JP2010111747A - Underfill agent composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an underfill agent suitable for a semiconductor device including a copper pillar bump. <P>SOLUTION: The underfill agent composition includes following component (A) through (D): (A) 100 pts.mass of an epoxy resin, (B) an amine curing agent or an acid anhydride curing agent in an amount of an equivalent ratio [component (A)/component (B)] being 0.7 to 1.2, (C) 50-500 pts.mass of an inorganic filler based on total 100 pts.mass of the component (A) and component (B), and (D) 0.01-10 pts.mass of silane having an episulfide group represented by formula (1) based on total 100 pts.mass of the component (A) and component (B), wherein R<SP>1</SP>is a hydrogen atom, methyl, or ethyl, R<SP>2</SP>is a 2C-10C organic group which may include oxygen and may form a ring structure together with a carbon atom of the episulfide group, X is a hydrolyzable group, and k is an integer of 1 to 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an underfill agent composition suitable for making a flip-chip type semiconductor device having a copper bump, and in particular, includes a silane compound having an episulfide group, and adheres to a copper bump and a substrate surface, and The present invention also relates to an underfill agent composition that gives a cured product excellent in 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 mounting 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. Furthermore, with the lead-free solder, it is also required to compensate for the reduced solder adhesion. Various types of lead-free bumps are used, but in recent years, materials called copper pillar bumps (hereinafter also referred to as “copper bumps”) have become mainstream.

In order to prevent the peeling, silane coupling agents are frequently used. Generally, a silane coupling agent includes a silyl group having a hydrolyzable group and an organic functional group. There are many types of functional groups such as an epoxy group, a vinyl group, and an amino group, and those having an epoxy group or an amino group are frequently used for underfill applications (Patent Document 1).
JP-A-2005-350646 JP 2007-56070 A Japanese Patent Laid-Open No. 11-180988

The present inventor has been researching to provide an underfill agent suitable for a semiconductor device having copper bumps (Japanese Patent Application Nos. 2008-12605, 2008-67855, and 2008-198029). The present invention has been made as part of this research.

（ここで、Ｒ^１は水素原子、メチル基もしくはエチル基であり、Ｒ^２は酸素を含んでいてよい炭素数２〜１０の有機基であり且つエピスルフィド基の炭素原子と共に環構造を形成していてもよく、Ｘは加水分解性基であり、ｋ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) Amine curing agent or acid anhydride curing agent
Amount (C) inorganic filler in which the equivalent ratio of [(A) component / (B) component] is 0.7 to 1.2
Silane having an episulfide group represented by the following formula (1): 50 to 500 parts by mass with respect to a total of 100 parts by mass of component (A) and component (B)
(A) 0.01-10 mass parts with respect to a total of 100 mass parts of a component and (B) component.

(Here, R ¹ is a hydrogen atom, a methyl group or an ethyl group, R ² is an organic group having 2 to 10 carbon atoms which may contain oxygen, and forms a ring structure with the carbon atoms of the episulfide group. X is a hydrolyzable group, and k is an integer of 1 to 3.)

  It is known that copper easily reacts with sulfur. Therefore, it is considered that a silane coupling agent containing sulfur is not suitable for copper. Surprisingly, however, it has been found that a silane coupling agent having an episulfide group improves the adhesion between the copper bump and the underfill agent. Although the silane coupling agent itself is known (for example, Patent Document 3), there is no example applied to an underfill agent. The cured product of the underfill agent of the present invention has a strong adhesive force to copper and does not cause peeling even in a high temperature and high humidity test.

Hereinafter, it demonstrates for every component.
(A) Epoxy Resin As (A) epoxy resin used in the present invention, bisphenol A type epoxy resin, bisphenol F type epoxy resin such as bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin novolak 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.

  An epoxy resin represented by the following formula (4), (5) or (6) is 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（７）〜（１０）いおいて、Ｒ^３〜Ｒ^６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 formulas (7) to (10), R ^{3 to} R ⁶ 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—. It is.

  The monovalent hydrocarbon group is preferably a group having 1 to 6 carbon atoms, particularly 1 to 3 carbon atoms, such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, and hexyl group. Alkyl groups, vinyl groups, allyl groups, propenyl groups, butenyl groups, hexenyl groups and other alkenyl groups, phenyl groups, etc., and some or all of the hydrogen atoms of these hydrocarbon groups are halogens such as chlorine, fluorine, bromine, etc. Mention may be made of halogen-substituted monovalent hydrocarbon groups such as a fluoromethyl group, a bromoethyl group, a trifluoropropyl group substituted by an atom.

  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.).

The blending amount of (B) curing agent is equivalent ratio of [(A) component / (B) component], that is, [molar amount of epoxy group in (A) component / (B) epoxy group in curing 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. The reactive group is an amino group or an acid anhydride group. 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 It is preferable to use a silane coupling agent such as aminosilane such as -β (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane. 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 100-300 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.

ここで、Ｒ^１は水素原子、メチル基もしくはエチル基、好ましくはメチル基もしくはエチル基である。Ｒ^２は酸素を含んでいてよい炭素数２〜１０、好ましくは３〜８の有機基、例えばアルキレン基、オキシアルキレン基、であり、エピスルフィド基の２つの炭素原子と共に環構造、例えば３，４−チオエポキシシクロアルキル基、を構成していてもよい。Ｘは加水分解性基、例えばアルコキシ基、アセトキシ基又はクロル原子、好ましくはアルコキシ基、より好ましくはメトキシ基であり、ｋは１〜３の整数である。 (D) Silane having an episulfide group Silane having an episulfide group can be represented by the following general formula.

Here, R ¹ is a hydrogen atom, a methyl group or an ethyl group, preferably a methyl group or an ethyl group. R ² is 2 to 10 carbon atoms and may contain an oxygen, preferably 3-8 organic group, for example an alkylene group, an oxyalkylene group, ring structure with two carbon atoms of the episulfide group, for example 3,4 -Thioepoxycycloalkyl group may be constituted. X is a hydrolyzable group such as an alkoxy group, an acetoxy group or a chloro atom, preferably an alkoxy group, more preferably a methoxy group, and k is an integer of 1 to 3.

The silane is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, more preferably 0.3 to 1 part by weight, based on 100 parts by weight in total of the components (A) and (B). By including, the adhesion to the copper bump is improved, and a highly reliable flip chip semiconductor device can be obtained. When the amount is less than the lower limit value, the adhesive force is not sufficiently improved. When the amount exceeds the upper limit value, voids may be generated or the adhesive force may be reduced.

For example, the silane is a method described in Patent Document 3, that is, a method in which an epoxy group-containing alkoxysilane is reacted with thiourea, or an alkenyl group-containing epoxy compound is reacted with thiourea to synthesize a thiirane ring. It can be produced by a method of adding an alkoxysilane having an H bond to an alkenyl group.

Preferred silanes include those represented by the following formulas (i) to (iv) (wherein Me represents a methyl group), and may be a condensate thereof such as a dimer, or a mixture thereof. It may be.

Other components The composition of the present invention includes a curing catalyst such as an imidazole derivative, and a silicone-modified epoxy resin, silicone rubber, silicone oil, liquid polybutadiene rubber, methyl methacrylate-butadiene- for the purpose of reducing the stress of the cured product. A flexible resin such as styrene, a pigment such as carbon black, a dye, and an antioxidant can be blended in an amount that does not impair the object of the present invention.

As the silicone-modified epoxy resin, an alkenyl group-containing epoxy resin or an alkenyl group-containing phenol resin, and the following average composition formula

H _a R ⁷ _b SiO _(4-ab)

(In the formula, R ⁷ 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, those having 1 to 10 carbon atoms, particularly 1 to 8 carbon atoms are preferable, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, hexyl group, Alkyl groups such as octyl and decyl groups, vinyl groups, allyl groups, propenyl groups, butenyl groups, alkenyl groups such as hexenyl groups, phenyl groups, xylyl groups, aryl groups such as tolyl groups, benzyl groups, phenylethyl groups, phenylpropoxy groups Halogen substitution such as chloromethyl group, bromoethyl group, trifluoropropyl group, 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 monovalent hydrocarbon 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.
Diorganopolysiloxane amount = (molecular weight of diorganopolysiloxane portion / molecular weight of silicone-modified epoxy resin) × blending amount of silicone-modified epoxy resin

The composition of the preparation the present invention compositions, the (A) ~ (D) component, and, optionally the other components simultaneously or separately, stirring while adding a heat treatment if necessary, dissolving, mixing, dispersing 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 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 of the composition are preferably 100 ° C. to 120 ° C. for 0.5 hour or longer, and then 150 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 Compositions (Examples 1 to 6, Comparative Examples 1 and 2) were obtained by uniformly kneading each component of each part by mass shown in Table 1 with three rolls. 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.)

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）

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

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

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.

Ｄ２：

Ｄ３：

Ｄ４：

比較例で使用のシラン
Ｄ５：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） (D) Episulfide group-containing silane D1:

D2:

D3:

D4:

Used in Comparative Example silane D5: .gamma.-glycidoxypropyltrimethoxysilane (KBM403: manufactured by Shin-Etsu Chemical Co., Ltd.)

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.)

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 composition was dropped and invaded and cured at 165 ° C. for 30 minutes, and then the presence or absence of voids was confirmed by C-SAM (manufactured by SONIX).

(3) Adhesive strength test Each 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 coated silicon Chips or copper plates were 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 composition was cured at 120 ° C. for 0.5 hours and 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.

  As shown in Table 1, the compositions of the examples have better wettability to copper and no voids than the compositions containing conventional silanes (Comparative Examples 1 and 2). Moreover, adhesiveness is maintained even after being subjected to a pressure cooker test.

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

Claims (9)

Underfill agent composition containing the following components (A) to (D) (A) Epoxy resin 100 parts by mass (B) Amine curing agent or acid anhydride curing agent
Amount (C) inorganic filler in which the equivalent ratio of [(A) component / (B) component] is 0.7 to 1.2
Silane having an episulfide group represented by the following formula (1) with respect to a total of 100 parts by mass of component (A) and component (B) (D)
(A) 0.01-10 mass parts with respect to a total of 100 mass parts of a component and (B) component.

(Here, R ¹ is a hydrogen atom, a methyl group or an ethyl group, R ² is an organic group having 2 to 10 carbon atoms which may contain oxygen, and forms a ring structure with the carbon atoms of the episulfide group. X is a hydrolyzable group, and k is an integer of 1 to 3.) (D) The composition of Claim 1 whose silane which has an episulfide group is at least 1 sort (s) chosen from the silane represented by following formula (2) or (3).

(R ¹ and k are as described above, and R ³ is a methyl group or an ethyl group independently of each other.) 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). Or the composition of 2.

(R is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and n is an integer of 1 to 4)
The composition according to any one of claims 1 to 3, wherein the component (A) comprises a silicone-modified epoxy resin. (B) The amine curing agent is at least one selected from amine curing agents represented by the following formula (7), (8), (9) or (10). A composition according to item.

(In the formula, R ^{3 to} R ⁶ 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—). (B) Acid anhydride curing agent is methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, 3,4-dimethyl-6- (2-methyl-1-propenyl) -1,2, At least one selected from 3,6-tetrahydrophthalic anhydride, 1-isopropyl-4-methyl-bicyclo [2.2.2] oct-5-ene-2,3-dicarboxylic anhydride and mixtures thereof The composition according to any one of claims 1 to 5, which is a seed. (C) The composition according to any one of claims 1 to 6, wherein the inorganic filler is spherical silica having an average particle size of 0.1 to 5 µm produced by a sol-gel method or a deflagration method. A semiconductor device to which the underfill agent composition according to claim 1 or a cured product thereof is applied. 9. The semiconductor device according to claim 8, wherein the semiconductor device includes a copper bump.