JP7539223B2 - Dicing tape and dicing tape with adhesive film - Google Patents

Description

The present invention relates to a dicing tape that can be used in the manufacturing process of semiconductor devices, and a dicing tape with an adhesive film.

In the manufacturing process of semiconductor devices, a dicing tape with an adhesive film may be used to obtain a semiconductor chip with an adhesive film of a size equivalent to the chip for die bonding, i.e., a semiconductor chip with an adhesive film. The dicing tape with an adhesive film has, for example, a dicing tape made of a base material and an adhesive layer, and an adhesive film releasably attached to the adhesive layer side. The adhesive film has a disk shape larger than the semiconductor wafer, which is the workpiece, and is concentrically attached to the adhesive layer side of the dicing tape, which has a disk shape larger than the adhesive film, for example. A SUS ring frame can be attached to the area around the adhesive film that is not covered by the adhesive film in the adhesive layer of the dicing tape. The ring frame is a member that, when attached to the dicing tape, mechanically contacts a transport mechanism such as a transport arm provided in various devices when transporting the workpiece.

As one method for obtaining semiconductor chips with an adhesive film using a dicing tape with an adhesive film, a method is known in which the dicing tape with the adhesive film is expanded and the adhesive film is cut. In this method, a semiconductor wafer is first laminated onto the adhesive film of the dicing tape with an adhesive film, with a ring frame attached to the area around the adhesive film of the dicing tape pressure-sensitive adhesive layer. This semiconductor wafer is processed so that it can be cut together with the cutting of the adhesive film and separated into multiple semiconductor chips. Next, a specific expansion device is used to cut the adhesive film so that multiple adhesive film pieces, each of which is in close contact with a semiconductor chip, are generated from the adhesive film on the dicing tape, and the dicing tape of the dicing tape with the adhesive film is expanded in the radial direction of the wafer at a low temperature (e.g., -20°C to 0°C) (cool expansion process). In this cool expansion process, the semiconductor wafer on the adhesive film is also cut at the locations corresponding to the adhesive film cut locations, and the semiconductor wafer is divided into a plurality of semiconductor chips on the dicing tape with adhesive film or on the dicing tape. Next, the dicing tape is expanded (separation expansion) to widen the separation distance between the chips on the dicing tape with adhesive film, and then each semiconductor chip is pushed up from the underside of the dicing tape together with the adhesive film of the size corresponding to the chip that is in close contact with it by the pin member of the pick-up mechanism and then picked up from the dicing tape (pick-up process). In this way, a semiconductor chip with an adhesive film is obtained. This semiconductor chip with an adhesive film is fixed to an adherend such as a mounting substrate by die bonding via the adhesive film. For example, the technology related to the dicing tape with adhesive film used as described above is described in, for example, Patent Documents 1 and 2 below.

JP 2007-2173 A JP 2010-177401 A

When the dicing tape is expanded in the above-mentioned cool expansion process, tension may concentrate, particularly in the portion of the adhesive film and dicing tape between the extended surface of the outer peripheral side of the semiconductor wafer and the extended surface of the inner peripheral side of the ring frame, causing a tear in the dicing tape. If a tear occurs in the dicing tape during the cool expansion process, the tension transmitted from the dicing tape is cut off, causing the inconvenience of the cutting of the semiconductor wafer and adhesive film not progressing. Furthermore, if the tear in the dicing tape becomes large, it becomes difficult to proceed to the next process.

The present invention was conceived in light of the above circumstances, and its purpose is to provide a dicing tape and a dicing tape with an adhesive film that are less likely to tear when the dicing tape is expanded in the cool expansion process.

According to a first aspect of the present invention, a dicing tape is provided. This dicing tape has a laminated structure including a substrate and an adhesive layer, and the adhesive layer contains a base polymer with a glass transition temperature (Tg) of -43°C or lower. A dicing tape having such a configuration, in which an adhesive film is releasably adhered to the adhesive layer and a semiconductor wafer is further laminated to the adhesive film, can be suitably used in a cleaving process (cool expansion process) in which the dicing tape is expanded at a low temperature (e.g., -15°C to 5°C) to cleave the semiconductor wafer and adhesive film to obtain individual semiconductor chips with the adhesive film.

As described above, the dicing tape according to the first aspect of the present invention has an adhesive layer containing a base polymer having a Tg of −43° C. or less. This configuration is suitable in that it can suppress tearing of the dicing tape in the cool expanding process. That is, under the low temperature conditions of the cool expanding process, the adhesive layer contains a base polymer having a Tg of −43° C. or less, so that the adhesive layer has a suitable flexibility and it is considered that tearing of the dicing tape originating from a crack in the adhesive layer can be suppressed. From the viewpoint of suppressing tearing of the dicing tape, the Tg of the base polymer is preferably −50° C. or less, more preferably −55° C. or less. The Tg of the base polymer is preferably −65° C. or more, more preferably −62° C. or more. The configuration in which the Tg of the base polymer is preferably −65° C. or more, more preferably −62° C. or more is suitable in that the tension of the dicing tape is transmitted to the adhesive film without being absorbed by the adhesive layer in the cool expanding process, and the semiconductor wafer can be well cut.

The base polymer of the dicing tape according to the first aspect of the present invention is preferably an acrylic polymer, since it is easy to control the Tg to -43°C or less.

In the dicing tape according to the first aspect of the present invention, the thickness of the adhesive layer is preferably 5 μm or more and 40 μm or less, more preferably 7 μm or more and 30 μm or less, and even more preferably 10 μm or more and 15 μm or less. Such a configuration is preferable in terms of suppressing tearing of the dicing tape while ensuring the cleavability of the semiconductor wafer. The configuration in which the thickness of the adhesive layer is 40 μm or less, preferably 30 μm or less, and even more preferably 15 μm or less is preferable in terms of suppressing the hardness as a bulk due to the thickening of the adhesive layer and suppressing tearing of the dicing tape due to cracking of the adhesive layer. The configuration in which the thickness of the adhesive layer is 5 μm or more, preferably 7 μm or more, and even more preferably 10 μm or more is preferable in terms of transmitting the tension of the dicing tape to the adhesive film in the cool expansion process and favorably cleaving the semiconductor wafer.

The breaking elongation of the dicing tape according to the first aspect of the present invention at -15°C is preferably 300% or more, more preferably 373% or more, and even more preferably 400% or more. Such a configuration is suitable for preventing tearing of the dicing tape. In addition, the breaking elongation is preferably 600% or less, and more preferably 500% or less.

The breaking strength of the dicing tape according to the first aspect of the present invention at -15°C is preferably 15 N/10 mm or more, more preferably 18 N/10 mm or more, and even more preferably 30 N/10 mm or more. Such a configuration is suitable for suppressing tearing of the dicing tape. In addition, from the viewpoint of transmitting the tension of the dicing tape to the adhesive film in the cool expansion process and favorably cleaving the semiconductor wafer, the breaking strength is preferably 35 N/10 mm or less, and more preferably 32 N/10 mm or less.

According to a second aspect of the present invention, a dicing tape with an adhesive film is provided. The dicing tape with an adhesive film provided by the present invention comprises the dicing tape according to the first aspect of the present invention and an adhesive film releasably adhered to the pressure-sensitive adhesive layer of the dicing tape. Such a dicing tape with an adhesive film comprising the dicing tape according to the first aspect of the present invention is suitable for use in a cool expansion process, i.e., it is suitable for suppressing tearing of the dicing tape during the cool expansion process and for favorably cleaving the semiconductor wafer and the adhesive film.

In the dicing tape with adhesive film according to the second aspect of the present invention, the breaking strength of the adhesive film at 25°C is preferably 5 N/10 mm or less, more preferably 3 N/10 mm or less, and even more preferably 1.5 N/10 mm or less. Such a configuration is suitable for reducing the load on the dicing tape and suppressing tearing of the dicing tape. In addition, from the viewpoint of appropriate breakability of the semiconductor wafer, the breaking strength is preferably 0.1 N/10 mm or more, more preferably 0.2 N/10 mm or more, and even more preferably 0.5 N/10 mm or more.

In the dicing tape with adhesive film according to the second aspect of the present invention, the breaking elongation of the adhesive film at 25°C is preferably 100% or less, more preferably 80% or less, even more preferably 50% or less, and most preferably 15% or less. Such a configuration is suitable for reducing the load on the dicing tape and suppressing tearing of the dicing tape. From the viewpoint of appropriate breakability of the semiconductor wafer, the breaking elongation is preferably 0.5% or more, more preferably 1% or more, even more preferably 3% or more, and most preferably 5% or more.

1 is a schematic cross-sectional view of a dicing tape with an adhesive film according to one embodiment of the present invention. FIG. 2 is a plan view of the dicing tape with the dicing adhesive film shown in FIG. 1. 2 illustrates some steps in an example of a semiconductor device manufacturing method in which the dicing tape with adhesive film shown in FIG. 1 is used. This represents a step subsequent to the step shown in FIG. This represents a step subsequent to the step shown in FIG. This represents a step subsequent to the step shown in FIG. This represents a step subsequent to the step shown in FIG. This represents a step subsequent to the step shown in FIG. This represents a step subsequent to the step shown in FIG. 4 illustrates some steps in another example of a semiconductor device manufacturing method in which the dicing tape with an adhesive film shown in FIG. 1 is used. This shows a process following the process shown in FIG. 4 illustrates some steps in another example of a semiconductor device manufacturing method in which the dicing tape with an adhesive film shown in FIG. 1 is used. This represents a step subsequent to the step shown in FIG.

1 is a schematic cross-sectional view of a dicing tape X with an adhesive film according to one embodiment of the present invention. The dicing tape X with an adhesive film has a laminated structure including a dicing tape 10 according to one embodiment of the present invention and an adhesive film 20. The dicing tape 10 has a laminated structure including a substrate 11 and an adhesive layer 12. The adhesive layer 12 has an adhesive surface 12a on the adhesive film 20 side. The adhesive film 20 is releasably adhered to the adhesive layer 12 of the dicing tape 10 or its adhesive surface 12a. In this embodiment, the dicing tape 10 and the adhesive film 20 have a disk shape and are arranged concentrically as shown in FIG. 2. A ring frame made of, for example, SUS can be attached to the area around the adhesive film that is not covered by the adhesive film 20 in the adhesive layer 12 of the dicing tape 10. The ring frame is a member that, when attached to the dicing tape 10, mechanically contacts a transport mechanism such as a transport arm provided in various devices when transporting a workpiece. Such a dicing tape X with adhesive film can be used in the process of obtaining semiconductor chips with adhesive film in the manufacture of semiconductor devices.

The substrate 11 of the dicing tape 10 in the dicing tape X with adhesive film is an element that functions as a support in the dicing tape 10 or the dicing tape X with adhesive film. The substrate 11 is, for example, a plastic substrate that is UV-transmissive, and a plastic film can be suitably used as the plastic substrate. Examples of the constituent material of the plastic substrate include polyolefin, polyester, polyurethane, polycarbonate, polyether ether ketone, polyimide, polyetherimide, polyamide, wholly aromatic polyamide, polyvinyl chloride, polyvinylidene chloride, polyphenyl sulfide, aramid, fluororesin, cellulose-based resin, and silicone resin. Examples of polyolefin include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, very low-density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolypropylene, polybutene, polymethylpentene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, ethylene-butene copolymer, and ethylene-hexene copolymer. Examples of polyesters include polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate. The substrate 11 may be made of one type of material, or may be made of two or more types of materials. The substrate 11 may have a single-layer structure or a multi-layer structure. In addition, when the substrate 11 is made of a plastic film, it may be a non-stretched film, a uniaxially stretched film, or a biaxially stretched film.

The surface of the substrate 11 facing the adhesive layer 12 may be subjected to a physical treatment, a chemical treatment, or a primer treatment to enhance adhesion to the adhesive layer 12. Examples of physical treatments include corona treatment, plasma treatment, sand mat processing, ozone exposure treatment, flame exposure treatment, high-voltage shock exposure treatment, and ionizing radiation treatment. Examples of chemical treatments include chromate treatment.

The thickness of the substrate 11 is preferably 40 μm or more, more preferably 50 μm or more, from the viewpoint of ensuring the strength required for the substrate 11 to function as a support in the dicing tape 10 or the dicing tape X with an adhesive film. In addition, from the viewpoint of realizing appropriate flexibility in the dicing tape 10 or the dicing tape X with an adhesive film, the thickness of the substrate 11 is preferably 200 μm or less, more preferably 180 μm or less.

The haze of the substrate 11 is preferably 50 to 98%. The haze of a substrate such as a plastic substrate can be measured, for example, using a haze measuring device (product name "HM-150", manufactured by Murakami Color Research Laboratory Co., Ltd.). A substrate 11 having a haze of 50% or more is suitable for enabling position recognition by an optical sensor provided in a lamination device used to laminate a semiconductor wafer to the dicing tape X with an adhesive film. A substrate 11 having a haze of 98% or less is suitable for UV curing the adhesive layer 12 of the dicing tape 10 by irradiating the adhesive layer 12 with UV light through the substrate 11.

The adhesive constituting the adhesive layer 12 of the dicing tape 10 may be an adhesive whose adhesive strength can be intentionally reduced by external action such as exposure to radiation or heating (adhesive strength reducing adhesive), or an adhesive whose adhesive strength is hardly or not reduced at all by external action (non-adhesive strength reducing adhesive), and can be appropriately selected depending on the method and conditions for singulating the semiconductor chips to be singulated using the dicing tape X with adhesive film.

When an adhesive with reduced adhesive force is used as the adhesive in the adhesive layer 12, it is possible to selectively use the adhesive layer 12 in a state where it exhibits relatively high adhesive force and a state where it exhibits relatively low adhesive force during the manufacturing process and use process of the dicing tape X with adhesive film. For example, when the adhesive film 20 is attached to the adhesive layer 12 of the dicing tape 10 during the manufacturing process of the dicing tape X with adhesive film, or when the dicing tape X with adhesive film is used in a specified wafer dicing process, it is possible to suppress and prevent the adhesive layer 12 from floating or peeling off the adherend, such as the adhesive film 20, from the adhesive layer 12 by utilizing the state where the adhesive layer 12 exhibits relatively high adhesive force, while in the subsequent pick-up process for picking up the semiconductor chip with adhesive film from the dicing tape 10 of the dicing tape X with adhesive film, it is possible to appropriately pick up the semiconductor chip with adhesive film from the adhesive layer 12 after reducing the adhesive force of the adhesive layer 12.

Examples of such adhesives include radiation-curable adhesives (adhesives having radiation curing properties) and heat-foamable adhesives. In the adhesive layer 12 of this embodiment, one type of adhesive may be used, or two or more types of adhesive may be used. The entire adhesive layer 12 may be formed from an adhesive-reduced adhesive, or a part of the adhesive layer 12 may be formed from an adhesive-reduced adhesive. For example, when the adhesive layer 12 has a single-layer structure, the entire adhesive layer 12 may be formed from an adhesive-reduced adhesive, or a predetermined portion of the adhesive layer 12 (e.g., a central region that is a region to be attached to the wafer) may be formed from an adhesive-reduced adhesive, and other portions (e.g., a region that is a region to be attached to the ring frame and is outside the central region) may be formed from an adhesive non-reduced adhesive. Furthermore, when the adhesive layer 12 has a laminated structure, all layers in the laminated structure may be formed from an adhesive-reduced adhesive, or only some layers in the laminated structure may be formed from an adhesive-reduced adhesive.

The radiation-curable adhesive in the adhesive layer 12 may be, for example, an adhesive that cures when irradiated with electron beams, ultraviolet light, alpha rays, beta rays, gamma rays, or X-rays, and it is particularly preferable to use an adhesive that cures when irradiated with ultraviolet light (ultraviolet light-curable adhesive).

As described above, the adhesive in the adhesive layer 12 of the dicing tape 10 contains a base polymer having a glass transition temperature (Tg) of -43°C or less. This configuration is suitable in that it can suppress tearing of the dicing tape 10 in the cool expansion process. That is, under the low temperature conditions of the cool expansion process, the adhesive layer 12 contains a base polymer having a Tg of -43°C or less, so that the adhesive layer 12 has appropriate flexibility and it is believed that tearing of the dicing tape 10 originating from a crack in the adhesive layer 12 can be suppressed. From the viewpoint of suppressing tearing of the dicing tape 10, the Tg of the base polymer is preferably -50°C or less, more preferably -55°C or less. The Tg of the base polymer is preferably -65°C or more, more preferably -62°C or more. The Tg of the base polymer is preferably -65°C or higher, more preferably -62°C or higher, which is advantageous from the viewpoint that the tension of the dicing tape 10 is transmitted to the adhesive film 20 without being absorbed by the adhesive layer 12 during the cool expansion process, allowing the semiconductor wafer to be smoothly cut.

The Tg of the base polymer may be measured according to, for example, JIS K 7121, or may be the calculated glass transition temperature calculated from the following Fox formula. The calculated glass transition temperature can be adjusted by selecting the type and amount of each monomer component that constitutes the base polymer (copolymer).

The calculated glass transition temperature (calculated Tg) can be calculated from Fox's formula [1].
1/Calculation Tg=W1/Tg(1)+W2/Tg(2)+...+Wn/Tn [1]
Here, W1, W2, ... Wn represent the weight fractions (% by weight) of monomer component (1), monomer component (2), ... monomer component (n) constituting the copolymer with respect to the total monomer components, and Tg(1), Tg(2), ... Tg(n) represent the glass transition temperatures (units: absolute temperature: K) of homopolymers of monomer component (1), monomer component (2), ... monomer component (n).
The glass transition temperature of homopolymers is known from various documents and catalogs, and is described, for example, in J. Brandup, EH Immergut, EA Grulke: Polymer Handbook: JOHN WILEY & SONS, INC. For monomers for which no numerical value is given in the various documents, a value measured by a general thermal analysis, for example, differential thermal analysis or dynamic viscoelasticity measurement method, can be used.

The content of the base polymer in the adhesive layer 12 is preferably 85% by weight or more, and more preferably 90% by weight or more, relative to the adhesive layer 12, from the viewpoint of imparting appropriate flexibility to the adhesive layer 12 under the low-temperature conditions of the cool expansion process. In addition, the content of the base polymer in the adhesive layer 12 is preferably 99% by weight or less, and more preferably 98% by weight or less, relative to the adhesive layer (100% by weight), from the viewpoint of blending functional components such as radiation-polymerizable monomer components, oligomer components, and polymerization initiators.

In order to adjust the Tg of the base polymer (including the calculated Tg calculated by Fox's formula) to -43°C or lower, it is preferable to adjust the blending ratio of a monomer component whose homopolymer has a low Tg (hereinafter referred to as a "low Tg monomer") and a monomer component whose homopolymer has a high Tg (hereinafter referred to as a "high Tg monomer").

From the viewpoint of easily adjusting the Tg of the base polymer to −43° C. or less, the Tg of the homopolymer of the low Tg monomer is preferably less than 100° C., more preferably less than 80° C., more preferably less than 60° C., more preferably less than 40° C., more preferably less than 20° C., more preferably less than 0° C., and even more preferably less than −10° C.
From the viewpoint of easily adjusting the Tg of the base polymer to −43° C. or lower, the Tg of the homopolymer of the high Tg monomer is preferably −10° C. or higher, more preferably 0° C. or higher, more preferably 20° C. or higher, more preferably 40° C. or higher, more preferably 60° C. or higher, more preferably 80° C. or higher, and even more preferably 100° C. or higher.

The ratio of low Tg monomers to high Tg monomers (molar ratio of low Tg monomers/high Tg monomers) may vary depending on the Tg of the monomer components used and their combination, but from the viewpoint of easily adjusting the Tg of the base polymer to -43°C or less and suppressing tearing of the dicing tape 10, it is preferably 5 or more, and more preferably 10 or more. Furthermore, from the viewpoint of adjusting the Tg of the base polymer to -65°C or more and ensuring the breakability of the semiconductor wafer, the above ratio is preferably 30 or less, and more preferably 25 or less.

The base polymer in the adhesive layer 12 may be, for example, an acrylic polymer for an acrylic adhesive, a urethane polymer for a urethane adhesive, or a silicone polymer for a silicone adhesive. Acrylic polymers are preferred from the viewpoint of ease of adjusting the calculated Tg calculated by the Fox formula.

The acrylic polymer preferably contains the largest amount of monomer units derived from (meth)acrylic acid esters by mass. "(Meth)acrylic" means "acrylic" and/or "methacrylic". Examples of (meth)acrylic acid esters that form monomer units of acrylic polymers, i.e., (meth)acrylic acid esters that are constituent monomers of acrylic polymers, include (meth)acrylic acid alkyl esters, (meth)acrylic acid cycloalkyl esters, and (meth)acrylic acid aryl esters.

Examples of (meth)acrylic acid alkyl esters include methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, s-butyl ester, t-butyl ester, pentyl ester, isopentyl ester, hexyl ester, heptyl ester, octyl ester, 2-ethylhexyl ester, isooctyl ester, nonyl ester, decyl ester, isodecyl ester, undecyl ester, dodecyl ester (i.e., lauryl ester), tridecyl ester, tetradecyl ester, hexadecyl ester, octadecyl ester, and eicosyl ester of (meth)acrylic acid. Examples of (meth)acrylic acid cycloalkyl esters include cyclopentyl ester and cyclohexyl ester of (meth)acrylic acid. Examples of (meth)acrylic acid aryl esters include phenyl (meth)acrylate and benzyl (meth)acrylate. As a constituent monomer of an acrylic polymer, one type of (meth)acrylic acid ester may be used, or two or more types of (meth)acrylic acid esters may be used. As the (meth)acrylic acid ester for the acrylic polymer, 2-ethylhexyl acrylate is preferably used. In order to appropriately express the basic properties such as adhesion due to the (meth)acrylic acid ester in the adhesive layer 12 and to adjust the Tg to -43°C or less, the proportion of the (meth)acrylic acid ester in the total constituent monomers of the acrylic polymer is preferably 70% by mass or more, more preferably 80% by mass or more.

The acrylic polymer may contain one or more monomer units derived from other monomers copolymerizable with the (meth)acrylic acid ester, for example, from the viewpoint of modifying the cohesive strength or heat resistance or adjusting the Tg to -43°C or less. Examples of other copolymerizable monomers for forming the monomer units of the acrylic polymer, that is, other copolymerizable monomers that are constituent monomers of the acrylic polymer, include, for example, carboxy group-containing monomers, acid anhydride monomers, hydroxy group-containing monomers, nitrogen-containing monomers, epoxy group-containing monomers, sulfonic acid group-containing monomers, and phosphoric acid group-containing monomers. Examples of carboxy group-containing monomers include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples of acid anhydride monomers include maleic anhydride and itaconic anhydride. 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. Examples of nitrogen-containing monomers include acryloylmorpholine, acrylamide, and acrylonitrile. Examples of epoxy group-containing monomers include glycidyl (meth)acrylate and methylglycidyl (meth)acrylate. Examples of sulfonic acid group-containing monomers include styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, and (meth)acryloyloxynaphthalenesulfonic acid. An example of a phosphate group-containing monomer is 2-hydroxyethyl acryloyl phosphate. As the copolymerizable monomer for the acrylic polymer, preferably, at least one selected from the group consisting of hydroxy group-containing monomers and nitrogen-containing monomers is used. As the copolymerizable monomer for the acrylic polymer, more preferably, at least one selected from the group consisting of 2-hydroxyethyl (meth)acrylate and acryloyl morpholine is used.

When the above acrylic polymer contains a monomer unit derived from a hydroxyl group-containing monomer (particularly 2-hydroxyethyl acrylate), i.e., when the acrylic polymer contains a hydroxyl group-containing monomer as a constituent monomer, the proportion of the hydroxyl group-containing monomer as a constituent monomer in the acrylic polymer is preferably 5 to 40 mol %, more preferably 10 to 30 mol %.

When the acrylic polymer contains a monomer unit derived from a nitrogen-containing monomer (particularly acryloylmorpholine), that is, when the acrylic polymer contains a nitrogen-containing monomer as its constituent monomer, the proportion of the nitrogen-containing monomer as a constituent monomer in the acrylic polymer is preferably 0 to 30 mol%, more preferably 5 to 20 mol%, and even more preferably 10 to 20 mol%. In the dicing tape 10, a configuration in which the content is 5 mol% or more, preferably 10 mol% or more, is suitable for realizing high polarity for the polymer in the adhesive layer 12, and is suitable for obtaining high elasticity of the adhesive layer 12, and for obtaining breakability of the semiconductor wafer and peelability of the semiconductor chip with the adhesive film from the dicing tape 10 after breaking. In the dicing tape 10, a configuration in which the content is 30 mol% or less, preferably 20 mol% or less, is suitable in that it can suppress tearing of the dicing tape 10.

The acrylic polymer may contain a monomer unit derived from a polyfunctional monomer that is copolymerizable with a monomer component such as a (meth)acrylic acid ester to form a crosslinked structure in the polymer backbone. Examples of such polyfunctional monomers include hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, polyglycidyl (meth)acrylate, polyester (meth)acrylate, and urethane (meth)acrylate. "(Meth)acrylate" means "acrylate" and/or "methacrylate". As a constituent monomer of the acrylic polymer, one type of polyfunctional monomer may be used, or two or more types of polyfunctional monomers may be used. In order to adequately express basic properties such as adhesion due to (meth)acrylic acid ester in the adhesive layer 12, the proportion of polyfunctional monomers in the total constituent monomers of the acrylic polymer is preferably 40 mol % or less, and preferably 30 mol % or less.

Examples of the high Tg monomer include acryloylmorpholine (homopolymer Tg: 145° C.), acrylonitrile (homopolymer Tg: 97° C.), and methyl methacrylate (homopolymer Tg: 105° C.), with acryloylmorpholine being preferred.
Examples of low Tg monomers include 2-ethylhexyl acrylate (homopolymer Tg: -70°C), 2-hydroxyethyl acrylate (homopolymer Tg: -15°C), butyl acrylate (homopolymer Tg: -55°C), and 4-hydroxybutyl acrylate (homopolymer Tg: -40°C), with 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate being preferred.

Acrylic polymers can be obtained by polymerizing the raw material monomers for forming them. Examples of polymerization methods include solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization. From the viewpoint of high cleanliness in the semiconductor device manufacturing process in which the dicing tape 10 or the dicing tape X with adhesive film is used, it is preferable that the amount of low molecular weight substances in the adhesive layer 12 of the dicing tape 10 or the dicing tape X with adhesive film is small, and the weight average molecular weight of the acrylic polymer is preferably 100,000 or more, more preferably 200,000 to 3,000,000. The weight average molecular weight (Mw) of the acrylic polymer refers to the value measured by gel permeation chromatography (GPC) and converted into standard polystyrene.

The adhesive layer 12 or an adhesive for forming the adhesive layer may contain, for example, a crosslinking agent to increase the average molecular weight of the base polymer such as an acrylic polymer. Examples of crosslinking agents for forming a crosslinked structure by reacting with the base polymer such as an acrylic polymer include polyisocyanate compounds, epoxy compounds, polyol compounds, aziridine compounds, and melamine crosslinking agents as isocyanate crosslinking agents. The content of the crosslinking agent in the adhesive layer 12 or an adhesive composition for forming the adhesive layer is preferably 0.01 parts by mass or more, more preferably 0.03 parts by mass or more, and more preferably 0.05 parts by mass or more, based on 100 parts by mass of the base polymer such as an acrylic polymer. The content is preferably 5 parts by mass or less, more preferably 4 parts by mass or less, and more preferably 3 parts by mass or less.
In the present invention, the "Tg of the base polymer" refers to the Tg of the base polymer before it reacts with a crosslinking agent.

When the adhesive layer 12 is an ultraviolet-curable adhesive layer whose adhesive strength decreases when exposed to ultraviolet light, examples of adhesives for forming the ultraviolet-curable adhesive layer include additive-type ultraviolet-curable adhesives that contain a base polymer, such as an acrylic polymer, which is an acrylic adhesive, and an ultraviolet-polymerizable monomer component or oligomer component that has a functional group, such as an ultraviolet-polymerizable carbon-carbon double bond.

Examples of the ultraviolet-polymerizable monomer components for forming the ultraviolet-curable adhesive include urethane (meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and 1,4-butanediol di(meth)acrylate. Examples of the ultraviolet-polymerizable oligomer components for forming the ultraviolet-curable adhesive include various oligomers such as urethane-based, polyether-based, polyester-based, polycarbonate-based, and polybutadiene-based oligomers, and those with a molecular weight of about 100 to 30,000 are suitable. The total content of ultraviolet-polymerizable monomer components and oligomer components in the ultraviolet-curable adhesive is determined within a range that can appropriately reduce the adhesive strength of the adhesive layer 12 to be formed, and is preferably 5 to 500 parts by mass, and more preferably 40 to 150 parts by mass, per 100 parts by mass of a base polymer such as an acrylic polymer. In addition, as an additive-type ultraviolet-curable adhesive, for example, one disclosed in JP-A-60-196956 may be used.

Examples of UV-curable adhesives for the adhesive layer 12 include inherent UV-curable adhesives that contain a base polymer having a functional group such as a UV-polymerizable carbon-carbon double bond on the polymer side chain, in the polymer main chain, or at the end of the polymer main chain. Such inherent UV-curable adhesives are suitable for suppressing unintended changes over time in adhesive properties caused by the movement of low molecular weight components within the adhesive layer 12 being formed.

The base polymer contained in the intrinsic type ultraviolet-curing adhesive is preferably one having an acrylic polymer as a basic skeleton. The above-mentioned acrylic polymer can be adopted as the acrylic polymer forming such a basic skeleton. As a method for introducing an ultraviolet-polymerizable carbon-carbon double bond into an acrylic polymer, for example, a method can be mentioned in which a raw material monomer including a monomer having a predetermined functional group (first functional group) is copolymerized to obtain an acrylic polymer, and then a compound having a predetermined functional group (second functional group) that can react with the first functional group to bond and an ultraviolet-polymerizable carbon-carbon double bond is subjected to a condensation reaction or addition reaction with the acrylic polymer while maintaining the ultraviolet polymerizability of the carbon-carbon double bond.
In the present invention, the "Tg of the base polymer" refers to the Tg of the base polymer before the ultraviolet-polymerizable carbon-carbon double bond is introduced by reaction with a compound having a second functional group and an ultraviolet-polymerizable carbon-carbon double bond, etc.

Examples of combinations of the first functional group and the second functional group include a carboxy group and an epoxy group, an epoxy group and a carboxy group, a carboxy group and an aziridyl group, an aziridyl group and a carboxy group, a hydroxy group and an isocyanate group, and an isocyanate group and a hydroxy group. Among these combinations, from the viewpoint of ease of reaction tracking, a combination of a hydroxy group and an isocyanate group, or a combination of an isocyanate group and a hydroxy group is preferred. In addition, since it is technically difficult to prepare a polymer having a highly reactive isocyanate group, from the viewpoint of ease of preparation or availability of an acrylic polymer, it is more preferred that the first functional group on the acrylic polymer side is a hydroxy group and the second functional group is an isocyanate group. In this case, examples of isocyanate compounds having both a UV-polymerizable carbon-carbon double bond and an isocyanate group as a second functional group, i.e., UV-polymerizable unsaturated functional group-containing isocyanate compounds, include methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate (MOI), and m-isopropenyl-α,α-dimethylbenzyl isocyanate.

The adhesive layer 12 preferably contains a photopolymerization initiator. Examples of the photopolymerization initiator include α-ketol compounds, acetophenone compounds, benzoin ether compounds, ketal compounds, aromatic sulfonyl chloride compounds, photoactive oxime compounds, benzophenone compounds, thioxanthone compounds, camphorquinone, halogenated ketones, acylphosphinoxides, and acylphosphonates. Examples of the α-ketol compounds include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, and 1-hydroxycyclohexylphenylketone. Examples of acetophenone compounds include methoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2,2-diethoxyacetophenone, and 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane-1. Examples of benzoin ether compounds include benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether. Examples of ketal compounds include benzyl dimethyl ketal. Examples of aromatic sulfonyl chloride compounds include 2-naphthalenesulfonyl chloride. Examples of photoactive oxime compounds include 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime. Examples of benzophenone compounds include benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone. Examples of thioxanthone compounds include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone. The content of the photopolymerization initiator in the adhesive layer 12 is, for example, 0.05 to 10 parts by mass per 100 parts by mass of the base polymer, such as an acrylic polymer.

The adhesive layer 12 or the adhesive for forming it may contain, in addition to the above-mentioned components, a crosslinking accelerator, a tackifier, an anti-aging agent, and a colorant such as a pigment or dye. The colorant may be a compound that becomes colored when exposed to radiation. An example of such a compound is a leuco dye.

The thickness of the adhesive layer 12 is preferably 5 μm or more and 40 μm or less, more preferably 7 μm or more and 30 μm or less, and even more preferably 10 μm or more and 15 μm or less. Such a configuration is preferable in terms of suppressing tearing of the dicing tape 10 while ensuring the cleavability of the semiconductor wafer. The configuration in which the thickness of the adhesive layer 12 is 40 μm or less, preferably 30 μm or less, and even more preferably 15 μm or less is preferable in terms of suppressing the hardness as a bulk due to the thickening of the adhesive layer 12 and suppressing tearing of the dicing tape 10 due to cracking of the adhesive layer 12. The configuration in which the thickness of the adhesive layer 12 is 5 μm or more, preferably 7 μm or more, and even more preferably 10 μm or more is preferable in terms of transmitting the tension of the dicing tape 10 to the adhesive film 20 in the cool expansion process and favorably cleaving the semiconductor wafer.

The breaking elongation of the dicing tape 10 configured as above at -15°C is preferably 300% or more, more preferably 373% or more, and more preferably 400% or more. Such a configuration is suitable for preventing tearing of the dicing tape 10. In addition, the breaking elongation is preferably 600% or less, and more preferably 500% or less.

The breaking strength of the dicing tape 10 at -15°C is preferably 15 N/10 mm or more, more preferably 18 N/10 mm or more, and even more preferably 30 N/10 mm or more. Such a configuration is suitable for preventing tearing of the dicing tape. The breaking strength is preferably 35 N/10 mm or less, and more preferably 32 N/10 mm or less, from the viewpoint of transmitting the tension of the dicing tape to the adhesive film in the cool expansion process and favorably cleaving the semiconductor wafer.

The adhesive film 20 in the dicing tape X with adhesive film has a configuration capable of functioning as a die bonding adhesive exhibiting thermosetting properties. The adhesive film 20 may have a composition containing a thermosetting resin and a thermoplastic resin as resin components, or may have a composition containing a thermoplastic resin with a thermosetting functional group that can react with a curing agent to form a bond. Such an adhesive film 20 may have a single layer structure, or may have a multilayer structure in which adjacent layers have different compositions.

When the adhesive film 20 has a composition containing a thermosetting resin and a thermoplastic resin, examples of the thermosetting resin include epoxy resin, phenol resin, amino resin, unsaturated polyester resin, polyurethane resin, silicone resin, and thermosetting polyimide resin. The adhesive film 20 may contain one type of thermosetting resin, or may contain two or more types of thermosetting resin. Epoxy resin is preferred as the thermosetting resin in the adhesive film 20 because it tends to contain a small amount of ionic impurities that can cause corrosion of the semiconductor chip to be die-bonded. In addition, phenol resin is preferred as a curing agent for expressing thermosetting properties in epoxy resin.

Epoxy resins include, for example, bisphenol A type, bisphenol F type, bisphenol S type, brominated bisphenol A type, hydrogenated bisphenol A type, bisphenol AF type, biphenyl type, naphthalene type, fluorene type, phenol novolac type, orthocresol novolac type, trishydroxyphenylmethane type, tetraphenylolethane type, hydantoin type, trisglycidyl isocyanurate type, and glycidylamine type epoxy resins. Phenol novolac type epoxy resins, orthocresol novolac type epoxy resins, biphenyl type epoxy resins, trishydroxyphenylmethane type epoxy resins, and tetraphenylolethane type epoxy resins are preferred as epoxy resins in the adhesive film 20 because they are highly reactive with phenol resins as a curing agent and have excellent heat resistance.

Examples of phenolic resins that can act as a curing agent for epoxy resins include novolac-type phenolic resins, resol-type phenolic resins, and polyoxystyrenes such as polyparaoxystyrene. Examples of novolac-type phenolic resins include phenol novolac resins, phenol aralkyl resins, cresol novolac resins, tert-butylphenol novolac resins, and nonylphenol novolac resins. The adhesive film 20 may contain one type of phenolic resin as a curing agent for epoxy resins, or may contain two or more types of phenolic resins. Phenol novolac resins and phenol aralkyl resins tend to improve the connection reliability of the adhesive when used as a curing agent for epoxy resins as a die bonding adhesive, and are therefore preferred as curing agents for epoxy resins in the adhesive film 20.

When the adhesive film 20 contains an epoxy resin and a phenolic resin as its curing agent, the two resins are mixed in a ratio of preferably 0.5 to 2.0 equivalents, more preferably 0.8 to 1.2 equivalents, of hydroxyl groups in the phenolic resin to 1 equivalent of epoxy groups in the epoxy resin. This configuration is preferable for allowing the curing reaction of the epoxy resin and phenolic resin to proceed sufficiently when the adhesive film 20 is cured.

The content of the thermosetting resin in the adhesive film 20 is preferably 5 to 60% by mass, and more preferably 10 to 50% by mass, from the viewpoint of allowing the adhesive film 20 to properly exhibit its function as a thermosetting adhesive.

The thermoplastic resin in the adhesive film 20 serves, for example, as a binder. When the adhesive film 20 has a composition containing a thermosetting resin and a thermoplastic resin, examples of the thermoplastic resin include acrylic resin, natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, polybutadiene resin, polycarbonate resin, thermoplastic polyimide resin, polyamide resin such as 6-nylon and 6,6-nylon, phenoxy resin, saturated polyester resin such as polyethylene terephthalate and polybutylene terephthalate, polyamideimide resin, and fluororesin. The adhesive film 20 may contain one type of thermoplastic resin or two or more types of thermoplastic resin. Acrylic resin is preferable as the thermoplastic resin in the adhesive film 20 because it has few ionic impurities and high heat resistance.

When the adhesive film 20 contains an acrylic resin as a thermoplastic resin, the acrylic resin preferably contains, by mass proportion, monomer units derived from (meth)acrylic acid ester.

(Meth)acrylic acid esters for forming monomer units of acrylic resin, i.e., (meth)acrylic acid esters that are constituent monomers of acrylic resin, include, for example, (meth)acrylic acid alkyl esters, (meth)acrylic acid cycloalkyl esters, and (meth)acrylic acid aryl esters. Examples of such (meth)acrylic acid esters include the (meth)acrylic acid alkyl esters described above as constituent monomers of the acrylic polymer for the adhesive layer 12. One type of (meth)acrylic acid ester may be used as the constituent monomer of the acrylic resin, or two or more types of (meth)acrylic acid esters may be used.

The acrylic resin may contain one or more monomer units derived from other monomers copolymerizable with the (meth)acrylic acid ester, for example, from the viewpoint of improving its cohesive strength or heat resistance. Examples of other copolymerizable monomers for forming the monomer units of the acrylic resin, i.e., other copolymerizable monomers that are constituent monomers of the acrylic resin, include, for example, carboxy group-containing monomers, acid anhydride monomers, hydroxy group-containing monomers, nitrogen-containing monomers, epoxy group-containing monomers, sulfonic acid group-containing monomers, and phosphoric acid group-containing monomers. Specific examples of these monomers include those mentioned above as the constituent monomers of the acrylic polymer for the pressure-sensitive adhesive layer 12.

When the adhesive film 20 has a composition containing a thermoplastic resin with a thermosetting functional group, the thermoplastic resin can be, for example, a thermosetting functional group-containing acrylic resin. The acrylic resin for forming the thermosetting functional group-containing acrylic resin preferably contains the most monomer units derived from (meth)acrylic acid esters in terms of mass ratio. As such (meth)acrylic acid esters, for example, the same (meth)acrylic acid esters as those described above as constituent monomers of the acrylic polymer for the adhesive layer 12 can be used. On the other hand, as thermosetting functional groups for forming the thermosetting functional group-containing acrylic resin, for example, glycidyl groups, carboxy groups, hydroxy groups, and isocyanate groups can be mentioned. Of these, glycidyl groups and carboxy groups can be preferably used. That is, as the thermosetting functional group-containing acrylic resin, glycidyl group-containing acrylic resins and carboxy group-containing acrylic resins can be preferably used. In addition, a curing agent that can react with the thermosetting functional group in the thermosetting functional group-containing acrylic resin is selected according to the type of the thermosetting functional group. When the thermosetting functional group of the thermosetting functional group-containing acrylic resin is a glycidyl group, the curing agent can be the same phenolic resin as described above as the curing agent for epoxy resins.

In order to achieve a certain degree of crosslinking in the adhesive film 20 before it is cured for die bonding, it is preferable to incorporate a polyfunctional compound that can react with the functional groups at the molecular chain ends of the resin components contained in the adhesive film 20 to form bonds as a crosslinking agent in the resin composition for forming the adhesive film. This configuration is suitable for improving the adhesive properties of the adhesive film 20 at high temperatures and for improving the heat resistance. Examples of such crosslinking agents include polyisocyanate compounds. Examples of polyisocyanate compounds include tolylene diisocyanate, diphenylmethane diisocyanate, p-phenylene diisocyanate, 1,5-naphthalene diisocyanate, and adducts of polyhydric alcohols and diisocyanates. The content of the crosslinking agent in the resin composition for forming the adhesive film is preferably 0.05 parts by mass or more per 100 parts by mass of the resin having the functional group capable of reacting with the crosslinking agent to form a bond, from the viewpoint of improving the cohesive strength of the adhesive film 20 to be formed, and is preferably 7 parts by mass or less from the viewpoint of improving the adhesive strength of the adhesive film 20 to be formed. In addition, as the crosslinking agent in the adhesive film 20, other polyfunctional compounds such as epoxy resins may be used in combination with the polyisocyanate compound.

The adhesive film 20 may contain a filler. Adding a filler to the adhesive film 20 is preferable in terms of adjusting the physical properties of the adhesive film 20, such as its elastic modulus, yield strength, and breaking elongation. Examples of the filler include inorganic fillers and organic fillers. The filler may have various shapes, such as spherical, acicular, and flake-like. The adhesive film 20 may contain one type of filler, or two or more types of fillers.

Examples of materials constituting the inorganic filler include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whiskers, boron nitride, crystalline silica, and amorphous silica. Examples of materials constituting the inorganic filler include simple metals such as aluminum, gold, silver, copper, and nickel, as well as alloys, amorphous carbon, and graphite. When the adhesive film 20 contains an inorganic filler, the content of the inorganic filler is preferably 10% by mass or more, and more preferably 20% by mass or more. The content is preferably 50% by mass or less, and more preferably 45% by mass or less.

Examples of materials that can be used for the organic filler include polymethylmethacrylate (PMMA), polyimide, polyamideimide, polyetheretherketone, polyetherimide, and polyesterimide. When the adhesive film 20 contains an organic filler, the content of the organic filler is preferably 2% by mass or more, and more preferably 5% by mass or more. The content is preferably 20% by mass or less, and more preferably 15% by mass or less.

When the adhesive film 20 contains a filler, the average particle size of the filler is preferably 0.005 to 10 μm, more preferably 0.05 to 1 μm. A configuration in which the average particle size of the filler is 0.005 μm or more is suitable for realizing high wettability and adhesion to an adherend such as a semiconductor wafer in the adhesive film 20. A configuration in which the average particle size of the filler is 10 μm or less is suitable for obtaining a sufficient filler addition effect in the adhesive film 20 and ensuring heat resistance. The average particle size of the filler can be determined, for example, using a photometric particle size distribution meter (product name "LA-910", manufactured by Horiba, Ltd.).

The adhesive film 20 may contain a thermosetting catalyst. The incorporation of a thermosetting catalyst into the adhesive film 20 is preferable in order to sufficiently advance the curing reaction of the resin components when curing the adhesive film 20 and to increase the curing reaction rate. Examples of such thermosetting catalysts include imidazole-based compounds, triphenylphosphine-based compounds, amine-based compounds, and trihalogen borane-based compounds. Examples of the imidazole compounds include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino- 6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole. Examples of triphenylphosphine compounds include triphenylphosphine, tri(butylphenyl)phosphine, tri(p-methylphenyl)phosphine, tri(nonylphenyl)phosphine, diphenyltolylphosphine, tetraphenylphosphonium bromide, methyltriphenylphosphonium bromide, methyltriphenylphosphonium chloride, methoxymethyltriphenylphosphonium chloride, and benzyltriphenylphosphonium chloride. The tolylphenylphosphine compounds include compounds having both a triphenylphosphine structure and a triphenylborane structure. Examples of such compounds include tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-triborate, benzyltriphenylphosphonium tetraphenylborate, and triphenylphosphine triphenylborane. Examples of amine compounds include monoethanolamine trifluoroborate and dicyandiamide. Examples of trihalogen borane compounds include trichloroborane. The adhesive film 20 may contain one type of thermosetting catalyst, or two or more types of thermosetting catalysts.

The adhesive film 20 may contain one or more other components as needed. Examples of such other components include a flame retardant, a silane coupling agent, and an ion trapping agent.

The breaking strength of the adhesive film 20 at 25°C is preferably 5 N/10 mm or less, more preferably 3 N/10 mm or less, and even more preferably 1.5 N/10 mm or less. Such a configuration is suitable for reducing the load on the dicing tape 10 and suppressing tearing of the dicing tape 10. In addition, from the viewpoint of appropriate breakability of the semiconductor wafer, the breaking strength is preferably 0.1 N/10 mm or more, more preferably 0.2 N/10 mm or more, and even more preferably 0.5 N/10 mm or more.

The breaking elongation of the adhesive film 20 at 25°C is preferably 100% or less, more preferably 80% or less, even more preferably 50% or less, and most preferably 15% or less. Such a configuration is suitable for reducing the load on the dicing tape 10 and suppressing tearing of the dicing tape 10. From the viewpoint of appropriate breakability of the semiconductor wafer, the breaking elongation is preferably 0.5% or more, more preferably 1% or more, even more preferably 3% or more, and most preferably 5% or more.

The above-described dicing tape X with adhesive film can be manufactured, for example, as follows.

The dicing tape 10 of the dicing tape X with adhesive film can be prepared by providing an adhesive layer 12 on a prepared substrate 11. For example, the resin substrate 11 can be prepared by a film-forming method such as a calendar film-forming method, a casting method in an organic solvent, an inflation extrusion method in a closed system, a T-die extrusion method, a co-extrusion method, or a dry lamination method. The film or substrate 11 after film formation is subjected to a predetermined surface treatment as necessary. In forming the adhesive layer 12, for example, after preparing an adhesive composition for forming the adhesive layer, the composition is first applied onto the substrate 11 or a predetermined separator to form an adhesive composition layer. Examples of the application method of the adhesive composition include roll coating, screen coating, and gravure coating. Next, the adhesive composition layer is dried by heating as necessary, and a crosslinking reaction is caused as necessary. The heating temperature is, for example, 80 to 150°C, and the heating time is, for example, 0.5 to 5 minutes. When the adhesive layer 12 is formed on a separator, the adhesive layer 12 with the separator is attached to the substrate 11, and then the separator is peeled off. This produces the above-mentioned dicing tape 10 having a laminated structure of the substrate 11 and the adhesive layer 12.

In preparing the adhesive film 20 of the dicing tape X with adhesive film, first, an adhesive composition for forming the adhesive film 20 is prepared, and then the composition is applied onto a predetermined separator to form an adhesive composition layer. Examples of the separator include polyethylene terephthalate (PET) film, polyethylene film, polypropylene film, and plastic films and papers whose surfaces are coated with a release agent such as a fluorine-based release agent or a long-chain alkyl acrylate-based release agent. Examples of the application method of the adhesive composition include roll coating, screen coating, and gravure coating. Next, the adhesive composition layer is dried by heating as necessary, and a crosslinking reaction is caused as necessary. The heating temperature is, for example, 70 to 160°C, and the heating time is, for example, 1 to 5 minutes. In this manner, the above-mentioned adhesive film 20 can be prepared in a form accompanied by a separator.

Two or more of the adhesive films 20 obtained above may be further laminated. The two or more adhesive films 20 to be laminated may have the same composition or different compositions. The thicknesses of the two or more adhesive films 20 to be laminated may be the same or different. Lamination of two or more adhesive films 20 can be performed, for example, by laminating the surfaces of the adhesive films 20 with separators obtained above that are not in contact with each other. The lamination temperature is, for example, 40 to 100°C, preferably 60 to 90°C. The lamination pressure (linear pressure) is, for example, 0.05 to 1.00 MPa, preferably 0.1 to 0.8 MPa. The lamination speed is, for example, 1 to 20 mm/s, preferably 5 to 15 mm/s. One of the separators of the laminate of the laminated adhesive films 20 may be peeled off, and another separator-attached adhesive film 20 may be further laminated.

In producing the dicing tape X with adhesive film, the adhesive film 20 with the separator is then punched into a disk shape of a specified diameter, and the adhesive film 20 is then pressed and bonded to the pressure-sensitive adhesive layer 12 side of the dicing tape 10. The bonding temperature is, for example, 30 to 50°C, and preferably 35 to 45°C. The bonding pressure (linear pressure) is, for example, 0.1 to 20 kgf/cm, and preferably 1 to 10 kgf/cm. Next, the dicing tape 10 bonded to the adhesive film 20 in this manner is punched into a disk shape of a specified diameter so that the center of the dicing tape 10 and the center of the adhesive film 20 coincide.

In this manner, the dicing tape X with adhesive film can be produced. The dicing tape X with adhesive film may have a separator (not shown) on the adhesive film 20 side, covering at least the adhesive film 20. The separator is an element for protecting the adhesive film 20 and the pressure-sensitive adhesive layer 12 from exposure, and is peeled off from the film when the dicing tape X with adhesive film is used.

Figures 3 to 9 show an example of a semiconductor device manufacturing method in which the above-described adhesive film-attached dicing tape X is used.

In this semiconductor device manufacturing method, first, as shown in Figures 3(a) and 3(b), a modified region 30a is formed in a semiconductor wafer W. The semiconductor wafer W has a first surface Wa and a second surface Wb. Various semiconductor elements (not shown) are already fabricated on the first surface Wa of the semiconductor wafer W, and wiring structures and the like (not shown) necessary for the semiconductor elements are already formed on the first surface Wa. In this process, a wafer processing tape T1 having an adhesive surface T1a is bonded to the first surface Wa of the semiconductor wafer W, and then, with the semiconductor wafer W held on the wafer processing tape T1, a laser beam focused on the inside of the wafer is irradiated on the semiconductor wafer W along its planned division line from the side opposite to the wafer processing tape T1, and a modified region 30a is formed in the semiconductor wafer W due to ablation caused by multiphoton absorption. The modified region 30a is a weakened region for separating the semiconductor wafer W into semiconductor chip units. A method for forming modified regions 30a on planned division lines in a semiconductor wafer by irradiating the wafer with laser light is described in detail, for example, in Japanese Patent Application Laid-Open No. 2002-192370. In this embodiment, the laser light irradiation conditions are appropriately adjusted, for example, within the following ranges:
<Laser light irradiation conditions>
(A) Laser light Laser source Semiconductor laser pumped Nd:YAG laser Wavelength 1064 nm
Laser light spot cross-sectional area: 3.14× ^{10-8 cm2}
Oscillation type: Q-switched pulse Repetition frequency: 100 kHz or less Pulse width: 1 μs or less Output: 1 mJ or less Laser light quality: TEM00
Polarization characteristics: Linearly polarized (B) Condenser lens Magnification: 100x or less NA 0.55
Transmittance to the laser light wavelength: 100% or less (C) Movement speed of the mounting table on which the semiconductor substrate is placed: 280 mm/sec or less

Next, while the semiconductor wafer W is held on the wafer processing tape T1, the semiconductor wafer W is thinned by grinding from the second surface Wb until it reaches a predetermined thickness, thereby forming a semiconductor wafer 30A that can be diced into a plurality of semiconductor chips 31, as shown in FIG. 3(c) (wafer thinning process). The grinding can be performed using a grinding device equipped with a grinding wheel.

Next, as shown in FIG. 4(a), the semiconductor wafer 30A held by the wafer processing tape T1 is bonded to the adhesive film 20 side of the adhesive film-attached dicing tape X. After this, as shown in FIG. 4(b), the wafer processing tape T1 is peeled off from the semiconductor wafer 30A.

Next, a ring frame 41 made of, for example, SUS is attached to the adhesive layer 12 around the adhesive film 20 in the dicing tape X with adhesive film, and then, as shown in FIG. 5(a), the dicing tape X with adhesive film and the semiconductor wafer 30A are fixed to the holder 42 of the expansion device via the ring frame 41.

Next, a first expansion process (cool expansion process) under a predetermined low-temperature condition is performed as shown in FIG. 5(b), in which the semiconductor wafer 30A is singulated into a plurality of semiconductor chips 31, and the adhesive film 20 of the dicing tape X with adhesive film is broken into small pieces of adhesive film 21 to obtain the semiconductor chips 31 with adhesive film. In this process, a hollow cylindrical push-up member 43 provided in the expansion device is raised while abutting against the dicing tape 10 on the lower side of the dicing tape X with adhesive film in the figure, and the dicing tape 10 of the dicing tape X with adhesive film attached to the semiconductor wafer 30A is expanded so as to be stretched in two-dimensional directions including the radial and circumferential directions of the semiconductor wafer 30A.

This cool expansion process is performed under conditions that generate a tensile stress of, for example, 15 to 32 MPa in the dicing tape 10. By controlling the tensile stress of the dicing tape 10 in the cool expansion process to within this range, the dicing tape 10 does not tear, and the semiconductor wafer 30A can be successfully cleaved in the modified region 30a.

The temperature conditions in the cool expansion process are, for example, 0°C or lower, preferably -20 to -5°C, more preferably -15 to -5°C, more preferably -15°C. By controlling the temperature conditions in the cool expansion process within this range, the semiconductor wafer 30A can be successfully cleaved in the modified region 30a without the dicing tape 10 tearing.

The expansion speed in the cool expansion process (the speed at which the push-up member 43 rises) is, for example, 1 to 400 mm/sec. By controlling the expansion speed within this range, the semiconductor wafer 30A can be successfully cleaved in the modified region 30a without tearing the dicing tape 10.

The expansion amount in the cool expansion process is, for example, 3 to 16 mm. By controlling the expansion amount within this range, the semiconductor wafer 30A can be successfully cleaved in the modified region 30a without the dicing tape 10 tearing.

These conditions regarding expansion in the cool expansion process also apply to the cool expansion process described below.

By such a cool expanding process, the adhesive film 20 of the dicing tape X with adhesive film is cut into small pieces of adhesive film 21 to obtain semiconductor chips 31 with adhesive film. Specifically, in this process, cracks are formed in the weak modified area 30a of the semiconductor wafer 30A, and the semiconductor wafer 30A is divided into individual semiconductor chips 31. At the same time, in this process, in the adhesive film 20 that is in contact with the adhesive layer 12 of the dicing tape 10 to be expanded, deformation is suppressed in each area where each semiconductor chip 31 of the semiconductor wafer 30A is in contact, while in the area facing the crack formation area of the wafer, tensile stress generated in the dicing tape 10 acts without such deformation suppression action. As a result, the adhesive film 20 is cut at the area facing the crack formation area between the semiconductor chips 31. After this process, as shown in FIG. 5(c), the push-up member 43 is lowered and the expanded state of the dicing tape 10 is released.

Next, the second expansion process (room temperature expansion process) is performed as shown in Figures 6(a) and 6(b), and the distance between the semiconductor chips 31 with adhesive film is expanded. In this process, the table 44 equipped in the expansion device is raised, and the dicing tape 10 of the dicing tape X with adhesive film is expanded. The table 44 is capable of vacuum-adsorbing the workpiece by applying negative pressure to the workpiece on the table surface. The temperature condition in the second expansion process is, for example, 10°C or higher, and preferably 15 to 30°C. The expansion speed in the second expansion process (the speed at which the table 44 rises) is, for example, 0.1 to 10 mm/sec. The expansion amount in the second expansion process is, for example, 3 to 16 mm. In this process, the dicing tape 10 is expanded by raising the table 44 (thereby widening the distance between the semiconductor chips 31 with adhesive film), and then the table 44 vacuum-adsorbs the dicing tape 10. Then, while maintaining the suction by the table 44, the table 44 is lowered with the workpiece as shown in FIG. 6(c). In this embodiment, in this state, the periphery of the semiconductor wafer 30A (the portion outside the semiconductor chip 31 holding area) of the dicing tape X with adhesive film is heated and shrunk (heat shrink process). After that, the vacuum suction state by the table 44 is released. Through the heat shrink process, the dicing tape X with adhesive film is in a state in which a predetermined degree of tension can act on the wafer bonding area that was stretched and relaxed in the first expansion process and the second expansion process described above, and the separation distance between the semiconductor chips 31 is fixed even after the vacuum suction state is released.

7, the adhesive layer 12 is irradiated with ultraviolet light to promote ultraviolet curing and reduce its adhesive strength (ultraviolet light irradiation step). Specifically, for example, a high-pressure mercury lamp is used to irradiate the entire adhesive layer 12 with ultraviolet light R from the substrate 11 side of the dicing tape 10. The cumulative amount of irradiation is, for example, 50 to 500 mJ/ ^cm2 , and preferably 100 to 300 mJ/ ^cm2 .

In this semiconductor device manufacturing method, next, a cleaning process is performed as necessary to clean the semiconductor chip 31 side of the dicing tape X with adhesive film using a cleaning liquid such as water, and then a pick-up process is performed using a dicing bonding device equipped with both a pick-up mechanism and an expand mechanism.

Specifically, as shown in FIG. 8(a), first, the dicing tape X with adhesive film or the dicing tape 10 with multiple semiconductor chips 31 is fixed to the holder 45 of the die bonding device via the ring frame 41, and a hollow cylindrical push-up member 46 provided in the device is raised up while abutting against the dicing tape 10 on the lower side of the dicing tape 10 in the figure. This causes the dicing tape 10 to expand so that it is stretched in two dimensions including the radial and circumferential directions (pre-pickup expansion).

Next, as shown in FIG. 8(b), the semiconductor chip 31 with the adhesive film is picked up from the dicing tape 10. For example, for the semiconductor chip 31 with the adhesive film to be picked up, the pin members 47 of the pick-up mechanism are raised on the lower side of the dicing tape 10 in the figure, pushed up through the dicing tape 10, and then sucked and held by the suction jig 48. In this pick-up, the pushing-up speed of the pin members 47 is, for example, 1 to 100 mm/sec, and the pushing-up amount of the pin members 47 is, for example, 50 to 3000 μm.

Next, as shown in FIG. 9(a), the picked-up semiconductor chip 31 with adhesive film is temporarily attached to a predetermined adherend 51 via the adhesive film 21. Examples of the adherend 51 include a lead frame, a TAB (Tape Automated Bonding) film, and a wiring board.

Next, as shown in FIG. 9(b), the electrode pads (not shown) of the semiconductor chip 31 and the terminals (not shown) of the adherend 51 are electrically connected via bonding wires 52 (wire bonding process). The electrode pads of the semiconductor chip 31 and the terminals of the adherend 51 are connected to the bonding wires 52 by ultrasonic welding accompanied by heating, so as not to thermally harden the adhesive film 21. The bonding wires 52 may be, for example, gold wires, aluminum wires, or copper wires. The wire heating temperature in wire bonding is, for example, 80 to 250°C. The heating time is from a few seconds to a few minutes.

9(c), the semiconductor chip 31 is sealed with a sealing resin 53 for protecting the semiconductor chip 31 and the bonding wires 52 on the adherend 51 (sealing process). In this process, the adhesive film 21 is thermally cured. In this process, the sealing resin 53 is formed, for example, by a transfer molding technique using a metal mold. The sealing resin 53 can be made of, for example, an epoxy resin. In this process, the heating temperature for forming the sealing resin 53 is, for example, 165 to 185°C, and the heating time is, for example, 60 seconds to several minutes. If the curing of the sealing resin 53 does not progress sufficiently in this process (sealing process), a post-curing process is performed after this process to completely cure the sealing resin 53. Even if the adhesive film 21 is not completely thermally cured in the sealing process, the adhesive film 21 can be completely thermally cured together with the sealing resin 53 in the post-curing process. In the post-curing process, the heating temperature is, for example, 165 to 185°C, and the heating time is, for example, 0.5 to 8 hours.

In this manner, a semiconductor device can be manufactured.

In this semiconductor device manufacturing method, instead of the above-described configuration in which the semiconductor wafer 30A is bonded to the dicing tape X with the adhesive film, the semiconductor wafer 30B produced as follows may be bonded to the dicing tape X with the adhesive film.

In the manufacture of the semiconductor wafer 30B, first, as shown in FIG. 10(a) and FIG. 10(b), a dividing groove 30b is formed in the semiconductor wafer W (dividing groove forming process). The semiconductor wafer W has a first surface Wa and a second surface Wb. Various semiconductor elements (not shown) are already fabricated on the first surface Wa of the semiconductor wafer W, and wiring structures (not shown) necessary for the semiconductor elements are already formed on the first surface Wa. In this process, after a wafer processing tape T2 having an adhesive surface T2a is attached to the second surface Wb of the semiconductor wafer W, a dividing groove 30b of a predetermined depth is formed on the first surface Wa of the semiconductor wafer W using a rotating blade of a dicing device or the like while the semiconductor wafer W is held by the wafer processing tape T1. The dividing groove 30b is a gap for separating the semiconductor wafer W into semiconductor chip units (the dividing groove 30b is shown in the drawings as a schematic thick line).

Next, as shown in FIG. 10(c), the wafer processing tape T3 having the adhesive surface T3a is bonded to the first surface Wa of the semiconductor wafer W, and the wafer processing tape T2 is peeled off from the semiconductor wafer W.

10(d), the semiconductor wafer W is held on the wafer processing tape T3, and is then thinned by grinding from the second surface Wb until it reaches a predetermined thickness (wafer thinning process). In this embodiment, this wafer thinning process forms a semiconductor wafer 30B that can be diced into a plurality of semiconductor chips 31. Specifically, the semiconductor wafer 30B has a portion (connecting portion) that connects the portions of the wafer that will be diced into a plurality of semiconductor chips 31 on the second surface Wb side. The thickness of the connecting portion in the semiconductor wafer 30B, that is, the distance between the second surface Wb of the semiconductor wafer 30B and the tip of the dividing groove 30b on the second surface Wb side, is, for example, 1 to 30 μm. The semiconductor wafer 30B thus produced may be attached to a dicing tape X with an adhesive film instead of the semiconductor wafer 30A, and the processes described above with reference to FIGS. 5 to 9 may then be carried out.

11(a) and 11(b) specifically show the first expanding process (cool expanding process) performed after the semiconductor wafer 30B is bonded to the dicing tape X with adhesive film. In this process, a hollow cylindrical push-up member 43 provided in the expanding device is raised in contact with the dicing tape 10 at the lower side of the dicing tape X with adhesive film in the figure, and the dicing tape 10 of the dicing tape X with adhesive film bonded to the semiconductor wafer 30B is expanded so as to be stretched in two-dimensional directions including the radial and circumferential directions of the semiconductor wafer 30B. This cool expanding process causes the semiconductor wafer 30B to be broken at thin and easily cracked parts, resulting in individualization into semiconductor chips 31. At the same time, in this process, deformation is suppressed in the areas where the semiconductor chips 31 are in contact with the adhesive film 20 that is in contact with the adhesive layer 12 of the expanded dicing tape 10, while the tensile stress generated in the dicing tape 10 acts on the areas facing the dividing grooves between the semiconductor chips 31 without such deformation suppression. As a result, the areas of the adhesive film 20 facing the dividing grooves between the semiconductor chips 31 are broken. The semiconductor chips 31 with the adhesive film thus obtained are subjected to the pickup process described above with reference to FIG. 8, and then are subjected to the mounting process in the semiconductor device manufacturing process.

In the present semiconductor device manufacturing method, instead of the wafer thinning step described above with reference to FIG. 10(d), a wafer thinning step shown in FIG. 12 may be performed. After the process described above with reference to FIG. 10(c), in the wafer thinning step shown in FIG. 12, the semiconductor wafer W is held on the wafer processing tape T3, and the wafer is thinned by grinding from the second surface Wb until it reaches a predetermined thickness, and a semiconductor wafer divided body 30C including a plurality of semiconductor chips 31 and held on the wafer processing tape T3 is formed. In this step, a method (first method) in which the wafer is ground until the dividing groove 30b itself is exposed on the second surface Wb side may be adopted, or a method (second method) in which the wafer is ground from the second surface Wb side to before it reaches the dividing groove 30b, and then a crack is generated between the dividing groove 30b and the second surface Wb by the action of the pressing force from the rotating grindstone to the wafer to form the semiconductor wafer divided body 30C may be adopted. Depending on the method used, the depth from the first surface Wa of the dividing groove 30b formed as described above with reference to Figures 10(a) and 10(b) is appropriately determined. In Figure 12, the dividing groove 30b that has been subjected to the first method or the dividing groove 30b that has been subjected to the second method and the cracks connected thereto are shown in bold lines. The semiconductor wafer divided body 30C thus produced may be attached to a dicing tape X with an adhesive film instead of the semiconductor wafer 30A or semiconductor wafer 30B, and the steps described above with reference to Figures 5 to 9 may be carried out.

13(a) and 13(b) specifically show the first expanding step (cool expanding step) performed after the semiconductor wafer divided body 30C is bonded to the dicing tape X with adhesive film. In this step, a hollow cylindrical push-up member 43 provided in the expanding device is raised while abutting against the dicing tape 10 on the lower side of the dicing tape X with adhesive film in the figure, and the dicing tape 10 of the dicing tape X with adhesive film bonded to the semiconductor wafer divided body 30C is expanded so as to be stretched in two-dimensional directions including the radial and circumferential directions of the semiconductor wafer divided body 30C. By this cool expansion process, in the adhesive film 20 that is in contact with the adhesive layer 12 of the expanded dicing tape 10, deformation is suppressed in each region where each semiconductor chip 31 of the semiconductor wafer division body 30C is in contact, while the tensile stress generated in the dicing tape 10 acts on the portion facing the dividing groove 30b between the semiconductor chips 31 without such deformation suppression effect. As a result, the portion of the adhesive film 20 facing the dividing groove 30b between the semiconductor chips 31 is broken. The semiconductor chip 31 with the adhesive film obtained in this way is subjected to the pickup process described above with reference to FIG. 8, and then is subjected to the mounting process in the semiconductor device manufacturing process.

[Examples 1 to 5, Comparative Examples 1 to 3]
<Preparation of dicing tape>
In a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer, and a stirrer, 2-ethylhexyl acrylate (2EHA; homopolymer Tg: -70°C), 2-hydroxyethyl acrylate (HEA; homopolymer Tg: -15°C), and acryloylmorpholine (ACMO; homopolymer Tg: 145°C) were used in the ratios (molar parts) shown in Table 1, and a mixture (base 55 wt%) containing benzoyl peroxide as a polymerization initiator and toluene as a polymerization solvent was stirred under a nitrogen atmosphere at 60°C for 10 hours (polymerization reaction). In this mixture, the content of benzoyl peroxide was 0.3 parts by mass relative to 100 parts by mass of the monomer components, and the content of toluene was 60 parts by mass relative to 100 parts by mass of the monomer components. A polymer solution containing an acrylic polymer P ₁ was obtained by this polymerization reaction. Table 1 shows the glass transition temperature (Tg) of the acrylic polymer P ₁ calculated from the monomer component composition by the Fox formula.

Next, a mixture containing the polymer solution containing the acrylic polymer _P1 , 2-methacryloyloxyethyl isocyanate (MOI), and dibutyltin dilaurate as an addition reaction catalyst was stirred in an air atmosphere at 50°C for 60 hours (addition reaction). In the reaction solution, the blending amount of MOI was 1.4 parts by mass relative to ₁₀₀ parts by mass of the acrylic polymer P1. In addition, in the reaction solution, the blending amount of dibutyltin dilaurate was 0.1 parts by mass relative to 100 parts by mass of the acrylic polymer _P1 . By this addition reaction, a polymer solution containing an acrylic polymer _P2 having a methacryloyl group in its side chain was obtained. Next, 1.1 parts by mass of _a polyisocyanate compound (trade name "Coronate L", manufactured by Tosoh Corporation) and 3 parts by mass of a photopolymerization initiator (trade name "Irgacure 184", manufactured by BASF Corporation) were added to the polymer solution relative to 100 parts by mass of the acrylic polymer P 2 and mixed, and the mixture was diluted with toluene so that the viscosity of the mixture at room temperature was 500 mPa·s to obtain an adhesive solution. Next, the adhesive solution was applied to the silicone release-treated surface of a PET separator having a silicone release-treated surface using an applicator to form a coating film, and this coating film was heated and dried at 120°C for 2 minutes to form an adhesive layer with a thickness of 10 μm on the PET separator. Next, a laminator was used to attach a substrate made of ethylene-vinyl acetate copolymer (EVA) (trade name "RB0103", thickness 125 μm, manufactured by Kurabo Industries Co., Ltd.) to the exposed surface of the adhesive layer at room temperature. In this manner, dicing tapes of Examples 1 to 5 and Comparative Examples 1 to 3 were produced.

Preparation of adhesive film
An adhesive composition solution having a concentration of 40 to 50% by weight was prepared by dissolving 15 parts by mass of an acrylic resin (product name "TEISAN RESIN SG-280", manufactured by Nagase Chemtec Corporation), 29 parts by mass of an epoxy resin (product name "EPPN 501HY", manufactured by Nippon Kayaku Co., Ltd.), 16 parts by mass of a phenolic resin (product name "HF-1M", manufactured by Meiwa Kasei Co., Ltd.), and 40 parts by mass of an inorganic filler (product name "SE-2050MCV", spherical silica, manufactured by Admatechs Co., Ltd.) in methyl ethyl ketone.
This adhesive composition solution was applied onto a PET separator made of a 50 μm-thick polyethylene terephthalate film treated with silicone release as a release liner, and then dried for 2 minutes at 130° C. to prepare an adhesive film having a thickness of 60 μm. The 60 μm adhesive films thus prepared were bonded together to prepare an adhesive film having a thickness of 120 μm (lamination conditions: 80° C., 0.15 MPa, 10 mm/s).

<Preparation of dicing tape with adhesive film>
The above-mentioned adhesive film with the PET separator was punched into a disk shape with a diameter of 330 mm. Next, the PET separator was peeled off from the adhesive film and the PET separator was peeled off from the above-mentioned dicing tape, and then the pressure-sensitive adhesive layer exposed in the dicing tape and the surface of the adhesive film exposed by peeling off the PET separator were bonded together using a roll laminator. In this bonding, the bonding speed was 10 mm/min, the temperature condition was 25°C, and the pressure condition was 0.15 MPa. Then, ultraviolet light was irradiated only on the bonded portion of the adhesive film (300 mJ/cm ² ). In this manner, dicing tapes with adhesive films of Examples 1 to 5 and Comparative Examples 1 to 3 having a laminated structure including a dicing tape and an adhesive film were prepared.

<Measurement of breaking elongation and breaking strength of dicing tape>
The breaking elongation and breaking strength of each dicing tape of Examples 1 to 5 and Comparative Examples 1 to 3 were measured as follows. A dicing tape test piece (width 10 mm x length 100 mm) was cut out from the dicing tape. A required number of dicing tape test pieces were prepared for each of the dicing tapes of Examples 1 to 5 and Comparative Examples 1 to 3. A tensile test was then performed on the dicing tape test piece using a tensile tester (product name "Autograph AGS-50NX", manufactured by Shimadzu Corporation), and the breaking elongation and breaking strength of the dicing tape test piece stretched at a predetermined tensile speed were measured. In the tensile test, the initial chuck distance was 50 mm, the temperature condition was -15°C, and the tensile speed was 300 mm/min. The measurement results are shown in Table 1.

<Measurement of breaking elongation and breaking strength of adhesive film>
The breaking elongation and breaking strength of each adhesive film of Examples 1 to 5 and Comparative Examples 1 to 3 were measured as follows. First, adhesive film test pieces (width 10 mm x length 40 mm) were cut out. The required number of adhesive film test pieces were prepared for each adhesive film of Examples 1 to 5 and Comparative Examples 1 to 3. Then, a tensile tester (product name "Autograph AGS-50NX", manufactured by Shimadzu Corporation) was used to perform a tensile test on the adhesive film test pieces, and the breaking elongation and breaking strength of the adhesive film test pieces stretched at a predetermined tensile speed were measured. In the tensile test, the initial chuck distance was 10 mm, the temperature condition was 25°C, and the tensile speed was 300 mm/min. The measurement results are shown in Table 1.

<Evaluation of dicing tape tearing and cleavability>
A 12-inch wafer with a chip size of 10 x 10 mm and a cutting line (blade half cut; width 20 μm, depth 100 μm) was back-ground to a thickness of 40 μm, and was bonded to the dicing tape with adhesive film prepared in Examples 1 to 5 and Comparative Examples 1 to 3 (wafer bonding temperature: 70°C, speed 10 mm/s).
Thereafter, the semiconductor wafer and adhesive film were cut using a die separator (product name "Die Separator DDS2300", manufactured by Disco Corporation), and the dicing sheet was thermally shrunk to evaluate the tearing and cuttability of the dicing tape.
First, the semiconductor wafer was cleaved in a cool expander unit under the conditions of an expansion temperature of −15° C., an expansion speed of 300 mm/sec, and an expansion amount of 14 mm.
Thereafter, the dicing tape was evaluated for tearing. Those in which no tearing occurred were rated ◯, and those in which tearing occurred were rated X.
The fracture rate of the semiconductor wafer was evaluated as ◯ when it was 80% or more, ⊚ when it was 90% or more, and x when it was less than 80%. The evaluation results are shown in Table 1.

X Dicing tape with adhesive film 10 Dicing tape 11 Substrate 12 Pressure-sensitive adhesive layer 20, 21 Adhesive film W, 30A, 30B Semiconductor wafer 30C Semiconductor wafer divided body 30a Modified region 30b Dividing groove 31 Semiconductor chip

Claims (7)

A dicing tape having a laminated structure including a substrate and a pressure-sensitive adhesive layer ;
A dicing tape with an adhesive film, the dicing tape having an adhesive film releasably adhered to the pressure-sensitive adhesive layer of the dicing tape ,
The pressure-sensitive adhesive layer contains a base polymer having a glass transition temperature of −43° C. or lower,
The dicing tape has a breaking elongation of 300% or more and 414% or less at −15° C.,
A dicing tape with an adhesive film, wherein the adhesive film has a breaking elongation of 15% or less at 25°C . The dicing tape with an adhesive film according to claim 1 , wherein the base polymer is an acrylic polymer. 3. The dicing tape with adhesive film according to claim 1, wherein the pressure-sensitive adhesive layer has a thickness of 5 μm or more and 40 μm or less. 4. The dicing tape with adhesive film according to claim 1, wherein the dicing tape has a breaking strength of 15 N/10 mm or more at -15°C. The base polymer contains, as monomer units, a low glass transition temperature monomer having a homopolymer glass transition temperature of less than −10° C. and a high glass transition temperature monomer having a homopolymer glass transition temperature of −10° C. or higher;
The dicing tape with an adhesive film according to any one of claims 1 to 4 , wherein the molar ratio of the low glass transition temperature monomer to the high glass transition temperature monomer (the molar ratio of the low glass transition temperature monomer/the high glass transition temperature monomer) is 5 or more and 85/6 or less . 6. The dicing tape with adhesive film according to claim 1 , wherein the adhesive film has a breaking strength of 5 N/10 mm or less at 25°C. The dicing tape with adhesive film according to any one of claims 1 to 6 , which is used in a semiconductor wafer cleaving step.

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