JP7392706B2 - adhesive film - Google Patents

Description

The present invention relates to an adhesive film and a dicing/die bonding film.

For example, a method has been proposed in which a metal base is placed under a die pad and a lead portion on which a semiconductor element is placed via an adhesive to enhance the heat dissipation effect of a semiconductor device package (see, for example, Patent Document 1). . However, since the metal base, semiconductor element, die pad, etc. have different coefficients of thermal expansion, the semiconductor element repeatedly generates heat, causing problems such as peeling of the metal base and generation of cracks.

By the way, as an adhesive film, for example, an adhesive film containing highly thermally conductive particles or a thermally conductive filler is known (see, for example, Patent Documents 2 and 3).

Japanese Patent Application Publication No. 5-198701 Japanese Patent Application Publication No. 2009-235402 JP2014-68020A

For example, adhesive films used for the above applications are required to have excellent adhesive properties and thermal conductivity after thermosetting.

However, the above-mentioned conventional adhesive films are not sufficient in terms of both adhesion and thermal conductivity after thermosetting.

Therefore, an object of the present invention is to provide an adhesive film that has excellent adhesive properties and thermal conductivity after thermosetting.

Specific embodiments of the present invention are shown below.
[1] A polyhedron containing (a) an acrylic resin, (b) an epoxy resin, (c) a curing agent, and (d) an α-alumina filler, wherein the α-alumina filler (d) has a purity of 99.90% by mass or more. The content of the above (d) α-alumina filler is the total amount of (a) acrylic resin, (b) epoxy resin, (c) curing agent, and (d) α-alumina filler. The adhesive film is 60 to 95 parts by weight per 100 parts by weight.
[2] The adhesive film according to [1], wherein the average particle diameter (d ₅₀ ) of the α-alumina filler (d) is 1/2 or less of the thickness of the adhesive film.
[3] The content of the above (d) α-alumina filler is based on 100 parts by mass of the total amount of (a) acrylic resin, (b) epoxy resin, (c) curing agent, and (d) α-alumina filler. , 60 to 90 parts by mass, the adhesive film according to [1] or [2].
[4] The acrylic resin (a) is an acrylic copolymer containing an epoxy group, has a weight average molecular weight of 100,000 or more, and has a glass transition temperature of -50°C to 30°C, [1] to [ 3].
[5] The adhesive film according to any one of [1] to [4], which has a thickness of 50 μm or less.
[6] Dicing/die bonding, comprising a dicing film and a die bonding film laminated on the dicing film, wherein the die bonding film is the adhesive film according to any one of [1] to [5]. film.

According to the present invention, it is possible to provide an adhesive film with excellent adhesiveness and thermal conductivity after thermosetting, and a dicing/die bonding film using the adhesive film.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

[Adhesive film]
The adhesive film of this embodiment includes (a) an acrylic resin, (b) an epoxy resin, (c) a curing agent, and (d) an α-alumina filler, and the α-alumina filler (d) has a purity of 99.90. % or more of polyhedral α-alumina filler, and the content of the above (d) α-alumina filler is (a) acrylic resin, (b) epoxy resin, (c) curing agent, and (d) α- The amount is 60 to 95 parts by mass based on 100 parts by mass of the total amount of alumina filler. The adhesive film of this embodiment has excellent adhesiveness and thermal conductivity after thermosetting. Furthermore, the adhesive film of this embodiment has excellent lamination properties and can have low surface roughness.

Incidentally, Patent Document 2 described above describes obtaining an adhesive film by applying pressure in the thickness direction to a primary film formed using varnish. On the other hand, according to the adhesive film of this embodiment, the step of applying pressure in the thickness direction to the primary film is not necessarily necessary.

[(a) Acrylic resin]
The (a) acrylic resin (hereinafter referred to as "component (a)" in some cases) according to the present embodiment may be an acrylic polymer having a structural unit derived from one type of monomer, or may be an acrylic resin having a structural unit derived from one type of monomer. It may also be an acrylic copolymer having a structural unit derived from. Examples of the acrylic copolymer include acrylic rubber. Examples of the acrylic rubber include copolymers of at least one selected from acrylic esters and methacrylic esters and acrylonitrile. Component (a) may be used alone or in combination of two or more.

Component (a) may have a reactive group (functional group) from the viewpoint of adhesiveness, heat resistance, and moisture absorption resistance after thermosetting.

Examples of the above-mentioned reactive group include a carboxy group, an amino group, a hydroxyl group, and an epoxy group.

The acrylic resin having a reactive group can be produced by, for example, polymerizing a monomer having the above-mentioned reactive group (glycidyl acrylate, glycidyl methacrylate, etc.) in a polymerization reaction to obtain an acrylic polymer so that the reactive group remains, or It can be produced by introducing a reactive group into an acrylic polymer.

The reactive group is an epoxy group from the viewpoint of easily reducing gelation in the varnish state, and from the viewpoint of increasing the degree of curing in the B-stage state and preventing a decrease in adhesive strength due to the increase in the degree of curing. It's okay. That is, component (a) may be an acrylic resin having an epoxy group.

The present inventors speculate as follows why such an effect is produced when the reactive group is an epoxy group.

When the reactive group is, for example, a carboxy group, the cross-linking reaction tends to proceed, and it is thought that gelation in the varnish state and an increase in the degree of curing in the B-stage state may occur. On the other hand, when the reactive group is an epoxy group, a cross-linking reaction is unlikely to occur, and it is considered that gelation in the varnish state and increase in the degree of curing in the B-stage state are unlikely to occur.

Examples of the acrylic resin having an epoxy group include acrylic resins having a structural unit derived from at least one selected from glycidyl acrylate and glycidyl methacrylate.

From the viewpoint of improving adhesiveness and heat resistance, component (a) contains, for example, 0.5% by mass or more of a structural unit derived from glycidyl acrylate or glycidyl methacrylate, based on the total mass of component (a). It may contain 2% by mass or more. From the viewpoint of reducing gelation, component (a) may contain, for example, 6% by mass or less of a structural unit derived from glycidyl acrylate or glycidyl methacrylate, based on the total mass of component (a). good. From these viewpoints, component (a) contains, for example, 0.5 to 6% by mass of structural units derived from glycidyl acrylate or glycidyl methacrylate, based on the total mass of component (a). It may contain 2 to 6% by mass.

Component (a) is, for example, a structural unit derived from at least one selected from the group consisting of an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms, an alkyl methacrylate having an alkyl group having 1 to 8 carbon atoms, styrene, and acrylonitrile. It may also include. Examples of the alkyl acrylate having an alkyl group having 1 to 8 carbon atoms include methyl acrylate, ethyl acrylate, and butyl acrylate. Examples of the alkyl methacrylate having an alkyl group having 1 to 8 carbon atoms include methyl methacrylate, ethyl methacrylate, and butyl methacrylate. Among these, from the viewpoint of adhesiveness, component (a) may contain a structural unit derived from ethyl (meth)acrylate and/or a structural unit derived from butyl (meth)acrylate. Here, in this specification, "(meth)acrylate" means "acrylate" or "methacrylate" corresponding thereto.

When component (a) is an acrylic copolymer, the copolymerization ratio of each monomer may be adjusted in consideration of the glass transition temperature (hereinafter referred to as "Tg" as the case may be) of the copolymer.

The polymerization method for producing component (a) is not particularly limited, and examples thereof include pearl polymerization and solution polymerization.

The Tg of the component (a) may be, for example, -50°C or higher, or -10°C or higher, from the viewpoint that the adhesive film in the B-stage state is difficult to increase tackiness and is easy to handle. . The Tg of component (a) may be, for example, -50°C to 30°C, or -10°C to 30°C, from the viewpoint of improving adhesiveness and heat resistance.

The weight average molecular weight of component (a) may be 100,000 or more from the viewpoint of improving adhesiveness and heat resistance.

In this specification, the weight average molecular weight (Mw) is a polystyrene equivalent value measured by gel permeation chromatography (GPC) using a standard polystyrene calibration curve.

The weight average molecular weight of component (a) may be, for example, 300,000 or more, from the viewpoint that strength and flexibility are less likely to decrease and tackiness is less likely to increase when formed into a sheet or film form. , 500,000 or more. From the viewpoint of high flowability and excellent circuit filling properties of wiring, the weight average molecular weight of component (a) may be, for example, 3,000,000 or less, or 2,000,000 or less. From these viewpoints, the weight average molecular weight of component (a) is preferably from 300,000 to 3,000,000, more preferably from 500,000 to 2,000,000.

Component (a) is an acrylic resin having a reactive group, preferably has a weight average molecular weight of 100,000 or more, and is an acrylic copolymer containing an epoxy group (epoxy group-containing acrylic copolymer). , and more preferably has a weight average molecular weight of 100,000 or more, is an acrylic copolymer containing an epoxy group, has a weight average molecular weight of 100,000 or more, and has a glass transition temperature of -50°C to 30°C. It is even more preferable that there be.

From the viewpoint of improving adhesiveness and heat resistance, component (a) contains 0.5 to 6% by mass of a structural unit derived from glycidyl acrylate or glycidyl methacrylate as a reactive group, and has a Tg of -50°C to 30°C. An acrylic copolymer having a weight average molecular weight of 100,000 or more is preferable.

Examples of acrylic copolymers containing 0.5 to 6% by mass of structural units derived from glycidyl acrylate or glycidyl methacrylate, having a Tg of -10°C to 30°C, and a weight average molecular weight of 100,000 or more include HTR- 860P-3 (manufactured by Nagase ChemteX Co., Ltd., trade name).

[(b) Epoxy resin]
The epoxy resin (b) according to the present embodiment (hereinafter referred to as "component (b)" in some cases) is, for example, one that exhibits an adhesive effect when cured.

From the viewpoint of heat resistance, component (b) is preferably an epoxy resin having two or more functional groups (an epoxy resin having two or more functional groups).

The weight average molecular weight of the component (b) may be, for example, less than 5,000, less than 3,000, or less than 2,000 from the viewpoint of heat resistance.

As the component (b), for example, bifunctional epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin; novolac type epoxy resins such as phenol novolac type epoxy resin and cresol novolac type epoxy resin; polyfunctional epoxy resin; Examples include amine type epoxy resins; heterocycle-containing epoxy resins; and alicyclic epoxy resins. As component (b), generally known epoxy resins other than those mentioned above can also be used.

Commercially available bisphenol A type epoxy resins include, for example, Epicote 807, Epicote 815, Epicote 825, Epicote 827, Epicote 828, Epicote 834, Epicote 1001, Epicote 1002, Epicote 1003, Epicote 1055, Epicote 1004, Epicote 1004AF, Epicote 1007. , Epicote 1009, Epicote 1003F, and Epicote 1004F (manufactured by Mitsubishi Chemical Corporation, product names); DER-330, DER-301, DER-361, DER-661, DER-662, DER-663U, DER-664, DER-664U, DER-667, DER-642U, DER-672U, DER-673MF, DER-668, and DER-669 (all manufactured by Dow Chemical Company, product names); and YD8125 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., product name).

Commercially available bisphenol F-type epoxy resins include, for example, YDF-2004 and YDF-8170C (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., trade name).

Commercially available phenol novolac type epoxy resins include, for example, Epicote 152 and Epicote 154 (trade names, manufactured by Mitsubishi Chemical Corporation); EPPN-201 (trade names, manufactured by Nippon Kayaku Co., Ltd.); and DEN-438 (trade names); (manufactured by Dow Chemical Company, trade name).

Commercially available cresol novolac type epoxy resins include, for example, Epicote 180S65 (manufactured by Mitsubishi Chemical Corporation, trade name); Araldite ECN1273, Araldite ECN1280, and Araldite ECN1299 (all trade names, made by Ciba Specialty Chemicals); YDCN-701. , YDCN-702, YDCN-703 and YDCN-704 (product names manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.); EOCN-102S, EOCN-103S, EOCN-104S, EOCN-1012, EOCN-1020, EOCN-1025 and Examples include EOCN-1027 (trade name, manufactured by Nippon Kayaku Co., Ltd.); and ESCN-195X, ESCN-200L, and ESCN-220 (trade names, manufactured by Sumitomo Chemical Co., Ltd.).

Commercially available polyfunctional epoxy resins include, for example, Epon 1031S, Epicote 1032H60, and Epicote 157S70 (trade names, manufactured by Mitsubishi Chemical Corporation); Araldite 0163 (trade name, manufactured by Ciba Specialty Chemicals); Denacol EX-611 , Denacol EX-614, Denacol EX-614B, Denacol EX-622, Denacol EX-512, Denacol EX-521, Denacol EX-421, Denacol EX-411 and Denacol EX-321 (manufactured by Nagase ChemteX Corporation, (trade name); and EPPN501H and EPPN502H (trade names, manufactured by Nippon Kayaku Co., Ltd.).

Commercially available amine type epoxy resins include, for example, Epicote 604 (manufactured by Mitsubishi Chemical Corporation, trade name); YH-434 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., trade name); TETRAD-X, and TETRAD-C (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., trade name); (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name); and ELM-120 (manufactured by Sumitomo Chemical Co., Ltd., trade name).

Examples of commercially available heterocycle-containing epoxy resins include Araldite PT810 (manufactured by Ciba Specialty Chemicals, trade name).

Examples of commercially available alicyclic epoxy resins include ERL4234, ERL4299, ERL4221, and ERL4206 (trade names, manufactured by UCC).

Component (b) may be used alone or in combination of two or more.

Component (b) may contain a bifunctional epoxy resin and a trifunctional or higher functional epoxy resin from the viewpoint of heat resistance. When component (b) contains a bifunctional epoxy resin and a trifunctional or higher functional epoxy resin, the content of the bifunctional epoxy resin is determined from the viewpoint of increasing the Tg of the adhesive film after thermosetting. For example, it may be 50% by mass or more and less than 100% by mass, or 50 to 90% by mass, based on the total mass of the trifunctional or higher functional epoxy resin. From the same viewpoint, the content of the trifunctional or higher functional epoxy resin may be, for example, more than 0 and 50% by mass or less, based on the total mass of the bifunctional epoxy resin and the trifunctional or higher functional epoxy resin, and 10 to 50% by mass. It may be 50% by mass.

[(c) Curing agent]
The curing agent (c) according to the present embodiment (hereinafter referred to as "component (c)" in some cases) can be used without particular limitation as long as it is capable of curing component (b). . Component (c) includes, for example, polyfunctional phenol compounds, amine compounds, acid anhydrides, organic phosphorus compounds and their halides, polyamides, polysulfides, and boron trifluoride.

Examples of the polyfunctional phenol compound include monocyclic bifunctional phenol compounds and polycyclic bifunctional phenol compounds. Examples of the monocyclic bifunctional phenol include hydroquinone, resorcinol, catechol, and alkyl group-substituted products thereof. Examples of the polycyclic bifunctional phenol compound include bisphenol A, bisphenol F, bisphenol S, naphthalene diol, biphenol, and alkyl group-substituted products thereof. Further, the polyfunctional phenol compound may be, for example, a polycondensate of at least one phenol compound selected from the group consisting of the monocyclic bifunctional phenol compound and the polycyclic bifunctional phenol compound and an aldehyde compound. good. The polycondensate is, for example, a phenol resin. Examples of the phenolic resin include phenol novolac resin, resol resin, bisphenol A novolak resin, and cresol novolac resin.

Commercial products of the above phenolic resin (phenolic resin curing agent) include, for example, Phenolyte LF2882, Phenolyte LF2822, Phenolyte TD-2090, Phenolyte TD-2149, Phenolyte VH4150, and Phenolyte VH4170 (all mentioned above, DIC Corporation (product name).

The hydroxyl equivalent of the phenol resin may be, for example, 250 g/eq or more, 200 g/eq or more, or 150 g/eq or more from the viewpoint of adhesiveness and heat resistance. Further, the phenol resin as the component (c) is preferably a novolac type or resol type resin from the viewpoint of improving the electrolytic corrosion resistance during moisture absorption.

From the viewpoint of improving moisture resistance, the phenol resin preferably has a water absorption rate of 2% by mass or less after being placed in a constant temperature and humidity chamber at 85° C. and 85% RH for 48 hours. In addition, the phenol resin as component (c) has a heating weight loss rate of less than 5% by weight at 350°C (heating rate: 5°C/min, atmosphere: nitrogen) measured with a thermogravimetric analyzer (TGA). Preferably. When such a phenolic resin is used as a curing agent, the volatile content is suppressed during heat processing, etc., thereby increasing the reliability of various properties such as heat resistance and moisture resistance. It is thought that contamination of equipment due to volatile matter can be reduced.

Specific examples of the phenol resin include compounds represented by the following formula (I).

In formula (I), R ¹ is a hydrogen atom, a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, a cyclic alkyl group, an aralkyl group, an alkenyl group, a hydroxyl group, an aryl group, or represents a halogen atom, n represents an integer of 1 to 3, and m represents an integer of 0 to 50. In formula (I), a plurality of R ¹ and n may be the same or different.

Examples of the compound represented by formula (I) include Mirex XLC-series and Mirex XL series (trade names, manufactured by Mitsui Chemicals, Inc.).

The compound represented by formula (I) can be obtained, for example, by reacting a phenol compound and a xylylene compound without a catalyst or in the presence of an acid catalyst (acidic catalyst). Note that the xylylene compound can form a divalent linking group through the reaction.

Examples of the phenol compound used in the production of the compound represented by formula (I) include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, p-ethylphenol, on-propyl Phenol, m-n-propylphenol, p-n-propylphenol, o-isopropylphenol, m-isopropylphenol, p-isopropylphenol, o-n-butylphenol, m-n-butylphenol, pn-butylphenol, o - Isobutylphenol, m-isobutylphenol, p-isobutylphenol, octylphenol, nonylphenol, 2,4-xylenol, 2,6-xylenol, 3,5-xylenol, 2,4,6-trimethylphenol, resorcinol, catechol, hydroquinone , 4-methoxyphenol, o-phenylphenol, m-phenylphenol, p-phenylphenol, p-cyclohexylphenol, o-allylphenol, p-allylphenol, o-benzylphenol, p-benzylphenol, o-chlorophenol , p-chlorophenol, o-bromophenol, p-bromophenol, o-iodophenol, p-iodophenol, o-fluorophenol, m-fluorophenol and p-fluorophenol. The above phenol compounds may be used alone or in combination of two or more.

From the viewpoints of adhesiveness, heat resistance, and moisture resistance, the phenol compound used in the production of the compound represented by formula (I) is preferably phenol, o-cresol, m-cresol, or p-cresol.

Examples of the xylylene compound used in the production of the compound represented by formula (I) include xylylene dihalide, xylylene diglycol, and derivatives thereof.

Specific examples of the above xylylene compounds include α,α'-dichloro-p-xylene, α,α'-dichloro-m-xylene, α,α'-dichloro-o-xylene, α,α'-dibromo-p- Xylene, α,α'-dibromo-m-xylene, α,α'-dibromo-o-xylene, α,α'-diiodo-p-xylene, α,α'-diiodo-m-xylene, α,α' -diiodo-o-xylene, α,α'-dihydroxy-p-xylene, α,α'-dihydroxy-m-xylene, α,α'-dihydroxy-o-xylene, α,α'-dimethoxy-p-xylene , α,α'-dimethoxy-m-xylene, α,α'-dimethoxy-o-xylene, α,α'-diethoxy-p-xylene, α,α'-diethoxy-m-xylene, α,α'- Diethoxy-o-xylene, α,α'-di-n-propoxy-p-xylene, α,α'-n-propoxy-m-xylene, α,α'-di-n-propoxy-o-xylene, α , α'-di-isopropoxy-p-xylene, α,α'-diisopropoxy-m-xylene, α,α'-diisopropoxy-o-xylene, α,α'-di-n-butoxy- p-xylene, α,α'-di-n-butoxy-m-xylene, α,α'-di-n-butoxy-o-xylene, α,α'-diisobutoxy-p-xylene, α,α'- Diisobutoxy-m-xylene, α,α'-diisobutoxy-o-xylene, α,α'-di-tert-butoxy-p-xylene, α,α'-di-tert-butoxy-m-xylene and α,α '-di-tert-butoxy-o-xylene. The above xylylene compounds may be used alone or in combination of two or more.

The above xylylene compounds are α,α'-dichloro-p-xylene, α,α'-dichloro-m-xylene, α,α' -dichloro-o-xylene, α,α'-dihydroxy-p-xylene, α,α'-dihydroxy-m-xylene, α,α'-dihydroxy-o-xylene, α,α'-dimethoxy-p-xylene , α,α'-dimethoxy-m-xylene, or α,α'-dimethoxy-o-xylene.

Examples of the acid catalyst include mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid, and polyphosphoric acid; organic carboxylic acids such as dimethyl sulfuric acid, diethyl sulfuric acid, p-toluenesulfonic acid, methanesulfonic acid, and ethanesulfonic acid; trifluoromethane; Super strong acids such as sulfonic acid; Strong acidic ion exchange resins such as alkanesulfonic acid type ion exchange resins; Super strong acidic ion exchange resins such as perfluoroalkanesulfonic acid type ion exchange resins (for example, Nafion, Du Pont Co., Ltd. natural and synthetic zeolite compounds; and activated clay (eg, acid clay).

The above reaction is carried out, for example, at 50 to 250° C. until the xylylene compound as a raw material substantially disappears and the reaction composition becomes constant.

The reaction time can be adjusted as appropriate depending on the raw materials and reaction temperature. The reaction time may be determined while monitoring the reaction composition using, for example, GPC (gel permeation chromatography). The reaction time may be, for example, about 1 hour to 15 hours.

When the above reaction proceeds in the presence of an acid catalyst, water or alcohol is usually produced.

On the other hand, for example, when using a halogenoxylene derivative such as α,α'-dichloro-p-xylene as a xylylene compound, the reaction proceeds without a catalyst while producing hydrogen halide gas, so an acid catalyst is not necessarily required. I don't.

The reaction molar ratio between the phenol compound and the xylylene compound is usually such that the phenol compound is in excess. In this case, unreacted phenol compounds are recovered after the reaction. The weight average molecular weight of the compound represented by formula (I) is usually determined by the reaction molar ratio between the phenol compound and the xylylene compound. The more the phenol compound is in excess, the more the weight average molecular weight of the compound represented by formula (I) tends to decrease.

The phenol resin may have, for example, an allylphenol skeleton. A phenol resin having an allylphenol skeleton can be obtained by, for example, producing an unallylated phenol resin, reacting it with allyl halide, converting it to allyl ether, and then allylating it by Claisen rearrangement. can.

Examples of the above amine compounds as component (c) include aliphatic or aromatic primary amines, secondary amines, tertiary amines, quaternary ammonium salts; aliphatic cyclic amine compounds; guanidine compounds; and urea derivatives.

Specific examples of the above amine compounds include N,N-benzyldimethylamine, 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, tetramethylguanidine, triethanolamine, N,N- '-dimethylpiperazine, 1,4-diazabicyclo[2.2.2]octane, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.4.0]-5 -Nonene, hexamethylenetetramine, pyridine, picoline, piperidine, pyrrolidine, dimethylcyclohexylamine, dimethylhexylamine, cyclohexylamine, diisobutylamine, di-n-butylamine, diphenylamine, N-methylaniline, tri-n-propylamine, tri- -n-octylamine, tri-n-butylamine, triphenylamine, tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium iodide, triethylenetetramine, diaminodiphenylmethane, diaminodiphenyl ether, dicyandiamide, tolylbiguanide, guanylurea and Contains dimethylurea. The above amine compounds include, for example, dihydrazide compounds such as adipic acid dihydrazide; guanamic acid; melamic acid; addition compounds of epoxy compounds and dialkylamine compounds; addition compounds of amines and thiourea; and addition compounds of amines and isocyanates. There may be. These amine compounds may have, for example, an adduct structure from the viewpoint of reducing activity at room temperature.

Examples of the acid anhydride as component (c) include phthalic anhydride, hexahydrophthalic anhydride, pyromellitic dianhydride, and benzophenonetetracarboxylic dianhydride.

The organic phosphorus compound as component (c) is not particularly limited as long as it is a phosphorus compound having an organic group. Examples of the organic phosphorus compounds include hexamethylphosphoric triamide, tri(dichloropropyl) phosphate, tri(chloropropyl) phosphate, triphenyl phosphite, trimethyl phosphate, phenylphosphonic acid, and triphenylphosphine. , tri-n-butylphosphine and diphenylphosphine.

Component (c) may be used alone or in combination of two or more.

[(d) α-Alumina filler]
(d) α-alumina filler (hereinafter referred to as component (d) in some cases) according to the present embodiment is (d1) a polyhedral α-alumina filler with a purity of 99.90% by mass or more (hereinafter referred to as (d1) in some cases). (referred to as ingredients). Note that in this specification, a polyhedron refers to a solid having a plurality of planes as a constituent part of its surface. A plurality of planes may intersect each other via a curved surface. A polyhedron may, for example, have from 4 to 100 planes as part of its surface.

Component (d) may further contain α-alumina fillers (for example, spherical α-alumina fillers) other than component (d1). In this case, the content of component (d1) in component (d) may be, for example, 50% by mass or more, or 70% by mass or more, based on the total mass of component (d). It may be 80% by mass or more. Moreover, the (d) component may be, for example, a mode consisting of the (d1) component, that is, the (d) component may be the (d1) component.

The average particle diameter (d ₅₀ ) of component (d) is preferably 1/2 or less, and 1/3 or less of the thickness of the adhesive film, from the viewpoint of further improving adhesive strength, lamination properties, and reliability. More preferably, it is 1/4 or less. The average particle size (d ₅₀ ) of the component (d) may be, for example, 1/1000 or more, 1/500 or more, or 1/100 or more of the thickness of the adhesive film. .

The average particle diameter ( _d90 ) of component (d) is preferably 1/2 or less, and 1/3 or less of the thickness of the adhesive film, from the viewpoint of further improving adhesive strength, lamination properties, and reliability. More preferably, it is 1/4 or less. The average particle diameter (d ₉₀ ) of the component (d) may be, for example, 1/1000 or more, 1/500 or more, or 1/100 or more of the thickness of the adhesive film. .

In this specification, the average particle size (d ₅₀ ) refers to the particle size at which the integrated value of the particle size distribution corresponds to 50%, and the average particle size (d ₉₀ ) refers to the particle size at which the integrated value of the particle size distribution corresponds to 90%. Refers to the corresponding particle size.

Component (d) may be, for example, a mixture of two or more types of α-alumina fillers having different average particle diameters (d ₅₀ ). In this case, the average particle size (d ₅₀ ) and average particle size (d ₉₀ ) of the mixture are preferably within the above-mentioned ranges.

The content of component (a) in the adhesive film of this embodiment is determined from the viewpoint of reducing the elastic modulus and imparting flowability during molding. d) It may be, for example, 3% by mass or more based on the total mass of the components. The content of component (a) is determined from the viewpoint of preventing fluidity from decreasing even when the pasting load is small and having excellent circuit filling properties. Based on the total mass, it may be, for example, 40% by mass or less, 30% by mass or less, or 20% by mass or less. From these viewpoints, the content of component (a) above is preferably 3 to 40% by mass based on the total mass of component (a), component (b), component (c), and component (d). The content is preferably 3 to 30% by mass, more preferably 3 to 20% by mass.

The content of component (b) in the adhesive film of this embodiment is, for example, 3% by mass or more based on the total mass of component (a), component (b), component (c), and component (d). It's okay. The content of component (b) may be, for example, 40% by mass or less, and 30% by mass based on the total mass of component (a), component (b), component (c), and component (d). It may be less than or equal to 20% by mass. The content of component (b) is based on the total mass of component (a), component (b), component (c), and component (d) from the viewpoint of adhesiveness, heat resistance, and moisture absorption resistance after thermosetting. For example, it may be 3 to 40% by weight, 3 to 30% by weight, or 3 to 20% by weight.

The content of component (c) in the adhesive film of this embodiment is not particularly limited as long as the curing reaction of component (b) can proceed, but based on 1 equivalent of epoxy group in component (b), The active group in component (c) that can react with an epoxy group (hydroxyl group, amino group, acid anhydride group, group containing a phosphorus atom, etc.) is, for example, in the range of 0.01 to 5.0 equivalents. The amount may be in the range of 0.8 to 1.2 equivalents.

For example, when component (c) is a phenol resin, the content of component (c) in the adhesive film of this embodiment is determined based on the epoxy equivalent of component (b) from the viewpoint of improving the curability of the adhesive film. and the equivalent ratio of the hydroxyl group equivalents of the phenol resin (epoxy equivalent/hydroxyl group equivalent), for example, it may be 0.70/0.30 to 0.30/0.70, or 0.65/0.35 to 0.35/0.65, 0.60/0.30 to 0.30/0.60, 0.55/0.45 to 0.45/0.55 There may be.

As mentioned above, the content of component (d) in the adhesive film of this embodiment is 60 parts by mass based on 100 parts by mass of the total amount of component (a), component (b), component (c), and component (d). ~95 parts by mass. The content of component (d) is determined based on 100 parts by mass of the total amount of component (a), component (b), component (c), and component (d), from the viewpoint of further improving the thermal conductivity of the adhesive film. , for example, may be 65 parts by mass or more, or may be 70 parts by mass or more. The content of component (d) is set to 100 parts by mass in total of component (a), component (b), component (c), and component (d) from the viewpoint of improving the flexibility and adhesiveness of the adhesive film. On the other hand, it may be, for example, 90 parts by mass or less. From these viewpoints, the content of component (d) is, for example, 60 to 90 parts by mass with respect to 100 parts by mass of the total amount of component (a), component (b), component (c), and component (d). The amount may be 70 to 90 parts by mass.

[Other ingredients]
The adhesive film of this embodiment may contain components other than those mentioned above. Examples of such components include a curing accelerator, fillers other than component (d), coupling agents, and ion scavengers.

(hardening accelerator)
The curing accelerator is not particularly limited, and examples thereof include imidazole compounds. Examples of imidazole compounds include imidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl-2-methylimidazole, 2- Heptadecylimidazole, 4,5-diphenylimidazole, 2-methylimidazoline, 2-phenylimidazoline, 2-undecylimidazoline, 2-heptadecylimidazoline, 2-isopropylimidazole, 2,4-dimethylimidazole, 2-phenyl-4 - Methylimidazole, 2-ethylimidazoline, 2-phenyl-4-methylimidazoline, benzimidazole, 1-cyanoethylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2-phenylimidazolium trimellitate. It will be done. The above curing accelerators may be used alone or in combination of two or more. Commercially available imidazole compounds include, for example, 2E4MZ, 2PZ-CN, and 2PZ-CNS (all trade names, manufactured by Shikoku Kasei Kogyo Co., Ltd.).

Moreover, from the viewpoint of extending the period of use of the film, the curing accelerator may be a curing accelerator having latent properties. Examples of such curing accelerators include addition compounds of epoxy compounds and imidazole compounds. From the viewpoint of reducing activity at room temperature, the curing accelerator may have an adduct-type structure.

The blending amount of the curing accelerator is, for example, 5.0% by mass based on the total mass of components (b) and (c), from the viewpoint of excellent storage stability and the viewpoint of easily ensuring a sufficient pot life. It may be less than or equal to 3.0% by mass. The blending amount of the curing accelerator is, for example, 0.02% by mass or more based on the total mass of components (b) and (c) from the viewpoint of adhesion, heat resistance, and moisture resistance after thermosetting. The content may be 0.03% by mass or more. From these viewpoints, the blending amount of the curing accelerator may be, for example, 0 to 5.0% by mass, or 0.02 to 3.0% by mass, based on the total mass of components (b) and (c). It may be 0% by mass or 0.03 to 3.0% by mass.

(Fillers other than component (d))
The adhesive film of this embodiment may contain various fillers other than the above component (d) for the purpose of improving the handling properties of the film, adjusting the melt viscosity, imparting thixotropic properties, improving moisture resistance, etc. . Examples of materials constituting such fillers include alumina other than α-alumina, aluminum nitride, hexagonal boron nitride, cubic boron nitride, silicon nitride, diamond, aluminum hydroxide, magnesium hydroxide, calcium carbonate, and carbonate. Examples include magnesium, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum borate whiskers, crystalline silica, amorphous silica and antimony oxide. These may be used alone or in combination of two or more.

From the viewpoint of improving thermal conductivity, the material constituting the filler may be crystalline silica or amorphous silica. From the viewpoint of adjusting melt viscosity and imparting thixotropic properties, the materials constituting the filler include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, It may be crystalline silica or amorphous silica. From the viewpoint of improving moisture resistance, the material constituting the filler may be silica, aluminum hydroxide, or antimony oxide.

When the adhesive film of the present embodiment contains a filler other than the component (d), the content of the filler other than the component (d) is, for example, 50 parts by mass with respect to 100 parts by mass of the total mass of the component (d). 20 parts by mass or less, or 10 parts by mass or less.

(coupling agent)
The adhesive film of this embodiment may contain various coupling agents, for example, from the viewpoint of improving interfacial bonding between different materials. Examples of the coupling agent include a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent.

There are no particular limitations on the silane coupling agent, and examples include vinyltrichlorosilane, vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxysilane, and γ-methacryloxypropyltrimethoxysilane. Roxypropylmethyldimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxy Silane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ- Aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-ureidopropyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-amino Propyltrimethoxysilane, 3-aminopropyl-tris(2-methoxy-ethoxy-ethoxy)silane, N-methyl-3-aminopropyltrimethoxysilane, triaminopropyl-trimethoxysilane, 3-(4,5-dihydro ) Imidazol-1-yl-propyltrimethoxysilane, 3-methacryloxypropyl-trimethoxysilane, 3-mercaptopropyl-methyldimethoxysilane, 3-chloropropyl-methyldimethoxysilane, 3-chloropropyl-dimethoxysilane, 3- Cyanopropyl-triethoxysilane, hexamethyldisilazane, N,O-bis(trimethylsilyl)acetamide, methyltrimethoxysilane, methyltriethoxysilane, ethyltrichlorosilane, n-propyltrimethoxysilane, isobutyltrimethoxysilane, amyltrimethoxysilane Chlorosilane, octyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, methyltri(methacryloyloxyethoxy)silane, methyltri(glycidyloxy)silane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltri Methoxysilane, octadecyldimethyl[3-(trimethoxysilyl)propyl]ammonium chloride, γ-chloropropylmethyldichlorosilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, trimethylsilyl isocyanate, dimethylsilyl isocyanate, Mention may be made of methylsilyltriisocyanate, vinylsilyltriisocyanate, phenylsilyltriisocyanate, tetraisocyanatesilane and ethoxysilaneisocyanate. These may be used alone or in combination of two or more.

There are no particular limitations on the titanium-based coupling agent, and examples include isopropyltrioctanoyltitanate, isopropyldimethacrylisostearoyltitanate, isopropyltridodecylbenzenesulfonyltitanate, isopropylisostearoyldiacryltitanate, isopropyltri(dioctylphosphate)titanate, Isopropyl tricumylphenyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, isopropyl tris(n-aminoethyl) titanate, tetraisopropyl bis(dioctyl phosphite) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, tetra(2, 2-diallyloxymethyl-1-butyl)bis(ditridecyl)phosphite titanate, dicumylphenyloxyacetate titanate, bis(dioctylpyrophosphate)oxyacetate titanate, tetraisopropyl titanate, tetra-n-butyl titanate, butyl titanate dimer, tetra( 2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium aethyl acetonate, titanium octylene glycolate, titanium lactate ammonium salt, titanium lactate, titanium lactate ethyl ester, titanium titanium amine, polyhydroxy titanium stearate, tetra Methyl orthotitanate, tetraethyl orthotitanate, tetrapropyl orthotitanate, tetraisobutyl orthotitanate, stearyl titanate, cresyl titanate monomer, cresyl titanate polymer, diisopropoxy-bis(2,4-pentadionate) titanium (IV), Diisopropyl-bis-triethanolaminotitanate, octylene glycol titanate, tetra-n-butoxytitanium polymer, tri-n-butoxytitanium monostearate polymer, and tri-n-butoxytitanium monostearate. These may be used alone or in combination of two or more.

The aluminum-based coupling agent is not particularly limited, and examples include ethyl acetoacetate aluminum diisopropylate, aluminum tois (ethylacetoacetate), alkyl acetoacetate aluminum diisopropylate, aluminum monoacetylacetate bis(ethylacetoacetate), Aluminum such as aluminum tris(acetylacetonate), aluminum monoisopropoxy monooleoxyethylacetoacetate, aluminum di-n-butoxide-mono-ethylacetoacetate, aluminum di-iso-propoxide-mono-ethylacetoacetate, etc. Chelate compounds; and aluminum alcoholates such as aluminum isopropylate, mono-sec-butoxyaluminum diisopropylate, aluminum-sec-butyrate, and aluminum ethylate. These may be used alone or in combination of two or more.

From the viewpoint of adhesion when adhering to a Si wafer, the coupling agent is preferably a silane-based coupling agent.

When the adhesive film of this embodiment contains a coupling agent, the content of the coupling agent is the sum of components (a), (b), and (c) from the viewpoint of its effect, heat resistance, and cost. For example, the amount may be 10 parts by weight or less, 0.1 to 5 parts by weight, or 0.2 to 3 parts by weight based on 100 parts by weight.

(ion scavenger)
The adhesive film of this embodiment may contain an ion scavenger, for example, from the viewpoint of adsorbing ionic impurities and improving insulation reliability during moisture absorption. Examples of the ion-trapping agent include copper damage inhibitors used to prevent copper from ionizing and dissolving. Examples of the copper damage inhibitor include triazinethiol compounds, bisphenol reducing agents, and inorganic ion adsorbents.

As a commercially available product of a copper damage inhibitor containing a triazinethiol compound, for example, Gisnet DB (manufactured by Sankyo Kasei Co., Ltd., trade name) can be mentioned.

Examples of bisphenol reducing agents include 2,2'-methylene-bis-(4-methyl-6-tert-butylphenol) and 4,4'-thio-bis-(3-methyl-6-tert-butylphenol). -butylphenol). Examples of commercially available bisphenol-based reducing agents include Yoshinox BB (manufactured by Yoshitomi Pharmaceutical Co., Ltd., trade name).

Examples of the inorganic ion adsorbent include zirconium compounds, antimony bismuth compounds, and magnesium aluminum compounds. Examples of commercially available inorganic ion adsorbents include IXE (trade name, manufactured by Toagosei Co., Ltd.).

From the viewpoint of the effect of addition, heat resistance and cost, the content of the ion scavenger is, for example, 1 part by mass per 100 parts by mass of the total amount of the resin composition (for example, varnish described below) used for forming the adhesive film. It may be up to 10 parts by mass.

There is no particular limit to the thickness of the adhesive film. The thickness of the adhesive film may be, for example, 5 μm or more, or 8 μm or more, from the viewpoint of improving the stress relaxation effect and embeddability. From the viewpoint of reducing costs, the thickness of the adhesive film may be, for example, 50 μm or less, or 40 μm or less. From these viewpoints, the thickness of the adhesive film may be, for example, 5 to 50 μm, 5 to 40 μm, or 8 to 40 μm.

[Method for manufacturing adhesive film]
The adhesive film of this embodiment is made of a varnish prepared by mixing the above-mentioned (a) component, (b) component, (c) component, (d) component, and optional components as necessary in a solvent, for example. It can be formed by applying the varnish onto a film (for example, a carrier film) and removing the solvent from the applied varnish.

There are no particular restrictions on the solvent used when preparing the varnish. Such solvents include, for example, methyl ethyl ketone, acetone, methyl isobutyl ketone, 2-ethoxyethanol, toluene, butyl cellosolve, methanol, ethanol, 2-methoxyethanol, dimethylacetamide, dimethylformamide, methylpyrrolidone and cyclohexanone. . Among these, from the viewpoint of improving coating properties, the solvent is preferably a high boiling point solvent such as methyl ethyl ketone, dimethylacetamide, dimethylformamide, methylpyrrolidone, or cyclohexanone. These solvents may be used alone or in combination of two or more.

There is no particular restriction on the content of the solvent in the varnish, but the content of non-volatile matter in the varnish is based on the total mass of the varnish, for example, from the viewpoint of reducing the amount of heat required for drying the varnish and being cost effective. , may be 40% by mass or more, or may be 50% by mass or more. The content of non-volatile matter in the varnish may be, for example, 90% by mass or less based on the total mass of the varnish, from the viewpoint of not increasing the viscosity of the varnish too much and easily reducing defects in the coating film caused by this. It may be 80% by mass or less. From these viewpoints, the content of nonvolatile matter in the varnish is preferably, for example, 40 to 90% by mass, more preferably 50 to 80% by mass, based on the total mass of the varnish.

The components can be mixed using, for example, a miller, a three-roll mill, a bead mill, or a combination thereof. Further, for example, the time required for mixing can be shortened by mixing the filler component and the low molecular weight material in advance and then adding the high molecular weight material. Moreover, it is preferable to remove air bubbles from the varnish by vacuum degassing before applying it onto the base film.

Next, an adhesive film can be formed on the base film by applying the prepared varnish onto the base film and removing the solvent, for example, by heating.

The above heating conditions are not particularly limited as long as they can remove the solvent without completely curing the adhesive film, and may be adjusted as appropriate depending on the components of the adhesive film and the type of solvent in the varnish, for example. can. Typical heating conditions are, for example, 80 to 140° C. for 5 to 60 minutes.

The adhesive film may be cured to about B stage by heating. The amount of solvent remaining in the adhesive film is preferably 3% by mass or less, more preferably 1.5% by mass or less, based on the total mass of the adhesive film.

Examples of the base film include polytetrafluoroethylene film, polyethylene terephthalate film, polyethylene film, polypropylene film, polymethylpentene film, polyimide film, polyethylene naphthalate film, polyether sulfone film, polyether amide film, polyether Examples include plastic films such as amide-imide film, polyamide film, and polyamide-imide film.

The base film may be subjected to surface treatments such as primer coating, UV treatment, corona discharge treatment, polishing treatment, etching treatment, mold release treatment, etc., as necessary.

Examples of commercially available polyimide films include Kapton (manufactured by DuPont-Toray Co., Ltd., trade name) and Apical (manufactured by Kaneka Corporation, trade name).

Examples of commercially available polyethylene terephthalate films include Lumirror (manufactured by DuPont-Toray Co., Ltd., trade name) and Purex (manufactured by Teijin Corporation, trade name).

[Dicing/die bonding film]
The adhesive film of this embodiment can be applied to, for example, a dicing die bonding film. Hereinafter, one embodiment of a dicing die bonding film will be described.

The dicing/die bonding film of this embodiment includes a dicing film and a die bonding film laminated on the dicing film. There is no particular restriction on the dicing film, and it can be determined as appropriate based on the knowledge of those skilled in the art, for example, taking into account the application and the like. Examples of the dicing film include plastic films such as polytetrafluoroethylene film, polyethylene terephthalate film, polyethylene film, polypropylene film, polymethylpentene film, and polyimide film. The dicing film may be subjected to surface treatments such as primer coating, UV treatment, corona discharge treatment, polishing treatment, etching treatment, etc., as necessary. The dicing film preferably has adhesive properties. Examples of the adhesive dicing film include the above-mentioned plastic film with adhesive properties, and the above-mentioned plastic film with an adhesive layer on one side. The adhesive layer is formed, for example, from a resin composition (resin composition for forming an adhesive layer) containing a liquid component and a high molecular weight component and having an appropriate tack strength. A dicing tape with an adhesive layer can be produced by, for example, applying a resin composition for forming an adhesive layer onto the above-mentioned plastic film and drying it, or applying the resin composition for forming an adhesive layer onto a base film such as a PET film. It can be manufactured by laminating an adhesive layer formed by coating and drying on the above-mentioned plastic film. The tack strength is set to a desired value by, for example, adjusting the ratio of liquid components and the Tg of high molecular weight components. The die bonding film is the adhesive film of this embodiment described above. For example, the dicing film and the die bonding film may be in direct contact with each other, or may be laminated with another layer such as an adhesive layer interposed therebetween.

There are no particular limitations on the method for manufacturing the dicing die bonding film of this embodiment, and it can be determined as appropriate based on the knowledge of those skilled in the art. The dicing/die bonding film of this embodiment can be manufactured, for example, by using a dicing film instead of the base film in the adhesive film manufacturing method described above. Further, the dicing/die bonding film of this embodiment can also be manufactured by, for example, separately preparing the adhesive film of this embodiment and a dicing film, and then laminating and integrating them.

Hereinafter, the present invention will be explained in more detail with reference to Examples. However, the present invention is not limited to these examples.

The following ingredients were prepared.
(a) Acrylic resin component:
・Epoxy group-containing acrylic rubber: HTR-860P-3 (manufactured by Nagase ChemteX Co., Ltd., trade name, weight average molecular weight 800,000, Tg 12°C)
(b) Epoxy resin component:
・Bisphenol F type epoxy resin: YDF-8170C (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., trade name, epoxy equivalent: 156)
・Cresol novolac type epoxy resin: YDCN-703 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., product name)
(c) Hardening agent component:
・Phenol resin: XLC-LL (manufactured by Mitsui Chemicals, Inc., product name)
Filler ingredients:
- Polyhedral α-alumina: Sumicorandom AA-3 (manufactured by Sumitomo Chemical Co., Ltd., trade name, purity Al ₂ O ₃ ≧99.90%, average particle size 2.7 to 3.6 μm)
- Spherical α-alumina: Alumina beads CB-P05 (manufactured by Showa Denko K.K., trade name, purity Al ₂ O ₃ 99.89%, average particle size 4 μm)
- Spherical alumina: DAW-05 (manufactured by Denka Co., Ltd., trade name, purity Al ₂ O ₃ >99.8%, average particle size 5 μm)
- Spherical alumina: DAW-03 (manufactured by Denka Co., Ltd., trade name, purity Al ₂ O ₃ >99.8%, average particle size 4 μm)
Curing accelerator:
・Curesol 2PZ-CN (manufactured by Shikoku Kasei Kogyo Co., Ltd., product name)
Coupling agent:
・A-189 (manufactured by Nippon Unicar Co., Ltd., trade name, γ-mercaptopropyltrimethoxysilane)
・A-1160 (manufactured by Nippon Unicar Co., Ltd., trade name, γ-ureidopropyltriethoxysilane)

(Example 1)
Epoxy group-containing acrylic rubber HTR-860P-3 (manufactured by Nagase ChemteX Co., Ltd., trade name) 4.50 parts by mass, bisphenol F-type epoxy resin YDF-8170C (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., trade name) 4.00 parts by mass 1.00 parts by mass of cresol novolac epoxy resin YDCN-703 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., trade name), 5.50 parts by mass of phenolic resin XLC-LL (manufactured by Mitsui Chemicals Co., Ltd., trade name), curing acceleration Agent Curesol 2PZ-CN (manufactured by Shikoku Kasei Kogyo Co., Ltd., trade name) 0.01 parts by mass, coupling agent A-189 (manufactured by Nippon Unicar Co., Ltd., trade name) 0.04 parts by mass, and coupling agent A -1160 (manufactured by Nippon Unicar Co., Ltd., trade name) cyclohexanone was added to a composition consisting of 0.08 parts by mass so that the solid content was approximately 57%, and polyhedral α-alumina Sumicorundum AA-3 (Sumitomo Chemical 85.00 parts by mass of (manufactured by Co., Ltd., trade name) was added to obtain a mixture.

Zirconia beads of 1 mm diameter having a mass equivalent to the total mass of the mixture were added to the above mixture, and the mixture was stirred twice for 30 minutes at 600 rpm using a bead mill. Zirconia beads were removed from the stirred mixture by filtration to obtain a varnish.

The obtained varnish was applied onto a release-treated polyethylene terephthalate film A31 (manufactured by Teijin DuPont Films Ltd., trade name) having a thickness of 38 μm as a base film. The applied varnish was heated and dried at 120° C. for 5 minutes to produce an adhesive film with a thickness of 25 μm on the base film.

(Example 2)
An adhesive film was produced in the same manner as in Example 1 except that the amounts of each component were changed to those shown in Table 1. Note that the blending amounts in Table 1 indicate parts by mass.

(Comparative example 1)
An adhesive film was produced in the same manner as in Example 1 except that the polyhedral α-alumina was changed to spherical α-alumina alumina beads CB-P05 (trade name, manufactured by Showa Denko K.K.).

(Comparative example 2)
An adhesive film was produced in the same manner as in Example 1 except that the polyhedral α-alumina was changed to spherical alumina DAW-05 (manufactured by Denka Co., Ltd., trade name).

(Comparative example 3)
An adhesive film was produced in the same manner as in Example 1 except that the polyhedral α-alumina was changed to spherical alumina DAW-03 (manufactured by Denka Co., Ltd., trade name).

(Comparative example 4 and comparative example 5)
An adhesive film was produced in the same manner as in Example 1 except that the amounts of each component were changed to those shown in Table 1.

[evaluation]
The resulting adhesive film was evaluated for thermal conductivity, surface roughness Ra, adhesive strength, and lamination properties as follows.

(Thermal conductivity)
A plurality of adhesive films peeled from the base film were bonded together to produce a laminated film having a thickness of 100 μm or more and less than 600 μm. The obtained laminated film was cured at 110° C. for 1 hour and at 170° C. for 3 hours to obtain a cured film (cured product). The obtained cured film was cut into 10 mm square pieces, which were used as samples for measurement.

Thermal diffusivity α (mm ² /s), specific heat Cp (J/(g·° C.) and specific gravity (g/cm ³ ) of the measurement sample were measured by the following methods.
- Thermal diffusivity α (mm ² /s): Thermal diffusivity α at 25° C. was measured in the thickness direction of the adhesive film using a laser flash method (manufactured by NETZSCH, LFA467HyperFlash (trade name)).
・Specific heat Cp (J/(g・℃)): By measuring using the DSC method (manufactured by Perkin Elmer, DSC8500 (trade name)) at a heating rate of 10℃/min and a temperature of 20 to 60℃ , specific heat Cp at 25°C was measured.
- Specific gravity (g/cm ³ ): Specific gravity was measured using an electronic hydrometer SD-200L (manufactured by Mirage, trade name).

The obtained thermal diffusivity α, specific heat Cp, and specific gravity were introduced into the following formula to calculate the thermal conductivity (W/m·K).
Thermal conductivity (W/m・K) = thermal diffusivity α (mm ² /s) x specific heat Cp (J/(g・℃)) x specific gravity (g/cm ³ )

(Surface roughness Ra)
The adhesive film peeled from the base film was bonded to a 300 μm thick silicon wafer using a hot roll laminator (80°C, 0.3m/min, 0.3MPa), and then heated at 110°C for 1 hour at 170°C. A sample was obtained by curing at ℃ for 3 hours. The arithmetic mean roughness (Ra) of the obtained sample in a range of 2.5 mm was calculated using a micro-shape measuring device Surf corder ET200 (manufactured by Kosaka Institute, trade name).

(adhesive strength)
The adhesive film on the base film was bonded to a semiconductor chip (5 mm square) using a hot roll laminator (80° C., 0.3 m/min, 0.3 MPa). The adhesive film on the semiconductor chip was adhered to a 42 alloy substrate at 120° C. and 250 g for 5 seconds, and then cured at 110° C. for 1 hour and at 170° C. for 3 hours to obtain a sample. The shear strength of the obtained sample before and after the moisture absorption test was measured using a universal bond tester (manufactured by Dage, series 4000, trade name). The conditions for the moisture absorption test were 85° C./85% RH for 48 hours.

The adhesive strength was evaluated as "good" when the shear strength was 2.0 MPa, and as "poor" when the shear strength was <2.0 MPa.

(Lamination property)
The laminate of the base film and adhesive film was cut into a width of 10 mm. The adhesive film surface of the laminate was bonded to a 300 μm thick silicon wafer using a hot roll laminator (80° C., 0.3 m/min, 0.3 MPa). Thereafter, the bonded adhesive film was peeled off at a 90° angle at a tensile speed of 50 mm/min in an atmosphere of 25°C using a small tabletop testing machine EZ-S manufactured by Shimadzu Corporation. The strength was measured. The lamination property was evaluated as "good" when the 90° peel strength was 20 N/m or more, and as "poor" when the 90° peel strength was less than 20 N/m.

From the results in Table 1, it can be seen that the adhesive films of Examples 1 and 2 have a thermal conductivity of ≧2 W/m·K after thermosetting, and are excellent in thermal conductivity after thermosetting. It can be seen that the adhesive films of Examples 1 and 2 have excellent adhesive properties (adhesive strength) and lamination properties, and also have low surface roughness.

Claims (4)

(a) acrylic resin (excluding silicone-acrylic particles), (b) epoxy resin, (c) curing agent, and (d) α-alumina filler,
(d) the α-alumina filler contains polyhedral α-alumina filler with a purity of 99.90% by mass or more,
The content of the (d) α-alumina filler is 60 to 60 parts by mass based on 100 parts by mass of the total amount of (a) acrylic resin, (b) epoxy resin, (c) curing agent, and (d) α-alumina filler. 95 parts by mass,
The acrylic resin (a) is an acrylic copolymer containing an epoxy group, has a weight average molecular weight of 500,000 to 2,000,000, and has a glass transition temperature of -50°C to 30°C,
The epoxy resin (b) contains a bifunctional epoxy resin and a trifunctional or higher functional epoxy resin (excluding epoxy group-containing acrylic resin),
An adhesive film, wherein the curing agent (c) is a compound represented by the following formula (I) .
[In formula (I), R ¹ is a hydrogen atom, a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, a cyclic alkyl group, an aralkyl group, an alkenyl group, a hydroxyl group, an aryl group, or represents a halogen atom, n represents an integer of 1 to 3, and m represents an integer of 0 to 50. In formula (I), a plurality of R ¹ and n may be the same or different. ] The adhesive film according to claim 1, wherein the average particle diameter (d ₅₀ ) of the α-alumina filler (d) is 1/2 or less of the thickness of the adhesive film. The content of the (d) α-alumina filler is 60 to 60 parts by mass based on 100 parts by mass of the total amount of (a) acrylic resin, (b) epoxy resin, (c) curing agent, and (d) α-alumina filler. The adhesive film according to claim 1 or 2, which contains 90 parts by mass. The adhesive film according to any one of claims 1 to 3 , having a thickness of 50 μm or less.