JP2010109285A - Adhesive composition for heat sink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive for heat sinks which properly spreads on a substrate and is superior in thermal conductivity. <P>SOLUTION: An adhesive composition for semiconductor chip heat sinks contains (A) 100 mass parts of epoxy resin, (B) 1 to 50 mass parts of a curing agent, (C) 30 to 1,000 mass parts of an inorganic filler having an average particle size of 0.1 to 10 μm and a maximum particle size of ≤75 μm, and (D) 1 to 20 mass parts of silica having an average particle size of 0.005 to <0.1 μm and has a surface silylated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a composition for adhering a heat sink of a semiconductor chip, such as a heat radiating fin, a metal plate, etc., to a substrate, and in particular, by containing a predetermined filler, it spreads on the substrate and has a good thermal resistance. The present invention relates to a composition that forms a cured product having a small value.

In recent years, due to the high-speed operation of semiconductor elements and electronic components, a large amount of heat is generated compared to the conventional case, causing malfunction of the semiconductor elements and electronic components. In order to remove heat, as shown in FIG. 1, a heat sink 1 such as a metal plate is attached to a semiconductor chip 3, particularly a CPU, placed on a substrate 2 via an underfill agent 2. . The heat sink is usually made of metal, and a fine gap is generated even when it is in close contact with the semiconductor chip 3. For this reason, the heat conductivity is improved by sandwiching a heat radiation material 4 such as a heat conductive silicone gel, rubber, or grease in the gap.

In order to bond the heat sink to the semiconductor chip 3 or the substrate 2, an epoxy resin adhesive (Patent Document 1) and a silicone rubber adhesive (Patent Document 2) are mainly used. However, these adhesives have poor wettability to the substrate and tend to form dumpling-like cured products. Therefore, there is a problem that heat conductivity is bad and heat dissipation of the heat sink is lowered. On the other hand, even if the wettability is good, the adhesive spreads too much on the substrate 2 and may contaminate the nearby semiconductor element 7.
JP 2006-222406 A JP-A-7-254668

Then, an object of this invention is to provide the adhesive agent for heat sinks which spreads moderately on a board | substrate and was excellent in thermal conductivity.

That is, this invention is the adhesive composition for semiconductor chip heat sinks containing the following (A)-(D).
(A) Epoxy resin 100 parts by mass (B) Curing agent 1-50 parts by mass (C) Inorganic filler having an average particle size of 0.1 to 10 μm and a maximum particle size of 75 μm or less
30 to 1,000 parts by mass (D) Silica having an average particle size of 0.005 μm or more and less than 0.1 μm and trimethylsilylated on its surface 1 to 20 parts by mass

The adhesive of the present invention does not form a dumpling on the substrate, and gives a cured product having excellent thermal conductivity.

Hereinafter, it demonstrates in order of a 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.

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。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。 The following epoxy resins are also preferably used.

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, 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%. 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.

Preferably, (A) the epoxy resin contains a silicone-modified epoxy resin. Examples of the silicone-modified epoxy resin include 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

(B) Curing agent As the curing agent for the epoxy resin, amine-based, polymercaptan-based, imidazole-based, dicyandiamide, and the like can be used, and preferably, an amine curing agent and an imidazole-based curing agent are used. In addition, many acid anhydride type hardening | curing agents are easy to volatilize, and are not suitable for this use. As the amine curing agent, at least one aromatic amine compound represented by the following general formulas (1) to (4) is preferable.

式中、Ｒ¹〜Ｒ^４は独立に炭素数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 ^{1 to} R ⁴ are groups independently selected from a monovalent hydrocarbon group having 1 to 6 carbon atoms, CH ₃ S—, and C ₂ H ₅ S—.

  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. .

（式中、Ｒ⁵及びＲ⁶は水素原子、メチル基、エチル基、ヒドロキシメチル基又はフェニル基を示し、Ｒ⁷はメチル基、エチル基、フェニル基又はアリル基を示し、Ｒ⁸は水素原子又は下記式（６）で示される基である。）

As the imidazole curing agent, an imidazole compound represented by the following formula (5) is preferable.

(Wherein R ⁵ and R ⁶ represent a hydrogen atom, a methyl group, an ethyl group, a hydroxymethyl group or a phenyl group, R ⁷ represents a methyl group, an ethyl group, a phenyl group or an allyl group, and R ⁸ represents a hydrogen atom. Or a group represented by the following formula (6).)

  Examples of the imidazole curing agent include 2,4-diamino-6- [2′-methylimidazolyl- (1) ′]-ethyl-S-triazine and 2,4-diamino-6- [2′-ethyl-4. '-Methylimidazolyl- (1)']-ethyl-S-triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1) ']-ethyl-S-triazine isocyanuric acid adduct, 2, -Phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4,5-diphenylimidazole, 2,4,5-triphenylimidazole and the like.

Preferably, an imidazole curing agent having a solubility in an epoxy resin of 1% by mass or less, such as 2-phenyl-4,5-dihydroxymethylimidazole, is used. Moreover, it is preferable that melting | fusing point is 170 degreeC or more, and it is preferable that it is a powder form whose average particle diameter is 1-5 micrometers and a maximum particle diameter is 20 micrometers or less. More preferably, the average particle size is 2 to 5 μm and the maximum particle size is 15 μm or less. When the average particle size is smaller than the lower limit, the specific surface area is increased and the viscosity when mixed with the resin may be increased. When the average particle size exceeds the upper limit, dispersion with the epoxy resin becomes non-uniform, which may cause a decrease in reliability.

Furthermore, the particle size and specific surface area of the curing agent are preferably larger than the particle size and specific surface area of the inorganic filler. If it is small, the powder aggregates during mixing and kneading and the curing agent is dispersed non-uniformly. As a result, the curability deteriorates and the reliability may be adversely affected. The purity is 90% or more, preferably 93% or more. If the purity is less than 90%, the reactivity may vary and the curability may vary. In the present invention, the particle diameter can be determined by a laser light diffraction method, and the average particle diameter means a weight average value (or median diameter d ₅₀ ).

  The compounding quantity of the said hardening | curing agent is 1-50 mass parts with respect to 100 mass parts of (A) liquid epoxy resins, and in the case of an amine hardening agent, 10-50 mass parts is in the case of an imidazole hardening agent. Is more preferably 1 to 10 parts by mass. If the blending amount is less than the lower limit, the curability is lowered, and if it exceeds the upper limit, the storage stability may be lowered.

(C) As an inorganic filler (C) having an average particle diameter of 0.1 to 10 μm and a maximum particle diameter of 75 μm or less , 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. Among them, spherical fused silica is preferable because the viscosity of the composition is lowered.

  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 coupling agents such as aminosilanes such as -β (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane can be used. About the compounding quantity of the coupling agent used for surface treatment here, and the surface treatment method, the method similar to the process of (D) component mentioned later can be used.

The inorganic filler preferably has an average particle diameter of 2 to 20 μm and a maximum particle diameter of 75 μm or less, particularly 50 μm or less. If the average particle size is less than the above lower limit, the composition has a high viscosity and may not be filled in a large amount. On the other hand, if the above upper limit is exceeded, voids may occur in the cured product. The average particle diameter (weight average value or median diameter d ₅₀ ) and the maximum particle diameter can be obtained by a particle size distribution measuring apparatus using a laser light diffraction method.

  (C) As a compounding quantity of an inorganic filler, it is 30-1,000 mass parts with respect to 100 mass parts of (A) component, Preferably it is 40-400, More preferably, it is 50-300 mass parts. If it is less than the said lower limit, the expansion coefficient of hardened | cured material is large and can generate | occur | produce a crack. When the above upper limit is exceeded, the viscosity of the composition becomes too high.

(D) Surface Silylated Silica By using the component (D) in the composition of the present invention, the cured product has a small expansion coefficient and a high elastic modulus. (D) The average particle diameter of the inorganic filler is 0.005 μm or more and less than 0.1 μm, preferably 0.008 μm to 0.08 μm. When the average particle size is less than the lower limit, the viscosity of the composition increases, and workability may be significantly deteriorated. When the upper limit is exceeded, the composition may come into contact with the element on the substrate or protrude from the end of the heat sink. The average particle diameter can be measured by a dynamic light scattering method / laser trap method.

  Examples of the component (D) include fumed silica such as Aerosil 130, Aerosil 200, Aerosil 300 (trade name, manufactured by Nippon Aerosil Co., Ltd.), Nipsil VN-3-LP (trade name, manufactured by Nippon Silica Kogyo Co., Ltd.), and the like. Wet silica or the like is preferably used.

The component (D) is, for example, CH ₃ Si (OCH ₃ ) ₃ , (CH ₃ ) ₃ SiOCH ₃ , PhSi (OCH ₃ ) ₃ , PhSiCH ₃ (OCH ₃ ) ₂ , {(CH ₃ ) ₃ Si} ₂ NH , CH ₃ CH ₂ Si (OCH ₃ ) _{3 and the} like (wherein “Ph” means a phenyl group).

  The surface treatment may be performed by treating the silica with the silylating agent in advance, or by an integral blend method in which the silylating agent is added and blended when preparing the composition of the present invention. The former method is preferable from the viewpoint of suppressing the amount of the silylating agent used.

  (D) The usage-amount of a component is 1-20 mass parts normally with respect to 100 mass parts of (A) component, Preferably it is 3-15 mass parts. If the amount used is less than the lower limit value, it becomes difficult to suppress the protrusion of the composition from the end of the heat sink, and conversely, if too much, the viscosity becomes too high, so that the flowability of the epoxy resin composition is low. It may fall and it may become difficult to obtain a substantially liquid epoxy resin composition.

Other components In the composition of the present invention, for the purpose of reducing the stress of the cured product, silicone rubber, silicone oil, liquid polybutadiene rubber, flexible resin such as methyl methacrylate-butadiene-styrene, curing accelerator, Silane coupling agents, pigments such as carbon black, dyes, antioxidants and the like can be blended in amounts that do not impair the object of the present invention.

Preparation of Adhesive Composition The composition of the present invention comprises the above components (A) to (D) and, if desired, the above and other components simultaneously or separately, with stirring and dissolution, if necessary, with heat treatment. Mix and disperse. 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. As for the curing conditions of the adhesive composition, it is preferable to first perform an oven cure at 100 to 120 ° C. for 0.5 hour or more, and then 150 to 175 ° C. for 2 hours or more. 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 to 3) 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: Trifunctional epoxy resin represented by the following formula (Epicoat 630H, manufactured by Japan Epoxy Resin Co., Ltd.)

(B) Curing agent Curing agent B1: 3,3'-diethyl-4,4'-diaminodiphenylmethane (Kayahard AA, manufactured by Nippon Kayaku Co., Ltd.)
Curing agent B2: 3,3 ′, 5,5′-tetraethyl-4,4′-diaminodiphenylmethane (C-300S, manufactured by Nippon Kayaku Co., Ltd.)
Curing agent B3: 2-phenyl-4,5-dihydroxymethylimidazole powder having an average particle size of 4.2 μm and a maximum particle size of 15 μm or less (imidazole 2PHZ-PW, manufactured by Shikoku Kasei Co., Ltd.)

(C) Inorganic filler having an average particle size of 0.1 to 10 µm and a maximum particle size of 75 µm or less Silica C: Spherical silica having a maximum particle size of 53 µm or less and an average particle size of 7 µm (Tatsumori Co., Ltd.) Manufactured and surface-treated with a silane coupling agent (KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.)

(D) the surface silylated silica <br/> Silica _{D1: {(CH 3) 3} Si} 2 NH and _{CH 3 CH 2 Si (OCH 3} ) average particle size _(d 50) treated with ₃ 0.008 .mu.m of Treated silica silica D2: treated silica silica D3 with an average particle size (d ₅₀ ) of 0.01 μm treated with {(CH ₃ ) ₃ Si} ₂ NH and CH ₃ CH ₂ Si (OCH ₃ ) ₃ : {(CH ₃ ) ₃ Silica used in Comparative Silica Examples Treated with Si} ₂ NH and CH ₃ CH ₂ Si (OCH ₃ ) ₃ Average Particle Size (d ₅₀ ) 0.08 μm: {(CH ₃ ) ₃ Si} ₂ NH, Treated silica treated with CH ₃ CH ₂ Si (OCH ₃ ) ₃ and having an average particle size (d ₅₀ ) of 0.12 μm

Other components Silane coupling agent: γ-glycidoxypropyltrimethoxysilane (KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.)
Reactive diluent: Phenyl glycidyl ether (PGE)

（式中、ｎは、該シロキサンの２５℃における粘度が400 ｃＳｔとなるような数である）
上記シリカＣ２００質量部（比較例４）、４００質量部（比較例５）を、夫々、プラネタリーミキサーで１時間混合後、さらに３本ロールで混練した。次に、この混練物に、メチルハイドロジェンシロキサン（ケイ素原子に結合する水素原子の含有量：０．８モル／１００ｇ）５．１質量部及び塩化白金酸のオクチルアルコール変性溶液（白金含有量２重量％）０．０２質量部を加えて攪拌し組成物を得た。 Comparative Examples 4 and 5
The curable silicone rubber used in these comparative examples was prepared by the following method.
100 parts by mass of water and then 20 parts by mass of a 60% by weight aqueous acetic acid solution were sequentially mixed with a solution in which 2 parts by mass of γ-glycidoxypropyltrimethoxysilane was dissolved in 50 parts by mass of methanol. This mixed solution was subjected to ultrasonic vibration for 1 hour to prepare a silane solution. In the solution, 100 parts by mass of a linear dimethylpolysiloxane in which both ends of a molecular chain represented by the following formula are blocked with a dimethylvinylsilyl group,

(Where n is a number such that the viscosity of the siloxane at 25 ° C. is 400 cSt)
200 parts by mass of the silica C (Comparative Example 4) and 400 parts by mass (Comparative Example 5) were mixed with a planetary mixer for 1 hour and then kneaded with three rolls. Next, 5.1 parts by mass of methylhydrogensiloxane (content of hydrogen atoms bonded to silicon atoms: 0.8 mol / 100 g) and an octyl alcohol-modified solution of chloroplatinic acid (platinum content 2) were added to this kneaded product. % By weight) was added and stirred to obtain a composition.

Each composition was evaluated by the following methods.
The aspect ratio of the cured product (h / d), which is the ratio of the height and diameter of the cured product, was used as an index of the shape maintenance performance of the composition.
The aspect ratio is measured by placing 0.1 g of a composition on a glass plate 11 (1 mm thickness) as shown in FIG. 1 and placing the plate on a hot plate set at 120 ° C. in advance after 5 minutes. Was installed. The composition was cured and then cooled, and the height (h) and diameter (d) of the cured product 12 were measured to determine (h / d), which is the ratio of the height and diameter of the cured product.

The tensile elastic modulus composition was cured by heating at 150 ° C. for 3 hours, and the tensile elastic modulus was measured according to JIS-K-7161.

Glass transition temperature [Tg], Tg or less expansion coefficient [CTE-1], Tg or more expansion coefficient [CTE-2]
The composition is cured by heating at 150 ° C. for 3 hours, the cured product is cooled to room temperature, a test piece of 5 mm × 5 mm × 15 mm is cut out, and 5 ° C./min by TMA (thermomechanical analyzer). The value when the temperature was raised at a speed was measured. In the measurement of the glass transition temperature, CTE-1 was determined in the temperature range of 20 to 50 ° C, and CTE-2 was determined in the temperature range of 200 to 230 ° C.

Thermal resistance value The apparatus shown in Fig. 2 was prepared. A silicon chip CPU3 (Celeron 300A, 15 mm × 15 mm × 0.75 mm) is flip-chip connected onto the CPU substrate 2 (38 mm × 38 mm × 2 mm) and sealed with an underfill agent 5 (SMC-377S, manufactured by Shin-Etsu Chemical Co., Ltd.). After that, a heat dissipation material (TIM 7772-4, manufactured by Shin-Etsu Chemical Co., Ltd.) was dispensed on the silicon chip 3, and about 1.0 g of each adhesive composition was dispensed on the substrate 2, and then a heat sink 1 (Ni of 38 mm × 38 mm × 2 mm) Coated copper plate, 1 W / ° C.) was placed and cured by heating at 150 ° C. for 3 hours. Thermocouples were placed at the locations indicated by a and b in FIG. 2, the chip 3 was operated at 450 MHz / power consumption 25.6 W, and the thermal resistance value when the operating rate was 100% was determined by the following formula.

Heat dissipation material thermal resistance Rja (° C./W)=(silicon chip temperature−heat sink temperature) /25.6

Thermal resistance value after cooling cycle After the thermal resistance value was measured, the device was subjected to a 500 cycle test with -45 ° C, 15 minutes → 125 ° C, 15 minutes as one cycle, and then the thermal resistance value was the same as above. Asked.

  As shown in Table 1, the cured products obtained from the compositions of the examples have a small aspect ratio, do not form dumplings, and have good thermal conductivity. In Comparative Example 3, the viscosity was too high to be molded. Moreover, since Comparative Examples 4 and 5 are rubber, there is no glass transition.

  The adhesive of the present invention is suitable for bonding a heat sink to a substrate.

It is a figure explaining the wettability of a composition. It is sectional drawing of the apparatus created in the Example.

Explanation of symbols

1: Heat sink 2: Substrate 3: Semiconductor chip 4: Heat dissipation material 5: Underfill agent 6: Adhesive 7: Semiconductor element

Claims (6)

The adhesive composition for semiconductor chip heat sinks containing the following (A)-(D).
(A) Epoxy resin 100 parts by mass (B) Curing agent 1-50 parts by mass (C) Inorganic filler having an average particle size of 0.1 to 10 μm and a maximum particle size of 75 μm or less
Silica whose surface has an average particle diameter of 30 to 1,000 parts by mass (D) of 0.005 μm or more and less than 0.1 μm.
1-20 parts by mass (C) Adhesive composition of Claim 1 whose inorganic filler is a spherical silica. The adhesive composition according to claim 1 or 2, wherein the component (A) is at least one selected from a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, and the following epoxy resin.

(R is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and n is an integer of 1 to 4) The adhesive composition according to any one of claims 1 to 3, wherein the component (A) comprises a silicone-modified epoxy resin. (B) The hardener is at least 1 sort (s) chosen from the hardener represented by following formula (1), (2), (3) and (4), The any one of Claims 1-4. Adhesive composition.

(Wherein R ^{1 to} R ⁴ 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) Curing agent is represented by following formula (5), The adhesive composition of any one of Claims 1-4 characterized by the above-mentioned.

(Wherein R ⁵ and R ⁶ represent a hydrogen atom, a methyl group, an ethyl group, a hydroxymethyl group or a phenyl group, R ⁷ represents a methyl group, an ethyl group, a phenyl group or an allyl group, and R ⁸ represents a hydrogen atom. Or a group represented by the following formula (6).)

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