JPH04337316A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain the title resin composition suitable for sealing material for semiconductor devices, requiring high heat resistance, low water absorption and solder immersion resistance, comprising an epoxidized bis(dihydroxynaphthyl)methane, a phenol resin and an inorganic filler. CONSTITUTION:1,6-Dihydroxynaphthalene is reacted with formaldehyde in the presence of sodium p-toluenesulfonate at 150 deg.C while stirring to give bis(1,6- dihydroxynaphthyl)methane, which is dissolved in epichlorohydrin, heated to 60 deg.C, reacted with 40% aqueous solution of sodium hydroxide, unreacted epichlorohydrin and water are removed, the resulting substance is extracted with an organic solvent to give an epoxy compound shown by the formula. Then an epoxy compound containing 30-100wt.% of the epoxy compound is blended with a phenol resin containing two or more phenolic hydroxyl groups and an inorganic filler to give the objective epoxy resin composition.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition having excellent heat resistance and crack resistance. In other words, it is related to resin compositions that aim to improve heat resistance and crack resistance as insulating materials, laminate materials, and resin sealing materials for electronic/electrical parts, semiconductor fields, etc., and particularly requires solder crack resistance. The present invention relates to an epoxy resin composition suitable for encapsulating semiconductor devices.

0002

BACKGROUND OF THE INVENTION In recent years, there has been a demand for resin compositions with excellent heat resistance and crack resistance in the fields of electric/electronic parts, semiconductors, etc. For example, in the field of electrical and electronic components, especially semiconductors, as equipment and equipment that use these components become smaller and thinner, there is a tendency for the density of mounting on wiring boards to be increased, and the components themselves are becoming smaller and thinner. There is a trend toward multifunctionality. As a material for sealing this, there is a strong desire to develop a resin composition that has excellent heat resistance against high-temperature soldering in the soldering process to wiring boards.

Conventionally, resin compositions for such uses, so-called semiconductor encapsulation resin compositions, have been made using epoxy resins such as O-cresol novolac type epoxy resins, phenol novolac resins and silica as curing agents. The resin composition as the main component has excellent moldability and reliability, and has become the mainstream in this field (Hiroshi Kakiuchi, ed., "Epoxy Resin", p. 80, Shokodo).

0004

However, resin-sealed semiconductor devices are being replaced by surface-mounted semiconductor devices due to the above-mentioned trend toward high-density packaging. In such a surface mount type semiconductor device, unlike a conventional insertion type semiconductor device, the entire semiconductor device is exposed to a soldering temperature of 200° C. or higher during the soldering process to a substrate. At this time, cracks occurred in the sealing resin, which caused a problem that significantly reduced the reliability of semiconductor devices (Nikkei Electronics, June 13, 1988 issue, p. 114).
-118). Cracks occur during soldering when moisture absorbed during storage of the semiconductor device expands explosively at temperatures of 200° C. or higher, generating stress, and when this stress exceeds the strength of the sealing resin, cracks occur. At this time, the stress applied to the resin is approximately expressed by the following formula (Narioka, Niwa, Yamada, Shiraishi, "Structural Mechanics 3", Maruzen).

σ=k・p・a2/t2 where σ: Stress applied to the resin k: Constant p: Water vapor pressure a: Length of the short side of the die pad t: Thickness of the resin at the bottom of the die pad Therefore, the glass of the sealing resin A resin made by epoxidizing a phenol compound obtained by reacting phenols or substituted phenols with parahydroxyphenylaldehyde in order to raise the transition temperature and give the resin enough strength to overcome the stress caused by expansion of water. For example, the EPPN500 series manufactured by Nippon Kayaku Co., Ltd. or the ESX220 series manufactured by Sumitomo Chemical Industries, Ltd. have been studied (for example, JP-A-1-158755, JP-A-2-75619, etc.). However, cured products obtained using such epoxy resins tend to have increased water absorption, and considering the above equation, this increases the stress applied to the resin and makes it impossible to take advantage of its high strength. Therefore, lowering the water vapor pressure during soldering by reducing the water absorption rate is an effective means for suppressing the occurrence of cracks.

An object of the present invention is to provide a resin composition with excellent heat resistance and crack resistance, which can be applied to resin-encapsulated semiconductor devices that require solder crack resistance during mounting. Furthermore, it is an object of the present invention to provide a resin composition that can be widely applied to electronic and electrical parts for improving the heat resistance and crack resistance of insulating materials, laminates, and the like.

[0007]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present inventors have conducted extensive research and found that bis(dihydroxynaphthyl)methane obtained by reacting dihydroxynaphthalene and formaldehyde is further reacted with epichlorohydrin. By using an epoxy compound having a naphthalene ring obtained by reacting with the epoxy compound or the above-mentioned bis(dihydroxynaphthyl)methane as the epoxy compound and its curing agent, the strength is significantly improved without increasing the water absorption rate of the sealing resin. The present invention was successfully completed.

That is, the present invention provides an organic component containing an epoxy compound having a naphthalene ring represented by the general formula (1) derived from bis(dihydroxynaphthyl)methane and a compound having two or more phenolic hydroxyl groups; The epoxy compound and bis(dihydroxynaphthyl)
This is an epoxy resin composition containing an organic component containing methane and an inorganic filler.

More specifically, as the component (A), (a)
Bis(dihydroxynaphthyl)methane obtained by reacting dihydroxynaphthalene and formaldehyde,
Furthermore, the general formula obtained by reacting with epichlorohydrin (
1) (chemical 2)

0010

Epoxy compounds containing 30 to 100% by weight of the epoxy compound represented by [Chemical Formula 2]; (b) an organic component mainly consisting of a phenolic resin having two or more phenolic hydroxyl groups; and (B) component: An epoxy resin composition containing an inorganic filler.

Alternatively, the phenolic resin of component (b) is 3
This is an epoxy resin composition containing 0 to 100% by weight of bis(dihydroxynaphthyl)methane, and is particularly suitable for semiconductor encapsulation with excellent solder crack resistance.

Component (a) used as the organic component (A) in the composition of the present invention is bis(dihydroxynaphthyl)methane obtained by reacting 2 moles of dihydroxynaphthalene with 1 mole of formaldehyde, and further with epichlorohydrin. These are epoxy compounds containing 30 to 100% by weight of the epoxy compound represented by the general formula (1) obtained by the reaction. In other words, even if the epoxy compound represented by general formula (1) is used alone as component (a),
Alternatively, other epoxy compounds may be mixed in a proportion of less than 70% by weight.

The epoxy compound represented by the general formula (1) is a bis(1,6-dihydroxy compound) obtained by a condensation reaction of 2 moles of 1,6-dihydroxynaphthalene or 2,7-dihydroxynaphthalene and 1 mole of formaldehyde. It is obtained by reacting naphthyl)methane or bis(2,7-dihydroxynaphthyl)methane with epichlorohydrin.

[0014] The polyvalent epoxy compound used in combination with the epoxy compound represented by the general formula (1), which is an essential component, is composed of phenol, substituted phenol, and aldehydes from the viewpoint of heat resistance and electrical properties. The general formula (2
) (Chem.3)

[0015]

The epoxy resin represented by the formula (wherein, R4 represents a hydrogen atom or an alkyl group having 1 to 9 carbon atoms, and p represents an integer of 1 or more) is most preferably used. Any compound having at least two epoxy groups can be used. Specifically, epoxy resins derived from compounds having two or more active hydrogens in one molecule, such as bisphenol A, bisphenol F, resorcinol,
Polyhydric phenols such as bishydroxydiphenyl ether, bishydroxybiphenyl, tetrabromobisphenol A, trihydroxyphenylmethane, tetrahydroxyphenylethane, alkanetetrakisphenol; ethylene glycol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, diethylene glycol , polyhydric alcohols such as polypropylene glycol; ethylenediamine, aniline,
Amines such as bis(4-aminophenyl)methane; epoxy resins obtained by reacting polyhydric carboxylic acids such as adipic acid, phthalic acid, and isophthalic acid with epichlorohydrin or 2-methylepichlorohydrin; and general formula (3) ( Chemical formula (4), General formula (4) (Chemical formula 5)

[0016]

[C4]

[0017]

embedded image (in each formula, x represents an integer of 0 to 5), and one or more of these epoxy resins are used. Furthermore, all of the above-mentioned epoxy resins can also be used after being modified with an oil-like, rubber-like silicone compound, or the like. For example, Japanese Patent Publication No. 62-270617
This is a silicone-modified epoxy resin prepared by dispersing fine particles of a silicone polymer in a reaction product of an epoxy resin and a vinyl polymer, as disclosed in JP-A No. 62-273222.

In the composition of the present invention, as the component (b), compounds having two or more phenolic hydroxyl groups in one molecule include phenol and general compounds which are reaction products of substituted phenols and aldehydes. Formula (5) (
6)

[0019]

A novolac type phenol resin represented by the following formula (wherein R3 represents a hydrogen atom, a hydroxyl group, or an alkyl group having 1 to 9 carbon atoms, and r represents an integer of 1 or more) is most preferably used, Other phenol compounds, such as general formula (6
) (Chemical Formula 7), General Formula (7) (Chemical Formula 8), General Formula (8) (Chemical Formula 9), and General Formula (9) (Chemical Formula 10)

[0020]

[C7]

[0021]

[Chemical formula 8]

[0022]

[Chemical formula 9]

[0023]

[Chemical formula 10] (In each formula, q represents an integer of 0 to 5.) Aralkyl resin represented by general formula (10) (Chemical formula 11)

002
4]

Dicyclopentadiene phenol resin represented by the formula (wherein, R2 represents a hydrogen atom or an alkyl group having 4 or less carbon atoms, and n represents an integer of 0 to 5), and trihydroxyphenylmethane , tetrahydroxyphenylethane, alkane tetrakisphenol, and the like. These phenol compounds can be used alone or in combination of two or more.

In the composition of the present invention, when component (b) contains 30 to 100% by weight of bis(dihydroxynaphthyl)methane, bis(dihydroxynaphthyl)methane may be used alone as component (b) or Compounds having two or more phenolic hydroxyl groups may be mixed and used in a proportion of less than 70% by weight.

As mentioned above, bis(dihydroxynaphthyl)methane is 1,6-dihydroxynaphthalene or 2,
Bis(1,6-
dihydroxynaphthyl)methane or bis(2,7-dihydroxynaphthyl)methane.

As the compound having two or more phenolic hydroxyl groups to be used in combination with bis(dihydroxynaphthyl)methane, all of the above-mentioned compounds having two or more phenolic hydroxyl groups in one molecule can be used.

[0028] In the composition of the present invention, component (a) and (
The ratio of component b) to the epoxy group of component (a) is
The equivalent ratio of hydroxyl groups in component b) is in the range of 0.1 to 10, preferably in the range of 0.5 to 2.0.

The inorganic filler used as component (B) in the composition of the present invention can be an inorganic powder or fibrous material, such as crystalline silica, fused silica, alumina, silicon nitride, etc. , silicon carbide, talc, calcium silicate, calcium carbonate, mica, clay, titanium white, and other powders; fibrous materials such as glass fiber and carbon fiber, but from the viewpoint of thermal expansion coefficient and thermal conductivity, crystalline , fusible silica powder is preferred. Furthermore, from the viewpoint of fluidity during molding, spherical silica powder or a mixture of spherical and irregularly shaped silica powders are preferred.

The blending amount of the inorganic filler (B) component is (A
) 100 to 9 parts by weight of the organic component of the component
00 parts by weight, preferably 200 parts by weight.
~600 parts by weight.

From the viewpoint of mechanical strength and heat resistance, it is preferable to use a coupling agent in combination with the above-mentioned inorganic filler for the purpose of improving adhesiveness with the resin. Examples of such coupling agent include silane-based, Coupling agents such as titanate, aluminate and zircoaluminate can be used. Among them, silane coupling agents are preferred;
In particular, a silane coupling agent having a reactive functional group is most preferred.

Examples of such silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, N-(2-aminoethyl)3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)3-
Aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4- Examples include epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane, and one or more of these may be used. These silane coupling agents are preferably fixed in advance on the surface of the inorganic filler by adsorption or reaction.

In the present invention, when curing the resin composition, it is desirable to contain a curing accelerator.
Such curing accelerators include 2-methylimidazole,
Imidazoles such as 2-methyl-4-ethylimidazole and 2-heptadecylimidazole; Amines such as triethanolamine, triethylenediamine, and N-methylmorpholine; Organic phosphines such as tributylphosphine, triphenylphosphine, and tritolylphosphine. ;
tetraphenylphosphonium tetraphenylborate,
Tetraphenylboron salts such as triethylammonium tetraphenylborate; 1,8-diaza-bicyclo(
5,4,0) undecene-7 and its derivatives. These curing accelerators may be used alone or in combination of two or more types. The content of these curing accelerators is (
The amount is in the range of 0.01 to 10% by weight based on the organic component of component A).

In addition to various components, the resin composition of the present invention may optionally contain various silicone oils; mold release agents such as fatty acids, fatty acid salts, and wax; flame retardants such as bromine compounds, antimony, and phosphorus; carbon black, etc. Adding coloring agents, etc.
It can be mixed and kneaded to form a molding material.

[0035]

[Examples] The present invention will be specifically explained below using examples. In addition, in the examples, the test method for the performance of the composition is as follows.・Glass transition temperature: TMA method ・Bending strength and flexural modulus: JIS K-6911 ・Water absorption: Using a test piece for bending test, after leaving it in a constant temperature and humidity chamber at 85 C and 85% for 120 hours Measure the weight increase.・V
PS test: After leaving the test semiconductor device in a constant temperature and humidity chamber at 85 C and 85% for 120 hours, it was immediately heated to 215 C.
Fluorinert liquid (FC-70; manufactured by Sumitomo 3M Co., Ltd.) was added to the package resin, and the number of semiconductor devices with cracks in the package resin was counted. (The numerator is the number of semiconductor devices with cracks, and the denominator is the total number of semiconductor devices subjected to the test.)

Synthesis example of bis(dihydroxynaphthyl)methane In a reaction vessel equipped with a thermometer, a stirrer and a condenser, 320 g of 1,6-dihydroxynaphthalene, 37
% formalin aqueous solution and 4.3 g of sodium p-toluenesulfonate were charged, and reacted at 150 C for 6 hours with stirring. After the reaction was completed, water was removed under reduced pressure of 5 mmHg to obtain bis(1,6-dihydroxynaphthyl)methane. This compound had a softening point of 162 C and a hydroxyl equivalent of 91.

Synthesis Example of Epoxy Compound In a reactor equipped with a thermometer, a stirrer, a separating tube and a dropping funnel, the above bis(1,6-dihydroxynaphthyl)
83 g of methane was dissolved in 945 g of epichlorohydrin. Next, the mixture was heated to 60 C, and 150 g of a 40% aqueous sodium hydroxide solution was continuously added dropwise over 2 hours. During this time, epichlorohydrin and water were azeotropically liquefied and separated into an organic layer and an aqueous layer using a separation tube.The aqueous layer was removed from the system and the organic layer was circulated into the system. After the reaction is complete, vacuum distillation (150 C, 5
After removing unreacted epichlorohydrin (mmHg), the reaction product was dissolved in methyl isobutyl ketone. Next, after the by-product salt was filtered off, methyl isobutyl ketone was removed by distillation to obtain an epoxy compound. This compound had a softening point of 93C and an epoxy equivalent of 161.

Examples 1 to 5 and Comparative Examples 1 and 2 Blends having the compositions (parts by weight) shown in Table 1 were mixed using a Henschel mixer, and then melted and kneaded for 3 minutes using heated rolls at 80 to 100 C. .

[0039] This mixture was cooled, pulverized, and tableted to obtain a molding resin composition.

[0040] Among the raw materials used in Table 1 other than those in the synthesis examples, the following were used.・Epoxy resin (1
); o-cresol novolac type epoxy resin (EOC
N-1020 manufactured by Nippon Kayaku Co., Ltd.) ・Epoxy resin (2); Tris(glycidoxyphenyl)methane (EPPN502H, manufactured by Nippon Kayaku Co., Ltd.) ・Epoxy resin (3); Brominated phenol novolak type epoxy Resin (BREN-S, manufactured by Nippon Kayaku Co., Ltd.) / Phenol compound (1); Novolac type phenol resin (PN
-80, Nippon Kayaku Co., Ltd.
(manufactured by Mitsui Toatsu Chemical Co., Ltd.) ・Phenol compound (2); aralkyl-type phenol resin (Millex XL-225L manufactured by Mitsui Toatsu Chemical Co., Ltd.)
・Inorganic filler; spherical fused silica (Halimic S-CO,
Micron Co., Ltd.) 50 parts by weight
and amorphous fused silica (Fuselex R
D-8 (manufactured by Tatsumori Co., Ltd.) 50 weight
Mixture with quantity/silane coupling agent; 3-
Glycidoxypropyltrimethoxysilane (A-187
Transfer molding (180 C) using the molding resin composition obtained as described above (manufactured by Nippon Unicar Co., Ltd.)
, 30 kg/cm 2 for 3 minutes) to form a test piece for measuring physical properties. In addition, test elements (10
mm x 10 mm square) and then transfer molding (
180 C, 30 kg/cm2, 3 minutes) to obtain a test semiconductor device. These test moldings were post-cured at 180 C for 6 hours before each test. The test results are shown in Table 2.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

[Effects of the Invention] As explained in the Examples and Comparative Examples, the epoxy resin composition according to the present invention can efficiently impart heat resistance without impairing water absorption.

Therefore, when a surface-mounted semiconductor device to which a reflow soldering method is applied is encapsulated with this epoxy resin composition, the resin-encapsulated semiconductor device exhibits excellent solder crack resistance and is highly reliable. This is an industrially useful invention.

Claims (5)

[Claims] Claim 1: As component (A), general formula (1) (chemical formula 1) obtained by further reacting bis(dihydroxynaphthyl)methane obtained by reacting (a) dihydroxynaphthalene and formaldehyde with epichlorohydrin; [
Epoxy compounds containing 30 to 100% by weight of the epoxy compound represented by formula 1; (b) an organic component mainly composed of a phenolic resin having two or more phenolic hydroxyl groups; and (B) an inorganic component as a component. An epoxy resin composition containing a filler. Claim 2: The phenolic resin of component (b) is 30 to 10
The epoxy resin composition according to claim 1, characterized in that it contains 0% by weight of bis(dihydroxynaphthyl)methane. 3. An epoxy resin composition for semiconductor encapsulation consisting essentially of the epoxy resin composition according to claim 1 or 2. Claim 4: The ratio of components (a) and (b) is such that the ratio of hydroxyl groups in component (b) to epoxy groups in component (a) is 0.
．． The epoxy resin composition according to claim 1 or 2, which has a molecular weight in the range of 1 to 10. Claim 5: The blending amount of the inorganic filler as component (B) is (A
) 100 to 900 parts per 100 parts by weight of the organic component of the component
The epoxy resin composition according to claim 1 or 2, which is in parts by weight.