JP2005194442A - Resin composition, film form adhesive and semiconductor package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a film form adhesive that retains sufficient adhesion strength even at elevated temperatures. <P>SOLUTION: The resin composition comprises (A) a polyimide resin, (B) an epoxy resin and (C) an imidazole silane bearing at least one of silane group substituted with an alkoxy group and an imidazole group in one molecule. The film form adhesive is composed of this resin composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a resin composition used for a film-like adhesive as a die-bonding material used for adhesion between semiconductor elements and adhesion between the semiconductor element and a support member when an electronic component such as a semiconductor package is manufactured. The present invention relates to a film adhesive comprising the same and a semiconductor package using the film adhesive.

  In recent years, film adhesives have been used in place of paste adhesives that have been used in the past for die-bonding materials used for bonding semiconductor elements such as ICs and LSIs and bonding them to supporting members. It is becoming. Especially for high-density mounting semiconductor packages with small mounting area such as chip size package, stack package, system-in package, etc., film adhesives with excellent thickness accuracy and protrusion controllability compared to paste adhesives are widely applied. Has been.

    On the other hand, in recent years, in view of serious environmental problems, lead-free solder used for joining a semiconductor package and a substrate is being advanced. Sn-Ag-Cu solder is cited as a promising candidate for lead-free solder, and its melting point is about 220 ° C, which is about 40 ° C higher than the melting point of current Sn-Pb solder of about 180 ° C. It is said that the surface temperature of the semiconductor package during mounting using lead-free solder reaches 250 to 260 ° C.

As a film-like adhesive, as shown in JP-A-11-228913 and the like, many things composed of a polyimide resin, a thermosetting resin and a filler have been developed. However, such a conventional film-like adhesive has a high temperature. Adhesive strength in the case was not sufficiently developed, and it was difficult to cope with lead-free. Therefore, there has been a demand for a film adhesive having sufficient adhesive strength even at high temperatures.
JP-A-11-228913

  The subject of this invention is providing the film adhesive which has sufficient adhesive strength also at high temperature.

    A film-like adhesive comprising a resin composition containing a polyimide resin (A) and an epoxy resin (B) as essential components and comprising an imidazole silane (C) having a specific structure solves the above problems. As a result, the present invention has been completed.

    Since the film-like adhesive comprising the resin composition of the present invention has sufficient adhesive strength even at high temperatures, the periphery of a semiconductor such as a die-bonding material used for bonding between semiconductor elements or bonding them to a support member It can be suitably used as a material.

Hereinafter, the present invention will be described in detail.
The resin composition of the present invention contains a polyimide resin (A), an epoxy resin (B), a silane group substituted with an alkoxy group in one molecule, and an imidazole silane (C) having at least one imidazole group.
The imidazole group in the imidazole silane (C) has a function as a curing agent when used as an adhesive, and the silane group having an alkoxy group as a substituent has a function as a silane coupling agent. In this case, sufficient adhesive strength is exhibited.
Examples of imidazole silane (C) include compounds represented by general formula (1).

（式（１）中、Ｒ₁は水素原子、ビニル基または炭素数１〜５のアルキル基を表し、Ｒ_２は水素原子または炭素数１〜２０のアルキル基を表し、Ｒ_３、Ｒ_４は炭素数１〜３のアルキル基を表し、Ｚは２価の連結基を表し、ｍは１〜３の整数を表す）
一般式（１）中、Ｚの２価の連結基としては、炭素数１〜１０のアルキレン、水酸基を有する炭素数１〜１０のアルキレンが挙げられ、アルキレン中のメチレンの一部が酸素原子等の他の原子で置換していても構わない。好ましくは、−ＣＨ_２−ＣＨ（ＯＨ）ＣＨ_２ＯＣＨ_２ＣＨ_２ＣＨ_２−である。

(In Formula (1), R ₁ represents a hydrogen atom, a vinyl group or an alkyl group having 1 to 5 carbon atoms, R ₂ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ₃ and R ₄ are (C represents an alkyl group having 1 to 3 carbon atoms, Z represents a divalent linking group, and m represents an integer of 1 to 3)
In the general formula (1), examples of the divalent linking group for Z include alkylene having 1 to 10 carbon atoms and alkylene having 1 to 10 carbon atoms having a hydroxyl group, and a part of methylene in the alkylene is an oxygen atom or the like. It may be substituted with another atom. _{Preferably, -CH 2 -CH (OH) CH} 2 OCH 2 CH 2 CH 2 - it is.

It is preferable to contain imidazole silane (C) in the ratio of 0.01-5 weight part with respect to 100 weight part of polyimide resins. More preferably, it is 0.5 to 2 parts by weight. When the amount is less than 0.01 part by weight or exceeds 5 parts by weight, sufficient adhesive strength may not be obtained at high temperature.
The polyimide resin (A) can be used without any particular limitation, but a polyimide containing a repeating structural unit represented by the general formula (2) is preferable because it can impart low-temperature adhesiveness.

（式（２）中、ｎは１〜５０の整数を表し、Ｘはそれぞれ独立に炭素数２〜１０のアルキレンを表し、Ｙは４価の有機基を表す。）
上記ポリイミド樹脂は、一般式（３）で表されるテトラカルボン酸二無水物と一般式（４）で表されるジアミン化合物を必須成分として反応させ得られるポリアミド酸を熱的あるいは化学的にイミド化することにより得られる。

(In formula (2), n represents an integer of 1 to 50, X independently represents an alkylene having 2 to 10 carbon atoms, and Y represents a tetravalent organic group.)
The polyimide resin is prepared by thermally or chemically immobilizing a polyamic acid obtained by reacting a tetracarboxylic dianhydride represented by the general formula (3) and a diamine compound represented by the general formula (4) as essential components. Can be obtained.

（式（３）中、Ｙは４価の有機基を表す）

(In formula (3), Y represents a tetravalent organic group)

（式（４）中、ｎは１〜５０の整数を表し、Ｘはそれぞれ独立に炭素数２〜１０のアルキレンを表す。）

(In formula (4), n represents an integer of 1 to 50, and each X independently represents an alkylene having 2 to 10 carbon atoms.)

There is no restriction | limiting in particular in the tetracarboxylic dianhydride represented by General formula (3), A conventionally well-known tetracarboxylic dianhydride can be used.
Y in the general formula (3) represents a tetravalent organic group, specifically, an aliphatic group, alicyclic group, monocyclic aromatic group, condensed polycyclic aromatic group having 2 to 27 carbon atoms. And non-condensed cyclic aromatic groups in which aromatic groups are connected to each other directly or by a bridging member.

  Specific examples of the tetracarboxylic dianhydride used here include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4. , 4′-biphenyltetracarboxylic dianhydride, oxy-4,4′-diphthalic dianhydride, ethylene glycol bistrimellitic dianhydride, 2,2-bis (4- (3,4-dicarboxyphenoxy) ) Phenyl) propane dianhydride and the like, and these may be used alone or in combination of two or more. Oxy-4,4'-diphthalic dianhydride is preferred.

The diamine having o-, m-, and p-aminobenzoic acid ester groups at both ends represented by the general formula (4) is not particularly limited as long as it is represented by the general formula (4). More preferably, both ends are p-aminobenzoic acid ester groups. In general formula (4), n represents an integer of 1 to 50, and X independently represents an alkylene having 2 to 10 carbon atoms. More preferably, n represents an integer of 3 to 25, and X represents each. Independently, it is alkylene having 2 to 5 carbon atoms.
Specific examples of the diamine represented by the general formula (4) include, for example, polytetramethylene oxide-di-o-aminobenzoate, polytetramethylene oxide-di-m-aminobenzoate, polytetramethylene oxide-di- Examples include, but are not limited to, p-aminobenzoate, polytrimethylene oxide-di-o-aminobenzoate, polytrimethylene oxide-di-m-aminobenzoate, polytrimethylene oxide-di-p-aminobenzoate, and the like. . Polytetramethylene oxide-di-p-aminobenzoate is preferable.
The amount contained in all diamine components of this diamine is 10 mol% or more, preferably 20 mol% or more. If it is less than 10 mol%, the bonding temperature may be undesirably high.

  Examples of other diamines include m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, bis (3-aminophenyl) sulfide, bis (4-aminophenyl) sulfide, bis (3-aminophenyl) sulfoxide, and bis (4-aminophenyl) sulfoxide, bis (3-aminophenyl) sulfone, bis (4-aminophenyl) sulfone, 2,2-bis [4- (3-aminophenoxy) phenyl] butane, 1,1,3 3-tetramethyl-1,3-bis (3-aminopropyl) disiloxane, 1,1,3,3-tetraphenyl-1,3-bis (3-aminopropyl) disiloxane, 1,3-bis ( 3-aminophenoxy) benzene, 1,3-bis (3- (3-aminophenoxy) phenoxy) benzene, 4,4′- Scan (3-aminophenoxy) but biphenyl, and the like, without limitation.

  As a method for producing a polyimide resin, all methods that can produce polyimide, including known methods, can be applied. Among these, it is preferable to perform the reaction in an organic solvent. Examples of the solvent used in such a reaction include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,2-dimethoxyethane, tetrahydrofuran, 1,3-dioxane, 1 , 4-dioxane, dimethyl sulfoxide, benzene, toluene, xylene, mesitylene, phenol, cresol and the like. These may be used alone or in combination of two or more.

  The concentration of the reaction raw material in this reaction is usually 2 to 50% by weight, preferably 5 to 40% by weight, and the reaction molar ratio of tetracarboxylic dianhydride and diamine compound is 0.8 to 1.2. A range is preferable. If it is less than 0.8 or exceeds 1.2, the heat resistance may decrease.

  The reaction temperature for the synthesis of polyamic acid, which is a polyimide precursor, is usually 60 ° C. or lower, preferably 50 ° C. or lower. The reaction pressure is not particularly limited, and can be sufficiently carried out at normal pressure. Moreover, although reaction time changes with the kind of reaction raw material, the kind of solvent, and reaction temperature, 0.5 to 24 hours is sufficient normally. The polyimide according to the present invention is such that the polyamic acid is heated to 100 to 400 ° C. to be imidized or chemically imidized by using an imidizing agent such as acetic anhydride to thereby form a repeating unit structure corresponding to the polyamic acid. Is obtained.

  Moreover, by performing reaction at 130 degreeC-250 degreeC, the production | generation of a polyamic acid and a thermal imidation reaction advance simultaneously, and the polyimide which concerns on this invention can be obtained. That is, by suspending or dissolving a diamine component and an acid dianhydride component in an organic solvent, reacting under heating at 130 to 250 ° C., and simultaneously generating polyamic acid and dehydrating imidization, The polyimide according to the present invention can be obtained.

There is no restriction | limiting in particular in the molecular weight of the polyimide of this invention, It can be set as arbitrary molecular weights according to a use or a processing method. The polyimide of the present invention is prepared by, for example, dissolving polyimide in N-methyl-2-pyrrolidone at a concentration of 0.5 g / dl by adjusting the amount ratio of diamine and tetracarboxylic dianhydride to be used, and then 35 ° C. The value of the logarithmic viscosity measured in step 1 can be set to an arbitrary value of 0.1 to 3.0 dl / g.
In the present invention, the expression “polyimide” includes, in addition to 100% imidized polyimide, a resin partially coexisting with its precursor polyamic acid.
Further, the polyimide solution obtained by the above reaction may be used as it is, but the polyimide solution may be put into a poor solvent to reprecipitate the polyimide.

The epoxy resin (B) is preferably an epoxy compound containing at least two epoxy groups in the molecule from the viewpoint of curability.
The compounding quantity of an epoxy resin is 1-200 weight part with respect to 100 weight part of polyimide resins, Preferably it is 1-100 weight part. If it is less than 1 part by weight, sufficient adhesive strength cannot be obtained at a high temperature, and if it exceeds 200 parts by weight, it becomes brittle, and when it is used as a film adhesive, it may become brittle.
Examples of the epoxy resin include bisphenol A, bisphenol S, glycidyl ether of bisphenol F, a phenol novolac type epoxy resin, a biphenyl type epoxy compound, and the like.
Moreover, you may contain other hardening | curing agents in addition to imidazole silane (C) in the resin composition of this invention as needed. Examples of other curing agents include imidazole curing agents, phenol curing agents, amine curing agents, and acid anhydride curing agents. From the viewpoint of the storage stability of the resin composition, those having thermal potential and long pot life are preferred.

  It is preferable that the compounding quantity of a hardening | curing agent exists in the range of 0-20 weight part with respect to 100 weight part of epoxy resins. If it exceeds 20 parts by weight, gel may easily occur in the resin solution state, and the storage stability of the resin solution may be significantly reduced.

  Moreover, you may contain a filler in the resin composition of this invention as needed. The filler is not particularly limited as long as it is a known one, but the organic filler is polymerized or crosslinked until insoluble in a resin dissolving solvent such as an epoxy resin, a melamine resin, a urea resin, or a phenol resin. Specific examples of the fine particle type fillers include inorganic fillers such as fine particles of metal oxides such as alumina, antimony oxide, and ferrite, or silicates such as talc, silica, mica, kaolin, and zeolite, barium sulfate, Specific examples include fine particles such as calcium carbonate. The said filler can be used individually or in mixture of 2 or more types.

The amount of the filler is 0 to 1000 parts by weight, preferably 0 to 100 parts by weight, based on 100 parts by weight of polyimide. If it exceeds 1000 parts by weight, the filler tends to settle in the resin solution state, the storage stability of the resin solution may be reduced, and the adhesiveness when used as a film adhesive may be greatly reduced. is there.
The method for producing a film adhesive using the resin composition of the present invention is not particularly limited. For example, a resin solution obtained by dissolving the resin composition in an organic solvent is used on one side of a resin film or a heat resistant film. Or after apply | coating to both surfaces, the method of heating and volatilizing a solvent and making it into a film is mentioned.

  The organic solvent used in the production of the film adhesive of the present invention is not limited as long as the material can be uniformly dissolved, kneaded or dispersed. For example, N, N-dimethylformamide, N, N-dimethylacetamide, N -Methyl-2-pyrrolidone, 1,2-dimethoxyethane, tetrahydrofuran, 1,3-dioxane, 1,4-dioxane, dimethyl sulfoxide, benzene, toluene, xylene, mesitylene, phenol, cresol and the like. These may be used alone or in combination of two or more.

  Here, the resin film used in the production of the film adhesive is insoluble in an organic solvent used for dissolving the resin composition and softened or thermally deteriorated in the process of forming a heated film in which the solvent is volatilized. Any material can be used as long as it does not. A resin film excellent in releasability from a film adhesive is preferable, and examples thereof include a polyethylene terephthalate film whose surface is treated with silicone or Teflon (registered trademark).

Examples of heat-resistant films include polyimide, polyphenylene sulfide, polyether, polyetherketone, film made of heat-resistant resin of polyetheretherketone, composite heat-resistant film such as epoxy resin-glass cloth, epoxy resin-polyimide-glass cloth, etc. Can be mentioned. Preferably, polyimide is used.
The thickness of the film adhesive is preferably 1 μm or more and 50 μm or less, and more preferably 5 μm or more and 40 μm or less. When the thickness is less than 1 μm, it is difficult to securely bond the film adhesive and the support member when used in a semiconductor package, and even when the thickness exceeds 50 μm, the embedding property to the support member is improved. Not.

  The film adhesive of the present invention can be suitably used for a so-called die-bonding material used for bonding a semiconductor element to a support member in a semiconductor package. The method for producing a semiconductor package comprising the film adhesive of the present invention is not particularly limited, and examples thereof include the following methods.

A film-like adhesive is rolled on the back surface of the heated semiconductor wafer, and the film is cut on the outer periphery of the wafer to obtain a wafer with the film-like adhesive. The wafer is diced to an arbitrary size to obtain a semiconductor element with a film adhesive. Subsequently, this is heat-pressed to the support member. Then, a semiconductor package is obtained through a wire bonding process and a molding process.
Examples of the support member include a rigid substrate, a flexible substrate, a lead frame, and the like, or a chip, a spacer, and the like when the chips are stacked in several layers.

EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to these Examples. In addition, each physical-property value in an Example was measured with the following method.
Logarithmic viscosity: A polyimide resin (in terms of solid content) was dissolved in N-methyl-2-pyrrolidone at a concentration of 0.5 g / dl, and then measured at 35 ° C. using an Ubbelohde viscometer.
Glass transition temperature: Under a nitrogen atmosphere, solid viscoelasticity was measured at a temperature increase of 5 ° C./min by RSA-II (manufactured by Rheometrics).

(Polyimide synthesis example 1)
In a 300 ml five-necked separable flask equipped with a stirrer, nitrogen inlet tube, thermometer, and Dean-Stark tube filled with mesitylene, 11.00 g of 1,3-bis (3-aminophenoxy) benzene, polytetramethylene oxide -Di-p-aminobenzoate (Ihara Chemical Industry Co., Ltd., trade name: Elastomer 650P, average molecular weight 836) 47.19 g, N-methyl-2-pyrrolidone 92 g, and mesitylene 40 g were weighed and measured at 50 ° C. in a nitrogen atmosphere. Then, 29.48 g of oxy-4,4′-diphthalic dianhydride was added in small portions. Thereafter, a nitrogen introduction tube was inserted into the solution (bubbling state), the temperature in the system was heated to 170 ° C. to 180 ° C., and maintained for 10 hours while removing water azeotropically. After cooling, 73 g of mesitylene was added and diluted to obtain a resin solution of polyimide (P-1). The logarithmic viscosity of this polyimide resin was 0.44 dl / g.

(Polyimide synthesis example 2)
A 1,1,3,3-tetramethyl-1,3-bis (3-amino) was added to a 300 ml five-necked separable flask equipped with a stirrer, nitrogen inlet tube, thermometer, and Dean-Stark tube filled with mesitylene. Propyl) disiloxane (Toray Dow Corning Silicone Co., Ltd., BY16-871EG, molecular weight 248.5) 23.00 g, polytetramethylene oxide di-p-aminobenzoate (Ihara Chemical Industry Co., Ltd., trade name: Erasmer 650P, average molecular weight 836) 19.34 g, N-methyl-2-pyrrolidone 83 g, and mesitylene 36 g were weighed and dissolved by heating to 50 ° C. in a nitrogen atmosphere, and oxy-4,4′-diphthalic acid 36.97 g of anhydride was added in small portions. Thereafter, a nitrogen introduction tube was inserted into the solution (bubbling state), the temperature in the system was heated to 170 ° C. to 180 ° C., held for 10 hours while removing water azeotropically, and polyimide (P-2) A resin solution was obtained. The logarithmic viscosity of this polyimide resin was 0.25 dl / g.

(Example 1)
With respect to 100 parts by weight of polyimide resin obtained in Synthesis Example 1 (in terms of solid content), 20 parts by weight of epoxy resin (manufactured by Mitsui Chemicals, VG3101L), Z in the general formula (1) is —CH ₂ —CH. (OH) 1 part by weight of imidazole silane (manufactured by Nikko Materials Co., Ltd., SP-1000) containing as a main component a compound that is (OH) CH ₂ OCH ₂ CH ₂ CH ₂ —, silica-based filler (manufactured by Tatsumori Co., Ltd., 1 -FX) 39 parts by weight was blended and thoroughly mixed with a stirrer to obtain a resin composition. The obtained resin composition was cast on a surface-treated PET film (Teijin DuPont Films Co., Ltd., A54, thickness 38 μm), heated at 110 ° C. for 30 minutes, then peeled off, and the film was 25 μm thick An adhesive was obtained. 30 sheets of this film adhesive were press-molded to a thickness of 600 μm, and solid viscoelasticity measurement was performed. As a result, the glass transition temperature was 70 ° C.
In order to evaluate the adhesiveness, a 25 μm film adhesive was sandwiched between a silicon chip and a resin substrate, and heat-pressed at 120 ° C., 4 MPa for 60 seconds, and then heated and cured at 180 ° C., no load, for 3 hours. The shear strength of the obtained test piece was measured using a shear tester at 260 ° C. for 30 seconds, and the result was 3 MPa.

(Example 2)
A resin composition was obtained by blending the resin in the same manner as in Example 1 except that the polyimide resin obtained in Synthesis Example 2 was used, and a film adhesive was obtained using it. Adhesive evaluation of the obtained film adhesive was performed. The results are listed in Table 1.

(Comparative Example 1)
A resin composition was obtained by blending the resin in the same manner as in Example 1 except that an imidazole compound (2PHZ-PW, manufactured by Shikoku Chemicals Co., Ltd.) was used instead of the imidazole silane in Example 1, and a film-like adhesion was obtained using it. An agent was obtained. Adhesive evaluation of the obtained film adhesive was performed. The results are listed in Table 1.
The film adhesives obtained in Examples 1 and 2 exhibit excellent adhesive strength even at a high temperature as compared with the film adhesive of Comparative Example 1 using a general curing agent.

(In Table 1, VG3101L is 2- [4- (2,3-epoxypropoxy) phenyl] -2- [4- [1,1-bis [4-([2,3-epoxypropoxy] phenyl)]] Ethyl] phenyl] propane and 1,3-bis [4- [1- [4- (2,3-epoxypropoxy) phenyl] -1- [4- [1- [4- (2,3-epoxypropoxyphenyl] ) -1-methylethyl] phenyl] ethyl] phenoxy] -2-propanol, 2PHZ-PW is 2-phenyl-4,5-dihydroxymethylimidazole)

    The film adhesive using the resin composition of the present invention exhibits sufficient adhesive strength even at high temperatures, and can be suitably used as a material for die bonding used in high-density mounting semiconductor packages and the like.

Claims (5)

A resin composition comprising a polyimide resin (A), an epoxy resin (B), a silane group substituted with an alkoxy group in one molecule, and an imidazole silane (C) having at least one imidazole group. The silane group substituted with an alkoxy group in one molecule and the compound (C) having at least one imidazole group is an imidazole silane having a structure represented by the general formula (1), and has a polyimide resin weight of 100%. It contains in the ratio of 0.01-5 weight part with respect to a part, The resin composition of Claim 1 characterized by the above-mentioned.

(In the formula (1), R ₁ represents a hydrogen atom, a vinyl group or an alkyl group having 1 to 5 carbon atoms, _{R 2} represents a hydrogen atom or an alkyl group having a carbon number of 1 to 20, _{R 3} and _{R 4} (C represents an alkyl group having 1 to 3 carbon atoms, Z represents a divalent linking group, and m represents an integer of 1 to 3) The said polyimide resin has a repeating structural unit represented by General formula (2), The resin composition of Claim 1 or 2 characterized by the above-mentioned.

(In formula (2), n represents an integer of 1 to 50, X independently represents an alkylene having 2 to 10 carbon atoms, and Y represents a tetravalent organic group.)     The film adhesive which consists of a resin composition in any one of Claims 1-3.     5. A semiconductor package comprising a support member and a semiconductor element, wherein the support member and the semiconductor element are bonded with the film adhesive according to claim 4.