JP4303705B2 - Adhesive film for semiconductor and semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive film for a semiconductor use capable of an adhesion at a low temperature of a semiconductor element and a support part for mounting the semiconductor element like a lead frame or the like. <P>SOLUTION: The adhesive film for the semiconductor use consists of (A) a thermoplastic resin, (B) a epoxy resin having a softening point over 40&deg;C and under 70&deg;C, (C) the epoxy resin having a softening point over 70&deg;C and under 100&deg;C, and (D) the resin composition containing a phenol resin having a softening point over 80&deg;C and under 130&deg;C. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to an adhesive film for a semiconductor and a semiconductor device using the same.

In recent years, there has been an increasing demand for higher density and higher integration of semiconductor devices in response to higher functions of electronic devices, and semiconductor packages have been increasing in capacity and density.
In order to meet such requirements, for example, a lead-on-chip (LOC) structure in which a lead is bonded onto a semiconductor element is employed.

  However, since the semiconductor element and the lead frame are bonded in the LOC structure, the bonding reliability at the bonded portion greatly affects the reliability of the semiconductor package.

Conventionally, a paste-like adhesive has been used for bonding a semiconductor element and a lead frame.
However, it is difficult to apply an appropriate amount of paste adhesive, and the adhesive sometimes protrudes from the semiconductor element.

  For example, in the LOC structure, a film adhesive in which an adhesive is applied to a heat resistant substrate such as a hot-melt adhesive film using a polyimide resin has been used (for example, see Patent Document 1).

  However, since the hot-melt adhesive film needs to be bonded at a high temperature, it may cause thermal damage to a high-density semiconductor element and lead frame.

  Particularly in recent semiconductor packages, the chip is stacked in multiple stages on the chip, thereby realizing a reduction in size, thickness and capacity of the package. In such packages, the use of organic substrates such as bismaleimide-triazine substrates and polyimide substrates instead of lead frames is increasing. With the increase in organic substrates, package cracking due to moisture absorption inside the package during infrared reflow for soldering the package has become a technical problem, and it has been found that the contribution of the semiconductor element adhesive is particularly significant.

However, the organic substrate has poor heat resistance compared to the lead frame, and further with the thinning of the package, the thinning of the chip has progressed, and the warping of the chip becomes significant at the past high temperature application temperature, There is an increasing demand for a film adhesive that can be thermocompression bonded at a lower temperature than ever before. As such a film adhesive, a hot melt type adhesive film made of a mixture of a thermoplastic resin and a thermosetting resin is used.

JP-A-6-264035 JP 2000-104040 A JP 2002-121530 A

However, the prior art described in the above literature has room for improvement in the following points.
First, in Patent Documents 2 and 3, a polyimide resin is used as a thermoplastic resin and an epoxy resin is used as a thermosetting resin. Such an adhesive film is excellent in heat resistance and reliability, Because the melt viscosity decreases for the first time in the state and the minimum melt viscosity is high, the wettability at low temperature is insufficient, making it difficult to apply at low temperature, and the chip is thin and stacked in multiple layers It had the problem that it was difficult to apply.
Second, in order to improve the wettability at low temperature, a method using a thermoplastic resin having a low glass transition temperature is also conceivable. However, when such a resin is used, the adhesive film is easily stretched at room temperature, and a transport roll. When the film is transported at, the problem that the film stretches occurs.
The present invention has been made in view of the above circumstances, and its purpose is to bond a semiconductor element and a support member for mounting a semiconductor element such as a lead frame or an organic substrate, thereby achieving low-temperature adhesion and workability. The object is to provide an excellent adhesive film for a semiconductor.

The first adhesive film for a semiconductor according to the present invention is:
(A) An adhesive film for semiconductor composed of a resin composition containing a thermoplastic resin, an epoxy resin, and a phenol resin,
The epoxy resin be one that is substantially composed of a solid epoxy resin, (B) a softening point 40 ° C. or higher 70 ° C. less than the epoxy resin, and (C) a softening point below 100 ° C. 70 ° C. or more epoxy The resin contains a resin , and the phenol resin is (D) an adhesive film for a semiconductor which is a phenol resin having a softening point of 80 ° C. or higher and 130 ° C. or lower.

The 1st adhesive film for semiconductors of this invention mix | blends the epoxy resin component comprised substantially with the solid epoxy resin from which a softening point differs, and limits the softening point of a phenol resin to a fixed temperature range. For this reason, the melt viscosity at low temperature is kept low and the tack of the film is reduced, so that the workability is excellent.

Moreover, the second adhesive film for a semiconductor according to the present invention is:
An adhesive film for a semiconductor containing an epoxy resin, wherein the epoxy resin is substantially composed of a solid epoxy resin,
(i) The value when evaluated by the probe tack method at 25 ° C. is 0 gf / 5 mmφ or more and 20 gf / 5 mmφ or less, and
(ii) When the temperature is raised from 25 ° C. at a rate of temperature increase of 10 ° C./min, the melt viscosity is 500 [Pa · s] or more and 2000 [Pa · s] or less in the region of 100 ° C. or more and 180 ° C. or less. It is a feature.

  In conventional adhesive films for semiconductors, it has been difficult to achieve both the configurations (i) and (ii) of the present invention. By satisfying the constitutions (i) and (ii), it is possible to realize the characteristics that the melt viscosity at a low temperature is kept low and the tack of the film is reduced and the workability is excellent. Such an adhesive film for a semiconductor includes, for example, (A) a thermoplastic resin, (B) an epoxy resin having a softening point of 40 ° C. or higher and lower than 70 ° C., (C) an epoxy resin having a softening point of 70 ° C. or higher and 100 ° C. or lower, and (D) It is obtained by a resin composition containing a phenol resin having a softening point of 80 ° C or higher and 130 ° C or lower.

  Moreover, the semiconductor device in this invention is related with the semiconductor device which has the structure which adhere | attached the semiconductor element and the to-be-adhered member using the adhesive film for semiconductors of this invention. By using the semiconductor adhesive film of the present invention, a highly reliable semiconductor device can be manufactured.

  According to the present invention, a semiconductor element and a support member for mounting a semiconductor element such as a lead frame and an organic substrate can be bonded, and low temperature adhesion and workability, particularly workability when a film is transported by a transport roll. An excellent adhesive film for a semiconductor can be provided.

Hereinafter, the 1st adhesive film for semiconductors of this invention is demonstrated.
The first adhesive film for a semiconductor of the present invention includes (A) a thermoplastic resin, (B) an epoxy resin having a softening point of 40 ° C. or higher and lower than 70 ° C., and (C) an epoxy resin having a softening point of 70 ° C. or higher and 100 ° C. or lower. (D) It is comprised with the resin composition containing the phenol resin whose softening point is 80 degreeC or more and 130 degrees C or less.

  Hereinafter, each component of the 1st adhesive film for semiconductors of this invention is demonstrated.

The (A) thermoplastic resin used in the present invention means a polymer resin having thermoplasticity and a linear chemical structure.
Specific examples include polyimide resins such as polyimide resins and polyetherimide resins, polyamide resins such as polyamide resins and polyamideimide resins, and acrylic resins such as acrylic ester copolymers.
Among these, acrylic resins are preferable. Since the acrylic resin has a low glass transition temperature, the initial adhesion can be improved.
Here, the initial adhesion refers to adhesion in an initial stage when the semiconductor element and the support member are bonded with the semiconductor adhesive film, that is, adhesion before the semiconductor adhesive film is cured.

The acrylic resin means a resin having acrylic acid and its derivatives as main monomers. Specifically, polymers such as acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, etc., methacrylates such as methyl methacrylate, ethyl methacrylate, acrylonitrile, acrylamide, and other monomers And the like.
An acrylic resin (particularly an acrylic acid copolymer) having a compound having an epoxy group, a hydroxyl group, a carboxyl group, a nitrile group, or the like is preferable. Thereby, the adhesiveness to adherends, such as a semiconductor element, can be improved more. Specific examples of the compound having a functional group include glycidyl methacrylate having a glycidyl ether group, hydroxy methacrylate having a hydroxyl group, carboxy methacrylate having a carboxyl group, and acrylonitrile having a nitrile group.
Among these, an acrylate copolymer containing a compound having a nitrile group is particularly preferable. Thereby, the adhesiveness to a to-be-adhered body can be improved especially.

  The content of the compound having a functional group is not particularly limited, but is preferably 0.5% by weight or more and 40% by weight or less, and particularly preferably 5% by weight or more and 30% by weight or less of the entire acrylic resin. If the content is too low, the effect of improving the adhesion may be reduced, and if the content is too high, the adhesive strength is too strong and the effect of improving workability may be reduced.

  (A) Although the weight average molecular weight of a thermoplastic resin, especially acrylic resin is not specifically limited, 100,000 or more are preferable and 150,000-1 million are especially preferable. When the weight average molecular weight is within this range, the film forming property of the adhesive film for a semiconductor can be improved. Further, when the weight average molecular weight is within this range, even when the thermoplastic resin contains a thermosetting functional group, the resin alone hardly exhibits the curing behavior by heat treatment.

  (A) Although the glass transition temperature of a thermoplastic resin is not specifically limited, -20 degreeC or more and 60 degrees C or less are preferable, and -10 degreeC or more and 50 degrees C or less are especially preferable. If the glass transition temperature is too low, the adhesive force of the adhesive film for semiconductors may become strong and the effect of improving workability may be reduced. If the glass transition temperature is too high, the effect of improving low-temperature adhesion may be reduced.

The epoxy resins (B) and (C) used in the present invention are any of monomers, oligomers and polymers. For example, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, aliphatic type epoxy resin, stilbene type epoxy resin, orthocresol novolak type epoxy resin, phenol novolak type epoxy resin, Modified phenol type epoxy resin, triphenol methane type epoxy resin, alkyl modified triphenol methane type epoxy resin, triazine nucleus-containing epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, dicyclopentadiene modified phenol type epoxy resin, glycidyl Examples include amine type epoxy resins.
The illustration of the epoxy resin is an example of an epoxy resin that can take a solid form. Depending on the molecular weight, some may take the form of a liquid as well as a solid. In the present invention, solid epoxy resins are selected as (B) and (C).

Specific examples of the (B) epoxy resin having a softening point of 40 ° C. or higher and lower than 70 ° C. used in the present invention include orthocresol novolac type epoxy resin, phenol novolac type epoxy resin, modified phenol type epoxy resin, naphthalene type epoxy resin, Dicyclopentadiene type epoxy resin, glycidylamine type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, aliphatic type epoxy resin, stilbene type epoxy resin, bisphenol A novolak type epoxy resin and the like. Among these epoxy resins, there is no particular limitation as long as it is compatible with the acrylate copolymer.
Examples of the epoxy resin include epoxy resins having various softening points. In the present invention, a specific epoxy resin having a softening point of 40 ° C. or higher and lower than 70 ° C. is appropriately selected from these epoxy resins. It can be selected and used.
When the softening point is lower than 40 ° C., the adhesive film for a semiconductor is tacky at room temperature, thereby reducing the workability in the semiconductor assembly process. On the other hand, when the temperature is higher than 100 ° C., wettability is reduced during thermocompression bonding, and voids are generated. The softening point is preferably 50 ° C or higher and 65 ° C or lower.

Specific examples of the (C) epoxy resin having a softening point of 70 ° C. or higher and 100 ° C. or lower used in the present invention include orthocresol novolac epoxy resin, phenol novolac epoxy resin, modified phenol epoxy resin, naphthalene epoxy resin, Examples thereof include a dicyclo type epoxy resin, a brominated phenol novolac type epoxy resin, a bisphenol A type epoxy resin, a hydrogenated bisphenol A type epoxy resin, a naphthol type epoxy resin, and a biphenyl type epoxy resin. Even if the structure of the epoxy resin used in the present invention is the same, the difference in the softening point is caused by the difference in molecular weight, so the structure of the epoxy resin used is not particularly limited.
Examples of the epoxy resin include epoxy resins having various softening points. In the present invention, specific epoxy resins having a softening point of 70 ° C. or higher and 100 ° C. or lower are appropriately selected from these epoxy resins. It can be selected and used. The softening point is preferably 80 ° C. or higher and 90 ° C. or lower.

  The content of the epoxy resin is preferably 10 to 150 parts by weight, particularly preferably 30 to 100 parts by weight, with respect to 100 parts by weight of the thermoplastic resin. If the content is too low, the effect of improving the heat resistance may be reduced, and if it is too high, the effect of improving the toughness of the adhesive film for a semiconductor may be reduced.

  Furthermore, when the total epoxy resin is 100 parts by weight, it is preferable that the epoxy resin having a softening point of 40 ° C. or higher and lower than 70 ° C. is 20 parts by weight or more and 80 parts by weight or less, preferably 40 parts by weight or more and 70 parts by weight or less. . When the content is less than the lower limit value, wettability is reduced during thermocompression bonding, and voids are generated. When the upper limit is exceeded, the adhesive film for a semiconductor is tacky, and workability at the time of pasting is lowered.

(D) The phenol resin having a softening point of 80 ° C. or higher and 130 ° C. or lower used in the present invention has at least two phenolic hydroxyl groups capable of forming a crosslinked structure by curing reaction with the above epoxy resin. Refers to monomers, oligomers, and polymers in general, and examples include phenol novolak resins, cresol novolak resins, phenol aralkyl (including phenylene and biphenylene skeleton) resins, naphthol aralkyl resins, triphenolmethane resins, dicyclopentadiene type phenol resins, and the like. . These may be used alone or in combination.
Examples of the phenol resin include phenol resins having various softening points. In the present invention, a specific phenol resin having a softening point of 80 ° C. or higher and 130 ° C. or lower is appropriately selected from these phenol resins. It can be selected and used.
When the softening point is lower than 80 ° C., the melt viscosity of the semiconductor adhesive film at 100 ° C. or more is lowered, and the semiconductor adhesive film flows during thermocompression bonding, which causes contamination of the semiconductor element. When the softening point is higher than 130 ° C., the melt viscosity of the adhesive film for semiconductor at 100 ° C. or higher is increased, the wettability is lowered during thermocompression bonding, and voids are generated. The softening point is preferably 90 ° C. or higher and 120 ° C. or lower.

  The content of the phenol resin is not particularly limited, but the ratio of the epoxy equivalent of the epoxy resin to the hydroxyl equivalent of the phenol curing agent is preferably 0.5 or more and 1.5 or less, particularly 0.7 or more and 1.3 or less. preferable. When the equivalent ratio is less than the lower limit, the effect of improving heat resistance may be reduced, and when the upper limit is exceeded, the storage stability may be reduced.

  In order to accelerate the curing reaction, the resin composition may contain (E) a curing accelerator as necessary. Specific examples of the curing accelerator include amine catalysts such as imidazoles, 1,8-diazabicyclo (5,4,0) undecene, and phosphorus catalysts such as triphenylphosphine.

  The type of (F) filler used in the present invention is not particularly limited, and examples thereof include inorganic fillers such as silver, titanium oxide, silica and mica, and fine organic fillers such as silicon rubber and polyimide. Among these, inorganic fillers, particularly silica fillers are preferable. In the case of a silica filler, there are crushed silica and fused silica as shapes, but fused silica is preferred in the present invention.

In the present invention, by containing a filler silica filler, the yield point stress of the adhesive film for semiconductors and the elastic modulus at 25 ° C. are improved, and the adhesive film during roll conveyance is suppressed from expanding in the MD direction. Workability of the adhesive film for a semiconductor can be improved.
Furthermore, by including a filler silica filler, when the surface of the adhesive film for semiconductor is made into a roll form by causing the surface of the adhesive film for semiconductor to partially appear on the surface of the adhesive film for semiconductor, By reducing the contact area, the frictional force between the semiconductor adhesive film and the back surface of the base film can be reduced, and the semiconductor adhesive film can be wound around the core with sufficient tension.

  The silica filler filler used in the present invention may be in the form of a powder, or may be a slurry in a solvent. Thereby, by improving the elastic modulus at 25 ° C. and improving the workability by giving a firmness to the adhesive film, and further making it difficult to stretch against the tension in the winding direction (MD direction) of the transport roll of the film, The effect of making it easy to form a roll-like shape by preventing the film from stretching when transporting the adhesive film with the transport roll, and further making it easy to slip between the adhesive film and the back surface of the base film. There is.

  The average particle size of the spherical silica filler used is preferably 0.01 μm or more and 20 μm or less, more preferably 0.1 μm or more and 5 μm or less. If the average particle size is less than 0.01 μm, the filler is likely to aggregate in the adhesive film, resulting in poor appearance. If it is larger than 20 μm, the silica filler filler tends to protrude from the adhesive film, and the chip may be destroyed during thermocompression bonding.

  The content of the silica filler filler is not particularly limited, but is preferably 1 part by weight or more and 200 parts by weight or less, particularly 10 parts by weight or more and 100 parts by weight or less with respect to 100 parts by weight of the resin component excluding the filler silica filler. Is preferred. When the content is less than the lower limit, the effect of improving workability may be reduced, and when the content exceeds the upper limit, the effect of improving the adhesion may be reduced.

The resin composition may contain an organic compound having a cyanate group as another component, if necessary. Thereby, the adhesiveness to a to-be-adhered body and heat resistance can be improved more.
Examples of the organic compound having a cyanate group include bisphenol A dicyanate, bisphenol F dicyanate, bis (4-cyanate phenyl) ether, bisphenol E dicyanate, and cyanate novolac resin.

Next, the second adhesive film for a semiconductor of the present invention will be described.
The second adhesive film for a semiconductor of the present invention is
An adhesive film for a semiconductor containing an epoxy resin,
(i) The tack value when evaluated by the probe tack method at 25 ° C. is 0 gf / 5 mmφ or more and 20 gf / 5 mmφ or less, and
(ii) When the temperature is raised from 25 ° C. at a rate of temperature increase of 10 ° C./min, the melt viscosity is 500 [Pa · s] or more and 2000 [Pa · s] or less in the region of 100 ° C. or more and 180 ° C. or less. It is the semiconductor adhesive film characterized.
The second adhesive film for a semiconductor of the present invention includes, for example, (A) a thermoplastic resin, (B) an epoxy resin having a softening point of 40 ° C. or higher and lower than 70 ° C., and (C) a softening point of 70 ° C. or higher and 100 ° C. or lower. An epoxy resin and (D) a resin composition containing a phenol resin having a softening point of 80 ° C. or higher and 130 ° C. or lower are obtained.

The tack value when evaluated by the probe tack method of the configuration (i) of the present invention represents the tackiness and adhesion of the film surface, and the higher the value, the higher the tackiness and adhesion. To do.
The measurement was carried out with a product of Reska Co., Ltd., TACKINES TESTER, pressure bonding time 3 sec, test speed 600 mm / min, and probe diameter 5 mmφ.

Configuration (ii) When the temperature is increased from 25 ° C. at a rate of 10 ° C./min, the melt viscosity is 500 [Pa · s] or more and 2000 [Pa · s] or less in the region of 100 ° C. or more and 180 ° C. or less. By means a requirement that the melt viscosity must meet in order to adhere at relatively low temperatures. In order to prevent thermal damage of the chip, it is necessary to apply it at a relatively low temperature.
The melt viscosity in the present invention can be measured, for example, using a rheometer which is a viscoelasticity measuring device by applying shear shear at a frequency of 1 Hz to a film-like sample at a heating rate of 10 ° C./min.

In the present invention, the yield point stress of 15 MPa or more when pulled at 25 ° C. at a speed of 100 mm / min is a requirement to prevent the film from sagging in the winding direction when the film is wound reel-to-reel. It is. If stretched in the winding direction, the width and thickness of the film will change, causing problems.
Here, the yield point stress and the elastic modulus at 25 ° C. of the adhesive film for semiconductor are values obtained by measuring a dumbbell test piece at a pulling rate of 100 mm / min using a mechanical strength measuring instrument.

In the present invention, the elastic modulus at 25 ° C. defines the strength of the film and is the same as the yield point stress.
Measurement is RTC-1250A manufactured by Orientec Co., Ltd., test piece shape is test piece type 5 described in JIS K 7127, test speed is 100 mm / min, tensile measurement is performed at a distance between grips of 45 mm, and elastic modulus is measured. did. The test speed of 100 mm / min is a speed set on the assumption of a load that is instantaneously applied to the film when transported on a reel-to-reel basis.

When the shear adhesion force at 25 ° C. between the back surface of the PET film and the adhesive film for semiconductors is 20 N / (25 mm × 25 mm) or less, both films become slippery, and the base film and the adhesive film for semiconductors are unnecessary. It will not adhere.
Here, the shear adhesion force of the adhesive film for a semiconductor is measured as follows. The adhesive strength for semiconductor and polyethylene terephthalate film (manufactured by Oji Paper Co., Ltd., product number RL-07, thickness 38μm) were obtained by cutting both films to a width of 25mm and pasting them at 25 ° C with an adhesive area of 25mm x 25mm. It is obtained by measuring the strength when both are pulled in the 180 ° direction at 1000 mm / min with a mechanical strength measuring instrument. Here, the speed of 1000 mm / min is a speed used when the adhesive film is wound up into a roll which is a form of the final product, and a higher load is applied than when transported on a reel-to-reel basis. High speed is used for measurement.

FIG. 1 schematically shows the relationship of the melt viscosity to the temperature of the adhesive film for semiconductors of the present invention.
As shown in FIG. 1, the adhesive film for semiconductor of the present invention has an initial decrease in melt viscosity when the temperature of the adhesive film for semiconductor is increased from 25 ° C. to a molten state at a temperature increase rate of 10 ° C./min. After reaching the minimum melt viscosity (η1) at the predetermined temperature (t1) in the figure, after maintaining the state in the temperature range of the mount temperature (t2), it further increases (arrow B in the figure) It has special characteristics.

  At this time, the melt viscosity is preferably 500 [Pa · s] or more and 2000 [Pa · s] or less in the region of 100 ° C. to 180 ° C. of the adhesive film for semiconductor. Further, the melt viscosity is preferably from 600 [Pa · s] to 1,500 [Pa · s], particularly preferably from 800 [Pa · s] to 1,200 [Pa · s]. If it is higher than 2000 [Pa · s], the wettability decreases during thermocompression bonding and voids are generated. If it is lower than 500 [Pa · s], the adhesive film for a semiconductor flows more than necessary, which causes contamination of the semiconductor element.

  By adding an epoxy resin having a softening point of 40 ° C. or higher and 70 ° C. or lower, the melt viscosity is lowered to 2000 [Pa · s] or lower until reaching 100 ° C., and the softening point is 70 ° C. or higher and 100 ° C. By adding the following epoxy resin and a phenol resin having a softening point of 80 ° C. or higher and 130 ° C. or lower, the melt viscosity can be maintained at a constant melt viscosity without decreasing to 180 ° C.

The minimum melt viscosity of a conventional adhesive film for a semiconductor (for example, a polyimide-based adhesive film) was about 3000 [Pa · s]. Therefore, it is necessary to bond the semiconductor element and the semiconductor element mounting support member at a high temperature of about 180 ° C. However, since the semiconductor element and the semiconductor element mounting support member are bonded at such a high temperature, the semiconductor element may be thermally damaged.
On the other hand, since the adhesive film for semiconductors of the present invention has a low minimum melt viscosity, the semiconductor element and the semiconductor mounting support member can be bonded even if the thermocompression bonding temperature is lowered. The thermocompression bonding temperature in the present invention is preferably 100 ° C to 150 ° C.

  The melt viscosity at 250 ° C. after heat treatment at 175 ° C. for 2 hours is 5,000 [Pa · s] or more. Further, it is preferably 10,000 [Pa · s] or more, particularly preferably 20,000 [Pa · s] or more. When the melt viscosity at 250 ° C. is within the above range, the heat resistance and the crack resistance during reflow are particularly excellent.

  In addition to having no tack and a melt viscosity of 500 [Pa · s] to 2000 [Pa · s] in the region of 100 ° C. to 180 ° C., the melt viscosity at 250 ° C. after heat treatment at 175 ° C. for 2 hours is If it is within the range, an adhesive film for a semiconductor having excellent workability, low-temperature adhesiveness and heat resistance can be obtained.

  The yield point stress and the elastic modulus at 25 ° C. of the adhesive film for semiconductor at this time are preferably such that the yield point stress is 15 MPa or more and the elastic modulus at 25 ° C. is 1500 MPa or more when pulled at a pulling speed of 100 mm / min. Further, the yield point stress is preferably 20 MPa or more and an elastic modulus at 25 ° C. of 150 MPa or more, and particularly preferably a yield point stress of 10 MPa or more and an elastic modulus at 25 ° C. of 2000 MPa or more. When the yield point stress is 15 MPa or less or the elastic modulus at 25 ° C. is 1500 MPa or less, the resistance of the adhesive film for semiconductor in the MD direction at the time of roll conveyance is insufficient, and the adhesive film for semiconductor stretches in the MD direction. This will hinder the bonding operation.

  The frictional force between the adhesive film for a semiconductor and the back surface of the base film can be measured by looking at the shear adhesion force of a sample obtained by bonding both at 25 ° C. When the adhesive area between the adhesive film for semiconductor and the back surface of the PET film used for the substrate is bonded at 25 mm × 25 mm, the shear adhesion is preferably 20 N / (25 mm × 25 mm) or less. Furthermore, 10 N / (25 mm × 25 mm) or less is preferable, and 5 N / (25 mm × 25 mm) or less is particularly preferable. When the adhesive film for a semiconductor is wound around the core when it is larger than 20 N / (25 mm × 25 mm), the adhesive film for a semiconductor and the substrate film are attached when the adhesive film for a semiconductor is wrapped with air bubbles on the back surface of the inner substrate film. Since the frictional force between the inner side and the inner side is large and no tension is applied in the MD direction, no slip occurs between the adhesive film for semiconductor and the back surface of the base film, so that the bubbles cannot be eliminated.

The adhesive film for semiconductors of the present invention is prepared by, for example, dissolving the resin composition in a solvent such as methyl ethyl ketone, acetone, toluene, dimethylformaldehyde, etc. to make a varnish, and then using a comma coater, die coater, gravure coater, etc. It can be obtained by coating the release sheet, drying it, and then removing the release sheet.
Although the thickness of the said adhesive film for semiconductors is not specifically limited, 3 micrometers or more and 100 micrometers or less are preferable, and 5 micrometers or more and 70 micrometers or less are especially preferable. When the thickness is within the above range, it is particularly easy to control the thickness accuracy.

  FIG. 2 is a schematic view showing the structure of a semiconductor device manufactured using the semiconductor adhesive film of the present invention. This semiconductor device has a structure in which a semiconductor element 2 is mounted on a BGA substrate 3. Between the semiconductor element 2 and the BGA substrate 3, the semiconductor adhesive film 1 is disposed. The semiconductor element 2 is flip-chip connected to the BGA substrate 3. Since the adhesive film for semiconductor 1 can be bonded at low temperature, it can be bonded without causing thermal damage to the semiconductor element 2 in the manufacturing process. A semiconductor device in which a semiconductor does not have a thermal history can realize high reliability.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited to this.

First, the Example and comparative example of the adhesive film for semiconductors are demonstrated.
Example 1
(1) Preparation of adhesive film resin varnish for semiconductor Acrylic acid copolymer (butyl acrylate-acrylonitrile-ethyl acrylate-glycidyl methacrylate copolymer, manufactured by Nagase ChemteX Corporation, SG-80HDR, Tg: 10 as a thermoplastic resin ℃, weight average molecular weight: 350,000) 100 parts by weight and epoxy resin (NC6000 (bisphenol A type epoxy resin), epoxy equivalent 200 g / eq, Nippon Kayaku Co., Ltd., softening point 60 ° C) as curable resin 36 parts by weight, epoxy resin (EOCN-1020-80 (orthocresol novolac type epoxy resin), epoxy equivalent 200 g / eq, Nippon Kayaku Co., Ltd., softening point 80 ° C.) 24 parts by weight, phenol resin (MEH- 7500 (triphenolmethane resin), hydroxyl equivalent 97g / OH group, 29% by weight, Meiwa Kasei Co., Ltd., softening point 110 ° C.), 0.1 part by weight of imidazole compound (2PHZ-PW, Shikoku Kasei Co., Ltd.) as a curing accelerator is dissolved in methyl ethyl ketone (MEK) Thus, a resin varnish having a resin solid content of 37% was obtained.
The softening point was measured using a value measured by the ring and ball method according to JIS K7234. The same applies hereinafter.

ＮＣ−６０００

NC-6000

(2) Manufacture of adhesive film for semiconductor After applying the above-mentioned resin varnish to a polyethylene terephthalate film (manufactured by Oji Paper Co., product number RL-07, thickness 38 μm) as a protective film using a comma coater, It was dried for 10 minutes to obtain an adhesive film for semiconductor having a thickness of 25 μm.

(3) Manufacture of semiconductor device The above-mentioned adhesive film surface for semiconductor is laminated on the back surface of a 5-inch, 100 μm semiconductor wafer under the conditions of 80 ° C., 0.1 MPa, 50 mm / sec, and the adhesive film surface for semiconductor is diced (Sumilite). FSL-N4003, manufactured by Sumitomo Bakelite Co., Ltd.). Then, using a dicing saw, the semiconductor wafer bonded with the semiconductor adhesive film is diced (cut) into a semiconductor element size of 5 mm × 5 mm square at a spindle rotation speed of 50,000 rpm and a cutting speed of 50 mm / sec. A semiconductor element to which an adhesive film was bonded was obtained. Next, after irradiating ultraviolet rays with an integrated light amount of 250 mJ / cm ² in 20 seconds from the light transmissive substrate side of the dicing film, the dicing film bonded to the adhesive film for semiconductor was peeled off. Then, the semiconductor element bonded with the above-described adhesive film for semiconductor is pressure-bonded to a 42-alloy alloy lead frame at 130 ° C., 5N for 1.0 second, die-bonded, sealed with resin, and 175 ° C. for 2 hours. Heat treatment was performed to cure the sealing resin, thereby obtaining 10 semiconductor devices.

(4) Evaluation of adhesive film for semiconductors Low temperature adhesion (initial adhesion)
For low temperature adhesion, the semiconductor adhesive film obtained on the semiconductor element (80-pin lead frame) was bonded at 130 ° C., 5 N for 1 second, and then the die shear strength was measured.
The die shear strength was measured using a push-pull gauge. Each code is as follows.
◎: Die shear strength is 3.0 MPa or more ○: Die shear strength is 2.0 MPa or more and less than 3.0 M △: Die shear strength is 1.0 MPa or more and less than 2.0 MPa ×: Die shear strength is less than 1.0 MPa

Heat resistance The heat resistance was evaluated based on a 5% weight reduction temperature of an adhesive film for semiconductor heat-treated at 180 ° C for 1 hour. Each code is as follows.
A: 5% weight reduction temperature is 300 ° C. or more. ○: 5% weight reduction temperature is 250 ° C. or more and less than 300 ° C. Δ: 5% weight reduction temperature is 200 ° C. or more and less than 250 ° C. ×: 5% weight reduction temperature is Less than 200 ° C

Presence or absence of tack The presence or absence of tack of the adhesive film for semiconductor was evaluated by the probe tack method. Each code is as follows.
A: No tack (0 gf / 5 mmφ to 20 gf / 5 mmφ)
○: Tack is slightly present, but there is no practical problem (20 gf / 5 mmφ to 50 gf / 5 mmφ)
Δ: Tack slightly, practically unusable (50 gf / 5 mmφ to 100 gf / 5 mmφ)
X: Tucked (100gf / 5mmφ or more)

Winding wrinkle A winding appearance was evaluated when a substrate PET was wound on the outside of a vinyl chloride reel having a width of 300 mm and an inner diameter of 77 mmφ, and a semiconductor adhesive film was wound on the inside. Each code is as follows.
A: No wrinkle is generated.
X: There is a winding wrinkle.
Film transportability The shape change of the winding direction of the adhesive film for semiconductors when only the adhesive film for semiconductors was wound with a winding roll was evaluated. Each code is as follows.
◎: No change in shape ○: There is a slight change in shape, but there is no problem in practical use △: There is a slight change in shape, and it cannot be used in practical use ×: It extends in the winding direction

(5) Evaluation of semiconductor device produced using adhesive film for semiconductor Adhesiveness after moisture absorption treatment The semiconductor device before resin sealing obtained in each Example and Comparative Example was subjected to moisture absorption treatment at 85 ° C./85% RH / 168 hours. Then, the shear strength at 260 ° C. between the semiconductor element and the lead frame was evaluated.
◎: Shear strength is 1.0 MPa or more ○: Shear strength is 0.75 or more and less than 1.0 MPa △: Shear strength is 0.5 or more and less than 0.75 MPa ×: Shear strength is less than 0.5 MPa

Crack resistance Crack resistance is determined by scanning ultrasonic flaw detection by performing moisture absorption treatment on the semiconductor devices obtained in each of the examples and comparative examples at 85 ° C./85% RH / 168 hours, followed by IR reflow at 260 ° C. three times. Machine (SAT). Each code is as follows.
A: Generated cracks 0 out of 10 O: Generated cracks 1 to 3 out of 10 Δ: Generated cracks 4 to 9 out of 10 ×: Generated cracks 10 out of 10

  Table 1 shows the physical properties of the semiconductor adhesive film obtained in Example 1, various evaluation results, and details of the evaluation results of the semiconductor device using the semiconductor adhesive film.

(Example 2)
An experiment was performed in the same manner as in Example 1 except that 130 parts by weight of silica filler (SE5101, average particle diameter of 1 μm, manufactured by Admafine Co., Ltd.) was used. The formulation and experimental results are shown in Table 1.

(Example 3)
As an epoxy resin (B), HP-7200 (dicyclopentadiene type epoxy resin), epoxy equivalent 263 g / eq, manufactured by Dainippon Ink Co., Ltd., softening point 60 ° C., 38 parts by weight, silica filler (SE5101, average) The experiment was performed in the same manner as in Example 1 except that 130 parts by weight of a particle size of 1 μm and manufactured by Admafine Co., Ltd. was used. The formulation and experimental results are shown in Table 1.

(Example 4)
As the epoxy resin (B), Epicron N865 (bisphenol A novolak type epoxy resin), epoxy equivalent 205 g / eq, manufactured by Dainippon Ink Co., Ltd., softening point 65 ° C., 36 parts by weight, silica filler (SE5101, average particle size) An experiment was performed in the same manner as in Example 1 except that 130 parts by weight of 1 μm in diameter and manufactured by Admafine Co., Ltd. was used. The formulation and experimental results are shown in Table 1.

(Example 5)
As the epoxy resin (C), ESLV-80DE (biphenyl type epoxy resin), epoxy equivalent 174 g / eq, manufactured by Nippon Steel Chemical Co., Ltd., softening point 78 ° C., 24 parts by weight, silica filler (SE5101, average particle size) An experiment was performed in the same manner as in Example 1 except that 130 parts by weight of a diameter of 1 μm, manufactured by Admafine Co., Ltd., and 0.05 parts by weight of a curing accelerator were used. The formulation and experimental results are shown in Table 1.

(Example 6)
As epoxy resin (C), NC7000 (naphthol type epoxy resin), epoxy equivalent 226 g / eq, manufactured by Nippon Kayaku Co., Ltd., softening point 90 ° C., 24 parts by weight, silica filler (SE5101, average particle size 1 μm, The experiment was conducted in the same manner as in Example 1 except that 130 parts by weight (manufactured by Admafine Co., Ltd.), 0.05 parts by weight of the curing accelerator, and 27 parts by weight of MEH-7500 were used. The formulation and experimental results are shown in Table 1.

(Example 7)
As the phenol resin (D), PR53647 (phenol novolac resin), hydroxyl group equivalent 104 g / OH group, manufactured by Sumitomo Bakelite Co., Ltd., softening point 92 ° C., 31 parts by weight, silica filler (SE5101, average particle size 1 μm, Adma The experiment was performed in the same manner as in Example 1 except that 130 parts by weight of Fine Co., Ltd. was used. The formulation and experimental results are shown in Table 1.

(Example 8)
As the phenol resin (D), PR51470 (phenol novolac resin), hydroxyl group equivalent 104 g / OH group, manufactured by Sumitomo Bakelite Co., Ltd., softening point 110 ° C., 31 parts by weight, silica filler (SE5101, average particle size 1 μm, Adma The experiment was performed in the same manner as in Example 1 except that 130 parts by weight of Fine Co., Ltd. was used. The formulation and experimental results are shown in Table 1.

(Comparative Example 1)
The experiment was performed in the same manner as in Example 1 except that the epoxy resin (B) was not used. The formulation and experimental results are shown in Table 1.

(Comparative Example 2)
The experiment was performed in the same manner as in Example 1 except that 130 parts by weight of silica filler (SE5101, average particle size 1 μm, manufactured by Admafine Co., Ltd.) was used without using the epoxy resin (B). The formulation and experimental results are shown in Table 1.

(Comparative Example 3)
The experiment was performed in the same manner as in Example 1 except that the epoxy resin (C) was not used. The formulation and experimental results are shown in Table 1.

(Comparative Example 4)
Except for using Eplon N868 (bisphenol A type epoxy resin), epoxy equivalent 190 g / eq, Japan Epoxy Resin Co., Ltd., softening point 25 ° C. or lower (liquid at room temperature), 36 parts by weight as the epoxy resin (B). The experiment was conducted in the same manner as in Example 1. The formulation and experimental results are shown in Table 1.

(Comparative Example 5)
The same as Example 1 except that Epicoat 1007 (bisphenol A type epoxy resin), epoxy equivalent 2000 g / eq, Japan Epoxy Resin Co., Ltd., softening point 128 ° C., 24 parts by weight were used as the epoxy resin (C). The experiment was conducted. The formulation and experimental results are shown in Table 1.

(Comparative Example 6)
As in Example 1, except that XLC-4L (phenol aralkyl resin), hydroxyl group equivalent 170 g / OH group, manufactured by Mitsui Chemicals, Inc., softening point 62 ° C., 50 parts by weight was used as the phenol resin (D). The experiment was conducted. The formulation and experimental results are shown in Table 1.

(Comparative Example 7)
Measurement was carried out using an adhesive film for semiconductors using a conventional polyimide. In addition, since it is unknown about a detailed composition, only adhesive film physical property, an adhesive film evaluation result, and the evaluation result of a semiconductor device are shown in Table 1.

  As shown in Table 1, in Examples 1-8, both the adhesive film evaluation results and the semiconductor device evaluation results showed good results, but in Comparative Examples 1-7, all of these showed good results. There wasn't. Moreover, although the adhesive film physical properties of Examples 1-8 all satisfy the characteristics of claims 8-10, none of the comparative examples, which are prior arts, satisfy the characteristics of claims 8-10.

It is the figure which showed typically the relationship of the melt viscosity with respect to the temperature of the adhesive film for semiconductors of this invention. It is sectional drawing of the semiconductor device which shows an example of the semiconductor device of this invention typically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Adhesive film for semiconductors 2 Semiconductor element 3 Support member for semiconductor mounting

Claims (10)

(A) An adhesive film for semiconductor composed of a resin composition containing a thermoplastic resin, an epoxy resin, and a phenol resin,
The epoxy resin is substantially composed of a solid epoxy resin, and (B) an epoxy resin having a softening point of 40 ° C. or higher and lower than 70 ° C. and (C) an epoxy having a softening point of 70 ° C. or higher and 100 ° C. or lower. The adhesive film for semiconductors which contains resin and the said phenol resin is a phenol resin whose softening point is 80 degreeC or more and 130 degrees C or less (D).   The adhesive film for semiconductor according to claim 1, wherein the thermoplastic resin (A) is an acrylate copolymer.   The content of the epoxy resin (B) in the total weight of the (B) epoxy resin having a softening point of 40 ° C. or higher and lower than 70 ° C. and the (C) epoxy resin having a softening point of 70 ° C. or higher and 100 ° C. or lower is 40% by weight. The adhesive film for a semiconductor according to claim 1, wherein the adhesive film is from 1% to 70% by weight.   The adhesive film for a semiconductor according to any one of claims 1 to 3, further comprising (E) a curing accelerator.   The semiconductor adhesive film according to claim 1, further comprising (F) a filler. Wherein the resin component 100 parts by weight of the resin composition, wherein (F) an adhesive film for a semiconductor according to claim 5 Symbol mounting the filler content is less than 200 parts by weight or more and 1 part by weight. An adhesive film for a semiconductor containing an epoxy resin,
The epoxy resin is substantially composed of a solid epoxy resin;
The tack value when evaluated by the probe tack method at 25 ° C. is 0 gf / 5 mmφ or more and 20 gf / 5 mmφ or less, and
When the temperature is raised from 25 ° C. at a rate of 10 ° C./min, the melt viscosity is 500 [Pa · s] or more and 2000 [Pa · s] or less in the region of 100 ° C. or more and 180 ° C. or less. Adhesive film for semiconductors. The adhesive film for a semiconductor according to claim 7 , wherein a yield point stress obtained when a tensile test is performed at 25 ° C and a speed of 100 mm / min is 15 MPa or more, and an elastic modulus at 25 ° C is 1500 MPa or more. The adhesive film for a semiconductor according to claim 7 or 8, wherein the shear adhesion at 25 ° C. with PET film back surface to be used for the adhesive film for a semiconductor and the substrate is 20N / (25mm × 25mm) or less. The semiconductor device having bonding structure of the semiconductor element and the bonded component using the adhesive film for a semiconductor according to any one of claims 1 to 9.

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