JP5013536B2 - Underfill agent composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an underfill agent suitable for a semiconductor device equipped with a copper bump. <P>SOLUTION: This underfill agent composition includes following components (A)-(D): an epoxy resin (A) of 100 pts.mass, an amine curing agent or an acid anhydride curing agent (B) of 0.7-1.2 equivalent based on an equivalent of an epoxy group in the component (A), an inorganic filler (C) of 50-500 pts.mass based on the sum of the component (A) and the component (B) of 100 pts.mass, and an imidazole silane coupling agent (D) of 0.01-10 pts.mass based on the sum of the component (A) and the component (B) of 100 pts.mass. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a resin composition suitable for making a flip chip type semiconductor device having copper bumps. Specifically, the present invention relates to a resin composition that contains a specific curing agent and a silane compound, and that provides a semiconductor device having excellent adhesion to copper bumps, adhesion to a substrate surface, and high temperature thermal shock resistance.

  Along with the downsizing, weight reduction, and higher functionality of electrical equipment, semiconductor mounting methods have become mainstream from pin insertion type to surface mounting. Among them, flip chip is a method in which a semiconductor chip is connected to a wiring pattern surface of an organic substrate via a plurality of bumps. For the purpose of protecting the connection, an underfill agent is filled in the gap between the organic substrate and the semiconductor chip and the gap between the solder bumps (Patent Documents 1 and 2).

The underfill agent is required not to cause peeling at the interface with the semiconductor chip or the substrate and to prevent the package from cracking when mounted on the substrate. In addition, it is also required to compensate for the lowered solder adhesion as the solder becomes lead-free. Various types of lead-free bumps are used, but in recent years, a material called copper pillar bump (hereinafter referred to as “copper bump”) has become mainstream.

By the way, in order to raise the adhesiveness of the prepreg for printed wiring boards and copper foil, it is known to process copper foil with an imidazole silane coupling agent and mix | blend with resin to impregnate (patent documents 3-3). 7). However, the imidazole silane coupling agent is quick to hydrolyze and easily gelled, so that it is difficult to handle. For example, when added to an epoxy resin composition, the storage stability is short. In addition, because of poor solubility in solvents, it is unsuitable as an additive to solvent-based resin compositions such as impregnating resins for prepregs, resists, varnishes, and paints. It is pointed out that there is a limitation (Patent Document 7).
JP-A-2005-350646 JP 2007-56070 A JP 05-186479 A Japanese Patent Laid-Open No. 05-039295 JP 09-295992 A JP 2000-297094 A Japanese Patent Laid-Open No. 2005-2000

The inventor has been researching to provide an underfill agent suitable for a semiconductor device having copper bumps (Japanese Patent Application Nos. 2008-12605 and 2008-67855). The present invention has been made as part of this research. Surprisingly, it has been found that even an imidazole silane for which the above problem has been pointed out can form an underfill agent suitable for copper bumps by using it in combination with a predetermined component, particularly a curing agent. Was completed.

（Ｒ ^１ は水素原子又は炭素数が１〜２０のアルキル基、Ｒ ^２ は水素原子、ビニル基又は炭素数が１〜５のアルキル基、Ｒ ^３ 、Ｒ ^４ は夫々炭素数が１〜３のアルキル基、ｎは１〜３の整数である。） That is, this invention is an underfill agent composition containing the following component (A)-(D).
(A) Epoxy resin 100 parts by mass,
(B) The amine curing agent is 0.7 to 1.2 equivalents relative to the equivalent of the epoxy group of the component (A),
(C) The inorganic filler is 50 to 500 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (B),
(D) The imidazole silane coupling agent represented by the following formula (1) or (2) or a combination thereof is 0.01 to 10 mass with respect to 100 mass parts in total of the component (A) and the component (B). Department.

(R ¹ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R ² is a hydrogen atom, a vinyl group or an alkyl group having 1 to 5 carbon atoms, R ³ and R ⁴ are each having 1 to 3 carbon atoms. Alkyl group, n is an integer of 1 to 3)

The underfill agent of the present invention has strong adhesion to copper and does not cause separation between cured products even when exposed to high temperatures during reflow or the like. There is no problem in storage stability.

Hereinafter, it demonstrates in order of a component.
(A) Epoxy Resin (A) Epoxy resin used in the present invention includes bisphenol A type epoxy resin, bisphenol F type epoxy resin and other bisphenol type epoxy resins, phenol novolak type epoxy resins, and cresol novolak type epoxy resins. Type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, cyclopentadiene type epoxy resin and the like, and mixtures thereof. Of these, bisphenol A type epoxy resins and bisphenol F type epoxy resins are preferred.

  Epoxy resins represented by the following formulas (4) to (6) are also preferably used.

ここで、Ｒは炭素数１〜２０、好ましくは１〜１０、更に好ましくは１〜３の一価炭化水素基であり、例えば、メチル基、エチル基、プロピル基等のアルキル基、ビニル基、アリル基等のアルケニル基等が挙げられる。また、ｎは１〜４の整数、特に１又は２である。なお、該エポキシ樹脂を使用する場合には、その含有量は、全エポキシ樹脂中２５〜１００重量％、より好ましくは５０〜１００重量％、更に好ましくは７５〜１００重量％であることが推奨される。２５重量％未満であると組成物の粘度が上昇したり、硬化物の耐熱性が低下したりする恐れがある。該エポキシ樹脂の例としては、日本化薬社製ＭＲＧＥ等が挙げられる。

Here, R is a monovalent hydrocarbon group having 1 to 20, preferably 1 to 10, more preferably 1 to 3 carbon atoms, such as an alkyl group such as a methyl group, an ethyl group or a propyl group, a vinyl group, Examples include alkenyl groups such as allyl groups. N is an integer of 1 to 4, particularly 1 or 2. In addition, when using this epoxy resin, it is recommended that the content is 25-100 weight% in all the epoxy resins, More preferably, it is 50-100 weight%, More preferably, it is 75-100 weight%. The If it is less than 25% by weight, the viscosity of the composition may increase or the heat resistance of the cured product may decrease. Examples of the epoxy resin include MRGE manufactured by Nippon Kayaku Co., Ltd.

(B) Amine curing agent or acid anhydride curing agent An amine curing agent or acid anhydride curing agent is used as a curing agent for the epoxy resin. As an amine hardening | curing agent, at least 1 type of the aromatic amine compound represented by either of following formula (7)-(10) is preferable.

（式中、Ｒ^５〜Ｒ^８は、互いに独立に、炭素数１〜６の一価炭化水素基、ＣＨ₃Ｓ−及びＣ₂Ｈ₅Ｓ−から選ばれる基である）

(In the formula, R ^{5 to} R ⁸ are each independently a group selected from a monovalent hydrocarbon group having 1 to 6 carbon atoms, CH ₃ S— and C ₂ H ₅ S—).

  In the above formula, as the monovalent hydrocarbon group, those having 1 to 6 carbon atoms, particularly 1 to 3 carbon atoms are preferable, and methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, Alkyl group such as hexyl group, vinyl group, allyl group, propenyl group, butenyl group, alkenyl group such as hexenyl group, phenyl group, etc. And halogen-substituted monovalent hydrocarbon groups such as a fluoromethyl group, a bromoethyl group, and a trifluoropropyl group substituted with a halogen atom such as

  The aromatic amine-based curing agent is usually solid at normal temperature, and if blended as it is, the resin viscosity increases and the workability is remarkably deteriorated. Therefore, it is preferable to melt and mix at a temperature that does not react with the epoxy resin. That is, it is desirable to melt and mix with the epoxy resin in a temperature range of 70 to 150 ° C. for 1 to 2 hours in a blending amount described later. If the mixing temperature is less than 70 ° C, the aromatic amine curing agent may not be sufficiently compatible, and if the temperature exceeds 150 ° C, it may react with the epoxy resin and increase the viscosity. Also, if the mixing time is less than 1 hour, the aromatic amine curing agent is not sufficiently compatible and may increase the viscosity, and if it exceeds 2 hours, it may react with the epoxy resin and increase the viscosity. .

Acid anhydride curing agents include methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, methylhymic anhydride, pyromellitic dianhydride, maleated alloocimene, benzophenonetetracarboxylic dianhydride 3,3 ′, 4,4′-biphenyltetrabisbenzophenonetetracarboxylic dianhydride, (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 3,4-dimethyl-6- (2-methyl-1-propenyl) -1,2,3,6-tetrahydrophthalic acid Anhydride, 1-isopropyl-4-methyl-bicyclo [2.2.2] oct-5-ene-2,3-dicarboxylic anhydride Mixtures thereof. In particular, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, 3,4-dimethyl-6- (2-methyl-1-propenyl) -1,2,3,6-tetrahydrophthalic anhydride , 1-isopropyl-4-methyl-bicyclo [2.2.2] oct-5-ene-2,3-dicarboxylic anhydride and mixtures thereof. Examples of such a curing agent are commercially available as Ricacid MH700 (manufactured by Shin Nippon Chemical Co., Ltd.), YH306, and YH307 (manufactured by Japan Epoxy Resin Co., Ltd.).

(B) The compounding quantity of a hardening | curing agent is the reactive group equivalent ratio of (A) component / (B) component, ie, [molar amount of the epoxy group in (A) component / (B) epoxy group in a hardening agent. And the molar amount of the reactive group] is in the range of 0.7 to 1.2, preferably 0.8 to 1.0. When the ratio is less than the lower limit, the cured product becomes hard and brittle, and cracks may occur during reflow or temperature cycling. On the other hand, when the ratio exceeds the above upper limit value, unreacted epoxy groups remain, resulting in a decrease in the glass transition temperature, and the adhesion may be decreased.

(C) Inorganic filler As the inorganic filler (C), various known inorganic fillers can be used. Examples thereof include fused silica, crystalline silica, alumina, boron nitride, ticker aluminum, ticker silicon, magnesia, magnesium silicate, aluminum and the like. Of these, spherical fused silica is preferable from the viewpoint of lowering the viscosity of the composition, and spherical silica produced by a sol-gel method or a deflagration method is more preferable.

  The inorganic filler is preferably blended in advance with a surface treatment with a coupling agent such as a silane coupling agent or a titanate coupling agent in order to increase the bond strength with the resin. As such a coupling agent, epoxy silane such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N Silane cups such as amino silanes such as -β (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and mercaptosilane such as γ-mercaptosilane It is preferable to use a ring agent. Here, the blending amount of the coupling agent used for the surface treatment and the surface treatment method are not particularly limited.

  The particle size of the inorganic filler is preferably adjusted as appropriate depending on the gap size of the semiconductor device, that is, the width of the gap between the substrate and the semiconductor chip. The gap size is typically about 10 to 200 μm. In this case, the average particle size is 0.1 to 5 μm, preferably 0. 0, from the viewpoint of the viscosity of the underfill agent and the linear expansion coefficient of the cured product. 5 to 2 μm. If the average particle size is less than the lower limit, the viscosity of the composition increases, making it difficult to penetrate into the gap. If the upper limit is exceeded, the filler inhibits penetration and an unfilled portion occurs. There is a fear.

Further, the inorganic filler has a particle size distribution such that the particle size of 1/2 or more of the gap size is 0.1% by mass or less, particularly 0.08% by mass or less of the entire inorganic filler. It is preferable. Preferably, an inorganic filler having an average particle diameter (d ₅₀ : median diameter) of about 1/10 or less and a maximum particle diameter (d ₉₈ : 98% cumulative diameter) of 1/2 or less with respect to the gap size is used. The particle size and particle size distribution of the filler can be obtained by measuring the particle size distribution by a laser light diffraction method. In addition, as a measuring method for particles having a particle size of 1/2 or more with respect to the gap size, for example, an inorganic filler and pure water are mixed at a ratio of 1: 9 (mass), and subjected to ultrasonic treatment to agglomerates. Can be used, and a particle size inspection method in which this is sieved with a filter having an opening of ½ of the gap size and the remaining amount on the sieve is weighed can be used.

It has been found that the sol-gel method or the deflagration method is most suitable for controlling the particle size and its distribution. The spherical silica produced by these methods is more spherical than fused silica and has an advantage that the particle size distribution can be easily designed. The sol-gel method and the deflagration method may be conventionally known methods.

  It is preferable that 80% by mass or more, particularly 90 to 100% by mass, and particularly 95 to 100% by mass of the total inorganic filler is spherical silica produced by a sol-gel method or a deflagration method. If it is less than 80 mass%, the fluidity | liquidity of a composition may be bad.

  As a compounding quantity of an inorganic filler (C), it is preferable to set it as 50-500 mass parts with respect to a total of 100 mass parts of (A) component and (B) component, More preferably, it is the range of 100-400 mass parts. It is. If it is less than the said lower limit, there exists a possibility that the expansion coefficient of hardened | cured material may become large. When the upper limit is exceeded, the viscosity of the composition increases and the penetration into the gap may be poor.

(D) Imidazole silane coupling agent The imidazole silane coupling agent is 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass with respect to 100 parts by mass in total of the component (A) and the component (B). More preferably, it contains 0.3 to 1 part by mass. Thereby, the adhesion to the copper bump is improved, and a highly reliable flip chip semiconductor device is obtained. If the amount is less than the lower limit value, the adhesive force is not sufficiently improved. If the amount exceeds the upper limit value, voids may be generated or the adhesive force may be reduced.

上式において、Ｒ^１は水素原子又は炭素数が１〜２０のアルキル基、好ましくは、水素原子、メチル基、エチル基、ウンデシル基、ヘプタデシル基である。Ｒ²は水素原子、ビニル基又は炭素数が１〜５のアルキル基であり、好ましくは水素原子、メチル基である。Ｒ³、Ｒ⁴は炭素数が１〜３のアルキル基、好ましくはメチル基及びエチル基であり、nは１〜３の整数である。 As an imidazole silane coupling agent, it is necessary that an imidazole ring and an alkoxyl group are contained in one molecule. The imidazole silane coupling agent can be obtained, for example, by a reaction between an imidazole compound and 3-glycidoxypropyltrimethoxysilane and a reaction between an imidazole compound and 3-methacryloxypropyltrimethoxysilane. Among these, compounds obtained by the reaction of an imidazole compound containing a hydroxyl group in the molecule and 3-glycidoxypropyltrimethoxysilane are more preferable, and those represented by the following formula are used. In particular, a silane coupling agent represented by the following formula (1), (2) or (3) or a combination thereof is preferable.

In the above formula, R ¹ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, preferably a hydrogen atom, a methyl group, an ethyl group, an undecyl group, or a heptadecyl group. R ² is a hydrogen atom, a vinyl group or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or a methyl group. R ³ and R ⁴ are alkyl groups having 1 to 3 carbon atoms, preferably methyl and ethyl groups, and n is an integer of 1 to 3.

Other components The composition of the present invention has a flexible resin such as silicone-modified epoxy resin, silicone rubber, silicone oil, liquid polybutadiene rubber, methyl methacrylate-butadiene-styrene for the purpose of reducing the stress of the cured product. In addition, pigments such as carbon-functional silane for improving adhesion, carbon black and the like, dyes, and antioxidants can be blended in amounts that do not impair the object of the present invention.

Examples of the silicone-modified epoxy resin include an alkenyl group-containing epoxy resin or an alkenyl group of an alkenyl group-containing phenol resin and the following average composition formula H _a R ⁹ _b SiO _(4-ab)
Wherein R ⁹ is a substituted or unsubstituted monovalent hydrocarbon group, a is 0.01 to 0.1, b is 1.8 to 2.2, and 1.81 ≦ a + b ≦ 2.3. is there.)
The number of silicon atoms in one molecule represented by is from 20 to 400, and the number of hydrogen atoms (SiH groups) directly bonded to the silicon atom is from 1 to 5, preferably from 2 to 4, particularly two. A silicone-modified epoxy resin comprising a copolymer obtained by addition reaction with an SiH group of an organopolysiloxane is preferred.

As the monovalent hydrocarbon group for R ⁹ in the above formula, those having 1 to 10 carbon atoms, particularly 1 to 8 carbon atoms are preferred, and methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert- Alkyl groups such as butyl, hexyl, octyl and decyl, alkenyl such as vinyl, allyl, propenyl, butenyl and hexenyl, aryl such as phenyl, xylyl and tolyl, and benzyl , Aralkyl groups such as phenylethyl group, phenylpropyl group, etc., and chloromethyl group, bromoethyl group, trifluoro, etc., in which part or all of hydrogen atoms of these hydrocarbon groups are substituted with halogen atoms such as chlorine, fluorine, bromine, etc. Mention may be made of halogen-substituted monovalent hydrocarbon groups such as propyl groups.

  The silicone-modified epoxy resin preferably has a structure represented by the following formula (11).

In the above formula, R ⁹ is as described above, and R ¹⁰ is —CH ₂ CH ₂ CH ₂ —, —OCH ₂ —CH (OH) —CH ₂ —O—CH ₂ CH ₂ CH ₂ — or — O—CH ₂ CH ₂ CH ₂ —, and each R ¹¹ is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. n is an integer of 4 to 199, preferably 19 to 109, p is an integer of 1 to 10, and q is an integer of 1 to 10.

When blending the silicone-modified epoxy resin, it is preferable to blend the diorganosiloxane unit in an amount of 1 to 20 parts by weight, particularly 2 to 15 parts by weight, based on 100 parts by weight of the epoxy resin (A). Thereby, the stress of hardened | cured material can be reduced and the adhesiveness to a board | substrate can also be improved. Here, the amount of diorganopolysiloxane is represented by the following formula.
Polysiloxane amount = (molecular weight of polysiloxane portion / molecular weight of silicone-modified epoxy resin) × added amount

Preparation of Adhesive Composition The composition of the present invention comprises the above components (A) to (D) and, optionally, optional components, simultaneously or separately, with stirring, dissolution, mixing and dispersion, if necessary with heat treatment. Let Although the apparatus used for these operations is not particularly limited, a lykai machine equipped with a stirring and heating apparatus, a three roll, a ball mill, a planetary mixer, and the like can be used. Moreover, you may combine these apparatuses suitably.

  The adhesive composition obtained by the above preparation method preferably has a viscosity of 1 to 500 Pa · s, particularly 1 to 150 Pa · s at 25 ° C. The curing conditions for the adhesive composition are preferably 100 ° C. to 120 ° C. for 0.5 hour or longer, and then 150 ° C. to 175 ° C. for 2 hours or longer. When heating at 100 to 120 ° C. is less than 0.5 hour, voids may occur after curing. Further, if the heating at 150 to 175 ° C. is less than 0.5 hours, sufficient cured product characteristics may not be obtained.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples.

Preparation of composition Adhesive compositions (Examples 1 to 6, Reference Example 1, Comparative Examples 1 and 2) were obtained by uniformly kneading each component of each part by mass shown in Table 1 with three rolls. It was.

In Table 1, each component is as follows.
(A) Epoxy resin Epoxy resin A1: Bisphenol F type epoxy resin (RE303S-L: manufactured by Nippon Kayaku Co., Ltd.)
Epoxy resin A2: HP4032D (Naphthalene type, manufactured by Dainippon Ink Co., Ltd.)
Epoxy resin A3: Trifunctional epoxy resin represented by the following formula (Epicoat 630H: manufactured by Japan Epoxy Resin Co., Ltd.)

(B) Curing agent Curing agent B1: Hexahydrophthalic anhydride mixture represented by the following formula (Licacid MH700: manufactured by Shin Nippon Rika Co., Ltd.)

硬化剤Ｂ２：下記式で示されるマレイン化アロオシメン（ＹＨ３０７：ジャパンエポキシレジン株式会社製）

Curing agent B2: maleated alloocimene represented by the following formula (YH307: manufactured by Japan Epoxy Resin Co., Ltd.)

硬化剤Ｂ３：３，３’−ジエチル−４，４’−ジアミノジフェニルメタン（カヤハードＡＡ：日本化薬社製）
硬化剤Ｂ４：３，３’，５，５’−テトラエチル−４，４’−ジアミノジフェニルメタン（Ｃ−３００Ｓ：日本化薬社製）

Curing agent B3: 3,3′-diethyl-4,4′-diaminodiphenylmethane (Kayahard AA: manufactured by Nippon Kayaku Co., Ltd.)
Curing agent B4: 3,3 ′, 5,5′-tetraethyl-4,4′-diaminodiphenylmethane (C-300S: manufactured by Nippon Kayaku Co., Ltd.)

(C) Inorganic filler Spherical silica: manufactured by the deflagration method in which the remaining amount of filter 1 (particle size of 25 μm or more) is 0.01% by mass and the average particle size is 2.5 μm in the following particle size inspection method. Spherical silica
Silica particle size inspection method Silica and pure water are mixed at a ratio of 1: 9 (mass), and ultrasonic treatment is performed to sufficiently break up the aggregate, and filter 1 (opening 25 μm) or filter 2 (opening 10 μm) is used. The remaining amount of silica was measured by sieving and the silica remaining on the sieve. The measurement was performed five times, and the average value was expressed as mass% as a measurement value.

（Ｒ^１はメチル基、Ｒ²は水素、Ｒ³はメチル基、n=３とする。） (D) Imidazole silane coupling agent

(R ¹ is a methyl group, R ² is hydrogen, R ³ is a methyl group, and n = 3.)

比較シランカップリング剤
D4：γ−グリシドキシプロピルトリメトキシシラン（ＫＢＭ４０３：信越化学工業株式会社製）
参考例で使用の硬化剤Ｂ５：フェノールアラールキル樹脂、水酸基当量１７５（三井化学（株）製） Other additives Solvent: Polyethylene glycol methyl ethyl acetate (PGMEA: boiling point 146 ° C)
Curing catalyst: 2-ethyl-4-methylimidazole (2E4MZ: manufactured by Shikoku Kasei Co., Ltd.)

Comparative silane coupling agent
D4: γ-glycidoxypropyltrimethoxysilane (KBM403: manufactured by Shin-Etsu Chemical Co., Ltd.)
Curing agent B5 used in Reference Example : Phenol aralkyl resin, hydroxyl equivalent 175 (manufactured by Mitsui Chemicals, Inc.)

Each composition was evaluated by the following methods. The results are shown in Table 1.
(1) Tg (glass transition temperature), CTE1 (linear expansion coefficient at temperatures below (Tg-30 ° C.)), CTE2 (expansion coefficient at temperatures above Tg)
The temperature was raised from room temperature at 10 ° C./min and held at a temperature of 200 to 260 ° C. for 30 seconds to 5 minutes to obtain a cured product. The cured product was cooled to room temperature, a test piece of 5 mm × 5 mm × 15 mm was cut out, and the temperature was raised at 5 ° C. per minute by TMA (thermomechanical analyzer) to measure Tg.
When (Tg-30 ° C) of the cured product was less than 100 ° C, CTE1 was measured at -30 to 0 ° C, and CTE2 was measured at 150 to 180 ° C.
When (Tg-30 ° C) was 100 ° C or higher, CTE1 was measured at 50 to 80 ° C, and CTE2 was measured at 200 to 230 ° C.

(2) Void test A 10 mm x 10 mm silicon chip coated with a polyimide (PI) film on a 30 mm x 30 mm FR-4 substrate is placed in the gap of a flip chip type semiconductor device in which the gap size is about 50 μm. Each resin composition was dropped and infiltrated, and after curing at 165 ° C. for 30 minutes, the presence or absence of voids was confirmed by C-SAM (manufactured by SONIX).

(3) Adhesive strength test Each resin composition was injected into a truncated cone-shaped polytetrafluoroethylene mold having an upper surface diameter of 2 mm, a lower surface diameter of 5 mm, and a height of 3 mm, and a polyimide (PI) film was coated thereon. A silicon chip or copper plate was placed and cured at 120 ° C. for 0.5 hours and 150 ° C. for 3 hours. After curing, the test piece obtained by removing the polytetrafluoroethylene mold was pushed at a constant speed (1 mm / sec) to measure the shear adhesive force, and set it as the initial value. Furthermore, after holding the cured test piece in a pressure cooker tester (121 ° C./2.1 atm) for 72 hours, the adhesive strength was measured in the same manner. In any case, the number of test pieces was five, and the average value was expressed as adhesive strength. In Table 1, “0” indicates peeling.

(4) Toughness value K _1c
Each resin composition was cured at 120 ° C. for 0.5 hours and at 150 ° C. for 3 hours, and the toughness value K _1c at room temperature was measured based on ASTM # D5045 for the obtained cured product.

(5) Storage stability After leaving each composition at 25 degreeC for 12 hours, the viscosity was measured with the B-type viscometer, and it compared with the initial viscosity.

  As shown in Table 1, the compositions of the examples have no voids and are excellent in adhesion to copper as compared with the compositions containing the conventional silane coupling agents (Comparative Examples 1 and 2). Moreover, it is excellent also in storage stability compared with the case where a phenol resin is included as a curing agent (Reference Example 1).

  The underfill agent of the present invention is suitable for flip-flop connection of a semiconductor device provided with a copper pillar bump.

Claims (7)

Underfill agent composition containing the following components (A) to (D) (A) Epoxy resin 100 parts by mass (B) Amine curing agent is used in an amount of 0.7 to 1. 2 equivalents of (C) inorganic filler, 50 to 500 parts by mass with respect to a total of 100 parts by mass of component (A) and component (B) (D) imidazolesilane represented by the following formula (1) or (2) The coupling agent or a combination thereof is 0.01 to 10 parts by mass with respect to 100 parts by mass in total of the components (A) and (B).

(R ¹ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R ² is a hydrogen atom, a vinyl group or an alkyl group having 1 to 5 carbon atoms, R ³ and R ⁴ are each having 1 to 3 carbon atoms. An alkyl group, n is an integer of 1 to 3). The component (A) is at least one selected from a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, and an epoxy resin represented by the following formula (4), (5) or (6). The underfill agent composition as described.

(R is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and n is an integer of 1 to 4) The underfill agent composition according to claim 1 or 2, wherein the component (A) comprises a silicone-modified epoxy resin. The (B) amine curing agent is at least one selected from compounds represented by the following formula (7), (8), (9) or (10): Underfill agent composition.

(In the formula, R ^{5 to} R ⁸ are each independently a group selected from a monovalent hydrocarbon group having 1 to 6 carbon atoms, CH ₃ S— and C ₂ H ₅ S—). (C) The underfill composition according to any one of claims 1 to 4 , wherein the inorganic filler is spherical silica having an average particle diameter of 0.1 to 5 µm produced by a sol-gel method or a deflagration method. The semiconductor device provided with the underfill agent composition of any one of Claims 1-5 , or its hardened | cured material. The semiconductor device according to claim 6 , wherein the semiconductor device includes a copper bump.