JPS63183918A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To provide the titled composition outstanding in heat resistance, having low elastic modulus with flexibility, for semiconductor sealing use, comprising an epoxy resin, specific trifunctional phenolic compound curing agent, curing accelerator, and inorganic filler. CONSTITUTION:The objective composition comprising (A) an epoxy resin (B) a trifunctional phenolic compound curing agent of formula I (R1 is H, methyl or phenyl; R2 and R3 are each H, alkyl, alkoxyl or halogen) [e.g., 1,1,3-tris(hydroxyphenyl)butane] (C) pref. 0.1-1.0wt.% of a curing accelerator (e.g., 2-ethyl-4-methylimidazole) and (D) pref. 60-85wt.% of inorganic filler (e.g., fused silica, alumina).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an epoxy resin composition for semiconductor encapsulation having excellent heat resistance and low elasticity.

[Industrial Application Field] The present invention is an epoxy resin composition for semiconductor encapsulation that has excellent heat resistance, low elasticity, and flexibility by using a trifunctional phenol compound as a curing agent, and is widely used in electrical and electronic components. used for.

[Conventional technology and its problems] Traditionally, diodes, transistors, and ICs.

A method of sealing electronic components such as LSI using epoxy resin has been used. This resin sealing is suitable for glass, metal,
It is economically advantageous compared to hermetic sealing methods using ceramics, so it is widely put into practical use. However, since this resin encapsulation directly seals the element by transfer molding, the difference in linear expansion coefficient between the element and the resin and thermal stress may cause distortion or breakage of the element, or bonding lines may be damaged. There are problems such as breakage, and it is desired to reduce stress on the element. Particularly in recent years, as semiconductor devices have become larger and more highly integrated, the demand has become stronger. In order to reduce stress, materials are being devised to lower the elastic modulus and linear expansion coefficient of cured products.

- That is, a method of blending a flexibility imparting agent is known as one method of reducing stress. However, when a flexibility imparting agent such as conventionally known polypropylene glycol diglycidyl ether or bisphenol A type epoxy resin having a long side chain is blended, the effect of lowering the elastic modulus is observed, but the glass The problem is that the transition point (Tg) drops rapidly and the electrical properties at high temperatures deteriorate.

Furthermore, when a cresol novolac type epoxy resin is modified with a rubber having unsaturated double bonds, the elastic modulus decreases, but the glass transition point also decreases considerably (JP-A-58-1
No. 74416, JP-A-60-8315).

Adding an inorganic filler with a small coefficient of thermal expansion is known as a method of lowering the coefficient of thermal expansion of a material. However, when the amount of added inorganic filler is increased, the modulus of elasticity increases at the same time as the coefficient of expansion decreases, which reduces stress. Sufficient reduction has not been achieved.

[Means for Solving the Problems] The present invention provides a) an epoxy resin b) a trifunctional phenol compound curing agent represented by the following general formula, where R+ is hydrogen, a methyl group or a phenyl group, and R2 and R3 are They are the same or different groups selected from the group consisting of hydrogen, alkyl groups, alkoxyl groups, and halogens.

The present invention relates to an epoxy resin composition for semiconductor encapsulation characterized by containing C) a curing accelerator and d) an inorganic filler component.

As long as the epoxy resin used in the present invention is a compound having at least two epoxy groups in its molecule, there is no particular restriction on the molecular structure, 9 molecular weight, etc., and a wide range of commonly used epoxy resins may be included. Can be done.

For example, bisphenol A epoxy resin.

Phenol novolac type epoxy resin, glycidyl ether type epoxy resin such as cresol novolac type epoxy resin, glycidylamine type epoxy resin, linear aliphatic, epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, and halogenated epoxy resin etc. Further, these epoxy compounds may be used alone or in combination of two or more.

b) The trifunctional phenol compound curing agent is a trifunctional phenol compound represented by the following general formula.

In the formula, R1 is hydrogen, a methyl group or a phenyl group, and R2 and R3 are the same or different groups selected from the group consisting of hydrogen, an alkyl group, an alkoxyl group, or a halogen.

For example, 1,1,3-)lis(hydroxyphenyl)butane represented by formula (I), 1 represented by formula (n),
1,3-tris(hydroxyphenyl)-3-phenylpropane, 1,1,3-)tris(
Examples include 3-methyl-4-hydroxyphenyl)butane.

CI) (II) d) As a curing accelerator, 2-ethyl-4-methylimidazole, ? -Methylimidazole? - Imidazoles such as phenylimidazole and 2-undecylimidazole, 2-(dimethylaminemethyl)phenol, 2.
4.6-tris(dimethylaminomethyl)phenol,
Tertiary amines such as benzyldimethylamine, organic phosphines such as triphenylphosphine, tributylphosphine, methyldiphenylphosphine, tricyclohexylphosphine, 1,8-diazabicyclo(5,4,0)
Undecene-7,1,8-diazabicyclo (7゜2.0
) Undecene-8,l.

8-diazabicyclo(7,5,0)tetradecene-8,
1,5-diazabicyclo(4,3,0)nonene-5,1
,, diazabicycloalkenes such as 5-diazabicyclo(4°2.0)octene-5, phenol salts thereof, formic acid 143, adipate, and the like. One or more types selected from these groups are used.

d) Waxy fillers include fused silica, crystalline silica, magnesium oxide, alumina, calcium carbonate, and the like.

In addition, in the combination of an epoxy resin and a trifunctional phenol compound curing agent, it is preferable to use them in a ratio such that the number of phenolic hydroxyl groups is 0.5 to 2.0 per epoxy group contained in the epoxy resin.

The amount of the curing accelerator added to the molding material is preferably 0.1 to 1.0% by weight.

The amount of the inorganic filler added is preferably 60 to 85% by weight based on the total composition, and if it exceeds 85% by weight, the fluidity of the composition will be low and the stability will be poor. Moreover, if it is less than 60% by weight, problems such as an increase in linear expansion coefficient occur. Therefore, although it varies depending on the type of inorganic filler, it is appropriately blended in the range of 60 to 85% by weight.

In the present invention, in addition to a) to d), natural waxes, synthetic waxes, mold release agents such as higher fatty acids and metal salts thereof, silane coupling agents, titanium coupling agents, etc. may be used as necessary. Coupling agents such as carbon, coloring agents such as carbon, and flame retardant aids such as antimony trioxide and antimony pentoxide can also be added.

In addition, in the present invention, components a) to d) and other components are blended, mixed with a Hensch 1 Lum mixer, etc.
By kneading at 70 to 110° C. using rolls, kneaders, etc., a molding material with the desired excellent properties can be obtained.

[Effects of the invention] Conventional epoxy resin compositions for semiconductor encapsulation using phenol nopolar resin as a hardening agent have a flexibilizing agent added to them in order to lower the flexural modulus and provide flexibility. A decrease in the glass transition temperature then occurs.

However, when the composition of the present invention is used, an epoxy resin composition for semiconductor encapsulation that has excellent heat resistance, low elastic modulus, and flexibility can be obtained.

[Example of the present invention] Materials used in Examples and Comparative Examples are shown below.

(1) Types of epoxy resins (I) Orthocresol novolak type epoxy resin (epoxy equivalent: 197, softening point: 73°C) (LI) Brominated phenol nopolar 2 type epoxy resin (epoxy equivalent: 27
5. Softening point: 84°C) (2) Type of curing agent (I) 1,1.3-)lis(hydroxyphenyl)butane, which is a condensate of phenol and crotonaldehyde (hydroxyl group output: 115, softening point: 110°C) (II) 1,1,3-tris(hydroxyphenyl)-3-, a condensate of phenol and cinnamaldehyde
Phenylpropane (fit 134 per hydroxyl group, softening point 11)
(m) 1,1.3-)lis(3-methyl-4-hydroxyphenyl)butane, a condensate of orthocresol and crotonaldehyde (hydroxyl equivalent: 127, softening point: 95°C)
) (IV)-y enol novolac resin (hydroxyl equivalent: 10
8, Softening point 96°C) (I) (II) (m) (3) Curing accelerator triphenylphosphine (4) Filler fused silica (5) Type III agent carnauba wax (6) Coupling agent γ-glyside Xyprobyltrimethoxysilane (7) Flame retardant aid Antimony dioxide carbon black (Examples 1 to 3 and Comparative Example 1) The materials shown in Table 1 are mixed, cross-wired with a heating roll, cooled and crushed to form an epoxy resin. The molding material was adjusted. Test pieces were prepared from these molding materials under molding conditions of 175° C. for 3 minutes, and after curing at 175° C. for 6 hours, their properties were evaluated. The results are also listed in Table-1.

Claims (1)

[Claims] a) Epoxy resin b) Trifunctional phenolic compound curing agent represented by the following general formula ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ In the formula, R_1 is hydrogen, a methyl group or a phenyl group, R_
2 and R_3 are the same or different groups selected from the group consisting of hydrogen, an alkyl group, an alkoxyl group, or a halogen. An epoxy resin composition characterized by containing c) a curing accelerator and d) an inorganic filler component.