or less, and a hydroxyl value in the range of 12.0 mg KOH/g or more and 55.0 mg KOH/g or less,
In the active energy ray-curable pressure-sensitive adhesive composition,
an equivalent ratio (NCO/OH) of an isocyanate group (NCO) of the polyisocyanate crosslinking agent to a hydroxyl group (OH) of the acrylic adhesive polymer is in the range of 0.02 or more and 0.20 or less;
the concentration of residual hydroxyl groups after the crosslinking reaction is in the range of 0.18 mmol or more and 0.90 mmol or less per 1 g of the active energy ray-curable pressure-sensitive adhesive composition,
The concentration of active energy ray-reactive carbon-carbon double bonds is in the range of 0.85 mmol or more and 1.60 mmol or less per gram of the active energy ray-curable pressure-sensitive adhesive composition.

In one embodiment, the active energy ray reactive carbon-carbon double bond concentration is in the range of 1.02 mmol or more and 1.51 mmol or less per gram of the active energy ray curable adhesive composition.

In one embodiment, the acrylic adhesive polymer has a weight average molecular weight Mw in the range of 200,000 or more and 600,000 or less.

In one embodiment, the acrylic adhesive polymer has an acid value in the range of 0 mgKOH/g or more and 9.0 mgKOH/g or less .

According to the present invention, even when a die bond film with high fluidity and a large thickness, such as a wire-embedded die bond film, is laminated as a dicing tape for use in the semiconductor manufacturing process, it is possible to provide a dicing tape that (1) has excellent heat resistance, (2) allows the semiconductor wafer with the die bond film to be satisfactorily cleaved by cool expansion and ensures a sufficient kerf width by room temperature expansion, (3) sufficiently prevents partial peeling (lifting) of the die bond film after cleavage from the adhesive layer of the dicing tape, and (4) allows for good pick-up of each cleaved semiconductor chip with the die bond film.

1 is a cross-sectional view showing an example of the configuration of a base film of a dicing tape to which the present embodiment is applied. 1 is a cross-sectional view showing an example of a configuration of a dicing tape to which the present embodiment is applied. 1 is a cross-sectional view showing an example of a dicing die-bonding film having a configuration in which a dicing tape to which the present embodiment is applied is laminated to a die-bonding film. 1 is a flowchart illustrating a method for manufacturing a dicing tape. 1 is a flowchart illustrating a method for manufacturing a semiconductor chip. 1 is a perspective view showing a state in which a ring frame (wafer ring) is attached to the outer edge of a dicing die bond film and a semiconductor wafer that has been processed to be dicable is attached to the center of the die bond film. 1A to 1F are cross-sectional views showing an example of a grinding step of a semiconductor wafer in which a plurality of modified regions have been formed by laser light irradiation, and a bonding step of the semiconductor wafer to a dicing die bond film. 1A to 1F are cross-sectional views showing an example of manufacturing a semiconductor chip using a thin-film semiconductor wafer having a plurality of modified regions to which a dicing die bond film is attached. FIG. 1 is a schematic cross-sectional view of one embodiment of a semiconductor device having a stacked structure using a semiconductor chip manufactured using a dicing die-bonding film in which a dicing tape to which this embodiment is applied is bonded to a die-bonding film. FIG. 11 is a schematic cross-sectional view of one embodiment of another semiconductor device using a semiconductor chip manufactured using a dicing die-bonding film configured by laminating a dicing tape to which this embodiment is applied and a die-bonding film . 1A to 1C are schematic diagrams for explaining a method for measuring the adhesive strength of a pressure-sensitive adhesive layer of a dicing tape to a die-bonding film (adhesive layer) after UV irradiation. FIG. 2 is a schematic diagram for explaining a method for measuring the shear adhesive strength at −30° C. of a pressure-sensitive adhesive layer of a dicing tape to a die-bonding film (adhesive layer). FIG. 13 is a plan view for explaining a method for measuring the distance (kerf width) between semiconductor chips after expansion. 14 is an enlarged plan view of the central portion of the semiconductor wafer in FIG. 13.

Below, a preferred embodiment of the present invention will be described in detail, with reference to the drawings as necessary. However, the present invention is not limited to the following embodiment.

(Configuration of dicing tape and dicing die bond film)
1A to 1D are cross-sectional views showing an example of the configuration of a substrate film 1 of a dicing tape to which this embodiment is applied. The substrate film 1 of the dicing tape of this embodiment may be a single layer of a single resin composition (see FIG. 1A 1-A), a laminate of multiple layers of the same resin composition (see FIG. 1B 1-B), or a laminate of multiple layers of different resin compositions (see FIG. 1C 1-C and FIG. 1D 1-D). When a laminate of multiple layers is used, the number of layers is not particularly limited, but is preferably in the range of 2 to 5 layers.

2 is a cross-sectional view showing an example of the configuration of a dicing tape to which this embodiment is applied. As shown in FIG. 2, the dicing tape 10 has a configuration in which an adhesive layer 2 is provided on the first surface of a base film 1. Although not shown, the surface of the adhesive layer 2 of the dicing tape 10 (the surface opposite to the surface facing the base film 1) may be provided with a base sheet (release liner) having releasability. The base film 1 is composed of a resin composition containing a resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer and a polyamide resin (B). As the adhesive that forms the adhesive layer 2, for example, an active energy ray curable acrylic adhesive that hardens and shrinks when irradiated with active energy rays such as ultraviolet rays (UV) to reduce the adhesive force to the adherend is used.

The dicing tape 10 having such a configuration is used, for example, as follows in the semiconductor manufacturing process. A semiconductor wafer with a dividing groove formed on its surface by a blade or a semiconductor wafer with a modified layer formed inside by a laser is attached and held (temporarily fixed) on the adhesive layer 2 of the dicing tape 10, and the semiconductor wafer is cleaved into individual semiconductor chips by cool expansion, after which the kerf width between the semiconductor chips is sufficiently expanded by room temperature expansion, and the individual semiconductor chips are peeled off from the adhesive layer 2 of the dicing tape 10 by a pick-up process. The obtained semiconductor chips are fixed to an adherend such as a lead frame, wiring board, or another semiconductor chip via a separately prepared adhesive or adhesive film.

Figure 3 is a cross-sectional view showing an example of a structure in which a dicing tape 10 to which this embodiment is applied is bonded and integrated with a die bond film (adhesive film) 3, a so-called dicing die bond film. As shown in Figure 3, the dicing die bond film 20 has a structure in which a die bond film (adhesive film) 3 is releasably adhered and laminated onto the adhesive layer 2 of the dicing tape 10.

The dicing die bond film 20 having such a configuration is used, for example, as follows in the semiconductor manufacturing process. A semiconductor wafer with a dividing groove formed on the surface by a blade or a semiconductor wafer with a modified layer formed inside by a laser is attached and held (adhered) on the die bond film 3 of the dicing die bond film 20, and the semiconductor wafer is cut together with the die bond film 3 by cool expansion to obtain individual semiconductor chips with the die bond film 3. Alternatively, a semiconductor wafer is attached and held (adhered) on the die bond film 3 of the dicing die bond film 20, and a modified layer is formed inside the semiconductor wafer by a laser in that state, and then the semiconductor wafer is cut together with the die bond film 3 by cool expansion to obtain individual semiconductor chips with the die bond film 3. Next, the kerf width between the semiconductor chips with the die bond film 3 is sufficiently expanded by room temperature expansion, and then the individual semiconductor chips with the die bond film 3 are peeled off from the adhesive layer 2 of the dicing tape 10 by a pick-up process. The obtained semiconductor chip with the die bond film (adhesive film) 3 is fixed to an adherend such as a lead frame, a wiring board, or another semiconductor chip via the die bond film (adhesive film) 3. Although not shown, the surface of the adhesive layer 2 of the dicing tape 10 (the surface opposite to the surface facing the base film 1) and the surface of the die bond film 3 (the surface opposite to the surface facing the adhesive layer 2) may each be provided with a base sheet (release liner) having releasability.

<Dicing tape>
(Base film)
The substrate film 1, which is the first constituent element of the dicing tape 10 of the present invention, will be described below. The substrate film 1 is a resin film made of a resin composition containing a resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer (hereinafter, sometimes simply referred to as an "ionomer"), and a polyamide resin (B).

The total amount of the resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer and the polyamide resin (B) in the entire base film 1 is not particularly limited as long as the stress of the base film 1 at 5% elongation at -15°C is within the above range, but it is preferable that it accounts for 75% by mass or more of the total amount of the resin composition constituting the entire base film 1. It is more preferable that it is 80% by mass, and particularly preferably 90% by mass or more.

The dicing tape 10 using the base film 1 of such a configuration, with the die bond film 3 adhered to the adhesive layer 2, is suitable for use in the cool expansion process and even the room temperature expansion process in the manufacturing process of semiconductor devices. That is, the cool expansion process is suitable for satisfactorily cleaving a semiconductor wafer with the die bond film 3 that has been processed so as to be singulated along the intended dicing line to obtain individual semiconductor chips with the die bond film 3 of a predetermined size with a good yield. Furthermore, even in the room temperature expansion process, the expandability required to ensure a sufficient kerf width between semiconductor chips is maintained.

[Resin (A) composed of ionomer of ethylene-unsaturated carboxylic acid copolymer]
In the base film 1 of the present embodiment, the resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer is an ethylene-unsaturated carboxylic acid copolymer in which some or all of the carboxyl groups have been neutralized with a metal (ion). In the following description, the "resin made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer" may be referred to as the "resin made of an ionomer" or simply as the "ionomer".

The ethylene-unsaturated carboxylic acid copolymer constituting the ionomer is at least a binary copolymer in which ethylene and an unsaturated carboxylic acid are copolymerized, and may be a ternary or higher multi-component copolymer in which a third copolymerization component is further copolymerized. The ethylene-unsaturated carboxylic acid copolymer may be used alone, or two or more types of ethylene-unsaturated carboxylic acid copolymers may be used in combination.

Examples of the unsaturated carboxylic acid constituting the ethylene-unsaturated carboxylic acid binary copolymer include unsaturated carboxylic acids having 4 to 8 carbon atoms, such as acrylic acid, methacrylic acid, ethacrylic acid, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, maleic acid, and maleic anhydride. In particular, acrylic acid or methacrylic acid is preferred.

When the ethylene-unsaturated carboxylic acid copolymer is a ternary or higher multi-component copolymer, in addition to the ethylene and unsaturated carboxylic acid constituting the binary copolymer, a third copolymer component forming a multi-component copolymer may be included. Examples of the third copolymer component include unsaturated carboxylic acid esters (e.g., (meth)acrylic acid alkyl esters having 1 to 12 carbon atoms in the alkyl portion, such as methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, dimethyl maleate, and diethyl maleate), unsaturated hydrocarbons (e.g., propylene, butene, 1,3-butadiene, pentene, 1,3-pentadiene, 1-hexene, etc.), vinyl esters (e.g., vinyl acetate, vinyl propionate, etc.), oxides such as vinyl sulfate and vinyl nitrate, halogen compounds (e.g., vinyl chloride, vinyl fluoride, etc.), vinyl group-containing primary and secondary amine compounds, carbon monoxide, and sulfur dioxide, and unsaturated carboxylic acid esters are preferred as the copolymer component.

The ethylene-unsaturated carboxylic acid copolymer may be in the form of a block copolymer, a random copolymer, or a graft copolymer, or may be in the form of a binary copolymer or a ternary copolymer. Among these, from the viewpoint of industrial availability, a binary random copolymer, a ternary random copolymer, a graft copolymer of a binary random copolymer, or a graft copolymer of a ternary random copolymer is preferred, and a binary random copolymer or a ternary random copolymer is more preferred.

Specific examples of the ethylene-unsaturated carboxylic acid copolymer include binary copolymers such as ethylene-acrylic acid copolymer and ethylene-methacrylic acid copolymer, and ternary copolymers such as ethylene-methacrylic acid-2-methyl-propyl acrylate copolymer. In addition, commercially available products that are marketed as ethylene-unsaturated carboxylic acid copolymers may be used, such as the Nucrel series (registered trademark) manufactured by DuPont-Mitsui Polychemicals.

In the ethylene-unsaturated carboxylic acid copolymer, the copolymerization ratio (mass ratio) of the unsaturated carboxylic acid ester is preferably in the range of 1% by mass to 20% by mass, and more preferably in the range of 5% by mass to 15% by mass from the viewpoints of expandability in the expanding process and heat resistance (blocking, fusion).

In the base film 1 of this embodiment, the ionomer used as the resin (A) is preferably one in which the carboxyl groups contained in the ethylene-unsaturated carboxylic acid copolymer are crosslinked (neutralized) at any ratio with metal ions. Metal ions used to neutralize the acid groups include lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions, zinc ions, magnesium ions, manganese ions, and other metal ions. Among these metal ions, magnesium ions, sodium ions, and zinc ions are preferred because of the ease of availability of industrialized products, and sodium ions and zinc ions are more preferred.

The neutralization degree of the ethylene-unsaturated carboxylic acid copolymer in the ionomer is preferably in the range of 10 mol% or more and 85 mol% or less, and more preferably in the range of 15 mol% or more and 82 mol % or less. By making the neutralization degree 10 mol% or more, the breakability of the semiconductor wafer with the die bond film can be further improved, and by making it 85 mol% or less, the film formability of the film can be further improved. The neutralization degree is the blending ratio (mol%) of metal ions to the number of moles of acid groups, particularly carboxyl groups, possessed by the ethylene-unsaturated carboxylic acid copolymer.

The resin (A) made of the ionomer has a melting point of about 85 to 100°C, and the melt flow rate (MFR) of the resin (A) made of the ionomer is preferably in the range of 0.2 g/10 min to 20.0 g/10 min, more preferably in the range of 0.5 g/10 min to 20.0 g/10 min, and even more preferably in the range of 0.5 g/10 min to 18.0 g/10 min. If the melt flow rate is within the above range, the film formability of the base film 1 is good. The MFR is a value measured at 190°C and a load of 2160 g according to a method conforming to JIS K7210-1999.

The resin composition constituting the base film 1 of this embodiment further contains a polyamide resin (B) in addition to the resin (A) made of the ionomer of the ethylene-unsaturated carboxylic acid copolymer described above. By constituting the base film 1 from a resin composition in which the mass ratio (A):(B) of the resin (A) made of the ionomer of the ethylene-unsaturated carboxylic acid copolymer and the polyamide resin (B) is mixed in the range of 72:28 to 95:5, not only can the heat resistance of the base film 1 be improved, but the tensile stress when stretched at a low temperature (for example, -15°C) can also be increased. By setting the tensile stress within an appropriate range, the dicing tape 10 using the base film 1 can be given a good breaking force that can individually separate semiconductor wafers with wire-embedded die bond films 3 with good yield in the cool expansion process, and further, in the room temperature expansion process, good expandability that can sufficiently secure the kerf width between semiconductor chips can be maintained. The mass ratio (A):(B) is preferably in the range of 74:26 to 92:8, more preferably in the range of 80:20 to 90:10. The upper and lower limits of the numerical ranges in this specification can be arbitrarily selected and combined.

[Polyamide resin (B)]
Examples of the polyamide resin (B) include polycondensates of carboxylic acids such as oxalic acid, adipic acid, sebacic acid, dodecanoic acid, terephthalic acid, isophthalic acid, and 1,4-cyclohexanedicarboxylic acid with diamines such as ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, decamethylenediamine, 1,4-cyclohexyldiamine, and m-xylylenediamine; ring-opening polymers of cyclic lactams such as ε-caprolactam and ω-laurolactam; polycondensates of aminocarboxylic acids such as 6-aminocaproic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid; and copolymers of the above-mentioned cyclic lactams, dicarboxylic acids, and diamines.

The polyamide resin (B) may be a commercially available product. Specific examples include nylon 4 (melting point 268°C), nylon 6 (melting point 225°C), nylon 46 (melting point 240°C), nylon 66 (melting point 265°C), nylon 610 (melting point 222°C), nylon 612 (melting point 215°C), nylon 6T (melting point 260°C), nylon 11 (melting point 185°C), nylon 12 (melting point 175°C), nylon copolymers (e.g., nylon 6/66, nylon 6/12, nylon 6/610, nylon 66/12, nylon 6/66/610, etc.), nylon MXD6 (melting point 237°C), nylon 46, etc. Among these polyamides, nylon 6 and nylon 6/12 are preferred from the viewpoint of film-forming properties and mechanical properties as the base film 1.

The content of the polyamide resin (B) is an amount such that the mass ratio (A):(B) of the resin (A) composed of the ionomer of the ethylene-unsaturated carboxylic acid copolymer to the polyamide resin (B) in the entire base film 1 is in the range of 72:28 to 95:5. If the mass ratio of the polyamide resin (B) is less than the above range, the effect of improving the heat resistance of the base film 1 and the effect of increasing the tensile stress at low temperatures may be insufficient. On the other hand, if the mass ratio of the polyamide resin (B) exceeds the above range, stable film formation may be difficult depending on the resin composition of the base film 1. In addition, the flexibility of the base film 1 may be impaired, and the expandability may not be maintained in the room temperature expansion process, or a pickup failure may occur due to cracking of the semiconductor chip when picking up the semiconductor chip with the die bond film 3. The content of the polyamide resin (B) is preferably such that the mass ratio (A):(B) of the resin (A) made of the ionomer of the ethylene-unsaturated carboxylic acid copolymer to the polyamide resin (B) in the entire base film 1 is in the range of 74:26 to 92:8.

When the base film 1 is a laminate consisting of multiple layers, the mass ratio of the resin (A) consisting of the ionomer of the ethylene-unsaturated carboxylic acid copolymer and the polyamide resin (B) refers to the value in the entire base film 1 (laminate) calculated from the mass ratio of the resin (A) consisting of the ionomer of the ethylene-unsaturated carboxylic acid copolymer and the polyamide resin (B) in each layer and the mass ratio of each layer in the entire base film 1 (laminate).

When the mass ratio of the resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer and the polyamide resin (B) in the entire base film 1 is within the above range, the heat resistance of the base film 1 can be improved to about 120 to 140°C, and in the cool expansion process when the base film 1 is processed into the shape of a dicing tape 10 and used in the manufacturing process of a semiconductor device, a tensile stress suitable for cleaving both the semiconductor wafer processed to be able to be diced and the die bond film 3 attached to the semiconductor wafer along the planned dicing line with good yield can be generated. Furthermore, even in the room temperature expansion process, it is possible to generate expandability that can sufficiently secure the kerf width between the cleaved semiconductor chips.

[others]
The resin composition constituting the substrate film 1 may contain other resins or various additives as necessary, as long as the effect of the present invention is not impaired. Examples of the other resins include polyolefins such as polyethylene and polypropylene, ethylene-unsaturated carboxylic acid copolymers, and polyether ester amides. Such other resins can be blended in an amount of, for example, 20 parts by mass or less per 100 parts by mass of the resin (A) made of the ionomer of the ethylene-unsaturated carboxylic acid copolymer and the polyamide resin (B). Examples of the additives include antistatic agents, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, pigments, dyes, lubricants, antiblocking agents, antifungal agents, antibacterial agents, flame retardants, flame retardant assistants, crosslinking agents, crosslinking assistants, foaming agents, foaming assistants, inorganic fillers, and fiber reinforcements. Such various additives can be blended in an amount of, for example, 5 parts by mass or less per 100 parts by mass of the resin (A) made of the ionomer of the ethylene-unsaturated carboxylic acid copolymer and the polyamide resin (B).

[Tensile stress of base film]
The tensile stress of the base film 1 at 5% elongation at -15 ° C. is in the range of 15.5 MPa to 28.5 MPa, regardless of whether the base film 1 is elongated in the MD direction (the flow direction during film formation of the base film) or the TD direction (the direction perpendicular to the MD direction). By setting the tensile stress of the base film 1 at -15 ° C. at 5% elongation within the above range, in the cool expansion process when the base film 1 is processed into the shape of a dicing tape 10 and used in the manufacturing process of a semiconductor device, the internal stress generated by the tension of the dicing tape 10 in all directions can become an external stress of sufficient magnitude to easily cleave the semiconductor wafer processed to be diced and the die bond film 3 attached to the semiconductor wafer along the planned dicing line. Furthermore, even in the room temperature expansion process, the kerf width between the cleaved semiconductor chips can be sufficiently secured. Furthermore, the low angle adhesive force of the dicing tape 10 to the die bond film 3 after ultraviolet (UV) irradiation can be appropriately reduced. As a result, in the dicing process, it is possible to improve the cleavage yield of the semiconductor chip with the die bond film 3. Furthermore, it is possible to suppress the induction of pick-up errors in the pick-up process. The tensile stress is preferably in the range of 16.0 MPa or more and 27.4 MPa or less, more preferably in the range of 17.3 MPa or more and 24.8 MPa or less.

[Thickness of base film]
The thickness of the base film 1 is not particularly limited, but considering its use as a dicing tape 10, it is preferably in the range of, for example, 70 μm or more and 120 μm or less. More preferably, it is in the range of 80 μm or more and 100 μm or less. If the thickness of the base film 1 is less than 70 μm, there is a risk that the ring frame (wafer ring) will not be held sufficiently when the dicing tape 10 is subjected to a dicing process. In addition, if the thickness of the base film 1 exceeds 120 μm, there is a risk that the warping of the base film 1 due to the release of residual stress during film formation will become large.

[Configuration of base film]
The structure of the base film 1 is not particularly limited, and may be a single layer of a single resin composition, a laminate of multiple layers of the same resin composition, or a laminate of multiple layers of different resin compositions. In the case of a laminate of multiple layers, the number of layers is not particularly limited, but is preferably in the range of 2 to 5 layers.
When the base film 1 is a laminate consisting of multiple layers, for example, it may be configured such that multiple layers formed using the resin composition of the present embodiment are laminated, or a layer formed using the resin composition of the present embodiment is laminated with a layer formed using a resin composition other than the resin composition of the present embodiment. However, the mass ratio (A):(B) of the resin (A) consisting of the ionomer of the ethylene-unsaturated carboxylic acid copolymer to the polyamide resin (B) in the entire laminate needs to be adjusted to be in the range of 72:28 to 95:5.

Examples of layers formed using the other resin compositions include linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), ethylene-α-olefin copolymer, polypropylene, ethylene-unsaturated carboxylic acid copolymer, ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid alkyl ester terpolymer, ethylene-unsaturated carboxylic acid alkyl ester copolymer, ethylene-vinyl ester copolymer, ethylene-unsaturated carboxylic acid alkyl ester-carbon monoxide copolymer, or a single or blend of any of these unsaturated carboxylic acid grafts, and a layer formed using a resin composition such as the ionomer (A) of the ethylene-unsaturated carboxylic acid copolymer. Among these, from the viewpoint of adhesion to the resin layer formed of the mixture of the resin (A) of the ionomer of the ethylene-unsaturated carboxylic acid copolymer of the present embodiment and the polyamide resin (B) and versatility, ethylene-unsaturated carboxylic acid copolymer, ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid alkyl ester terpolymer, ethylene-unsaturated carboxylic acid alkyl ester copolymer, and ionomers of these copolymers are preferred.

Specific examples of the base film 1 of the present embodiment having a laminated structure include base films having the following two-layer structure, three-layer structure, and the like.
As a two-layer structure, for example,
(1) [Resin layer (AB-1) made of a mixture of resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer of the present embodiment and polyamide resin (B)]/[Resin layer (AB-1) made of a mixture of resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer of the present embodiment and polyamide resin (B)],
(2) [Resin layer (AB-1) made of a mixture of resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer of the present embodiment and polyamide resin (B)]/[Resin layer (AB-2) made of a mixture of resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer of the present embodiment and polyamide resin (B)],
(3) [Resin layer (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer: (A-1)]/[Resin layer (A) made of a mixture of an ionomer of an ethylene-unsaturated carboxylic acid copolymer of the present embodiment and a polyamide resin (B): (AB-1)],
(4) [Resin layer made of ethylene-unsaturated carboxylic acid copolymer: (C-1)]/[Resin layer made of a mixture of resin (A) made of ionomer of ethylene-unsaturated carboxylic acid copolymer of the present embodiment and polyamide resin (B): (AB-1)],
and the like. Examples of the resin layers include a two-layer (first layer/second layer) structure made of the same resin layer or different resin layers.
As a three-layer structure, for example,
(5) [Resin layer made of a mixture of resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer of the present embodiment and polyamide resin (B): (AB-1)] / [Resin layer made of a mixture of resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer of the present embodiment and polyamide resin (B): (AB-1)] / [Resin layer made of a mixture of resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer of the present embodiment and polyamide resin (B): (AB-1)],
(6) [Resin layer made of a mixture of resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer of the present embodiment and polyamide resin (B): (AB-1)] / [Resin layer made of a mixture of resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer of the present embodiment and polyamide resin (B): (AB-2)] / [Resin layer made of a mixture of resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer of the present embodiment and polyamide resin (B): (AB-1)],
(7) [Resin layer made of a mixture of resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer of the present embodiment and polyamide resin (B): (AB-1)] / [Resin layer made of resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer: (A-1)] / [Resin layer made of a mixture of resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer of the present embodiment and polyamide resin (B): (AB-1)],
(8) [Resin layer (AB-1) made of a mixture of resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer of the present embodiment and polyamide resin (B)]/[Resin layer (C-1) made of an ethylene-unsaturated carboxylic acid copolymer]/[Resin layer (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer of the present embodiment and a mixture of polyamide resin (B): (AB-1)],
and the like. Examples of the resin layers include a three-layer (first layer/second layer/third layer) structure made of layers of the same resin or different resin layers.

[Method of forming substrate film]
The film-forming method of the substrate film 1 of this embodiment can employ a conventional method. The resin composition obtained by melt-kneading the ionomer resin (A) and the polyamide resin (B) and, if necessary, other components, can be processed into a film shape by various forming methods such as T-die casting, T-die nip molding, inflation molding, extrusion lamination, and calendar molding. In addition, when the substrate film 1 is a laminate consisting of multiple layers, each layer can be separately formed into a film by means of calendar molding, extrusion, inflation molding, etc., and laminated by means of heat lamination or adhesion with an appropriate adhesive, etc., to produce a laminate. Examples of the adhesive include the above-mentioned various ethylene copolymers, or blends of any of a plurality of these selected from unsaturated carboxylic acid grafts. In addition, the resin compositions of each layer can be simultaneously extruded by a co-extrusion lamination method to produce a laminate. The surface of the substrate film 1 that contacts the pressure-sensitive adhesive layer 2 may be subjected to corona treatment or plasma treatment, etc., for the purpose of improving adhesion to the pressure-sensitive adhesive layer 2, which will be described later. In addition, the surface of the base film 1 opposite to the surface in contact with the pressure-sensitive adhesive layer 2 may be subjected to an embossing treatment using a embossing roll or the like for the purpose of stabilizing the winding of the base film 1 during film formation and preventing blocking after film formation.

(Adhesive Layer)
The second constituent element of the dicing tape 10 of the present invention, the pressure-sensitive adhesive layer 2 containing an active energy ray-curable pressure-sensitive adhesive composition, will be described below.

[Acrylic adhesive polymer]
The acrylic adhesive polymer contained as a main component in the active energy ray-curable pressure-sensitive adhesive composition is an acrylic adhesive polymer having an active energy ray-reactive carbon-carbon double bond and a hydroxyl group. The acrylic adhesive polymer preferably accounts for 90 mass% or more, more preferably 95 mass% or more, of the total mass of the active energy ray-curable pressure-sensitive adhesive composition.

The above-mentioned acrylic adhesive polymer having active energy ray reactive carbon-carbon double bonds and hydroxyl groups is described in detail below, but is usually obtained by copolymerizing a (meth)acrylic acid alkyl ester monomer and a hydroxyl group-containing monomer as a base polymer to obtain a copolymer (acrylic adhesive polymer having hydroxyl groups), and then adding a compound having an isocyanate group and a carbon-carbon double bond (active energy ray reactive compound) capable of undergoing an addition reaction with the hydroxyl groups of the copolymer.

The main chain (main skeleton) of the acrylic adhesive polymer having a hydroxyl group is composed of a copolymer containing at least a (meth)acrylic acid alkyl ester monomer and a hydroxyl group-containing monomer as copolymer components, as described above. The copolymer composition of the acrylic adhesive polymer having a hydroxyl group (copolymer) is adjusted so that the glass transition temperature (Tg) of the main chain is in the range of -65°C or more and -50°C or less. Here, the glass transition temperature (Tg) is a theoretical value calculated from the Fox formula shown in the following general formula (1) based on the composition of the monomer (monomer) components constituting the acrylic adhesive polymer.
1/Tg=W ₁ /Tg ₁ +W ₂ /Tg ₂ +...+W _n /Tg _n General formula (1)
[In the above general formula (1), Tg is the glass transition temperature (unit: K) of the acrylic adhesive polymer, Tg _i (i = 1, 2, ... n) is the glass transition temperature (unit: K) when monomer i forms a homopolymer, and W _i (i = 1, 2, ... n) represents the mass fraction of monomer i in all monomer components.]
The glass transition temperatures (Tg) of homopolymers can be found, for example, in "Polymer Handbook," edited by J. Brandrup and E. H. Immergut, Interscience Publishers.

If the glass transition temperature (Tg) of the main chain of the acrylic adhesive polymer (copolymer) having the hydroxyl group is less than -65°C, the adhesive layer 2 containing the copolymer becomes excessively soft, and in the pick-up process after ultraviolet irradiation, the semiconductor chip with the die bond film may be difficult to peel off from the adhesive layer 2, or adhesive residue (contamination) may occur on the surface of the die bond film. As a result, the yield of good semiconductor chips decreases. On the other hand, if the glass transition temperature (Tg) exceeds -50°C, the toughness of the adhesive layer 2 containing these components decreases, so that the wettability and followability to the die bond film 3 may deteriorate, and the initial adhesion to the die bond film 3 may deteriorate, or the impact force when the semiconductor wafer or die bond film 3 is broken at low temperatures may not be sufficiently alleviated and may easily propagate to the interface between the adhesive layer 2 and the die bond film 3. As a result, in the cool expansion process, the die bond film 3 is likely to float from the adhesive layer 2, and the yield of good semiconductor chips decreases. The glass transition temperature (Tg) is preferably in the range of -63°C or higher and -51°C or lower, and more preferably in the range of -61°C or higher and -54°C or lower.

Examples of the (meth)acrylic acid alkyl ester monomer include those having 6 to 18 carbon atoms, such as hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, and dodecyl (meth)acrylate. Examples of the monomers include tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, and monomers having 5 or less carbon atoms, such as pentyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, ethyl (meth)acrylate, and methyl (meth)acrylate. Among these, it is preferable to use 2-ethylhexyl acrylate, and it is preferable to include 40% by mass or more and 85% by mass or less of the total amount of monomer components constituting the main chain of the acrylic adhesive polymer (copolymer) having a hydroxyl group.

Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl (meth)acrylate. The purpose of copolymerizing the hydroxyl group monomer is, first, to provide an addition reaction site (-OH) for introducing an active energy ray reactive carbon-carbon double bond to the acrylic adhesive polymer by an addition reaction, second, to provide a crosslinking reaction site for polymerizing the acrylic adhesive polymer by reacting with an isocyanate group (-NCO) of a polyisocyanate crosslinking agent to be described later, and third, to provide an active site (polarity site) for improving the initial adhesion between the adhesive layer 2 and the die bond film 3 after the crosslinking reaction. When the active energy ray reactive carbon-carbon double bond is introduced by an addition reaction using the hydroxyl group of the acrylic adhesive polymer, it is preferable to adjust the content of the hydroxyl group monomer to be in the range of 15% by mass or more and 31% by mass or less with respect to the total amount of the copolymer monomer components. In other words, adjusting the content of the hydroxyl group monomer in the copolymer within the above range is preferable because it makes it easier to control the constituent elements of the adhesive composition of the present invention, namely, the hydroxyl group value of the acrylic adhesive polymer, the equivalent ratio (NCO/OH) between the isocyanate group (NCO) of the polyisocyanate crosslinking agent described below and the hydroxyl group (OH) of the acrylic adhesive polymer, the residual hydroxyl group concentration after the crosslinking reaction, and the active energy ray reactive carbon-carbon double bond concentration, within the above-mentioned predetermined ranges.

The acrylic adhesive polymer having the active energy ray reactive carbon-carbon double bond and hydroxyl group is most preferably obtained by a method of copolymerizing the acrylic adhesive polymer having the hydroxyl group and then adding a compound having an isocyanate group and a carbon-carbon double bond (active energy ray reactive compound) capable of undergoing an addition reaction with the hydroxyl group in the side chain of the copolymer, from the viewpoint of ease of reaction tracking (control stability) and technical difficulty. Examples of such compounds having an isocyanate group and a carbon-carbon double bond (active energy ray reactive compound) include isocyanate compounds having a (meth)acryloyloxy group. Specific examples include 2-methacryloyloxyethyl isocyanate, 4-methacryloyloxy-n-butyl isocyanate, 2-acryloyloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, etc.

In the above addition reaction, it is preferable to use a polymerization inhibitor so as to maintain the reactivity of the carbon-carbon double bond to active energy rays. As such a polymerization inhibitor, a quinone-based polymerization inhibitor such as hydroquinone monomethyl ether is preferable. The amount of the polymerization inhibitor is not particularly limited, but is preferably in the range of 0.01 parts by mass or more and 0.1 parts by mass or less per 100 parts by mass of the acrylic adhesive polymer.

When carrying out the above-mentioned addition reaction, it is necessary to make a certain amount of hydroxyl groups remain in the adhesive composition after the crosslinking reaction in order to (1) crosslink the acrylic adhesive polymer with a polyisocyanate-based crosslinking agent added later to further increase the molecular weight, and (2) improve the initial adhesion between the adhesive layer 2 and the die bond film 3 after the crosslinking reaction. On the other hand, it is also necessary to control the concentration of active energy ray reactive carbon-carbon double bonds within a certain range. It is necessary to take these two viewpoints into consideration. For example, when reacting an isocyanate compound having a (meth)acryloyloxy group with a copolymer having a hydroxyl group in its side chain, it is preferable to carry out the addition reaction using an amount of the isocyanate compound having a (meth)acryloyloxy group in a ratio of 37 mol% to 85 mol% with respect to the hydroxyl group-containing monomer of the above-mentioned acrylic adhesive polymer.

In addition to the (meth)acrylic acid alkyl ester monomer and the hydroxyl group-containing monomer, the acrylic adhesive polymer may contain other copolymerizable monomer components copolymerized therein as necessary for the purpose of adjusting adhesive strength, glass transition temperature (Tg), etc. Examples of such other copolymerization monomer components include monomers having a functional group, such as carboxyl group-containing monomers such as (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid; acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; amide monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylolpropane(meth)acrylamide, N-methoxymethyl(meth)acrylamide, and N-butoxymethyl(meth)acrylamide; amino group-containing monomers such as aminoethyl(meth)acrylate, N,N-dimethylaminoethyl(meth)acrylate, and t-butylaminoethyl(meth)acrylate; and glycidyl group-containing monomers such as glycidyl(meth)acrylate. The content of such monomers having functional groups is not particularly limited, but is preferably in the range of 0.5% by mass or more and 30% by mass or less based on the total amount of copolymerization monomer components.

When such a monomer having a functional group other than a hydroxyl group is copolymerized, an active energy ray reactive carbon-carbon double bond can be introduced into the acrylic adhesive polymer by utilizing the functional group. For example, when the acrylic adhesive polymer has a carboxyl group in the side chain, it can be reacted with an active energy ray reactive compound such as glycidyl (meth)acrylate or 2-(1-aziridinyl)ethyl (meth)acrylate, or when the acrylic adhesive polymer has a glycidyl group in the side chain, it can be reacted with an active energy ray reactive compound such as (meth)acrylic acid, to introduce an active energy ray reactive carbon-carbon double bond into the acrylic adhesive polymer. However, when a monomer having a functional group other than a hydroxyl group is copolymerized and an active energy ray reactive carbon-carbon double bond is introduced into the acrylic adhesive polymer by utilizing the functional group, it is preferable to adjust the content of the hydroxyl group monomer to be copolymerized at the same time to a range of 3% by mass to 15% by mass with respect to the total amount of the copolymer monomer components. This is preferable because it makes it easy to control the hydroxyl value of the acrylic adhesive polymer, the equivalent ratio (NCO/OH) between the isocyanate group (NCO) of the polyisocyanate crosslinking agent described below and the hydroxyl group (OH) of the acrylic adhesive polymer, and the residual hydroxyl group concentration after the crosslinking reaction within the above-mentioned predetermined ranges.

Furthermore, the acrylic adhesive polymer having the above functional group may contain other copolymerization monomer components as necessary for the purpose of cohesive strength, heat resistance, etc., within a range that does not impair the effects of the present invention. Specific examples of such other copolymerization monomer components include cyano group-containing monomers such as (meth)acrylonitrile, olefin monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene, styrene monomers such as styrene, α-methylstyrene, and vinyltoluene, vinyl ester monomers such as vinyl acetate and vinyl propionate, vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether, halogen atom-containing monomers such as vinyl chloride and vinylidene chloride, (meth)acrylonitrile, and other cyano group-containing monomers. ) Alkoxy group-containing monomers such as methoxyethyl acrylate and ethoxyethyl (meth)acrylate, and monomers having a nitrogen atom-containing ring such as N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholine, N-vinylcaprolactam, and N-(meth)acryloylmorpholine. These other copolymerization monomer components may be used alone or in combination of two or more.

In the present embodiment, specific examples of suitable copolymers having hydroxyl groups obtained by copolymerizing the above-mentioned monomers include a binary copolymer of 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate, a terpolymer of 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, and methacrylic acid, a terpolymer of 2-ethylhexyl acrylate, n-butyl acrylate, and 2-hydroxyethyl acrylate, a terpolymer of 2-ethylhexyl acrylate, methyl methacrylate, and 2-hydroxyethyl acrylate, a quaternary copolymer of 2-ethylhexyl acrylate, n-butyl acrylate, 2-hydroxyethyl acrylate, and methacrylic acid, a quaternary copolymer of 2-ethylhexyl acrylate, methyl methacrylate, 2-hydroxyethyl acrylate, and methacrylic acid, and a quaternary copolymer of 2-ethylhexyl acrylate, methyl methacrylate, 2-hydroxyethyl acrylate, and methacrylic acid, but are not limited to these. It is preferable to add 2-methacryloyloxyethyl isocyanate, an isocyanate compound having a (meth)acryloyloxy group, to these suitable copolymers to produce an acrylic adhesive polymer having an active energy ray-reactive carbon-carbon double bond and a hydroxyl group.

The thus obtained acrylic adhesive polymer having active energy ray reactive carbon-carbon double bonds and hydroxyl groups has a hydroxyl value in the range of 12.0 mgKOH/g to 55.0 mgKOH/g. When the hydroxyl value is less than 12.0 mgKOH/g, the residual hydroxyl concentration after the crosslinking reaction in the adhesive composition is small, and the initial adhesion of the adhesive layer 2 to the die bond film 3 may be reduced. As a result, in the cool expand process, the die bond film 3 is likely to lift off from the adhesive layer 2, and the yield of non-defective semiconductor chips is reduced. On the other hand, when the hydroxyl value exceeds 55.0 mgKOH/g, the residual hydroxyl concentration after the crosslinking reaction in the adhesive composition is excessively large, and the initial adhesion of the adhesive layer 2 to the die bond film 3 may be greater than necessary. As a result, in the pick-up process after ultraviolet irradiation, the semiconductor chip with the die bond film is difficult to peel off from the adhesive layer 2, and the pick-up yield of the semiconductor chip is reduced. The hydroxyl value is preferably in the range of 12.7 mgKOH/g or more and 53.2 mgKOH/g or less, and more preferably in the range of 17.0 mgKOH/g or more and 39.0 mgKOH/g or less.

The acrylic adhesive polymer having the active energy ray reactive carbon-carbon double bond and hydroxyl group preferably has an acid value in the range of 0 mgKOH/g to 9.0 mgKOH/g. When the acid value is within the above range, the die bond film 3 can be prevented from lifting off the adhesive layer 2 in the cool expand process without interfering with the effect of reducing the adhesive strength of the adhesive layer 2 by ultraviolet irradiation. The acid value is preferably in the range of 2.0 mgKOH/g to 8.2 mgKOH/g, more preferably in the range of 2.5 mgKOH/g to 5.5 mgKOH/g.

Furthermore, the acrylic adhesive polymer having the active energy ray reactive carbon-carbon double bond and hydroxyl group preferably has a weight average molecular weight Mw in the range of 200,000 to 600,000. When the weight average molecular weight Mw of the acrylic adhesive polymer is less than 200,000, it is difficult to obtain a solution of the active energy ray curable acrylic adhesive composition having a high viscosity of several thousand cP to several tens of thousands cP, taking into consideration the coating property, etc., and is not preferable. In addition, the cohesive force of the adhesive layer 2 before the active energy ray irradiation is reduced, and when the semiconductor chip with the die bond film 3 is detached from the adhesive layer 2 after the active energy ray irradiation, the semiconductor wafer with the die bond film 3 may be contaminated. On the other hand, when the weight average molecular weight Mw exceeds 600,000, the wettability and followability of the adhesive layer 2 to the die bond film 3 decreases, and the initial adhesion decreases, so that the die bond film 3 may float from the adhesive layer 2 in the cool expansion process. Here, the weight average molecular weight Mw means a standard polystyrene equivalent value measured by gel permeation chromatography. The weight average molecular weight Mw is preferably in the range of 330,000 to 550,000, more preferably in the range of 350,000 to 400,000.

[Crosslinking agent]
The active energy ray curable adhesive composition of the present embodiment further contains a polyisocyanate-based crosslinking agent in order to increase the molecular weight of the acrylic adhesive polymer having the above-mentioned active energy ray reactive carbon-carbon double bond and hydroxyl group. Examples of the polyisocyanate-based crosslinking agent include a polyisocyanate compound having an isocyanurate ring, an adduct polyisocyanate compound obtained by reacting trimethylolpropane with hexamethylene diisocyanate, an adduct polyisocyanate compound obtained by reacting trimethylolpropane with tolylene diisocyanate, an adduct polyisocyanate compound obtained by reacting trimethylolpropane with xylylene diisocyanate, and an adduct polyisocyanate compound obtained by reacting trimethylolpropane with isophorone diisocyanate. These may be used alone or in combination of two or more. Among these, from the viewpoint of versatility, an adduct polyisocyanate compound obtained by reacting trimethylolpropane with tolylene diisocyanate and/or an adduct polyisocyanate compound obtained by reacting trimethylolpropane with hexamethylene diisocyanate are preferably used.

The amount of the polyisocyanate-based crosslinking agent added is adjusted so that the equivalent ratio (NCO/OH) between the isocyanate group (NCO) of the polyisocyanate-based crosslinking agent and the hydroxyl group (OH) of the acrylic adhesive polymer is in the range of 0.02 to 0.20, relative to the acrylic adhesive polymer having an active energy ray reactive carbon-carbon double bond and a hydroxyl group, in which the glass transition temperature (Tg) of the polymer main chain is in the range of -65°C to -50°C and the hydroxyl value is in the range of 12.0 mgKOH/g to 55.0 mgKOH/g. By adjusting the amount of the polyisocyanate-based crosslinking agent added in this way, the residual hydroxyl group concentration after the crosslinking reaction per 1 g of the active energy ray curable adhesive composition can be controlled to a range of 0.18 mmol to 0.90 mmol. In the present invention, "1 g of active energy ray-curable adhesive composition" means "1 g of adhesive composition (solid content) excluding the photopolymerization initiator described below", that is, "1 g of adhesive composition (solid content) composed of an acrylic adhesive polymer and a polyisocyanate crosslinking agent". When the adhesive composition contains other components described below, the weight of the adhesive composition includes the other components. The above-mentioned equivalent ratio (NCO/OH) is preferably in the range of 0.04 to 0.19, more preferably in the range of 0.07 to 0.14.

Here, the equivalent ratio (NCO/OH) of the isocyanate groups (NCO) of the polyisocyanate-based crosslinking agent to the hydroxyl groups (OH) of the acrylic adhesive polymer is a theoretically calculated value obtained by dividing the total number of moles of isocyanate groups, calculated from the content of the polyisocyanate-based crosslinking agent in the active energy ray-curable adhesive composition and the average number of isocyanate groups per molecule of the polyisocyanate-based crosslinking agent, by the total number of moles of hydroxyl groups in the acrylic adhesive polymer after the active energy ray-reactive carbon-carbon double bonds have been introduced. For example, when an isocyanate compound having a (meth)acryloyloxy group is added to an acrylic adhesive polymer having hydroxyl groups as a base polymer to introduce active energy ray reactive carbon-carbon double bonds, the total number of moles of hydroxyl groups is the value obtained by subtracting the number of moles of hydroxyl groups theoretically consumed by the crosslinking reaction with the isocyanate groups of the isocyanate compound having a (meth)acryloyloxy group (= the number of moles of isocyanate groups of the isocyanate compound having a (meth)acryloyloxy group) from the total number of moles of hydroxyl groups in the acrylic adhesive polymer as the base polymer.

Similarly, the concentration of residual hydroxyl groups after the crosslinking reaction per 1 g of active energy ray-curable adhesive composition is calculated by subtracting the number of moles of hydroxyl groups theoretically consumed by the crosslinking reaction with the isocyanate groups of the added polyisocyanate-based crosslinking agent (= the number of moles of isocyanate groups of the crosslinking agent) from the total number of moles of hydroxyl groups possessed by the acrylic adhesive polymer having active energy ray-reactive carbon-carbon double bonds and hydroxyl groups, and converting the value into a value per 1 g of active energy ray-curable adhesive composition.

If the above-mentioned equivalent ratio (NCO/OH) is less than 0.02, the cohesive strength of the adhesive layer 2 becomes insufficient, and the semiconductor chip with the die bond film 3 may be difficult to peel off from the adhesive layer 2 in the pick-up process after ultraviolet irradiation, adhesive residue (contamination) may occur on the surface of the die bond film, or the breakability of the die bond film 3 may be deteriorated. In addition, particularly when the hydroxyl value is large, the concentration of residual hydroxyl groups after the crosslinking reaction becomes too large, and the initial adhesion between the adhesive layer 2 and the die bond film 3 becomes greater than necessary, and the semiconductor chip with the die bond film 3 may be difficult to peel off from the adhesive layer 2 in the pick-up process after ultraviolet irradiation. As a result, the yield of non-defective semiconductor chips decreases. On the other hand, when the above-mentioned equivalent ratio (NCO/OH) exceeds 0.20, depending on the size of the hydroxyl value, the toughness of the adhesive layer 2 after the crosslinking reaction may be too low, i.e., it may become too hard, and the wettability and followability of the adhesive layer 2 to the die bond film 3 may be poor, and the initial adhesion to the die bond film 3 may be poor, or the impact force when the semiconductor wafer or the die bond film 3 is broken by the cool expansion may not be sufficiently mitigated, and the impact force may be easily propagated to the interface between the adhesive layer 2 and the die bond film 3. As a result, the die bond film 3 is likely to lift off the adhesive layer 2 during the cool expansion process, and the yield of good semiconductor chips may decrease.

When the equivalent ratio (NCO/OH) of the isocyanate group (NCO) of the polyisocyanate crosslinking agent to the hydroxyl group (OH) of the acrylic adhesive polymer is within the range of 0.02 to 0.20, the residual hydroxyl group concentration after the crosslinking reaction per 1 g of the active energy ray-curable adhesive composition mainly composed of an acrylic adhesive polymer having a glass transition temperature (Tg) of the polymer main chain in the range of -65°C to -50°C and a hydroxyl value in the range of 12.0 mgKOH/g to 55.0 mgKOH/g can be easily controlled to a range of 0.18 mmol to 0.90 mmol. By doing so, the interaction between the hydroxyl group and the silica filler on the surface of the die bond film 3 is enhanced, the initial adhesion between the adhesive layer 2 and the die bond film 3 is appropriately improved, and furthermore, the toughness of the adhesive layer 2 itself after the crosslinking reaction is suppressed from decreasing more than necessary, and the tackiness and impact relaxation properties can be appropriately maintained. As a result, in the cool expanding process, the die bond film 3 is prevented from floating off the adhesive layer 2, and the yield of good semiconductor chips is improved. The residual hydroxyl group concentration is preferably in the range of 0.29 mmol to 0.60 mmol, more preferably in the range of 0.30 mmol to 0.37 mmol.

After forming the adhesive layer 2 from the active energy ray-curable adhesive composition, the aging conditions for reacting the polyisocyanate-based crosslinking agent with the acrylic adhesive polymer having a hydroxyl group are not particularly limited, but may be set appropriately, for example, at a temperature in the range of 23°C or higher and 80°C or lower, and for a time in the range of 24 hours or higher and 168 hours or lower.

[Photopolymerization initiator]
The active energy ray-curable pressure-sensitive adhesive composition of the present embodiment contains a photopolymerization initiator that generates radicals by irradiation with active energy rays. The photopolymerization initiator senses the irradiation of the active energy ray-curable acrylic pressure-sensitive adhesive composition with active energy rays, generates radicals, and initiates a crosslinking reaction of the carbon-carbon double bonds of the active energy ray-curable acrylic pressure-sensitive adhesive polymer.

The photopolymerization initiator is not particularly limited, and conventionally known initiators can be used. Examples of the photopolymerization initiator include alkylphenone radical polymerization initiators, acylphosphine oxide radical polymerization initiators, and oxime ester radical polymerization initiators. Examples of the alkylphenone radical polymerization initiator include benzyl methyl ketal radical polymerization initiators, α-hydroxyalkylphenone radical polymerization initiators, and aminoalkylphenone radical polymerization initiators. Specific examples of the benzyl methyl ketal radical polymerization initiator include 2,2'-dimethoxy-1,2-diphenylethan-1-one (e.g., trade name Omnirad 651, manufactured by IGM Resins B.V.). Specific examples of the α-hydroxyalkylphenone radical polymerization initiator include 2-hydroxy-2-methyl-1-phenylpropan-1-one (trade name Omnirad 1173, manufactured by IGM Resins B.V.), 1-hydroxycyclohexyl phenyl ketone (trade name Omnirad 184, manufactured by IGM Resins B.V.), 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one (trade name Omnirad 2959, manufactured by IGM Resins B.V.), and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one (trade name Omnirad 127, manufactured by IGM Resins B.V.). Specific examples of the aminoalkylphenone radical polymerization initiator include 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one (trade name Omnirad 907, manufactured by IGM Resins B.V.) and 2-benzylmethyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone (trade name Omnirad 369, manufactured by IGM Resins B.V.). Specific examples of acylphosphine oxide radical polymerization initiators include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (trade name OmniradTPO, manufactured by IGM Resins B.V.), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (trade name Omnirad819, manufactured by IGM Resins B.V.), and oxime ester radical polymerization initiators include (2E)-2-(benzoyloxyimino)-1-[4-(phenylthio)phenyl]octan-1-one (trade name OmniradOXE-01, manufactured by IGM Resins B.V.). These photopolymerization initiators may be used alone or in combination of two or more.

The amount of the photopolymerization initiator added is preferably in the range of 0.1 parts by mass to 10.0 parts by mass relative to 100 parts by mass of the solid content of the active energy ray-curable acrylic adhesive polymer. If the amount of the photopolymerization initiator added is less than 0.1 parts by mass, the photoreactivity to active energy rays is insufficient, so that the photoradical crosslinking reaction of the acrylic adhesive polymer does not occur sufficiently even when irradiated with active energy rays. As a result, the adhesive strength reduction effect of the adhesive layer 2 after irradiation with active energy rays is reduced, and there is a risk of an increase in pickup failure of semiconductor chips. On the other hand, if the amount of the photopolymerization initiator added exceeds 10.0 parts by mass, the effect is saturated and is not preferable from the viewpoint of economy. In addition, depending on the type of photopolymerization initiator, the adhesive layer 2 may turn yellow and have a poor appearance.

In addition, compounds such as dimethylaminoethyl methacrylate and 4-dimethylaminobenzoic acid isoamyl may be added to the active energy ray-curable acrylic adhesive composition as a sensitizer for such photopolymerization initiators.

[others]
To the active energy ray-curable pressure-sensitive adhesive composition of the present embodiment, additives such as an active energy ray-curable compound (e.g., a polyfunctional urethane acrylate oligomer), a tackifier, a filler, an antioxidant, a colorant, a flame retardant, an antistatic agent, a surfactant, a silane coupling agent, and a leveling agent may be added as necessary within a range that does not impair the effects of the present invention.

[Active energy ray reactive carbon-carbon double bond concentration]
The active energy ray curable adhesive composition of the present embodiment is adjusted so that the active energy ray reactive carbon-carbon double bond concentration is in the range of 0.85 mmol or more and 1.60 mmol or less per 1 g of the active energy ray curable adhesive composition. If the active energy ray reactive carbon-carbon double bond concentration per 1 g of the active energy ray curable adhesive composition is less than 0.85 mmol, when the residual hydroxyl group concentration after the crosslinking reaction per 1 g of the active energy ray curable adhesive composition described above is large, the adhesive strength of the adhesive layer 2 after ultraviolet irradiation may not be sufficiently reduced, and the semiconductor chip with the die bond film 3 may be difficult to peel from the adhesive layer 2 in the pick-up process. On the other hand, if the active energy ray reactive carbon-carbon double bond concentration per 1 g of the active energy ray curable adhesive composition exceeds 1.60 mmol, it may be difficult to ensure the residual hydroxyl group concentration after the crosslinking reaction per 1 g of the active energy ray curable adhesive composition described above, or depending on the copolymerization composition of the acrylic adhesive polymer, gelation may occur during polymerization or reaction during synthesis, making synthesis difficult. When checking the carbon-carbon double bond content of the acrylic adhesive polymer, the iodine value of the acrylic adhesive polymer can be measured to calculate the carbon-carbon double bond content.

When the active energy ray reactive carbon-carbon double bond concentration is within the range of 0.85 mmol to 1.60 mmol per 1 g of the active energy ray curable adhesive composition, even when an adhesive layer 2 containing an active energy ray curable adhesive composition that improves the initial adhesion of the adhesive layer 2 to the die bond film 3 and the toughness of the adhesive layer 2 itself is applied, the adhesive strength of the adhesive layer 2 to the die bond film 3 after ultraviolet irradiation is sufficiently reduced, and the semiconductor chip with the die bond film 3 is peeled off (pickup property) from the adhesive layer 2 is good. The active energy ray reactive carbon-carbon double bond concentration is preferably within the range of 1.02 mmol to 1.51 mmol per 1 g of the active energy ray curable adhesive composition.

[Thickness of adhesive layer]
The thickness of the adhesive layer 2 in this embodiment is not particularly limited, but is preferably in the range of 5 μm to 50 μm, more preferably in the range of 6 μm to 20 μm, and particularly preferably in the range of 7 μm to 15 μm. If the thickness of the adhesive layer 2 is less than 5 μm, the adhesive strength of the dicing tape 10 may be excessively reduced. In this case, in the cool expansion process, the die bond film 3 is likely to float from the adhesive layer 2, and the yield of good semiconductor chips is reduced. In addition, when used as a dicing die bond film, poor adhesion between the adhesive layer 2 and the die bond film 3 may occur. On the other hand, if the thickness of the adhesive layer 2 exceeds 50 μm, the internal stress generated when the dicing tape 10 is cool expanded may be difficult to transmit as external stress to the semiconductor wafer with the die bond film 3, and in that case, the cleavage yield of the semiconductor chip with the die bond film 3 may be reduced in the dicing process. In addition, from the viewpoint of economy, it is not very preferable in practice.

(Anchor coat layer)
In the dicing tape 10 of this embodiment, an anchor coat layer matching the composition of the base film 1 may be provided between the base film 1 and the pressure-sensitive adhesive layer 2, depending on the manufacturing conditions of the dicing tape 10 and the use conditions of the dicing tape 10 after manufacture, within a range that does not impair the effects of the present invention. By providing an anchor coat layer, the adhesion between the base film 1 and the pressure-sensitive adhesive layer 2 is improved.

(Release Liner)
In addition, a release liner may be provided on the surface side (one surface side) of the pressure-sensitive adhesive layer 2 opposite to the base film 1, if necessary. The material that can be used as the release liner is not particularly limited, but examples thereof include synthetic resins such as polyethylene, polypropylene, and polyethylene terephthalate, and papers. In addition, the surface of the release liner may be subjected to a release treatment using a silicone-based release treatment agent, a long-chain alkyl-based release treatment agent, a fluorine-based release treatment agent, or the like, in order to improve the releasability of the pressure-sensitive adhesive layer 2. The thickness of the release liner is not particularly limited, but a release liner in the range of 10 μm to 200 μm can be preferably used.

(Dicing tape manufacturing method)
4 is a flow chart explaining the manufacturing method of the dicing tape 10. First, a release liner is prepared (step S101: release liner preparation step). Next, a coating solution for the adhesive layer 2 (adhesive layer forming coating solution), which is a material for forming the adhesive layer 2, is prepared (step S102: coating solution preparation step). The coating solution can be prepared, for example, by uniformly mixing and stirring an acrylic adhesive polymer, which is a component of the adhesive layer 2, a crosslinking agent, and a dilution solvent. As the solvent, for example, a general-purpose organic solvent such as toluene or ethyl acetate can be used.

Then, the coating solution for the adhesive layer 2 prepared in step S102 is applied to the release-treated surface of the release liner and dried to form an adhesive layer 2 of a predetermined thickness (step S103: adhesive layer formation step). The coating method is not particularly limited, and for example, a die coater, a comma coater (registered trademark), a gravure coater, a roll coater, a reverse coater, etc. can be used for coating. In addition, the drying conditions are not particularly limited, but for example, it is preferable that the drying temperature is in the range of 80°C to 150°C and the drying time is in the range of 0.5 minutes to 5 minutes. Next, the base film 1 is prepared (step S104: base film preparation step). Then, the base film 1 is laminated on the adhesive layer 2 formed on the release liner (step S105: base film lamination step). Finally, the formed adhesive layer 2 is aged for 72 hours in an environment of, for example, 40°C to react with the acrylic adhesive polymer and the crosslinking agent to crosslink and harden (step S106: heat curing step). By the above steps, a dicing tape 10 can be manufactured that has a pressure-sensitive adhesive layer 2 and a release liner on a base film 1, in that order from the base film side. In the present invention, a laminate that has a release liner on the pressure-sensitive adhesive layer 2 may also be referred to as a dicing tape 10.

As a method for forming the adhesive layer 2 on the base film 1, a method in which a coating solution for the adhesive layer 2 is applied onto a release liner and dried, and then the base film 1 is laminated onto the adhesive layer 2 has been exemplified, but a method in which a coating solution for the adhesive layer 2 is directly applied onto the base film 1 and dried may also be used. From the viewpoint of stable production, the former method is preferably used.

The dicing tape 10 is preferably such that the low-angle adhesive strength (peel angle 30°, peel speed 600 mm/min) of the pressure-sensitive adhesive layer 2 to the die-bonding film 3 after ultraviolet irradiation at 23° C. is 0.95 N/25 mm or less, and the shear adhesive strength (tensile speed 1,000 mm/min) of the pressure-sensitive adhesive layer 2 to the die-bonding film 3 before ultraviolet irradiation at −30° C. is 100.0 N/100 mm2 or more, as will be described in ^detail later.

The dicing tape 10 of this embodiment may be in a rolled form or in a form in which wide sheets are stacked. The dicing tape 10 in these forms may also be in a sheet or tape form formed by cutting the dicing tape 10 to a predetermined size.

<Dicing die bond film>
The dicing tape 10 of the present embodiment can also be used in the semiconductor manufacturing process in the form of a dicing die bond film 20 in which a die bond film (adhesive layer) 3 is peelably adhered and laminated on the adhesive layer 2 of the dicing tape 10. The die bond film (adhesive layer) 3 is for adhering and connecting the semiconductor chips that have been cut and divided by cool expansion to a lead frame or a wiring board (supporting board). In addition, when semiconductor chips are laminated, it also serves as an adhesive layer between the semiconductor chips. In this case, the first-stage semiconductor chip is adhered to a semiconductor chip mounting wiring board on which terminals are formed by the die bond film (adhesive layer) 3, and the second-stage semiconductor chip is further adhered to the first-stage semiconductor chip by the die bond film (adhesive layer) 3. The connection terminals of the first-stage semiconductor chip and the second-stage semiconductor chip are electrically connected to the external connection terminals via wires, but the wires for the first-stage semiconductor chip are embedded in the die bond film (adhesive layer) 3, i.e., the wire-embedded die bond film (adhesive layer) 3 described above, during pressure bonding (die bonding). Hereinafter, an example of the die bond film (adhesive layer) 3 when the dicing tape 10 of this embodiment is used in the form of a dicing die bond film 20 will be shown, but the present invention is not limited to this example.

(Die bond film)
The die bond film (adhesive layer) 3 is a layer made of a thermosetting adhesive composition that is cured by heat. The adhesive composition is not particularly limited, and any conventionally known material can be used. An example of a preferred embodiment of the adhesive composition is a thermosetting adhesive composition obtained by adding a curing accelerator, an inorganic filler, a silane coupling agent, etc. to a resin composition containing a glycidyl group-containing (meth)acrylic acid ester copolymer as a thermoplastic resin, an epoxy resin as a thermosetting resin, and a phenolic resin as a curing agent for the epoxy resin. The die bond film (adhesive layer) 3 made of such a thermosetting adhesive composition has excellent adhesion between a semiconductor chip/support substrate and between a semiconductor chip/semiconductor chip, and can also be given electrode embedding and/or wire embedding, and can be bonded at a low temperature in the die bonding process, can be cured excellently in a short time, and has excellent reliability after being molded with a sealant, which are preferable.

General-purpose die bond films used in a form in which the wire is not embedded in the adhesive layer and wire-embedded die bond films used in a form in which the wire is embedded in the adhesive layer often have almost the same types of materials constituting their adhesive compositions, but the mixing ratio of the materials used and the physical properties and characteristics of each material are changed according to the respective purposes to customize them for use as general-purpose die bond films or wire-embedded die bond films. In addition, if there is no problem with the reliability of the final semiconductor device, wire-embedded die bond films may be used as general-purpose die bond films. In other words, wire-embedded die bond films are not limited to wire-embedding applications, and can also be used in applications such as bonding semiconductor chips to substrates having unevenness due to wiring, metal substrates such as lead frames, etc.

(General-purpose adhesive composition for die-bonding film)
First, an example of an adhesive composition for a general-purpose die-bonding film will be described, but the present invention is not limited to this example. As an index of the fluidity of the die-bonding film 3 formed from the adhesive composition during die-bonding, for example, the shear viscosity characteristic at 80°C can be mentioned, and in the case of a general-purpose die-bonding film, the shear viscosity at 80°C generally shows a value in the range of 20,000 Pa·s to 40,000 Pa·s, preferably 25,000 Pa·s to 35,000 Pa·s. An example of a preferred embodiment of the adhesive composition for general-purpose die-bonding films is an adhesive composition that, when the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer, the epoxy resin, and the phenol resin, which are resin components of the adhesive composition, is taken as 100 parts by mass, (a) contains the glycidyl group-containing (meth)acrylic acid ester copolymer in the range of 52 parts by mass or more and 90 parts by mass or less, the epoxy resin in the range of 5 parts by mass or more and 25 parts by mass or less, and the phenol resin in the range of 5 parts by mass or more and 23 parts by mass or less, so that the total amount of the resin components is 100 parts by mass, (b) contains a curing accelerator in the range of 0.1 parts by mass or more and 0.3 parts by mass or less relative to 100 parts by mass of the total amount of the epoxy resin and the phenol resin, and (c) contains an inorganic filler in the range of 5 parts by mass or more and 20 parts by mass or less relative to 100 parts by mass of the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer, the epoxy resin, and the phenol resin.

[Glycidyl Group-Containing (Meth)Acrylic Acid Ester Copolymer]
The glycidyl group-containing (meth)acrylic acid ester copolymer preferably contains at least an alkyl (meth)acrylate having an alkyl group having 1 to 8 carbon atoms and glycidyl (meth)acrylate as copolymer units. From the viewpoint of ensuring appropriate adhesive strength, the copolymer unit of glycidyl (meth)acrylate is preferably contained in the range of 0.5% by mass to 6.0% by mass, more preferably in the range of 2.0% by mass to 4.0% by mass, in the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer. In addition, the glycidyl group-containing (meth)acrylic acid ester copolymer may contain other monomers such as styrene and acrylonitrile as copolymer units, if necessary, from the viewpoint of adjusting the glass transition temperature (Tg).

The glass transition temperature (Tg) of the glycidyl group-containing (meth)acrylic acid ester copolymer is preferably in the range of -50°C or more and 30°C or less, and from the viewpoint of improving the handleability as a die-bonding film (suppressing tackiness), it is more preferably in the range of -10°C or more and 30°C or less. In order to give the glycidyl group-containing (meth)acrylic acid ester copolymer such a glass transition temperature, it is preferable to use ethyl (meth)acrylate and/or butyl (meth)acrylate as the (meth)acrylic acid alkyl ester having an alkyl group with 1 to 8 carbon atoms.

The weight average molecular weight Mw of the glycidyl group-containing (meth)acrylic acid ester copolymer is preferably in the range of 500,000 to 2,000,000, and more preferably in the range of 700,000 to 1,000,000. When the weight average molecular weight Mw is within the above range, it is easy to obtain appropriate adhesive strength, heat resistance, and flowability. Here, the weight average molecular weight Mw means a standard polystyrene equivalent value measured by gel permeation chromatography.

The content of the glycidyl group-containing (meth)acrylic acid ester copolymer in the die bond film (adhesive layer) 3 is preferably in the range of 52% by mass or more and 90% by mass or less, and more preferably in the range of 60% by mass or more and 80% by mass or less, based on 100 parts by mass of the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer, which is the resin component in the adhesive composition, and the epoxy resin and phenolic resin described below.

[Epoxy resin]
The epoxy resin is not particularly limited, but examples thereof include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, phenol novolac type epoxy resin, alkylphenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, diglycidyl ether of biphenol, diglycidyl ether of naphthalene diol, diglycidyl ether of phenols, diglycidyl ether of alcohols, and alkyl-substituted, halogenated, and hydrogenated bifunctional epoxy resins and novolac type epoxy resins. In addition, other commonly known epoxy resins such as polyfunctional epoxy resins and heterocyclic epoxy resins may be used. These may be used alone or in combination of two or more.

From the viewpoint of adhesive strength and heat resistance, the softening point of the epoxy resin is preferably in the range of 70°C or more and 130°C or less. In addition, from the viewpoint of sufficiently proceeding with the curing reaction with the phenolic resin described below, the epoxy equivalent of the epoxy resin is preferably in the range of 100 or more and 300 or less.

The content ratio of the epoxy resin in the die bond film (adhesive layer) 3 is preferably in the range of 5% by mass or more and 25% by mass or less, and more preferably in the range of 10% by mass or more and 20% by mass or less, based on 100 parts by mass of the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer, the epoxy resin, and the phenolic resin described below, which are the resin components in the adhesive composition, from the viewpoint of allowing the die bond film (adhesive layer) 3 to properly exhibit its function as a thermosetting adhesive.

[Phenol resin: hardener for epoxy resin]
The curing agent for the epoxy resin is not particularly limited, but may be, for example, a phenolic resin that can be obtained by reacting a phenolic compound with a xylylene compound, which is a divalent linking group, in the absence of a catalyst or in the presence of an acid catalyst. Examples of the phenolic resin include novolac-type phenolic resins, resol-type phenolic resins, and polyoxystyrenes such as polyparaoxystyrene. Examples of the novolac-type phenolic resins include phenolic novolac resins, phenolic aralkyl resins, cresol novolac resins, tert-butylphenolic novolac resins, and nonylphenolic novolac resins. These phenolic resins may be used alone or in combination of two or more. Among these phenolic resins, phenolic novolac resins and phenolic aralkyl resins tend to improve the connection reliability of the die bond film (adhesive layer) 3, and are therefore preferably used.

From the viewpoints of adhesive strength and heat resistance, the softening point of the phenolic resin is preferably in the range of 70°C or more and 90°C or less. In addition, from the viewpoint of sufficiently progressing the curing reaction with the epoxy resin, the hydroxyl group equivalent of the phenolic resin is preferably in the range of 100 or more and 200 or less.

From the viewpoint of sufficiently proceeding with the curing reaction between the epoxy resin and the phenolic resin in the thermosetting resin composition, the phenolic resin is preferably blended in an amount such that the hydroxyl groups in the total phenolic resin components are preferably in the range of 0.5 to 2.0 equivalents, more preferably 0.8 to 1.2 equivalents, per equivalent of epoxy groups in the total epoxy resin components. Since it depends on the functional group equivalent of each resin, it cannot be said in general, but for example, the content of the phenolic resin is preferably in the range of 5 to 23% by mass, assuming that the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer, the epoxy resin, and the phenolic resin, which are the resin components in the adhesive composition, is 100 parts by mass.

[Curing accelerator]
In addition, the thermosetting resin composition may contain, as necessary, a curing accelerator such as a tertiary amine, an imidazole, or a quaternary ammonium salt. Specific examples of such curing accelerators include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2-phenylimidazolium trimellitate. These may be used alone or in combination of two or more. The amount of the curing accelerator added is preferably in the range of 0.1 parts by mass or more and 0.3 parts by mass or less with respect to 100 parts by mass of the total of the epoxy resin and the phenolic resin.

[Inorganic filler]
Furthermore, the thermosetting resin composition may contain an inorganic filler as necessary in order to control the fluidity of the die bond film (adhesive layer) 3 and improve the elastic modulus. Examples of inorganic fillers include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whisker, boron nitride, crystalline silica, and amorphous silica, and these may be used alone or in combination of two or more. Among these, crystalline silica and amorphous silica are preferably used from the viewpoint of versatility. Specifically, for example, Aerosil (registered trademark: ultrafine particle dry silica) having an average particle size of nano size is preferably used. The content ratio of the inorganic filler in the die bond film (adhesive layer) 3 is preferably in the range of 5% by mass or more and 20% by mass or less, when the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer, epoxy resin, and phenolic resin, which are the resin components described above, is taken as 100 parts by mass as the standard.

[Silane coupling agent]
Furthermore, in order to improve the adhesive strength to the adherend, the thermosetting resin composition may contain a silane coupling agent as necessary. Examples of the silane coupling agent include β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane, and these may be used alone or in combination of two or more. The amount of the silane coupling agent added is preferably in the range of 1.0 parts by mass or more to 7.0 parts by mass or less with respect to 100 parts by mass of the epoxy resin and the phenolic resin in total.

[others]
Furthermore, the thermosetting resin composition may contain a flame retardant, an ion trapping agent, etc., within a range that does not impair the function of the die bond film. Examples of the flame retardant include antimony trioxide, antimony pentoxide, and brominated epoxy resin. Examples of the ion trapping agent include hydrotalcites, bismuth hydroxide, hydrous antimony oxide, zirconium phosphate of a specific structure, magnesium silicate, aluminum silicate, triazole-based compounds, tetrazole-based compounds, and bipyridyl-based compounds.

(Adhesive composition for wire-embedded die-bonding film)
Next, an example of the adhesive composition for wire-embedded die-bonding film will be described, but the present invention is not limited to this example. As an index of fluidity of the die-bonding film 3 formed from the adhesive composition during die-bonding, for example, shear viscosity characteristics at 80°C can be mentioned. In the case of a wire-embedded die-bonding film, the shear viscosity at 80°C generally shows a value in the range of 200 Pa·s to 11,000 Pa·s, preferably 2,000 Pa·s to 7,000 Pa·s. An example of a preferred embodiment of the adhesive composition for wire-embedded die-bonding films is an adhesive composition that, when the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer, the epoxy resin, and the phenol resin, which are resin components of the adhesive composition, is taken as 100 parts by mass, (a) contains the glycidyl group-containing (meth)acrylic acid ester copolymer in the range of 17 parts by mass to 51 parts by mass, the epoxy resin in the range of 30 parts by mass to 64 parts by mass, and the phenol resin in the range of 19 parts by mass to 53 parts by mass, so that the total amount of the resin components is 100 parts by mass; (b) contains a curing accelerator in the range of 0.01 parts by mass to 0.07 parts by mass relative to 100 parts by mass of the total amount of the epoxy resin and the phenol resin; and (c) contains an inorganic filler in the range of 10 parts by mass to 80 parts by mass relative to 100 parts by mass of the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer, the epoxy resin, and the phenol resin.

[Glycidyl Group-Containing (Meth)Acrylic Acid Ester Copolymer]
The glycidyl group-containing (meth)acrylic acid ester copolymer preferably contains, as copolymer units, at least an alkyl (meth)acrylic acid ester having an alkyl group having 1 to 8 carbon atoms and glycidyl (meth)acrylate. In the case of a wire-embedded die-bonding film, it is necessary to achieve both improved fluidity during die-bonding and securing adhesive strength after curing, so it is preferable to use a glycidyl group-containing (meth)acrylic acid ester copolymer (A) having a high copolymer unit ratio of glycidyl (meth)acrylate and a low molecular weight in combination with a glycidyl group-containing (meth)acrylic acid ester copolymer (B) having a low copolymer unit ratio of glycidyl (meth)acrylate and a high molecular weight, and it is preferable that the former (A) component is contained in a certain amount or more in the combination.

That is, the glycidyl group-containing (meth)acrylic acid ester copolymer in the adhesive composition for wire-embedded die-bonding films is preferably composed of a mixture of "glycidyl group-containing (meth)acrylic acid ester copolymer (A) containing glycidyl (meth)acrylate copolymer units in the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer in a range of 5.0% by mass to 15.0% by mass, having a glass transition temperature (Tg) in the range of -50°C to 30°C, and a weight average molecular weight Mw in the range of 100,000 to 400,000" and "glycidyl group-containing (meth)acrylic acid ester copolymer (B) containing glycidyl (meth)acrylate copolymer units in the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer in a range of 1.0% by mass to 7.0% by mass, having a glass transition temperature (Tg) in the range of -50°C to 30°C, and a weight average molecular weight Mw in the range of 500,000 to 900,000." Here, the weight average molecular weight Mw refers to the standard polystyrene equivalent value measured by gel permeation chromatography.

The content of the glycidyl group-containing (meth)acrylic acid ester copolymer (A) is preferably in the range of 60% by mass or more and 90% by mass or less of the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer (the sum of (A) and (B)). In addition, the glycidyl group-containing (meth)acrylic acid ester copolymer may contain other monomers such as styrene and acrylonitrile as copolymer units, if necessary, from the viewpoint of adjusting the glass transition temperature (Tg).

The glass transition temperature (Tg) of the entire glycidyl group-containing (meth)acrylic acid ester copolymer is preferably in the range of -50°C to 30°C, and from the viewpoint of improving the handleability as a die-bonding film (suppressing tackiness), it is more preferably in the range of -10°C to 30°C. In order to give the glycidyl group-containing (meth)acrylic acid ester copolymer such a glass transition temperature, it is preferable to use ethyl (meth)acrylate and/or butyl (meth)acrylate as the (meth)acrylic acid alkyl ester having an alkyl group with 1 to 8 carbon atoms.

The content ratio of the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer (the sum of (A) and (B)) in the wire-embedded die-bonding film (adhesive layer) 3 is preferably in the range of 17% by mass or more and 51% by mass or less, and more preferably in the range of 20% by mass or more and 45% by mass or less, based on 100 parts by mass of the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer, which is the resin component in the adhesive composition, and the epoxy resin and phenolic resin described below, from the viewpoint of fluidity during die bonding and adhesive strength after curing.

[Epoxy resin]
The epoxy resin is not particularly limited, but the same as the epoxy resin exemplified for the adhesive composition for the general-purpose die-bonding film can be used. These may be used alone or in combination of two or more kinds, but in the case of a wire-embedded die-bonding film, it is necessary to ensure the adhesive strength and to suppress the occurrence of voids on the adhesive surface while imparting good embeddability of the wire, so it is preferable to use two or more kinds of epoxy resins in combination in order to control the fluidity and elastic modulus.

A preferred embodiment of the epoxy resin used in the wire-embedded die-bonding film (adhesive layer) 3 is a mixture of an epoxy resin (C) that is liquid at room temperature and an epoxy resin (D) that has a softening point of 98°C or less, preferably 85°C or less. The content of the epoxy resin (C) that is liquid at room temperature is preferably in the range of 15% by mass to 75% by mass, more preferably 30% by mass to 50% by mass, of the total amount of epoxy resin (the sum of (C) and (D)). The epoxy equivalent of the epoxy resin is preferably in the range of 100 to 300, from the viewpoint of sufficiently proceeding with the curing reaction with the phenolic resin described later.

The content ratio of the epoxy resin in the die bond film (adhesive layer) 3 is preferably in the range of 30% by mass or more and 64% by mass or less, and more preferably in the range of 35% by mass or more and 50% by mass or less, based on 100 parts by mass of the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer, the epoxy resin, and the phenolic resin described below, which are the resin components in the adhesive composition, from the viewpoint of allowing the die bond film (adhesive layer) 3 to properly exhibit its function as a thermosetting adhesive.

[Phenol resin: hardener for epoxy resin]
The curing agent for the epoxy resin is not particularly limited, but the same as the phenolic resin exemplified for the adhesive composition for the general-purpose die-bonding film can be used in the same manner. From the viewpoint of adhesive strength and fluidity, the softening point of the phenolic resin is preferably in the range of 70°C or more and 115°C or less. In addition, from the viewpoint of sufficiently proceeding with the curing reaction with the epoxy resin, the hydroxyl equivalent of the phenolic resin is preferably in the range of 100 or more and 200 or less.

From the viewpoint of sufficiently proceeding with the curing reaction between the epoxy resin and the phenolic resin in the thermosetting resin composition, the phenolic resin is preferably blended in an amount such that the hydroxyl group in the total phenolic resin components is preferably in the range of 0.5 to 2.0 equivalents per equivalent of epoxy groups in the total epoxy resin components, and more preferably in the range of 0.6 to 1.0 equivalents per equivalent of epoxy groups in the total epoxy resin components, from the viewpoint of compatibility with fluidity during die bonding. Since it depends on the functional group equivalent of each resin, it cannot be said in general, but for example, the content ratio of the phenolic resin is preferably in the range of 19% by mass to 53% by mass, assuming that the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer, the epoxy resin, and the phenolic resin, which are the resin components in the adhesive composition, is 100 parts by mass.

[Curing accelerator]
In addition, the thermosetting resin composition may contain, as necessary, a curing accelerator such as a tertiary amine, an imidazole, or a quaternary ammonium salt. As such a curing accelerator, the same as those exemplified as the curing accelerator for the adhesive composition for the general-purpose die-bonding film may be used. The amount of the curing accelerator added is preferably in the range of 0.01 to 0.07 parts by mass relative to 100 parts by mass of the epoxy resin and the phenolic resin in total, from the viewpoint of suppressing the occurrence of voids on the adhesive surface.

[Inorganic filler]
Furthermore, an inorganic filler can be added to the thermosetting resin composition as necessary from the viewpoints of improving the handleability of the die bond film (adhesive layer) 3, adjusting the fluidity during die bonding, imparting thixotropic properties, improving the adhesive strength, etc. As the inorganic filler, the same as those exemplified as the inorganic filler for the adhesive composition for the general-purpose die bond film described above can be used in the same manner, but among these, silica filler is preferably used from the viewpoint of versatility. The content ratio of the inorganic filler in the die bond film (adhesive layer) 3 is preferably in the range of 10% by mass or more and 80% by mass or less, and more preferably in the range of 15% by mass or more and 50% by mass or less, when the total amount of the glycidyl group-containing (meth)acrylic acid ester copolymer, epoxy resin, and phenolic resin, which are the resin components described above, is taken as 100 parts by mass as the standard, from the viewpoints of fluidity during die bonding, cleavability during cool expansion, and adhesive strength.

The above-mentioned inorganic filler is preferably a mixture of two or more inorganic fillers with different average particle sizes in order to improve the breakability of the die bond film (adhesive layer) 3 during cool expansion and to fully express the adhesive strength after curing. Specifically, it is preferable to use an inorganic filler with an average particle size in the range of 0.1 μm to 5 μm as the main inorganic filler component, which accounts for 80 mass% or more based on the total mass of the inorganic filler. When it is necessary to suppress foaming of the adhesive layer 3 during the semiconductor chip manufacturing process due to excessively high fluidity of the die bond film (adhesive layer) 3 and to improve the adhesive strength after curing, an inorganic filler with an average particle size of less than 0.1 μm may be used in combination with the above-mentioned main inorganic filler component in an amount of 20 mass% or less based on the total mass of the inorganic filler.

[Silane coupling agent]
Furthermore, in order to improve the adhesive strength to the adherend, the thermosetting resin composition may contain a silane coupling agent as necessary. As the silane coupling agent, the same silane coupling agent as exemplified for the adhesive composition for the general-purpose die-bonding film may be used. The amount of the silane coupling agent added is preferably in the range of 0.5 parts by mass or more to 2.0 parts by mass or less with respect to 100 parts by mass of the epoxy resin and the phenolic resin in total, in order to suppress the generation of voids on the adhesive surface.

[others]
Furthermore, a flame retardant, an ion trapping agent, or the like may be added to the thermosetting resin composition within a range that does not impair the function of the die bond film 3. As these flame retardants and ion trapping agents, the same ones as those exemplified as the flame retardants and ion trapping agents for the adhesive composition for general-purpose die bond films described above can be used in the same manner.

(Thickness of die bond film (adhesive layer))
The thickness of the die bond film (adhesive layer) 3 is not particularly limited, but is preferably in the range of 5 μm to 200 μm in order to ensure adhesive strength, properly embed wires for connecting semiconductor chips, or sufficiently fill unevenness in wiring circuits of a substrate. If the thickness of the die bond film (adhesive layer) 3 is less than 5 μm, the adhesive strength between the semiconductor chip and the lead frame or wiring substrate may be insufficient. On the other hand, if the thickness of the die bond film (adhesive layer) 3 exceeds 200 μm, it becomes uneconomical and is likely to be insufficient in response to miniaturization and thinning of semiconductor devices. In addition, in terms of high adhesiveness and thinning of semiconductor devices, the thickness of the film-like adhesive is more preferably in the range of 10 μm to 100 μm, and particularly preferably in the range of 20 μm to 75 μm.

More specifically, when used as a general-purpose die bond film (adhesive layer), the thickness is preferably, for example, in the range of 5 μm or more and less than 30 μm, particularly in the range of 10 μm or more and 25 μm or less, and when used as a wire-embedded die bond film (adhesive layer), the thickness is preferably, for example, in the range of 30 μm or more and 100 μm or less, particularly in the range of 40 μm or more and 80 μm or less.

(Manufacturing method of die bond film)
The die bond film (adhesive layer) 3 is manufactured, for example, as follows. First, a release liner is prepared. The release liner can be the same as the release liner placed on the pressure-sensitive adhesive layer 2 of the dicing tape 10. Next, a coating solution for the die bond film (adhesive layer) 3, which is a material for forming the die bond film (adhesive layer) 3, is prepared. The coating solution can be prepared by uniformly mixing and dispersing a thermosetting resin composition containing, for example, a glycidyl group-containing (meth)acrylic acid ester copolymer, an epoxy resin, a curing agent for the epoxy resin, an inorganic filler, a curing accelerator, and silane coupling, which are components of the die bond film (adhesive layer) 3 as described above, and a dilution solvent. As the solvent, for example, a general-purpose organic solvent such as methyl ethyl ketone or cyclohexanone can be used.

Next, the coating solution for the die bond film (adhesive layer) 3 is applied to the release-treated surface of the release liner, which serves as a temporary support, and dried to form a die bond film (adhesive layer) 3 of a predetermined thickness. After that, the release-treated surface of another release liner is attached to the die bond film (adhesive layer) 3. There is no particular limitation on the coating method, and it can be applied using, for example, a die coater, a comma coater (registered trademark), a gravure coater, a roll coater, a reverse coater, etc. In addition, as for the drying conditions, for example, the drying temperature is preferably in the range of 60°C to 200°C, and the drying time is preferably in the range of 1 minute to 90 minutes. In addition, in the present invention, a laminate having a release liner on both sides or one side of the die bond film (adhesive layer) 3 may also be referred to as a die bond film (adhesive layer) 3.

The low-angle adhesive strength after ultraviolet irradiation of the adhesive layer 2 of the dicing tape 10 to the die bond film 3 at 23 ° C. is preferably 0.95 N / 25 mm or less, more preferably 0.85 N / 25 mm or less, and even more preferably 0.70 N / 25 mm or less from the viewpoint of improving pick-up properties. The lower the low-angle adhesive strength after ultraviolet irradiation, the better from the viewpoint of improving pick-up properties. However, in the stage before picking up the semiconductor chip 30a with the die bond film 3 from the dicing tape 10, the semiconductor chip 30a with the die bond film 3 can be prevented from peeling off or shifting unintentionally from the dicing tape 10, and pick-up can be performed better, so that it is preferably 0.05 N / 25 mm or more. In addition, the shear adhesive strength of the pressure-sensitive adhesive layer 2 of the dicing tape 10 to the die bond film 3 before ultraviolet irradiation at -30 ° C. is preferably 100.0 N / 100 mm 2 or more, more preferably in the range of 105.0 N / 100 mm ² or more and 140 N / 100 mm ^{2 or less, and even more preferably in the range of 107.7 N / 100 mm 2 or} more and 123.0 N / 100 mm ² or less, from the viewpoint of both suppressing partial peeling (lifting) of the die bond film 3 from the pressure-sensitive adhesive layer 2 of the dicing tape 10 after ^expansion and improving pick-up properties.

The low-angle adhesive strength after UV irradiation at 23°C and the shear adhesive strength before UV irradiation at -30°C of the adhesive layer 2 of the dicing tape 10 against the die bond film 3 can be measured using the test methods described in the Examples. In addition, as long as the pickup properties are not impaired, the failure mode in the shear adhesive strength measurement test before UV irradiation may be cohesive failure of the adhesive layer.

(Dicing die bond film manufacturing method)
The manufacturing method of the dicing die bond film 20 is not particularly limited, but can be manufactured by a conventionally known method. For example, the dicing die bond film 20 is prepared by first preparing the dicing tape 10 and the die bond film 20 separately, then peeling off the release liners of the pressure-sensitive adhesive layer 2 of the dicing tape 10 and the die bond film (adhesive layer) 3, respectively, and bonding the pressure-sensitive adhesive layer 2 of the dicing tape 10 and the die bond film (adhesive layer) 3, for example, by a pressure-bonding roll such as a hot roll laminator. The bonding temperature is not particularly limited, and is preferably in the range of, for example, 10°C to 100°C, and the bonding pressure (linear pressure) is preferably in the range of, for example, 0.1 kgf/cm to 100 kgf/cm. In the present invention, the dicing die bond film 20 may also be referred to as a laminate having a release liner on the pressure-sensitive adhesive layer 2 and the die bond film (adhesive layer) 3. In the dicing die bond film 20, the release liners provided on the pressure-sensitive adhesive layer 2 and the die bond film (adhesive layer) 3 may be peeled off when the dicing die bond film 20 is provided to a workpiece.

The dicing die bond film 20 may be in the form of a roll or a laminate of wide sheets. It may also be in the form of a sheet or tape formed by cutting the dicing tape 10 in these forms to a predetermined size.

For example, as disclosed in JP 2011-159929 A, the dicing tape 10 can be manufactured in the form of a film roll in which a large number of precut adhesive layers (die bond film 3) and adhesive films (dicing tape 10) are formed in the shape of a wafer constituting a semiconductor element on a release substrate (release liner) in the form of islands. In this case, the dicing tape 10 is formed in a circular shape with a larger diameter than the die bond film (adhesive layer) 3, and the die bond film (adhesive layer) 3 is formed in a circular shape with a larger diameter than the semiconductor wafer 30. When the precut processing is performed in such a film roll form, the dicing tape 10 may be locally heated and/or cooled in order to continuously and satisfactorily peel off and remove the excess dicing tape 10 without breaking it. Here, the heating temperature is appropriately selected, but is preferably 30°C to 120°C. The heating time is appropriately selected, but is preferably 0.1 to 10 seconds. The dicing tape 10 of the present invention has a certain degree of heat resistance, so even if it is subjected to heat treatment at a high temperature of 120°C, there will be no particular problems in handling it.

<Method of manufacturing semiconductor chip>
FIG. 5 is a flow chart explaining a method for manufacturing a semiconductor chip using a dicing die bond film 20 in which a die bond film (adhesive layer) 3 is laminated on the adhesive layer 2 of the dicing tape 10 of this embodiment. FIG. 6 is a schematic diagram showing a state in which a ring frame (wafer ring) 40 is attached to the outer edge portion (adhesive layer 2 exposed portion) of the dicing tape 10 of the dicing die bond film 20, and a semiconductor wafer processed to be dicable is attached to the die bond film (adhesive layer) 3 in the center. Furthermore, FIGS. 7(a) to (f) are cross-sectional views showing an example of a grinding process of a semiconductor wafer in which a plurality of modified regions are formed by laser light irradiation and a bonding process of the semiconductor wafer to a dicing die bond film. FIGS. 8(a) to (f) are cross-sectional views showing an example of manufacturing a semiconductor chip using a thin-film semiconductor wafer having a plurality of modified regions to which a dicing die bond film is bonded.

(Method for manufacturing a semiconductor chip using a dicing die bond film 20)
The method for manufacturing a semiconductor chip using the dicing die bond film 20 is not particularly limited and may be any of the methods described above. Here, however, a manufacturing method using SDBG (Stealth Dicing Before Griding) will be described as an example.

First, as shown in FIG. 7(a), a semiconductor wafer W is prepared, for example made of silicon, with multiple integrated circuits (not shown) mounted on its first surface Wa (step S201 in FIG. 5: preparation step). Then, a wafer processing tape (backgrind tape) T having an adhesive surface Ta is attached to the first surface Wa of the semiconductor wafer W.

Next, as shown in FIG. 7(b), while the semiconductor wafer W is held on the wafer processing tape T, a laser beam focused inside the wafer is irradiated from the side opposite the wafer processing tape T, i.e., the second surface Wb side of the semiconductor wafer W, along the grid-like division lines X, and modified regions 30b are formed in the semiconductor wafer W due to ablation caused by multiphoton absorption (step S202 in FIG. 5: modified region formation process). The modified regions 30b are weakened regions for breaking and separating the semiconductor wafer W into semiconductor chips by the cool expand process. For methods of forming modified regions 30b along the division lines by irradiating the semiconductor wafer W with laser beams, see, for example, the methods disclosed in Japanese Patent Publication No. 3408805, Japanese Patent Publication No. 2002-192370, Japanese Patent Publication No. 2003-338567, etc.

7(c), while the semiconductor wafer W is held on the wafer processing tape T, the semiconductor wafer W is thinned by grinding from the second surface Wb until it reaches a predetermined thickness. Here, the thickness of the semiconductor wafer 30 is adjusted to preferably 100 μm or less, more preferably 10 μm or more and 50 μm or less, from the viewpoint of thinning the semiconductor device. This results in a thin semiconductor wafer 30 having therein a modified region 30b that facilitates singulation into a plurality of semiconductor chips 30a by the subsequent cool expand process (step S203 in FIG. 5: grinding and thinning process). In this grinding and thinning process, depending on the final thickness of the semiconductor wafer 30 after grinding, the number of scans of the laser light irradiation (input power), the physical properties of the wafer processing tape T, etc., when the grinding load of the grinding wheel is applied, cracks may grow vertically from the modified region 30b, and the semiconductor wafer 30 may already be broken into individual semiconductor chips 30a at this stage, or the cracks may not grow and the wafer may not be broken.

Next, as shown in Figures 7 (d) and (e), a thin-film semiconductor wafer 30 having multiple modified regions 30b therein (or multiple semiconductor chips 30a if the semiconductor wafer 30 has already been cleaved into semiconductor chips 30a) held on a wafer processing tape T is bonded to the die bond film 3 of a dicing die bond film 20 prepared separately (step S204 in Figure 5: bonding process). In this process, after peeling off the release liner from the adhesive layer 2 and the die bond film (adhesive layer) 3 of the dicing die bond film 20 cut into a circle, as shown in FIG. 6, a ring frame (wafer ring) 40 is attached to the outer edge portion (exposed portion of the adhesive layer 2) of the dicing tape 10 of the dicing die bond film 20, and a thin-film semiconductor wafer 30 (a plurality of semiconductor chips 30a if the semiconductor wafer 30 has already been cleaved into semiconductor chips 30a) processed to be individualized is attached on the die bond film (adhesive layer) 3 laminated on the upper center portion of the adhesive layer 2 of the dicing tape 10. After this, as shown in FIG. 7(f), the wafer processing tape T is peeled off from the thin-film semiconductor wafer 30 (a plurality of semiconductor chips 30a if the semiconductor wafer 30 has already been cleaved into semiconductor chips 30a). The attachment is performed while pressing with a pressing means such as a pressure roller. The application temperature is not particularly limited, but is preferably in the range of 20°C to 130°C, and more preferably in the range of 40°C to 100°C from the viewpoint of reducing warpage of the semiconductor wafer 30. The application pressure is not particularly limited, but is preferably in the range of 0.1 MPa to 10.0 MPa. The dicing tape 10 of the present invention has a certain degree of heat resistance, so that even if the application temperature is high, there is no particular problem in handling it.

Next, after a ring frame 40 is attached onto the adhesive layer 2 of the dicing tape 10 in the dicing die bond film 20, the dicing die bond film 20 with the thin-film semiconductor wafer 30 (or multiple semiconductor chips 30a if the semiconductor wafer 30 has already been cleaved into semiconductor chips 30a) that has been processed to be singulated is fixed to a holder 41 of an expanding device, as shown in FIG. 8(a). As shown in FIG. 8(b), multiple modified regions 30b are formed inside the thin-film semiconductor wafer 30 along the intended dicing line X so that the thin-film semiconductor wafer 30 can be singulated into multiple semiconductor chips 30a.

Next, a first expanding step under a relatively low temperature condition (for example, -30°C or higher and 0°C or lower), i.e., a cool expanding step, is performed as shown in FIG. 8(c), in which the semiconductor wafer 30 is singulated into a plurality of semiconductor chips 30a, and the die bond film (adhesive layer) 3 of the dicing die bond film 20 is cut into small pieces of die bond film (adhesive layer) 3a corresponding to the size of the semiconductor chip 30a, to obtain the semiconductor chip 30a with the die bond film 3a (step S205 in FIG. 5: cool expanding step). In this step, a hollow cylindrical push-up member (not shown) provided in the expanding device is raised in contact with the dicing tape 10 on the underside of the dicing die bond film 20, and the dicing tape 10 of the dicing die bond film 20 to which the semiconductor wafer 30 processed to be singulated is attached is expanded so as to be stretched in two-dimensional directions including the radial and circumferential directions of the semiconductor wafer 30. The internal stress caused by the tensile force of the dicing tape 10 in all directions by the cool expansion is transmitted as an external stress to the semiconductor wafer 30 processed to be diced and the die bond film 3 attached to the semiconductor wafer 30. This external stress causes cracks to grow vertically from the multiple lattice-shaped modified regions 30b formed inside the semiconductor wafer 30, and the semiconductor wafer 30 is cleaved into individual semiconductor chips 30a. The die bond film 3 embrittled at low temperature is also cleaved into small pieces of die bond film 3a of the same size as the semiconductor chips 30a. If the semiconductor wafer 30 has already been cleaved into individual semiconductor chips 30a in the grinding and thinning process, only the die bond film 3 embrittled at low temperature that is in close contact with the semiconductor chips 30a is cleaved by the cool expansion into small pieces of die bond film 3a corresponding to the size of the semiconductor chips 30a, and the semiconductor chips 30a with the die bond film 3a are obtained.

The temperature conditions in the cool expansion step are, for example, in the range of −30° C. or higher and 0° C. or lower, preferably in the range of −20° C. or higher and −5° C. or lower, and more preferably in the range of −15° C. or higher and −5° C. or lower.
The expansion speed in the cool expanding step (the speed at which the hollow cylindrical push-up member rises) is preferably in the range of 0.1 mm/sec to 1000 mm/sec, more preferably in the range of 10 mm/sec to 300 mm/sec. The expansion amount in the cool expanding step (the push-up height of the hollow cylindrical push-up member) is preferably in the range of 3 mm to 16 mm.

Here, the dicing tape 10 of the present invention first comprises a base film 1 made of a resin composition whose main component is an ionomer of an ethylene-unsaturated carboxylic acid copolymer containing a specific amount of polyamide resin, thereby making it possible to keep the tensile stress at 5% elongation at -15°C within an appropriate range. Therefore, the internal stress generated by the tension of the dicing tape 10 in all directions by cool expansion is efficiently transmitted as external stress to the semiconductor wafer 30 that has been processed to be diced into individual pieces and the die bond film 3 attached to the semiconductor wafer 30, and as a result, the semiconductor wafer 30 and the die bond film 3 are simultaneously cut with good yield. Furthermore, the dicing tape 10 of the present invention is composed of an adhesive layer 2 made of an adhesive composition mainly composed of an acrylic adhesive polymer having a specific glass transition temperature (Tg) and hydroxyl value, and by controlling the amount of polyisocyanate-based crosslinking agent added, the toughness and residual hydroxyl concentration of the adhesive composition after the crosslinking reaction can be set within an appropriate range. This gives the interface between the die bond film 3 and the adhesive layer 2 appropriate impact relaxation properties and initial adhesive strength at low temperatures, and as a result, the adhesive layer 2 relaxes the impact force when the semiconductor wafer 30 or die bond film 3 processed to be diced by cool expansion is broken, and the small piece of die bond film 3a (adhesive layer) holding the semiconductor chip 30a is prevented from lifting or peeling off from the adhesive layer 2 on all four edges.

After the cool expansion process, the hollow cylindrical push-up member of the expansion device is lowered, and the expanded state of the dicing tape 10 is released.

Next, a second expansion process under relatively high temperature conditions (e.g., 10°C or higher and 30°C or lower), i.e., a room temperature expansion process, is performed as shown in FIG. 8(d), and the distance (kerf width) between the semiconductor chips 30a with the die bond film (adhesive layer) 3a is expanded. In this process, a cylindrical table (not shown) equipped with an expansion device is raised in contact with the dicing tape 10 on the underside of the dicing die bond film 20, and the dicing tape 10 of the dicing die bond film 20 is expanded (step S206 in FIG. 5: room temperature expansion process). By sufficiently securing the distance (kerf width) between the semiconductor chips 30a with the die bond film (adhesive layer) 3a by the room temperature expansion process, the recognition of the semiconductor chips 30a by a CCD camera or the like can be improved, and re-adhesion between the semiconductor chips 30a with the die bond film (adhesive layer) 3a caused by contact between adjacent semiconductor chips 30a during pick-up can be prevented. As a result, in the pick-up process described below, the pick-up properties of the semiconductor chip 30a with the die bond film (adhesive layer) 3a are improved.

The temperature conditions in the room temperature expansion process are, for example, 10°C or higher, and preferably in the range of 15°C to 30°C. The expansion speed (the speed at which the cylindrical table rises) in the room temperature expansion process is, for example, in the range of 0.1 mm/sec to 50 mm/sec, and preferably in the range of 0.3 mm/sec to 30 mm/sec. The expansion amount in the room temperature expansion process is, for example, in the range of 3 mm to 20 mm.

After the dicing tape 10 is expanded at room temperature by the rise of the table, the table vacuum-adsorbs the dicing tape 10. Then, while maintaining the adsorption by the table, the table is lowered together with the work, and the expanded state of the dicing tape 10 is released. In order to prevent the kerf width of the semiconductor chip 30a with the die bond film (adhesive layer) 3a on the dicing tape 10 from narrowing after the expanded state is released, it is preferable to maintain a taut state by heat-shrinking (heat shrinking) the circumferential portion outside the semiconductor chip 30a holding area of the dicing tape 10 by blowing hot air while the dicing tape 10 is vacuum-adsorbed to the table, thereby eliminating the slack in the dicing tape 10 caused by the expansion. After the heat shrinkage, the vacuum adsorption state by the table is released. The temperature of the hot air may be adjusted according to the physical properties of the base film 1, the distance between the hot air outlet and the dicing tape, the air volume, etc., but is preferably in the range of 200°C to 250°C, for example. In addition, the distance between the hot air outlet and the dicing tape is preferably, for example, in the range of 15 mm to 25 mm. In addition, the air volume is preferably, for example, in the range of 35 L/min to 45 L/min. When performing the heat shrink process, the stage of the expansion device is rotated at a rotation speed in the range of, for example, 3°/sec to 10°/sec, while hot air is blown along the circumferential portion of the dicing tape 10 outside the semiconductor chip 30a holding area.

The dicing tape 10 of the present invention has a certain degree of heat resistance because its base film 1 is made of a resin film composed of a resin composition whose main component is an ionomer of an ethylene-unsaturated carboxylic acid copolymer containing a specific amount of polyamide resin. Therefore, even if high-temperature hot air is blown onto the dicing tape 10 during the heat shrink process, no thermal wrinkles or the like are generated, and the circumferential portion of the dicing tape 10 can be heat-shrunk without any problems.

Next, the dicing tape 10 is irradiated with active energy rays from the base film 1 side to cure and shrink the adhesive layer 2, thereby reducing the adhesive force of the adhesive layer 2 to the die bond film 3a (step S207 in FIG. 5: active energy ray irradiation step). Here, examples of the active energy rays used in the post-irradiation include ultraviolet rays, visible light, infrared rays, electron beams, β rays, and γ rays. Among these active energy rays, ultraviolet rays (UV) and electron beams (EB) are preferred, and ultraviolet rays (UV) are particularly preferred. The light source for irradiating the ultraviolet rays (UV) is not particularly limited, but for example, black lights, ultraviolet fluorescent lamps, low pressure mercury lamps, medium pressure mercury lamps, high pressure mercury lamps, ultra-high pressure mercury lamps, carbon arc lamps, metal halide lamps, xenon lamps, etc. can be used. In addition, ArF excimer lasers, KrF excimer lasers, excimer lamps, synchrotron radiation, etc. can also be used. The amount of ultraviolet (UV) radiation is not particularly limited, and is preferably in the range of 100 mJ/cm ² to 2,000 J/cm ² , and more preferably in the range of 300 mJ/cm ² to 1,000 J/cm ² .

As described above, the dicing tape 10 of the present invention improves the adhesion of the adhesive layer 2 to the die bond film (adhesive layer) 3 at low temperatures, but on the other hand, in the active energy ray curable adhesive composition constituting the adhesive layer 2, the active energy ray reactive carbon-carbon double bond concentration is controlled to a range of 0.85 mmol to 1.60 mmol per 1 g of the active energy ray curable adhesive composition, so that the adhesive layer 2 after ultraviolet (UV) irradiation has a high crosslink density due to a three-dimensional crosslinking reaction of the carbon-carbon double bonds, i.e., the storage modulus increases significantly, the glass transition temperature increases, and the volume shrinkage increases, so that the adhesive force to the die bond film 3a can be sufficiently reduced. As a result, in the pick-up process described later, the pick-up property of the semiconductor chip 30a with the die bond film (adhesive layer) 3a is improved.

Next, the semiconductor chips 30a with the die bond film (adhesive layer) 3a that have been cut and divided by the above-mentioned expanding process are peeled off from the adhesive layer 2 of the dicing tape 10 after ultraviolet (UV) irradiation, which is called pick-up (step S208 in FIG. 5: peeling (pick-up) process).

As a method of picking up the semiconductor chip 30a with the die bond film (adhesive layer) 3a, for example, as shown in FIG. 8(e), a push-up pin (needle) 60 is used to push up the second surface of the base film 1 of the dicing tape 10, and as shown in FIG. 8(f), the pushed-up semiconductor chip 30a with the die bond film (adhesive layer) 3a is sucked up by a suction collet 50 of a pick-up device (not shown) and peeled off from the adhesive layer 2 of the dicing tape 10. As a result, a semiconductor chip 30a with the die bond film (adhesive layer) 3a is obtained.

The pickup conditions are not particularly limited as long as they are within a practically acceptable range, and the thrust speed of the thrust pin (needle) 60 is usually set within a range of 1 mm/sec to 100 mm/sec, but when the thickness of the semiconductor chip 30a (thickness of the semiconductor wafer) is as thin as 100 μm or less, it is preferable to set it within a range of 1 mm/sec to 20 mm/sec from the viewpoint of suppressing damage to the thin-film semiconductor chip 30a. From the viewpoint of productivity, it is more preferable to set it within a range of 5 mm/sec to 20 mm/sec.

The push-up height of the push-up pin that allows the semiconductor chip 30a to be picked up without being damaged is preferably set within a range of 100 μm or more and 600 μm or less from the same viewpoint as above, and more preferably within a range of 100 μm or more and 450 μm or less from the viewpoint of reducing stress on the semiconductor thin-film chip. From the viewpoint of productivity, it is particularly preferable that the push-up height be set within a range of 100 μm or more and 350 μm or less. A dicing tape that can reduce such a push-up height can be said to have excellent pick-up properties.

As explained above, the dicing tape 10 of the present invention, which is composed of a base film 1 mainly composed of an ionomer of a specific polyamide resin-containing ethylene-unsaturated carboxylic acid copolymer and an adhesive layer 2 composed of a specific active energy ray-curable adhesive composition, when used in the semiconductor manufacturing process in the form of a dicing die bond film 20 in which a die bond film (adhesive layer) 3 is peelably adhered and laminated on the adhesive layer 2 of the dicing tape 10, has heat resistance that can withstand the heat treatments of each process, even when a die bond film with high fluidity and a large thickness such as a wire-embedded die bond film is applied by laminating it, and the semiconductor wafer 30 with the die bond film 3 is well cut by cool expansion, and the kerf width can be sufficiently secured by room temperature expansion, and partial peeling (floating) of the die bond film 3a after cutting from the adhesive layer 2 of the dicing tape 10 is sufficiently suppressed, and the cut semiconductor chips 30a with the die bond film 3a can be well picked up.

8(a) to (f) is an example (SDBG) of a method for manufacturing a semiconductor chip 30a using the dicing die bond film 20, and the method for using the dicing tape 10 as the dicing die bond film 20 is not limited to the above method. In other words , the dicing die bond film 20 can be used in any manner without being limited to the above method as long as it can be attached to the semiconductor wafer 30 during dicing.

In particular, the dicing tape 10 of the present invention is suitable as a dicing tape to be integrated with a wire-embedded die bond film and used as a dicing die bond film in manufacturing methods for obtaining thin-film semiconductor chips, such as DBG, stealth dicing, SDBG, etc. Of course, it can also be integrated with a general-purpose die bond film for use.

<Method of Manufacturing Semiconductor Device>
A semiconductor device mounted with a semiconductor chip manufactured using a dicing die bond film 20 obtained by integrating the dicing tape 10 and the die bond film 3 to which the present embodiment is applied will be specifically described below.

The semiconductor device (semiconductor package) can be obtained, for example, by bonding the semiconductor chip 30a with the die bond film (adhesive layer) 3a described above to a support member for mounting the semiconductor chip or to the semiconductor chip by heat and pressure bonding, and then going through processes such as a wire bonding process and a sealing process using a sealing material.

Figure 9 is a schematic cross-sectional view of one embodiment of a semiconductor device having a stacked structure, which is mounted with a semiconductor chip manufactured using a dicing die bond film 20 that integrates a dicing tape 10 and a wire-embedded die bond film 3 to which this embodiment is applied. The semiconductor device 70 shown in Figure 9 includes a support substrate 4 for mounting a semiconductor chip, cured die bond films (adhesive layers) 3a1 and 3a2, a first-stage semiconductor chip 30a1, a second-stage semiconductor chip 30a2, and an encapsulant 8. The support substrate 4 for mounting a semiconductor chip, the cured die bond film 3a1, and the semiconductor chip 30a1 constitute a support member 9 for the semiconductor chip 30a2.

A plurality of external connection terminals 5 are arranged on one surface of the support substrate 4 for mounting the semiconductor chip, and a plurality of terminals 6 are arranged on the other surface of the support substrate 4 for mounting the semiconductor chip. The support substrate 4 for mounting the semiconductor chip has wires 7 for electrically connecting the connection terminals (not shown) of the semiconductor chips 30a1 and 30a2 to the external connection terminals 5. The semiconductor chip 30a1 is bonded to the support substrate 4 for mounting the semiconductor chip by the hardened die bond film 3a1 in such a way that the unevenness caused by the external connection terminals 5 is embedded. The semiconductor chip 30a2 is bonded to the semiconductor chip 30a1 by the hardened die bond film 3a2. The semiconductor chips 30a1, 30a2, and the wires 7 are sealed by the sealing material 8. In this way, the wire-embedded die bond film 3a is suitably used for a semiconductor device having a stacked structure in which a plurality of semiconductor chips 30a are stacked.

10 is a schematic cross-sectional view of one aspect of another semiconductor device mounted with a semiconductor chip manufactured using a dicing die bond film 20 in which the dicing tape 10 to which the present embodiment is applied and the general-purpose die bond film 3 are integrated. The semiconductor device 80 shown in FIG. 10 includes a semiconductor chip mounting support substrate 4, a hardened die bond film 3a, a semiconductor chip 30a, and a sealing material 8. The semiconductor chip mounting support substrate 4 is a support member for the semiconductor chip 30a, and has wires 7 for electrically connecting the connection terminals (not shown) of the semiconductor chip 30a to external connection terminals (not shown) arranged on the main surface of the semiconductor chip mounting support substrate 4. The semiconductor chip 30a is bonded to the semiconductor chip mounting support substrate 4 by the hardened die bond film 3a. The semiconductor chip 30a and the wires 7 are sealed by the sealing material 8.

The present invention will be explained in more detail with reference to the following examples, but the present invention is not limited to these.

1. Preparation of Base Film 1 The following resins were prepared as materials for preparing base films 1(a) to 1(s).

(Resin (A) composed of ionomer of ethylene-unsaturated carboxylic acid copolymer)
Resin (IO1)
Terpolymer consisting of ethylene/methacrylic acid/2-methyl-propyl acrylate in a mass ratio of 80/10/10, degree of neutralization with Zn ²⁺ ions: 60 mol%, melting point: 86°C, MFR: 1 g/10 min (190°C/2.16 kg load), density: 0.96 g/cm ³
・Resin (IO2)
A binary copolymer consisting of ethylene/methacrylic acid = 85/15 mass ratio, degree of neutralization with Zn2 ⁺ ions: 23 mol%, melting point: MFR: 5 g/10 min (190 ° C / 2.16 kg load), melting point: 91 ° C, density: 0.95 g / cm ³

(Polyamide resin (B))
・Resin (PA1)
Nylon 6, melting point: 225°C, density: 1.13g/ ^cm3
・Resin (PA2)
Nylon 6-12, melting point: 215°C, density: 1.06g/ ^cm3

(Other Resins (C))
Resin (EMAA1)
A binary copolymer having a mass ratio of ethylene/methacrylic acid = 91/9, melting point: 99 ° C, MFR: 3 g / 10 min (190 ° C / 2.16 kg load), density: 0.93 g / cm ³
Resin (EMAA2)
A binary copolymer having a mass ratio of ethylene/methacrylic acid = 91/9, melting point: 98 ° C, MFR: 5 g / 10 min (190 ° C / 2.16 kg load), density: 0.93 g / cm ³
・Resin (PP)
Random copolymer polypropylene, melting point 138℃
・Resin (EVA)
Ethylene-vinyl acetate copolymer, vinyl acetate content 20% by mass, melting point 82°C, density: 0.94 g/ ^cm3
・Resin (PVC)
Vinyl chloride, melting point 95℃

(Substrate Film 1 (a))
(IO1) was prepared as the resin (A) made of ionomer, and (PA1) was prepared as the polyamide resin (B). First, the resin (A) made of the ionomer = (IO1) and the polyamide resin (B) = (PA1) were dry-blended at a mass ratio of (A): (B) = 95: 5. Next, the dry-blended mixture was fed into the resin inlet of a twin-screw extruder, and melt-kneaded at a die temperature of 230 ° C. to obtain a resin composition for the base film 1 (a). The obtained resin composition was fed into each extruder using a one-type (same resin) three-layer T-die film molding machine, and molded under a processing temperature condition of 240 ° C. to produce a base film 1 (a) having a thickness of 90 μm and a three-layer structure of the same resin. The thickness of each layer was set to 1st layer (the surface side in contact with the pressure-sensitive adhesive layer 2) / 2nd layer / 3rd layer = 30 μm / 30 μm / 30 μm. The mass ratio of the total amount of the ionomer resin (A) to the total amount of the polyamide resin (B) in the entire layer was (A):B)=95:5.

(Substrate Film 1 (b))
A 90 μm thick substrate film 1 (b) having a three-layer structure of the same resin was produced in the same manner as the substrate film 1 (a), except that the ionomer resin (A) = (IO1) and the polyamide resin (B) = (PA1) were dry-blended at a mass ratio of (A): (B) = 90: 10. The thicknesses of the layers were 1st layer (the surface side in contact with the pressure-sensitive adhesive layer 2) / 2nd layer / 3rd layer = 30 μm / 30 μm / 30 μm. The mass ratio of the total amount of the ionomer resin (A) to the total amount of the polyamide resin (B) in the entire layer was the total amount of (A): the total amount of (B) = 90: 10.

(Substrate Film 1 (c))
The ionomer resin (A) = (IO1) and the polyamide resin (B) = (PA1) were dry-blended in a mass ratio of (A): (B) = 85: 15 in the same manner as the substrate film 1 (a), except that a substrate film 1 (c) having a thickness of 90 μm and a three-layer structure of the same resin was produced. The thicknesses of the layers were 1st layer (the surface side in contact with the pressure-sensitive adhesive layer 2) / 2nd layer / 3rd layer = 30 μm / 30 μm / 30 μm. The mass ratio of the total amount of the ionomer resin (A) to the total amount of the polyamide resin (B) in the entire layer was the total amount of (A): the total amount of (B) = 85: 15.

(Substrate Film 1 (d))
The ionomer resin (A) = (IO1) and the polyamide resin (B) = (PA1) were dry-blended in a mass ratio of (A): (B) = 80: 20 in the same manner as the substrate film 1 (a), except that a substrate film 1 (d) having a thickness of 90 μm and a three-layer structure of the same resin was produced. The thicknesses of the layers were 1st layer (the surface side in contact with the pressure-sensitive adhesive layer 2) / 2nd layer / 3rd layer = 30 μm / 30 μm / 30 μm. The mass ratio of the total amount of the ionomer resin (A) to the total amount of the polyamide resin (B) in the entire layer was the total amount of (A): the total amount of (B) = 80: 20.

(Substrate Film 1 (e))
The above ionomer resin (A) = (IO1) and the above polyamide resin (B) = (PA1) were dry-blended in a mass ratio of (A): (B) = 74: 26 in the same manner as in the substrate film 1 (a), except that a substrate film 1 (e) having a thickness of 90 μm and a three-layer structure of the same resin was produced. The thicknesses of the layers were 1st layer (the surface side in contact with the pressure-sensitive adhesive layer 2) / 2nd layer / 3rd layer = 30 μm / 30 μm / 30 μm. The mass ratio of the total amount of the ionomer resin (A) to the total amount of the polyamide resin (B) in the entire layer was the total amount of (A): the total amount of (B) = 74: 26.

(Substrate Film 1 (f))
The ionomer resin (A) = (IO1) and the polyamide resin (B) = (PA1) were dry-blended in a mass ratio of (A): (B) = 72: 28 in the same manner as the substrate film 1 (a), except that a substrate film 1 (f) having a thickness of 90 μm and a three-layer structure of the same resin was produced. The thicknesses of the layers were 1st layer (the surface side in contact with the pressure-sensitive adhesive layer 2) / 2nd layer / 3rd layer = 30 μm / 30 μm / 30 μm. The mass ratio of the total amount of the ionomer resin (A) to the total amount of the polyamide resin (B) in the entire layer was the total amount of (A): the total amount of (B) = 72: 28.

(Substrate film 1 (g))
The resin (A) made of ionomer (IO1) and the polyamide resin (B) made of polyamide resin (PA1) were prepared. First, the resins for the first and third layers were dry-blended with the resin (A)=(IO1) made of the ionomer and the polyamide resin (B)=(PA1) in a mass ratio of (A):(B)=72:28. The dry-blended mixture was then fed into the resin inlet of a twin-screw extruder and melt-kneaded at a die temperature of 230°C to obtain a resin composition for the first and third layers of the base film 1 (g). The resin (A)=(IO1) made of the ionomer was used alone as the resin for the second layer. Each resin composition and resin was fed into each extruder using a two-type (two types of resin) three-layer T-die film molding machine and molded under the condition of a processing temperature of 240°C to produce a base film 1 (g) having a thickness of 90 μm and a three-layer structure of two types of resin. The thicknesses of the first layer (the surface in contact with the pressure-sensitive adhesive layer 2)/second layer/third layer were 30 μm/30 μm/30 μm. The mass ratio of the total amount of the ionomer resin (A) to the total amount of the polyamide resin (B) in the entire layer was (A):B)=81:19.

(Substrate film 1 (h))
The resin (A) made of ionomer (IO1), the polyamide resin (B) (PA1), and the other resin (C) (EMAA1) were prepared. First, the resin (A) made of ionomer = (IO1) and the polyamide resin (B) = (PA1) were dry-blended in a mass ratio of (A): (B) = 85: 15 as the resin for the first layer and the third layer. Next, the dry-blended mixture was put into the resin inlet of a twin-screw extruder and melt-kneaded at a die temperature of 230 ° C. to obtain a resin composition for the first layer and the third layer of the base film 1 (h). In addition, the other resin (C) (EMAA1) was used alone as the resin for the second layer. Each resin composition and resin was put into each extruder using a two-type (two types of resin) three-layer T-die film molding machine, and molded under the condition of a processing temperature of 240 ° C., to produce a substrate film 1 (h) having a thickness of 80 μm and a three-layer structure of two types of resin. The thickness of each layer was 1st layer (the surface side contacting the pressure-sensitive adhesive layer 2) / 2nd layer / 3rd layer = 30 μm / 20 μm / 30 μm. The mass ratio of the total amount of resin (A) consisting of ionomer to the total amount of polyamide resin (B) in the entire layer is the total amount of (A): the total amount of (B) = 85: 15. In addition, the content ratio of the total amount of resin (A) and resin (B) in the entire layer is 75 mass%.

(Substrate Film 1 (i))
The resin (A) made of ionomer (IO1), the polyamide resin (B) (PA1), and the other resin (C) (EMAA2) were prepared. First, the resin (A) made of ionomer = (IO1) and the polyamide resin (B) = (PA1) were dry-blended in a mass ratio of (A): (B) = 90: 10 as the resin for the first layer and the third layer. Next, the dry-blended mixture was put into the resin inlet of a twin-screw extruder and melt-kneaded at a die temperature of 230 ° C. to obtain a resin composition for the first layer and the third layer of the base film 1 (i). In addition, the other resin (C) (EMAA2) was used alone as the resin for the second layer. Each resin composition and resin was put into each extruder using a two-type (two types of resin) three-layer T-die film molding machine, and molded under the condition of a processing temperature of 240 ° C., to produce a substrate film 1 (i) having a thickness of 90 μm and a three-layer structure of two types of resin. The thickness of each layer was 1st layer (the surface side contacting the pressure-sensitive adhesive layer 2) / 2nd layer / 3rd layer = 35 μm / 20 μm / 35 μm. The mass ratio of the total amount of resin (A) consisting of ionomer to the total amount of polyamide resin (B) in the entire layer is the total amount of (A): the total amount of (B) = 90: 10. In addition, the content ratio of the total amount of resin (A) and resin (B) in the entire layer is 78 mass%.

(Substrate Film 1 (j))
(IO1) was prepared as the resin (A) made of ionomer, and (PA1) was prepared as the polyamide resin (B). First, the resin (A) made of the ionomer = (IO1) and the polyamide resin (B) = (PA1) were dry-blended at a mass ratio of (A): (B) = 90: 10 as the resins for the first and second layers. Next, the dry-blended mixture was charged into the resin inlet of a twin-screw extruder, and melt-kneaded at a die temperature of 230 ° C. to obtain a resin composition for the first and second layers of the base film 1 (j). Each resin composition was charged into each extruder using a one-type (same resin) two-layer T-die film molding machine, and molded under a processing temperature condition of 240 ° C. to produce a base film 1 (j) having a thickness of 90 μm and a two-layer structure of the same resin. The thickness of each layer was set to the first layer (the surface side in contact with the pressure-sensitive adhesive layer 2) / second layer = 45 μm / 45 μm. The mass ratio of the total amount of the ionomer resin (A) to the total amount of the polyamide resin (B) in the entire layer was (A):B)=90:10.

(Substrate film 1 (k))
As the resin (A) made of ionomer, (IO1) and as the polyamide resin (B), (PA1) were prepared. First, as the resin for the first layer, the ionomer resin (A)=(IO1) and the polyamide resin (B)=(PA1) were dry-blended in a mass ratio of (A):(B)=90:10. Next, the dry-blended mixture was introduced into the resin inlet of a twin-screw extruder and melt-kneaded at a die temperature of 230°C to obtain a resin composition for the first layer of the base film 1 (k). Next, as the resin for the second layer, the ionomer resin (A)=(IO1) and the polyamide resin (B)=(PA1) were dry-blended in a mass ratio of (A):(B)=80:20. Next, the dry-blended mixture was introduced into the resin inlet of a twin-screw extruder and melt-kneaded at a die temperature of 230°C to obtain a resin composition for the second layer of the base film 1 (k). Each resin composition was put into each extruder using a two-type (same resin) two-layer T-die film molding machine and molded under the condition of a processing temperature of 240°C to produce a substrate film 1 (k) having a thickness of 100 μm and a two-layer structure of two types of resin. The thickness of each layer was 1st layer (the surface side contacting the pressure-sensitive adhesive layer 2)/2nd layer = 50 μm/50 μm. The mass ratio of the total amount of the resin (A) consisting of an ionomer to the total amount of the polyamide resin (B) as a whole layer was the total amount of (A): the total amount of (B) = 90:10.

(Substrate film 1 (l))
(IO1) was prepared as the resin (A) made of ionomer, and (PA1) was prepared as the polyamide resin (B). The above-mentioned resin (A) made of ionomer = (IO1) and the above-mentioned polyamide resin (B) = (PA1) were dry-blended at a mass ratio of (A): (B) = 70: 30. Next, the dry-blended mixture was put into the resin inlet of a twin-screw extruder, and melt-kneaded at a die temperature of 230 ° C. to obtain a resin composition for the base film 1 (l). The obtained resin composition was put into an extruder using a T-die film molding machine, and molded under the condition of a processing temperature of 240 ° C., to produce a base film 1 (l) having a thickness of 90 μm and a single layer structure.

(Base film 1 (m))
(IO1) was prepared as the resin (A) made of ionomer, and (PA2) was prepared as the polyamide resin (B). The above-mentioned resin (A) made of ionomer = (IO1) and the above-mentioned polyamide resin (B) = (PA2) were dry-blended at a mass ratio of (A): (B) = 88: 12, except that a substrate film 1 (m) having a thickness of 90 μm and a three-layer structure of the same resin was prepared in the same manner as the substrate film 1 (a). The thickness of each layer was 1st layer (the surface side contacting the pressure-sensitive adhesive layer 2) / 2nd layer / 3rd layer = 30 μm / 30 μm / 30 μm. The mass ratio of the total amount of the resin (A) made of ionomer to the total amount of the polyamide resin (B) in the entire layer was the total amount of (A): the total amount of (B) = 88: 12.

(Substrate film 1 (n))
(IO2) was prepared as the resin (A) made of ionomer, and (PA1) was prepared as the polyamide resin (B). The resin (A) made of ionomer = (IO2) and the polyamide resin (B) = (PA1) were dry-blended in a mass ratio of (A): (B) = 92: 8, except that the substrate film 1 (a) was used to prepare a substrate film 1 (n) having a thickness of 90 μm and a three-layer structure of the same resin. The thicknesses of the layers were 1st layer (the surface side in contact with the pressure-sensitive adhesive layer 2) / 2nd layer / 3rd layer = 30 μm / 30 μm / 30 μm. The mass ratio of the total amount of the resin (A) made of ionomer to the total amount of the polyamide resin (B) in the entire layer was the total amount of (A): the total amount of (B) = 92: 8.

(Base film 1 (o))
(IO1) was prepared as the resin (A) made of ionomer. A substrate film 1(o) having a three-layer structure of the same resin (only the resin (A) made of ionomer) and a thickness of 90 μm was prepared in the same manner as the substrate film 1(a), except that the polyamide resin (B) = (PA1) was not dry-blended. The thicknesses of the layers were 1st layer (the surface side in contact with the pressure-sensitive adhesive layer 2)/2nd layer/3rd layer = 30 μm/30 μm/30 μm.

(Substrate film 1 (p))
The ionomer resin (A) = (IO1) and the polyamide resin (B) = (PA1) were dry-blended in a mass ratio of (A): (B) = 97: 3 in the same manner as the substrate film 1 (a), except that a substrate film 1 (p) having a thickness of 90 μm and a three-layer structure of the same resin was produced. The thicknesses of the layers were 1st layer (the surface side in contact with the pressure-sensitive adhesive layer 2) / 2nd layer / 3rd layer = 30 μm / 30 μm / 30 μm. The mass ratio of the total amount of the ionomer resin (A) to the total amount of the polyamide resin (B) in the entire layer was the total amount of (A): the total amount of (B) = 97: 3.

(Substrate film 1 (q))
The above-mentioned ionomer resin (A)=(IO1) and the above-mentioned polyamide resin (B)=(PA1) were dry-blended at a mass ratio of (A):(B)=70:30 in the same manner as the substrate film 1(q), except that a substrate film 1(q) having a thickness of 90 μm and a three-layer structure of the same resin was produced. The thicknesses of the layers were 1st layer (the surface side in contact with the pressure-sensitive adhesive layer 2)/2nd layer/3rd layer=30 μm/30 μm/30 μm. The mass ratio of the total amount of the ionomer resin (A) to the total amount of the polyamide resin (B) in the entire layer was the total amount of (A):total amount of (B)=70:30.

(Substrate film 1 (r))
As other resins (C), (PP) and (EVA) were prepared. (PP) was used as the resin for the first and third layers, and (EVA) was used as the resin for the second layer. Each resin was put into each extruder using a two-type (two types of resin) three-layer T-die film molding machine, and molded under the condition of a processing temperature of 150 ° C., to produce a two-type three-layered substrate film 1 (r) having a thickness of 80 μm. The thickness of each layer was set to the first layer (the surface side in contact with the pressure-sensitive adhesive layer) / second layer / third layer = 8 μm / 64 μm / 8 μm.

(Substrate film 1 (s))
As another resin (C), (PVC) was prepared. This resin was put into an extruder using a T-die film molding machine and molded under the condition of a processing temperature of 150° C. to produce a substrate film 1 (s) having a single layer configuration and a thickness of 90 μm.

[Stress of the base film at 5% elongation at −15° C.]
The stress of the substrate films 1(a) to (s) produced above was determined when they were elongated by 5% in a temperature environment of −15° C. As test pieces, when the extrusion direction during melt molding in a T-die is defined as the MD direction and the direction perpendicular to the MD direction is defined as the TD direction, two types of test pieces were prepared: (1) a test piece cut to a size of 70 mm in the MD direction and 10 mm in the TD direction, and (2) a test piece cut to a size of 70 mm in the TD direction and 10 mm in the MD direction. Next, using a tensile compression tester (model: MinebeaTechnoGraph TG-5kN) manufactured by MinebeaMitsumi Inc., the test piece was placed in a thermostatic chamber (model: THB-A13-038) manufactured by MinebeaMitsumi Inc. at -15°C for 1 minute, and then the test piece was elongated in the length direction with a chuck distance of 50 mm and an elongation speed (tensile speed) of 300 mm/min, and the strength (unit: N) when elongated 5% from the initial length (chuck distance of 50 mm) was measured. The value obtained by dividing the obtained strength by the cross-sectional area of the tape (unit: ^mm2 ) was taken as the stress (unit: MPa) at 5% elongation at -15°C.

[Heat resistance of base film]
The heat resistance at 140°C was evaluated for the substrate films 1(a) to (s) prepared above. Test pieces were cut to a length of 100 mm in the MD direction and a width of 30 mm in the TD direction, and a 60 mm long marked line was written in the MD direction with a marker in the center of the test piece. Each test piece was hung in a thermostatic chamber (adjusted to 140°C) so that the MD direction was up and down, and a load of 5 g was applied to the lower side of each test piece. After storing in an environment of 140°C for 2 minutes, the marked line length L1 (mm) was measured, and the rate of change relative to the marked line length L0 (=60 mm) before the heating test was calculated.
Rate of change (%) = [(L1 - L0) / L0] x 100
The heat resistance of the base film 1 was evaluated according to the following criteria, and a rating of B or higher was determined to indicate good heat resistance.
A: The rate of change was within the range of ±10%.
B: The rate of change exceeded the range of ±10% and was within the range of ±14%.
C: The rate of change exceeded the range of ±14%.

2. Preparation of Solutions of Adhesive Compositions As adhesive compositions for the adhesive layer 2 of the dicing tape 10, solutions of the following active energy ray-curable acrylic adhesive compositions 2(a) to (r) were prepared.
The copolymerizable monomer components constituting the base polymer (acrylic acid ester copolymer) of these pressure-sensitive adhesive compositions are
2-Ethylhexyl acrylate (2-EHA, molecular weight: 184.3, Tg: -70°C),
- 2-hydroxyethyl acrylate (2-HEA, molecular weight: 116.12, Tg: -15°C),
Butyl acrylate (BA, molecular weight: 128.17, Tg: -54°C),
Methyl methacrylate (MMA, molecular weight: 100.12: Tg: 105°C),
Methacrylic acid (MAA, molecular weight: 86.06: Tg: 130°C),
was prepared.
As a polyisocyanate-based crosslinking agent, a TDI-based polyisocyanate-based crosslinking agent manufactured by Tosoh Corporation (product name: Coronate L-45E, solid content: 45% by mass, isocyanate group content in solution: 8.05% by mass, isocyanate group content in solid content: 17.89% by mass, calculated number of isocyanate groups: average 2.8/molecule, molecular weight: 656.64) was used.
- HDI-based polyisocyanate crosslinking agent (product name: Coronate HL, solid content: 75% by mass, isocyanate group content in solution: 12.8% by mass, isocyanate group content in solid content: 17.07% by mass, calculated number of isocyanate groups: average 2.6/molecule, molecular weight: 638.75),
was prepared.

(Solution of active energy ray-curable acrylic pressure-sensitive adhesive composition 2(a))
As copolymerization monomer components, 2-ethylhexyl acrylate (2-EHA), 2-hydroxyethyl acrylate (2-HEA), and methyl methacrylate (MMA) were prepared. These copolymerization monomer components were mixed to a copolymerization ratio of 2-EHA/2-HEA/MMA = 78.5 parts by mass/21.0 parts by mass/0.5 parts by mass (= 425.94 mmol/180.85 mmol/5.81 mmol), and a solution of a base polymer (acrylic acid ester copolymer) having a hydroxyl group was synthesized by solution radical polymerization using ethyl acetate as a solvent and azobisisobutyronitrile (AIBN) as an initiator. The Tg of the obtained base polymer calculated from the Fox formula was -60 ° C.

Next, 21.0 parts by mass (135.35 mmol: 74.8 mol% relative to 2-HEA) of 2-isocyanate ethyl methacrylate (product name: Karenz MOI, molecular weight: 155.15, isocyanate group: 1 per molecule, double bond group: 1 per molecule) having an isocyanate group and an active energy ray reactive carbon-carbon double bond manufactured by Showa Denko K.K. was blended with 100 parts by mass of the solid content of this base polymer as an active energy ray reactive compound manufactured by Showa Denko K.K., and reacted with some of the hydroxyl groups of 2-HEA to synthesize a solution of acrylic adhesive polymer (A) having a carbon-carbon double bond in the side chain (solid content concentration: 50 mass%, weight average molecular weight Mw: 380,000, solid content hydroxyl value: 21.1 mg KOH/g, solid content acid value: 2.7 mg KOH/g, carbon-carbon double bond content: 1.12 mmol/g). In the above reaction, 0.05 parts by mass of hydroquinone monomethyl ether was used as a polymerization inhibitor to maintain the reactivity of the carbon-carbon double bond.

Next, 2.0 parts by mass of an α-hydroxyalkylphenone-based photopolymerization initiator (product name: Omnirad 184) manufactured by IGM Resins B.V., 0.4 parts by mass of an acylphosphine oxide-based photopolymerization initiator (product name: Omnirad 819) manufactured by IGM Resins B.V., and 2.56 parts by mass (1.15 parts by mass in terms of solid content, 1.75 mmol) of a TDI-based polyisocyanate-based crosslinking agent manufactured by Tosoh Corporation (product name: Coronate L-45E, solid content concentration: 45% by mass) were mixed with 200 parts by mass (100 parts by mass in terms of solid content) of the solution of the acrylic adhesive polymer (A) synthesized above, diluted with ethyl acetate, and stirred to prepare a solution of active energy ray-curable acrylic adhesive composition 2 (a) with a solid content concentration of 22% by mass. In the active energy ray-curable acrylic adhesive composition 2(a), the equivalent ratio (NCO/OH) of the isocyanate group (NCO) in the polyisocyanate crosslinking agent to the hydroxyl group (OH) in the acrylic adhesive polymer was 0.13, the residual hydroxyl group concentration was 0.32 mmol/g, and the carbon-carbon double bond content was 1.11 mmol/g.

(Solutions of active energy ray-curable acrylic pressure-sensitive adhesive compositions 2(b) to 2(t))
The copolymerization ratio of the copolymerization monomer components, the amount of the active energy ray reactive compound, and the copolymerization monomer components were appropriately changed for the acrylic adhesive polymer (A) as shown in Tables 3 to 6, respectively, to synthesize solutions of the acrylic adhesive polymers (B) to (Q). The Tg, weight average molecular weight Mw, acid value, and hydroxyl value of the base polymer in the synthesized acrylic adhesive polymers (B) to (Q) are as shown in Tables 3 to 6, respectively. Next, using these solutions of the acrylic adhesive polymers, a photopolymerization initiator and a polyisocyanate-based crosslinking agent were appropriately mixed with 100 parts by mass of the acrylic adhesive polymers (A) to (Q) in terms of solid content as shown in Tables 3 to 6, respectively, to prepare solutions of the active energy ray-curable acrylic adhesive compositions 2(b) to 2(t). In the active energy ray-curable acrylic pressure-sensitive adhesive compositions 2(b) to 2(t), the equivalent ratio (NCO/OH) of the isocyanate group (NCO) in the polyisocyanate crosslinking agent to the hydroxyl group (OH) in the acrylic pressure-sensitive adhesive polymer, the residual hydroxyl group concentration, and the carbon-carbon double bond content are as shown in Tables 3 to 6, respectively.

3. Preparation of Solutions of Adhesive Compositions As adhesive compositions for the die bond film (adhesive layer) 3 of the dicing die bond film 20, solutions of the following adhesive compositions 3(a) to 3(d) were prepared.

(Solution of Adhesive Composition 3(a))
For wire-embedded die-bonding films, the following adhesive composition solution 3 (a) was prepared. First, 26 parts by mass of a bisphenol-type epoxy resin (trade name: R2710, epoxy equivalent: 170, molecular weight: 340, liquid at room temperature) manufactured by Printec Co., Ltd. as a thermosetting resin, 36 parts by mass of a cresol novolac-type epoxy resin (trade name: YDCN-700-10, epoxy equivalent: 210, softening point: 80 ° C.) manufactured by Tohto Kasei Co., Ltd. as a crosslinking agent, 1 part by mass of a phenolic resin (trade name: Milex XLC-LL, hydroxyl equivalent: 175, softening point: 77 ° C., water absorption rate: 1 mass%, heat mass reduction rate: 4 mass%) manufactured by Mitsui Chemicals, Inc. as a crosslinking agent, and 25 parts by mass of a phenolic resin (trade name: HE200C-10, hydroxyl equivalent: 200, softening point: 71 ° C., water absorption rate: 1 mass%, heat mass reduction rate: 4 mass%) manufactured by Air Water Inc. 12 parts by mass of phenolic resin manufactured by Air Water Inc. (trade name: HE910-10, hydroxyl equivalent: 101, softening point: 83°C, water absorption: 1 mass%, heat mass loss rate: 3 mass%), 15 parts by mass of silica filler dispersion liquid manufactured by Admatechs Co., Ltd. (trade name: SC2050-HLG, average particle size: 0.50 μm) as an inorganic filler, 14 parts by mass of silica filler dispersion liquid manufactured by Admatechs Co., Ltd. (trade name: SC1030-HJA, average particle size: 0.25 μm), and 1 part by mass of silica manufactured by Nippon Aerosil Co., Ltd. (trade name: Aerosil R972, average particle size: 0.016 μm). Cyclohexanone was added as a solvent to the resin composition, which was stirred and mixed, and further dispersed for 90 minutes using a bead mill.

Next, to the resin composition, 37 parts by mass of a glycidyl group-containing (meth)acrylic acid ester copolymer having a low weight average molecular weight Mw as a thermoplastic resin, 9 parts by mass of a glycidyl group-containing (meth)acrylic acid ester copolymer having a high weight average molecular weight Mw , 0.7 parts by mass of γ-ureidopropyltriethoxysilane (trade name: NUC A-1160) manufactured by GE Toshiba Corporation as a silane coupling agent, 0.3 parts by mass of γ-ureidopropyltriethoxysilane (trade name: NUC A-189) manufactured by GE Toshiba Corporation as a curing accelerator, and 0.03 parts by mass of 1-cyanoethyl-2-phenylimidazole (trade name: Curesol 2PZ-CN) manufactured by Shikoku Kasei Co., Ltd. as a curing accelerator were added, stirred and mixed, filtered through a 100 mesh filter, and then vacuum degassed to prepare a solution of adhesive composition 3 (a) having a solids concentration of 20% by mass. The content ratio of each resin component in the total amount of the resin components (total mass of the thermoplastic resin, the thermosetting resin, and the crosslinking agent) was glycidyl group-containing (meth)acrylic acid ester copolymer:epoxy resin:phenolic resin=31.5% by mass:42.5% by mass:26.0% by mass. The content of the inorganic filler was 20.5% by mass relative to the total amount of the resin components.

(Solution of Adhesive Composition 3(b))
For a wire-embedded die-bonding film, the following adhesive composition solution 3(b) was prepared and prepared. First, 21 parts by mass of bisphenol F type epoxy resin (product name: YDF-8170C, epoxy equivalent: 159, molecular weight: 310, liquid at room temperature) manufactured by Tohto Kasei Co., Ltd. as a thermosetting resin, 33 parts by mass of cresol novolac type epoxy resin (product name: YDCN-700-10, epoxy equivalent: 210, softening point: 80°C) manufactured by Tohto Kasei Co., Ltd. as a crosslinking agent, 46 parts by mass of phenol resin (product name: HE200C-10, hydroxyl equivalent: 200, softening point: 71°C, water absorption: 1% by mass, heat mass loss rate: 4% by mass) manufactured by Air Water Inc. as an inorganic filler, and 18 parts by mass of silica filler dispersion (product name: SC1030-HJA, average particle size: 0.25 μm) manufactured by Admatechs Co., Ltd. as an inorganic filler were added to a resin composition, which was stirred and mixed, and further dispersed for 90 minutes using a bead mill.

Next, to the resin composition, 16 parts by mass of a glycidyl group-containing (meth)acrylic acid ester copolymer having a low weight average molecular weight Mw as a thermoplastic resin, 64 parts by mass of a glycidyl group-containing (meth)acrylic acid ester copolymer having a high weight average molecular weight Mw , 1.3 parts by mass of γ-ureidopropyltriethoxysilane (trade name: NUC A-1160) manufactured by GE Toshiba Corporation as a silane coupling agent, 0.6 parts by mass of γ-ureidopropyltriethoxysilane (trade name: NUC A-189) manufactured by GE Toshiba Corporation as a curing accelerator, and 0.05 parts by mass of 1-cyanoethyl-2-phenylimidazole (trade name: Curesol 2PZ-CN) manufactured by Shikoku Kasei Co., Ltd. as a curing accelerator were added, stirred and mixed, filtered through a 100 mesh filter, and then vacuum degassed to prepare a solution of adhesive composition 3 (b) having a solids concentration of 20% by mass. The content ratio of each resin component in the total amount of the resin components (total mass of the thermoplastic resin, the thermosetting resin, and the crosslinking agent) was glycidyl group-containing (meth)acrylic acid ester copolymer:epoxy resin:phenolic resin=44.4% by mass:30.0% by mass:25.6% by mass. The content of the inorganic filler was 10.0% by mass relative to the total amount of the resin components.

(Solution of Adhesive Composition 3(c))
For the wire-embedded die bond film, the following adhesive composition solution 3 (c) was prepared. First, 11 parts by mass of bisphenol type epoxy resin (trade name: R2710, epoxy equivalent: 170, molecular weight: 340, liquid at room temperature) manufactured by Printec Co., Ltd. as a thermosetting resin, 40 parts by mass of dicyclopentadiene type epoxy resin (trade name: HP-7200H, epoxy equivalent: 280, softening point: 83°C) manufactured by DIC Corporation, 18 parts by mass of bisphenol S type epoxy resin (trade name: EXA-1514, epoxy equivalent: 300, softening point: 75°C) manufactured by DIC Corporation, 1 part by mass of phenol resin (trade name: Milex XLC-LL, hydroxyl equivalent: 175, softening point: 77°C, water absorption rate: 1% by mass, heat mass loss rate: 4% by mass) manufactured by Mitsui Chemicals, Inc. as a crosslinking agent, and 1 part by mass of phenol resin (trade name: Milex XLC-LL, hydroxyl equivalent: 175, softening point: 77°C, water absorption rate: 1% by mass, heat mass loss rate: 4% by mass) manufactured by Air Water Inc. Product name: HE200C-10, hydroxyl equivalent: 200, softening point: 71 ° C., water absorption: 1 mass%, heat mass loss rate: 4 mass%) 20 parts by mass, phenolic resin manufactured by Air Water Inc. (product name: HE910-10, hydroxyl equivalent: 101, softening point: 83 ° C., water absorption: 1 mass%, heat mass loss rate: 3 mass%) 10 parts by mass, silica filler dispersion liquid (product name: SC1030-HJA, average particle size: 0.25 μm) manufactured by Admatechs Co., Ltd. as an inorganic filler (product name: SC1030-HJA, average particle size: 0.25 μm) 24 parts by mass, silica (product name: Aerosil R972, average particle size: 0.016 μm) manufactured by Nippon Aerosil Co., Ltd. 0.8 parts by mass, cyclohexanone was added as a solvent to the resin composition, stirred and mixed, and further dispersed for 90 minutes using a bead mill.

Next, to the resin composition, 30 parts by mass of a glycidyl group-containing (meth)acrylic acid ester copolymer having a low weight average molecular weight Mw as a thermoplastic resin, 7.5 parts by mass of a glycidyl group-containing (meth)acrylic acid ester copolymer having a high weight average molecular weight Mw , 0.57 parts by mass of γ-ureidopropyltriethoxysilane (trade name: NUC A-1160) manufactured by GE Toshiba Corporation as a silane coupling agent, 0.29 parts by mass of γ-ureidopropyltriethoxysilane (trade name: NUC A-189) manufactured by GE Toshiba Corporation as a curing accelerator, and 0.023 parts by mass of 1-cyanoethyl-2-phenylimidazole (trade name: Curesol 2PZ-CN) manufactured by Shikoku Kasei Co., Ltd. as a curing accelerator were added, stirred and mixed, filtered through a 100 mesh filter, and then vacuum degassed to prepare a solution of adhesive composition 3 (c) having a solids concentration of 20% by mass. The content ratio of each resin component in the total amount of the resin components (total mass of the thermoplastic resin, the thermosetting resin, and the crosslinking agent) was glycidyl group-containing (meth)acrylic acid ester copolymer:epoxy resin:phenolic resin=27.3 mass %:50.2 mass %:22.5 mass %. The content of the inorganic filler was 18.0 mass % relative to the total amount of the resin components.

(Solution of Adhesive Composition 3(d))
For general-purpose die-bonding films, the following adhesive composition 3 (d) solution was prepared. First, 54 parts by mass of cresol novolac epoxy resin (trade name: YDCN-700-10, epoxy equivalent 210, softening point 80 ° C.) manufactured by Tohto Kasei Co., Ltd. as a thermosetting resin, 46 parts by mass of phenolic resin (trade name: Milex XLC-LL, hydroxyl equivalent: 175, water absorption rate: 1.8%) manufactured by Mitsui Chemicals Inc. as a crosslinking agent, and 32 parts by mass of silica (trade name: Aerosil R972, average particle size 0.016 μm) manufactured by Nippon Aerosil Co., Ltd. as an inorganic filler were added to a resin composition consisting of cyclohexanone as a solvent, stirred and mixed, and further dispersed for 90 minutes using a bead mill.

Next, 74 parts by mass of glycidyl group-containing (meth)acrylic acid ester copolymer 2 as a thermoplastic resin, 5.0 parts by mass of γ-ureidopropyltriethoxysilane (product name: NUC A-1160) manufactured by GE Toshiba Corporation as a silane coupling agent, 1.7 parts by mass of γ-ureidopropyltriethoxysilane (product name: NUC A-189) manufactured by GE Toshiba Corporation as a silane coupling agent, and 0.1 parts by mass of 1-cyanoethyl-2-phenylimidazole (product name: Curesol 2PZ-CN) manufactured by Shikoku Kasei Co., Ltd. as a curing accelerator were added to the above resin composition, and the mixture was stirred and mixed, filtered through a 100 mesh filter, and then vacuum degassed to prepare a solution of adhesive composition 3(d) with a solids concentration of 20% by mass. The content ratio of each resin component in the total amount of the resin components (total mass of the thermoplastic resin, the thermosetting resin, and the crosslinking agent) was glycidyl group-containing (meth)acrylic acid ester copolymer:epoxy resin:phenolic resin=73.3 mass %:14.4 mass %:12.3 mass %. The content of the inorganic filler was 8.6 mass % relative to the total amount of the resin components.

4. Preparation of dicing tape 10 and dicing die bond film 20 (Example 1)
A solution of the active energy ray-curable acrylic pressure-sensitive adhesive composition (a) was applied to the release-treated surface of a release liner (thickness 38 μm, polyethylene terephthalate film) so that the thickness of the pressure-sensitive adhesive layer 2 after drying would be 8 μm, and the solvent was dried by heating at a temperature of 100° C. for 3 minutes, and then the surface of the first layer side of the base film 1 (a) was bonded onto the pressure-sensitive adhesive layer 2 to produce a raw sheet of dicing tape 10. Thereafter, the raw sheet of dicing tape 10 was stored at a temperature of 23° C. for 96 hours to crosslink and cure the pressure-sensitive adhesive layer 2.

Next, a solution of adhesive composition 3(a) for forming a die bond film (adhesive layer) 3 was prepared, and the solution of adhesive composition 3(a) was applied to the release-treated surface of a release liner (thickness 38 μm, polyethylene terephthalate film) so that the thickness of the die bond film (adhesive layer) 3 after drying was 50 μm. The solvent was dried by heating in two stages, first at a temperature of 90°C for 5 minutes and then at a temperature of 140°C for 5 minutes, to prepare a die bond film (adhesive layer) 3 equipped with a release liner. If necessary, a protective film (e.g., a polyethylene film, etc.) may be attached to the dried surface side of the die bond film (adhesive layer) 3.

Next, the die bond film (adhesive layer) 3 with the release liner prepared above was cut into a circle with a diameter of 335 mm together with the release liner, and the adhesive layer exposed surface (the surface without the release liner) of the die bond film (adhesive layer) 3 was attached to the adhesive layer 2 surface of the dicing tape 10 from which the release liner had been peeled off. The attachment conditions were 23°C, 10 mm/sec, and linear pressure of 30 kgf/cm.

Finally, the dicing tape 10 was cut into a circle having a diameter of 370 mm to produce a dicing die bond film 20 (DDF (a)) in which a circular die bond film (adhesive layer) 3 having a diameter of 335 mm was laminated onto the upper center of the adhesive layer 2 of the circular dicing tape 10 having a diameter of 370 mm.

(Examples 2 to 14)
Dicing die bond films 20 (DDF(b) to DDF(n)) were produced in the same manner as in Example 1, except that the base film 1(a) was changed to the base films 1(b) to 1(n) shown in Tables 1 to 3. However, only in Examples 10 and 12, the thicknesses of the pressure-sensitive adhesive layer 2 were set to 7 μm and 15 μm, respectively.

(Examples 15 to 27)
Dicing die bond films 20 (DDF(o) to DDF(aa)) were produced in the same manner as in Example 2, except that the solution of active energy ray-curable acrylic pressure-sensitive adhesive composition 2(a) was changed to the solutions of active energy ray-curable acrylic pressure-sensitive adhesive compositions 2(b) to 2(n) shown in Tables 3 to 5, respectively.

(Example 28)
A dicing die bond film 20 (DDF(bb)) was produced in the same manner as in Example 2, except that the thickness of the pressure-sensitive adhesive layer 2 after drying was changed to 6 μm.

(Example 29)
A dicing die bond film 20 (DDF (cc)) was produced in the same manner as in Example 2, except that the thickness of the pressure-sensitive adhesive layer 2 after drying was changed to 20 μm.

(Example 30)
A dicing die bond film 20 (DDF (dd)) was produced in the same manner as in Example 2, except that the solution of adhesive composition 3 (a) was changed to a solution of adhesive composition 3 (b) and the thickness of the die bond film (adhesive layer) 3 after drying was changed to 30 μm.

(Example 31)
A dicing die bond film 20 (DDF(ee)) was produced in the same manner as in Example 2, except that the solution of adhesive composition 3(a) was changed to a solution of adhesive composition 3(c).

(Example 32)
A dicing die bond film 20 (DDF (ff)) was produced in the same manner as in Example 2, except that the solution of adhesive composition 3(a) was changed to a solution of adhesive composition 3(d) and the thickness of the die bond film (adhesive layer) 3 after drying was changed to 20 μm.

(Comparative Examples 1 to 6)
Dicing die bond films 20 (DDF(gg) to DDF(ll)) were produced in the same manner as in Example 1, except that the base film 1(a) was changed to the base film 1(o) and the solution of the active energy ray curable acrylic pressure-sensitive adhesive composition 2(a) was changed to the solutions of the active energy ray curable acrylic pressure-sensitive adhesive compositions 2(o) to 2(t) shown in Table 6.

(Comparative Examples 7 to 12)
Dicing die bond films 20 (DDF (mm) to DDF (rr)) were produced in the same manner as in Example 2, except that the solution of the active energy ray-curable acrylic pressure-sensitive adhesive composition 2(a) was changed to the solutions of the active energy ray-curable acrylic pressure-sensitive adhesive compositions 2(o) to 2(t) shown in Table 7.

(Comparative Example 13)
A dicing die bond film 20 (DDF(ss)) was produced in the same manner as in Example 1, except that the base film 1(a) was changed to the base film 1(o).

(Comparative Example 14)
A dicing die bond film 20 (DDF(tt)) was produced in the same manner as in Example 1, except that the base film 1(a) was changed to the base film 1(p).

(Comparative Example 15)
A dicing die bond film 20 (DDF (uu)) was produced in the same manner as in Example 1, except that the base film 1 (a) was changed to the base film 1 (q).

(Comparative Example 16)
A dicing die bond film 20 (DDF(vv)) was produced in the same manner as in Comparative Example 1, except that the base film 1(a) was changed to the base film 1(r).

(Comparative Example 17)
A dicing die bond film 20 (DDF(ww)) was produced in the same manner as in Comparative Example 1, except that the base film 1(a) was changed to the base film 1(s).

5. Evaluation method of dicing die bond film Various measurements and evaluations were performed on the dicing tape 10 and the dicing die bond film 20 (DDF(a) to DDF(ww)) produced in Examples 1 to 32 and Comparative Examples 1 to 17 by the methods shown below.

5.1 Measurement of shear viscosity of die bond film (adhesive layer) 3 at 80 ° C. The shear viscosity at 80 ° C. of each die bond film (adhesive layer) 3 formed from the solution of adhesive composition 3 (a) to 3 (d) was measured by the following method. That is, a laminate was produced by laminating a plurality of die bond films (adhesive layers) 3 from which the release liner had been removed at 70 ° C. so that the total thickness was 200 to 210 μm. Next, the laminate was punched out in the thickness direction to a size of 10 mm x 10 mm to obtain a measurement sample. Next, a dynamic viscoelasticity device ARES (manufactured by Rheometric Scientific F.E. Co., Ltd.) was used to attach a circular aluminum plate jig with a diameter of 8 mm, and then the measurement sample was set. The shear viscosity was measured while heating the measurement sample at a temperature rise rate of 5 ° C. / min while applying a 5% strain to the measurement sample at 35 ° C., and the value of the shear viscosity at 80 ° C. was obtained.

5.2 Measurement of adhesive strength of the adhesive layer 2 of the dicing tape 10 to the die bond film (adhesive layer) 3 after UV irradiation The dicing tape 10 and the die bond film (adhesive layer) 3 produced in each example and comparative example were prepared separately. The dicing tape 10 was cut to a width (TD direction of the base film 1) of 30 mm and a length (MD direction of the base film 1) of 300 mm, and the die bond film 20 was cut to a width of 30 mm and a length of 100 mm. The adhesive layer exposed surface (surface without release liner) of the die bond film (adhesive layer) 3 was neatly laminated to a portion 100 mm from the end of the adhesive layer 2 surface from which the release liner of the dicing tape 10 was peeled off, while being pressed using a 2 kg rubber roller in an environment of temperature 23 ° C. and humidity 50% RH. After aging this laminate in an environment of 5°C for 24 hours, in an environment of a temperature of 23°C and a humidity of 50% RH, the surface of the die bond film (adhesive layer) 3 from which the release liner had been peeled off was adhered to the adhesive layer side of OPP film substrate single-sided adhesive tape 11 (trade name: Easy Cut Tape 207H, thickness 70 μm) manufactured by Oji Tack Co., Ltd., while pressing the surface, and backing was performed. This laminate was cut again with a new cutter blade to a width of 25 mm, to obtain a test piece as shown in FIG. 11(a). Next, as shown in FIG. 11(b), the surface of the OPP film substrate single-sided adhesive tape 11 side of the above test piece was fixed to the center of a flat cross stage for an angle-free type adhesive/film peeling analysis device (model: VPA-2S, manufactured by Kyowa Interface Science Co., Ltd.) using a paper double-sided adhesive tape 12 (trade name: No. 5486, thickness 140 μm) manufactured by Maxell Co., Ltd., while pressing the tape with a 2 kg rubber roller. Next, ultraviolet (UV) rays with a central wavelength of 365 nm were irradiated from the base film 1 side of the dicing tape 10 of the dicing die bond film 20 using a metal halide lamp (irradiation intensity: 70 mW/cm ² , accumulated light amount 150 mJ/cm ² ), and then the flat cross stage to which the test piece was fixed was attached to an angle-adjustable type adhesion/film peeling analysis device, and the dicing tape 10 side was pulled (in reality, the flat cross stage moved) at a peel angle of 30° and a peel speed of 600 mm/min in an environment of 23°C and 50% RH, as shown in Figure 11 (c) (schematic diagram of the device viewed from directly above), and the low-angle (peel angle 30°) adhesive strength (unit: N/25 mm) of the dicing tape 10 to the die bond film (adhesive layer) 3 was measured (average value of N=3 test pieces).

5.3 Shear adhesive strength of the adhesive layer 2 of the dicing tape 10 to the die bond film 3 (adhesive layer) at -30 ° C. The dicing tape 10 and the die bond film (adhesive layer) 3 were prepared separately. The dicing tape 10 was laminated to the base film 1 side while pressing the adhesive layer side of the PET film base single-sided adhesive tape 14 (product name: No. 626001, thickness 55 μm) manufactured by Maxell Co., Ltd. as a backing tape using a 2 kg rubber roller, and then cut to a width (TD direction of the base film 1) of 10 mm and a length (MD direction of the base film 1) of 100 mm. The die bond film 20 was cut to a width of 30 mm and a length of 100 mm. In addition, the die bond film 20 used had a protective film (polyethylene film) on the dry side of the die bond film (adhesive layer) 3. First, the surface of the die bond film 20 from which the release liner was carefully peeled off was attached to the surface of a semiconductor wafer W (silicon mirror wafer, width 40 mm, length 100 mm, thickness 0.725 mm) while pressing it using a 2 kg rubber roller, and then sandwiched between two glass plates and pressed with a load of 2 kg for 1 minute at a temperature of 40 ° C. Next, both end surfaces of the semiconductor wafer W to which this die bond film (adhesive layer) 3 was attached were firmly fixed to a SUS plate 15 using a PET film base single-sided adhesive tape 14 (product name: No. 626001, thickness 55 μm) manufactured by Maxell Co., Ltd., and the protective film of the die bond film (adhesive layer) 3 was peeled off to prepare an adherend for a shear adhesive strength test. Next, the adhesive layer 2 side of the dicing tape 10 from which the release liner had been peeled off was attached to the surface of the die bond film (adhesive layer) 3 of this adherend so that a portion 10 mm from the end in the longitudinal direction was in close contact, i.e., the size of the contact surface was 10 mm x 10 mm (contact area: 100 ^mm2 ), and the adhesive was pressed with a 2 kg rubber roller and aged for 20 minutes in an environment of a temperature of 23°C and a humidity of 50% RH to obtain a test object as shown in Figure 12 (the PET film-based single-sided adhesive tape 14 for fixing is not shown). Next, using a MinebeaMitsumi Inc. tensile compression testing machine (model: MinebeaTechnoGraph TG-5kN), the test object was placed in a MinebeaMitsumi Inc. thermostatic chamber (model: THB-A13-038) at -30°C for 1 minute, and then pulled in the vertical direction at a speed of 1,000 mm/min, and the adhesive strength in the shear direction required at this time (unit: N/100 mm ² ) was measured (average value of N=3 test pieces).

5.4 Evaluation of stealth dicing properties of dicing die bond film 20 5.4.1 Semiconductor wafer cleavability and die bond film (adhesive layer) cleavability First, a semiconductor wafer (silicon mirror wafer, thickness 750 μm, outer diameter 12 inches) W was prepared, and a commercially available backgrind tape was attached to one side. Next, a stealth dicing laser saw (device name: DFL7361) manufactured by Disco Corporation was used from the side opposite to the side where the backgrind tape was attached to the semiconductor wafer W, and a modified region 30b was formed at a predetermined depth position of the semiconductor wafer W by irradiating laser light under the following conditions along the lattice-shaped division lines so that the size of the semiconductor chip 30a after cleavage was 4.7 mm × 7.2 mm.
Laser irradiation conditions (1) Laser oscillator type: Semiconductor laser pumped Q-switched solid-state laser (2) Wavelength: 1342 nm
(3) Oscillation type: Pulse (4) Frequency: 90 kHz
(5) Output: 1.7W
(6) Moving speed of semiconductor wafer stage: 700 mm/sec

Next, a backgrinding device (device name: DGP8761) manufactured by Disco Corporation was used to grind and thin the 750 μm-thick semiconductor wafer W on which the modified region 30b was formed and held by the backgrinding tape, thereby obtaining a 30 μm-thick semiconductor wafer 30. Next, a cool expand process was carried out by the following method, and the semiconductor wafer breakability and adhesive layer breakability, which are indicators of stealth dicing performance, were evaluated. Specifically, a laminating device (device name: DFM2800) manufactured by Disco Corporation was used to bond the dicing die bond film 20 to the semiconductor wafer 30 under conditions of a laminating temperature of 70° C. and a laminating speed of 10 mm/sec so that the adhesive layer 3 exposed by peeling off the release liner from the dicing die bond film 20 produced in each example and comparative example was adhered to the side opposite to the side to which the backgrind tape was attached, on which the modified region 30b obtained by the above method was formed. The dicing die bond film 20 was then attached to the semiconductor wafer 30 under conditions of a laminating temperature of 70° C. and a laminating speed of 10 mm/sec, and a ring frame (wafer ring) 40 was attached to the exposed part of the adhesive layer 2 at the outer edge of the dicing tape 10, and then the backgrind tape was peeled off. Here, the dicing die bond film 20 is attached to the semiconductor wafer 30 so that the MD direction of the base film 1 coincides with the vertical line direction of the lattice-shaped division lines of the semiconductor wafer 30 (the TD direction of the base film 1 and the horizontal line direction of the lattice-shaped division lines of the semiconductor wafer 30).

The laminate (semiconductor wafer 30/adhesive layer 3/adhesive layer 2/base film 1) including the semiconductor wafer 30 after the formation of the modified region 30b held by the ring frame (wafer ring) 40 was fixed to an expanding device (device name: DDS2300 Fully Automatic Die Separator) manufactured by Disco Corporation. Next, the dicing tape 10 (adhesive layer 2/base film 1) of the dicing die bond film 20 with the semiconductor wafer 30 was cool expanded under the following conditions to break the semiconductor wafer 30 and the adhesive layer 3. As a result, a semiconductor chip 30a with a die bond film (adhesive layer) 3 was obtained. In this embodiment, the cool expanding process was performed under the following conditions, but the cool expanding process may be performed after appropriately adjusting the expanding conditions (such as "expanding speed" and "expanding amount") according to the physical properties and temperature conditions of the base film 1.
・Conditions for the cool expansion process: Temperature: -15°C, Cooling time: 80 seconds,
Expand speed: 300 mm/sec.
Expanded amount: 11 mm,
(4) Standby time: 0 seconds

The semiconductor wafer 30 and the adhesive layer 3 after the cool expansion were observed from the front side of the semiconductor wafer 30 at a magnification of 200 times using an optical microscope (model: VHX-1000) manufactured by Keyence Corporation, and the number of sides that were not cut among the sides to be cut was measured. Then, for each of the semiconductor wafer 30 and the adhesive layer 3, the ratio of the number of cut sides to the total number of sides to be cut was calculated as the cutting rate (%) from the total number of sides to be cut and the total number of uncut sides. The observation points using the optical microscope were performed on the entire surface of the semiconductor wafer 30. The cutting property of each of the semiconductor wafer 30 and the adhesive layer 3 was evaluated according to the following criteria, and a rating of B or higher was determined to be good cutting property.
A: The fracture rate was 95% or more and 100% or less.
B: The fracture rate was 90% or more and less than 95%.
C: The fracture rate was less than 90%.

5.4.2 Peeling (Lifting) of the Die Bond Film (Adhesive Layer) 3 from the Pressure-Sensitive Adhesive Layer 2 of the Dicing Tape 10
After the cool expansion state was released, an expansion device manufactured by Disco Corporation (device name: DDS2300 Fully Automatic Die Separator) was used again to carry out a room temperature expansion step in the heat expander unit under the following conditions.
Room temperature expansion process conditions: 23°C,
Expand speed: 30 mm/sec.
Expanded amount: 9 mm,
(4) Waiting time: 15 seconds

Next, while maintaining the expanded state, the dicing tape 10 was adsorbed by a suction table, and while the suction by the suction table was maintained, the suction table was lowered together with the workpiece. Then, a heat shrink process was carried out under the following conditions, and the circumferential portion of the dicing tape 10 outside the semiconductor chip 30a holding area was heat shrunk (heat shrunk).
Heat shrink process conditions Hot air temperature: 200°C,
Air volume: 40L/min,
Distance between hot air outlet and dicing tape 10: 20 mm,
Stage rotation speed: 7°/sec

Next, after releasing the dicing tape 10 from the suction table, the state in which the die bond film (adhesive layer) 3 is peeled off from the pressure-sensitive adhesive layer 2 of the dicing tape 10 around the four sides of each broken semiconductor chip was observed from the front side of the semiconductor wafer 30 using an optical microscope (model: VHX-1000) manufactured by Keyence Corporation at a magnification of 50 times. Since the peeling state of the die bond film (adhesive layer) 3 was observed as being in almost the same state in any position of the semiconductor chip 30a, the number of observations of the semiconductor chips with the die bond film in this evaluation was set to a predetermined 20 chips located in the center of the semiconductor wafer 30, and the average peeling state was observed. According to the following criteria, the level of peeling (floating) of the die bond film (adhesive layer) 3 from the pressure-sensitive adhesive layer 2 of the dicing tape 10 in the dicing die bond film 20 when expanded was evaluated, and an evaluation of B or higher was judged to be good.
A: Peeling of the die bond film from the pressure-sensitive adhesive layer was not observed.
B: Peeling of the die bond film from the adhesive layer was slightly observed around the four sides of the semiconductor chip, but the ratio of the area where peeling was observed to the total area of the semiconductor chip was less than 20%.
C: Peeling of the die bond film from the pressure-sensitive adhesive layer was clearly observed around the four sides of the semiconductor chip, and the ratio of the area of the part where peeling was observed was 20% or more with respect to the total area of the semiconductor chip.

5.4.3 Extensibility of the dicing tape 10 in the dicing die bond film 20 (kerf width)
In order to evaluate the level of peeling (floating) of the above-mentioned die bond film (adhesive layer) 3 from the pressure-sensitive adhesive layer 2 of the dicing tape 10, when the dicing tape 10 was released from suction by the suction table in the room temperature expansion process, the distance (kerf width) between adjacent semiconductor chips 30a in that state was simultaneously observed and measured at a magnification of 200 times using an optical microscope (model: VHX-1000) manufactured by Keyence Corporation from the front surface side of the semiconductor wafer 30, thereby evaluating the expandability of the dicing tape 10 in the dicing die bond film 20.

Specifically, four locations of one cleavage cross line portion formed by four adjacent semiconductor chips 30a in the center 31 of the semiconductor wafer 30 shown in FIG. 11 (MD direction of the base film 1: two locations of kerf MD1 and kerf MD2, TD direction of the base film 1: two locations of kerf TD1 and kerf TD2, see FIG. 12 ), seven locations of two cleavage cross line portions formed by six adjacent semiconductor chips 30a in the left portion 32 (MD direction: three locations of kerf MD3 to kerf MD5, TD direction: four locations of kerf TD3 to kerf TD6, not shown), seven locations of two cleavage cross line portions formed by six adjacent semiconductor chips 30a in the right portion 33 (MD direction: three locations of kerf MD6 to kerf MD8, TD direction: four locations of kerf TD7 to kerf TD10, The separation distance between adjacent semiconductor chips 30a was measured at a total of 32 locations (16 locations in the MD direction and 16 locations in the TD direction) including: seven locations in the two fracture cross line portions formed by six adjacent semiconductor chips 30a in the upper portion 34 (MD direction: four locations from kerf MD9 to kerf MD12, TD direction: three locations from kerf TD11 to kerf TD13, not shown); and seven locations in the two fracture cross line portions formed by six adjacent semiconductor chips 30a in the lower portion 35 (MD direction: four locations from kerf MD13 to kerf MD16, TD direction: three locations from kerf TD14 to kerf TD16, not shown). The average value of the 16 locations in the MD direction was calculated as the MD-direction kerf width, and the average value of the 16 locations in the TD direction was calculated as the TD-direction kerf width. According to the following criteria, the expandability of the dicing tape 10 in the dicing die bond film 20 was evaluated, and a rating of B or higher was determined to be good expandability.
A: Both the MD kerf width and the TD kerf width were 30 μm or more.
B: The MD kerf width was 30 μm or more, and the TD kerf width was 25 μm or more and less than 30 μm.
C: Either the kerf width in the MD direction or the kerf width in the TD direction was less than 25 μm.

5.5 Evaluation of pick-up property of dicing tape 10 in dicing die bond film 20 From the base film 1 side of the dicing tape 10 holding the semiconductor chip 30a with the die bond film (adhesive layer) 3a that was fractured and divided by the above-mentioned expanding process, ultraviolet (UV) rays with a central wavelength of 365 nm were irradiated so that the accumulated light amount was 150 mJ/ ^cm2 at an irradiation intensity of 70 mW/ ^cm2 to harden the adhesive layer 2, thereby preparing a sample for evaluation of pick-up property.

Next, a pickup test was performed using a device (device name: Die Bonder DB-830P) having a pickup mechanism manufactured by Fasford Technology Co., Ltd. (formerly Hitachi High-Technologies Corporation). The size of the pickup collet was 4.5 x 7.1 mm, the number of push-up pins was 12, and the pickup conditions were a push-up speed of the push-up pin of 10 mm/sec and a push-up height of the push-up pin of 200 μm. The number of samples in the pickup trial was 50 (chips) at a predetermined position, and the pickup property of the dicing tape 10 in the dicing die bond film 20 was evaluated according to the following criteria, and a rating of B or higher was judged to be good pickup property.
A: 50 chips were picked up consecutively, and the number of chips that did not break or fail to be picked up (number of successfully picked up chips) was 48 or more and 50 or less.
B: 50 chips were picked up consecutively, and the number of chips that did not break or fail to be picked up (number of successfully picked up chips) was 45 or more and less than 48.
C: 50 chips were picked up consecutively, and the number of chips without chip breakage or pick-up failure (number of successfully picked-up chips) was less than 45.

6. Evaluation Results The evaluation results for the dicing tape 10 and the dicing die bond film 20 (DDF(a) to DDF(ww)) produced in Examples 1 to 32 and Comparative Examples 1 to 17 are shown in Tables 1 to 9 together with the configuration of the dicing tape 10 and the dicing die bond film 20 and the configuration of the base film 1 used.

As shown in Tables 1 to 6, it was confirmed that the dicing die bond films 20 (DDF(a) to DDF(ff)) of Examples 1 to 32, which were produced using dicing tape 10 having base film 1(a) to (n) that satisfies the requirements of the present invention and adhesive layer 2 containing adhesive composition 2(a) to 2(n), gave favorable results in both the evaluation of stealth dicing properties and pick-up properties when used in the manufacturing process of semiconductor devices. In addition, the evaluation of heat resistance was also favorable.

When comparing the Examples in detail, it was found that the dicing die bond films 20 of Examples 2 to 4, 7 and 8, 10 to 14, 20, 22 and 23, and 30 to 32 were particularly excellent, being able to achieve high levels of both stealth dicing and pick-up properties. As is clear from the evaluation results of the dicing die bond films 20 of Examples 3 to 6, it was found that the heat resistance was better when the content ratio of polyamide resin (B) in the base film 1 was increased.

For the dicing die bond film 20 of Example 1 and Example 9, the stress at 5% elongation in the TD direction of the base film 1 at -15°C was slightly small at 15.8 MPa and 16.0 MPa, respectively, so the cleavability of the die bond film 3 was slightly inferior. In addition, the extensibility of the dicing tape 10 was also slightly inferior. For the dicing die bond film 20 of Example 16, the equivalent ratio (NCO/OH) of the isocyanate group (NCO) of the polyisocyanate crosslinking agent in the adhesive composition to the hydroxyl group (OH) of the acrylic adhesive polymer was 0.02, which was the lower limit of the range, so the cohesive force of the adhesive layer 2 was slightly smaller, and the cleavability of the die bond film 3 was slightly inferior. In addition, the low-angle adhesive force after UV irradiation was slightly large, and the pick-up property was also slightly inferior. Similarly, for the dicing die bond film 20 of Example 26, the equivalent ratio (NCO/OH) in the adhesive composition was slightly small, so the cohesive strength of the adhesive layer 2 was slightly small, and the cleavability of the die bond film 3 was slightly inferior. In addition, the active energy ray reactive carbon-carbon double bond concentration of the adhesive composition was 0.85 mmol/g, which was the lower limit of the range, so the low angle adhesive strength after UV irradiation was slightly large, and further, combined with the influence of the weight average molecular weight Mw of the acrylic adhesive polymer, the die bond film 3 also slightly lifted, and the pick-up properties were also slightly inferior.

In addition, for the dicing die bond film 20 of Example 5 and Example 6, the mass ratio (A):(B) of the ionomer resin (A) and the polyamide resin (B) in the entire base film 1 was 74:26 and 72:28, respectively, and the content ratio of the polyamide resin (B) was somewhat large, so that the low-angle adhesive strength after UV irradiation was somewhat large due to the influence of the rigidity of the base film 1, and the pick-up property was somewhat inferior. In addition, for the dicing die bond film 20 of Example 17, the residual hydroxyl group concentration after the crosslinking reaction in the adhesive composition was 0.90 mmol/g, which was the upper limit of the range, so that the shear adhesive strength of the adhesive layer 2 before UV irradiation to the die bond film 3 at -30°C was somewhat large, and the pick-up property was somewhat inferior. Furthermore, for the dicing die bond film 20 of Example 18, the active energy ray reactive carbon-carbon double bond concentration of the adhesive composition was 0.85 mmol/g, which is the lower limit of the range, so the low angle adhesive strength after UV irradiation was slightly large and the pick-up properties were slightly inferior. Furthermore, for the dicing die bond film 20 of Example 21, the glass transition temperature of the main chain of the acrylic adhesive polymer in the adhesive composition was slightly high, while butyl acrylate (BA), a copolymer component of the acrylic adhesive polymer, had a strong interaction with the die bond film 3. Although no lifting of the die bond film 3 was observed, the shear adhesive strength of the adhesive layer 2 before UV irradiation to the die bond film 3 at -30 ° C. was slightly large, and the low angle adhesive strength after UV irradiation was also slightly large, and the pick-up properties were slightly inferior.

In addition, for the dicing die bond film 20 of Example 15 and Example 19, the equivalent ratio (NCO/OH) of the isocyanate group (NCO) of the polyisocyanate crosslinking agent in the adhesive composition to the hydroxyl group (OH) of the acrylic adhesive polymer is 0.20, which is the upper limit of the range, so the adhesive layer 2 becomes slightly hard, the shear adhesive strength of the adhesive layer 2 before UV irradiation to the die bond film at -30 ° C is slightly small, and the die bond film 3 is slightly lifted. As a result, the pick-up property of the dicing die bond film 20 of Example 15 was slightly inferior. Furthermore, for the dicing die bond film 20 of Example 19, although the die bond film 3 was slightly lifted, the active energy ray reactive carbon-carbon double bond concentration of the adhesive composition is large at 1.51 mmol / g, so the pick-up property was barely A level (48 pieces successfully picked up). Furthermore, for the dicing die bond film 20 of Example 24, the residual hydroxyl group concentration after the crosslinking reaction in the adhesive composition was 0.18 mmol/g, which was the lower limit of the range, so the shear adhesive strength of the adhesive layer 2 before UV irradiation to the die bond film 3 at -30 ° C was slightly small, and some lifting of the die bond film 3 was observed, resulting in slightly inferior pick-up properties. Furthermore, for the dicing die bond film 20 of Example 25, the weight average molecular weight Mw of the acrylic adhesive polymer was slightly large, so the shear adhesive strength of the adhesive layer 2 before UV irradiation to the die bond film at -30 ° C was slightly small, and some lifting of the die bond film 3 was observed, resulting in slightly inferior pick-up properties. Furthermore, for the dicing die bond film 20 of Example 27, the glass transition temperature of the base polymer of the acrylic adhesive polymer in the adhesive composition was slightly high, so the shear adhesive strength of the adhesive layer 2 before UV irradiation to the die bond film at -30 ° C was slightly small, and the die bond film 3 was slightly lifted, which affected the pickup properties. Furthermore, for the dicing die bond film 20 of Example 28, the thickness of the adhesive layer 2 was slightly thin, so the shear adhesive strength of the adhesive layer 2 before UV irradiation to the die bond film 3 at -30 ° C was slightly small, and the die bond film 3 was slightly lifted, which affected the pickup properties. Furthermore, for the dicing die bond film 20 of Example 29, the thickness of the adhesive layer 2 was slightly thick, so the expandability of the dicing tape 10 was slightly poor, and the low-angle adhesive strength after UV irradiation was also slightly large, which affected the pickup properties.

In contrast, as shown in Table 7, the dicing die bond films 20 (DDF(gg) to DDF(ll)) of Comparative Examples 1 to 6, which were produced using a dicing tape 10 having a base film 1(o) that does not satisfy the requirements of the present invention and an adhesive layer 2 containing an adhesive composition 2(o) to 2(t) that does not satisfy the requirements of the present invention, all had insufficient heat resistance and were inferior to the dicing die bond films 20 (DDF(a) to DDF(ff)) of Examples 1 to 32 in the evaluation of any of the four stealth dicing properties and the evaluation of pick-up properties. Similarly, as shown in Table 9, the dicing die bond films 20 (DDF(vv), DDF(ww)) of Comparative Examples 16 and 17, which were produced using the base films 1(r) and 1(s) that do not satisfy the requirements of the present invention, and the dicing tape 10 having the adhesive layer 2 containing the adhesive composition 2(o) that does not satisfy the requirements of the present invention, also had insufficient heat resistance, and were inferior to the dicing die bond films 20 (DDF(a) to DDF(ff)) of Examples 1 to 32 in the evaluation of any of the four stealth dicing properties and the evaluation of pick-up properties.

As shown in Table 8, the dicing die bond films 20 (DDF(mm) to DDF(rr)) of Comparative Examples 7 to 12, which were produced using a dicing tape 10 having a pressure-sensitive adhesive layer 2 containing a base film 1(b) that satisfies the requirements of the present invention but contains a pressure-sensitive adhesive composition 2(o) to (t) that does not satisfy the requirements of the present invention, were found to have good heat resistance, breakability of the semiconductor wafer 30, breakability of the die bond film 3, and extensibility of the dicing tape 10, but were inferior to the dicing die bond films 20 (DDF(a) to DDF(ff)) of Examples 1 to 32 in the evaluation of any of the four stealth dicing properties and the evaluation of pick-up properties.

As shown in Table 9, the dicing die bond films 20 (DDF(ss) to DDF(uu)) of Comparative Examples 13 to 15, which were produced using a dicing tape 10 having an adhesive layer containing a pressure-sensitive adhesive composition 2(a) that satisfies the requirements of the present invention but a substrate film 1(o) to (q) that does not satisfy the requirements of the present invention, were found to have inferior results to the dicing die bond films 20 (DDF(a) to DDF(ff)) of Examples 1 to 32 in the evaluation of heat resistance, evaluation of any of the four stealth dicing properties, and evaluation of pick-up properties.

Specifically, the dicing die bond films 20 of Comparative Examples 1 to 6 and 13, which use a base film 1 (o) composed only of resin (A) consisting of an ionomer of an ethylene-unsaturated carboxylic acid copolymer and which does not contain polyamide resin (B), all have insufficient heat resistance. Furthermore, the stress of the base film 1 at 5% elongation in the TD direction at -15°C is small at 12.5 MPa, below the lower limit of the range of 15.5 MPa. As a result, the breakability of the die bond film 3 and the extensibility of the dicing tape 10 are significantly inferior, and this has a significant impact on the deterioration of pick-up properties. In addition, for the dicing die bond film 20 of Comparative Example 1 and Comparative Example 4, the equivalent ratio (NCO/OH) in the adhesive composition was 0.47 and 0.33, respectively, exceeding the upper limit of the range of 0.20, so that the adhesive layer 2 became hard, the shear adhesive strength of the adhesive layer 2 before UV irradiation with respect to the die bond film 3 at -30 ° C. was small, and the die bond film 3 was lifted, and as a result, the pick-up property was significantly inferior. On the other hand, for the dicing die bond film 20 of Comparative Example 3, the equivalent ratio (NCO/OH) in the adhesive composition was 0.01, which was below the lower limit of the range of 0.02, so that the cohesive strength of the adhesive layer 2 was small, the low-angle adhesive strength after UV irradiation was large, and the pick-up property was significantly inferior. In addition, for the dicing die bond film 20 of Comparative Example 2, the residual hydroxyl group concentration after the crosslinking reaction in the adhesive composition is 1.21 mmol/g, which exceeds the upper limit of the range, and the active energy ray reactive carbon-carbon double bond concentration of the adhesive composition is 0.80 mmol/g, which is below the lower limit of the range, so that the low-angle adhesive force after UV irradiation is large and the pick-up property is significantly inferior. In addition, for the dicing die bond film 20 of Comparative Example 5, the residual hydroxyl group concentration after the crosslinking reaction in the adhesive composition is 0.95 mmol/g, which exceeds the upper limit of the range, so that the active energy ray reactive carbon-carbon double bond concentration of the adhesive composition is 0.58 mmol/g, which is significantly below the lower limit of the range, and in addition, due to the effect of the large acid value of the acrylic adhesive polymer of the adhesive composition, the low-angle adhesive force after UV irradiation is large and the pick-up property is significantly inferior. For the dicing die bond film 20 of Comparative Example 6, the glass transition temperature of the main chain of the acrylic adhesive polymer in the adhesive composition was 40°C, exceeding the upper limit of the range, so the adhesive layer 2 became hard, the shear adhesive strength of the adhesive layer 2 to the die bond film 3 before UV irradiation at -30°C was small, and the die bond film 3 was lifted, resulting in significantly poor pick-up properties.

In addition, for the dicing die bond films 20 of Comparative Examples 7 to 12, which have adhesive layers 2 containing the same adhesive compositions as Comparative Examples 1 to 6, the evaluation results for the lifting and pick-up properties of the die bond film 3 were similar to those described above.

In addition, the dicing die bond film 20 of Comparative Example 13, which is outside the scope of the present invention, in which the base film 1 does not contain polyamide resin (B) and is composed only of resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer, and Comparative Example 14, which is outside the scope of the present invention, in which the mass ratio (A):(B) of the resin (A) made of ionomer to the polyamide resin (B) in the entire base film 1 is 97:3, the content ratio of polyamide resin (B) is small, had insufficient heat resistance, and furthermore, the stress at 5% elongation in the TD direction of the base film 1 at -15°C was small at 12.5 MPa and 15.0 MPa, respectively, which did not meet the lower limit of the range of 15.5 MPa, resulting in insufficient breakability of the die bond film 3 and insufficient extensibility of the dicing tape 10, and as a result, the pick-up ability was significantly inferior. Furthermore, the mass ratio (A):(B) of the ionomer resin (A) to the polyamide resin (B) in the entire base film 1 was 70:30, meaning that the content of polyamide resin (B) was high. The dicing die bond film 20 of Comparative Example 15, which is outside the scope of the present invention, had good heat resistance, but due to the influence of the rigidity of the base film 1, the low-angle adhesive force after UV irradiation was large and the pickup properties were significantly poor.

In addition, for the dicing die bond film 20 (DDF (vv)) of Comparative Example 16, which was exemplified as a conventional dicing die bond film, the stress of the base film 1 having a three-layer structure of PP/EVA/PP at 5% elongation at -15°C was extremely small at 10.8 MPa in the MD direction and 10.3 MPa in the TD direction, which is less than the lower limit of the range of 15.5 MPa, so the cleavability of the die bond film 3 and the extensibility of the dicing tape 10 were insufficient, and in addition, the equivalent ratio (NCO/OH) in the adhesive composition was 0.47, exceeding the upper limit of the range of 0.20, so the adhesive layer 2 became hard, the shear adhesive strength of the adhesive layer 2 before UV irradiation to the die bond film 3 at -30°C was small, and the die bond film 3 was lifted, and due to these effects, the pick-up property was significantly inferior. As a result, the pick-up property was significantly inferior. Furthermore, for the dicing die bond film 20 (DDF (ww)) of Comparative Example 16, which was exemplified as a conventional dicing die bond film, the stress of the PVC single-layered base film 1 at 5% elongation at -15°C was extremely large at 45.6 MPa in the MD direction and 42.8 MPa in the TD direction, exceeding the upper limit of the range of 28.5 MPa, resulting in insufficient extensibility of the dicing tape 10. In addition, the equivalent ratio (NCO/OH) in the adhesive composition was 0.47, exceeding the upper limit of the range of 0.20, resulting in a hard adhesive layer 2, a small shear adhesive strength of the adhesive layer 2 to the die bond film 3 before UV irradiation at -30°C, and lifting of the die bond film 3 was observed, resulting in significantly poor pick-up properties.

1...Base film,
2...Adhesive layer,
3, 3a1, 3a2... die bond film (adhesive layer, adhesive film),
4...Support substrate for mounting semiconductor chips,
5...External connection terminal,
6...Terminal,
7...Wire,
8...Sealing material,
9...support member,
10... dicing tape,
11... OPP film-based single-sided adhesive tape (backing tape),
12...Paper double-sided adhesive tape (fixing tape),
13... Flat cross stage,
14...PET film-based single-sided adhesive tape (backing tape, fixing tape),
15...SUS plate,
20...Dicing die bond film,
W, 30...semiconductor wafer,
30a, 30a1, 30a2...semiconductor chip,
30b...modified region,
31...semiconductor wafer center portion 32...semiconductor wafer left portion 33...semiconductor wafer right portion 34...semiconductor wafer upper portion 35...semiconductor wafer lower portion 40...ring frame (wafer ring),
41... holder,
50...suction collet,
60...Push-up pin (needle)
70, 80...Semiconductor device

Claims (4)

A dicing tape comprising a base film and a pressure-sensitive adhesive layer on the base film, the pressure-sensitive adhesive layer comprising an active energy ray-curable pressure-sensitive adhesive composition,
(1) The base film contains a resin (A) made of an ionomer of an ethylene-unsaturated carboxylic acid copolymer and a polyamide resin (B),
the base film is composed of a resin composition in which the mass ratio (A):(B) of the resin (A) to the resin (B) in the entire base film is in the range of 72:28 to 95:5;
the stress at 5% elongation at −15° C. is in the range of 15.5 MPa or more and 28.5 MPa or less when the base film is stretched in either the MD direction (the machine direction during the production of the base film) or the TD direction (the direction perpendicular to the MD direction);
(2) The active energy ray-curable pressure-sensitive adhesive composition comprises an acrylic pressure-sensitive adhesive polymer having an active energy ray-reactive carbon-carbon double bond and a hydroxyl group, a photopolymerization initiator, and a polyisocyanate-based crosslinking agent that crosslinks with the hydroxyl group;
The acrylic adhesive polymer has a main chain glass transition temperature (Tg) in the range of −65° C. or more and −50° C. or less, and a hydroxyl value in the range of 12.0 mg KOH/g or more and 55.0 mg KOH/g or less,
In the active energy ray-curable pressure-sensitive adhesive composition,
an equivalent ratio (NCO/OH) of an isocyanate group (NCO) of the polyisocyanate crosslinking agent to a hydroxyl group (OH) of the acrylic adhesive polymer is in the range of 0.02 or more and 0.20 or less;
the residual hydroxyl group concentration after the crosslinking reaction is in the range of 0.18 mmol or more and 0.90 mmol or less per 1 g of the active energy ray-curable pressure-sensitive adhesive composition,
the concentration of active energy ray reactive carbon-carbon double bonds is in the range of 0.85 mmol or more and 1.60 mmol or less per 1 g of the active energy ray curable pressure-sensitive adhesive composition;
1. A dicing tape comprising: The dicing tape according to claim 1, wherein the concentration of active energy ray reactive carbon-carbon double bonds is in the range of 1.02 mmol to 1.51 mmol per 1 g of the active energy ray curable adhesive composition. The dicing tape according to claim 1 or 2, wherein the weight average molecular weight Mw of the acrylic adhesive polymer is in the range of 200,000 or more and 600,000 or less. 4. The dicing tape according to claim 1, wherein the acid value of the acrylic adhesive polymer is in the range of 0 mgKOH/g to 9.0 mgKOH/g .

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