JPH0651780B2 - Epoxy resin composition for semiconductor encapsulation - Google Patents

Description

TECHNICAL FIELD The present invention relates to a low stress epoxy resin composition for semiconductor encapsulation, which is excellent in crack resistance when exposed to thermal shock and moisture resistance.

[Prior art]

In recent years, semiconductor-related technologies have been remarkably advanced, and the degree of integration of LSIs has been improved at an accelerating rate. Along with this, the miniaturization of wiring and the increase in chip size have been progressing. This tendency is due to resin-sealed LS
The problems of aluminum wiring deformation, passivation cracks, resin cracks, etc. of I were exacerbated. In order to solve these problems, it is currently strongly required to reduce the stress of the resin for semiconductor encapsulation.

Conventionally, various studies have been made on low stress epoxy resin compositions using silicone, but a method using silicone oil or organically modified silicone oil [JP-A-58-2141]
7, JP-A-59-81328, JP-A-60-30157, JP-A-60-138
41], in any case, moldability (especially curability, burr,
There was a problem in releasability) and moisture resistance.

In addition, various low stress resin compositions that do not use silicone have been investigated. For example, it has been considered to add synthetic rubber or to react it with an epoxy resin or a curing agent.
(JP-A-58-176958, JP-A-60-31251, JP-A-60-831
5) However, it had the same drawbacks as when using silicone.

[Object of the Invention]

The present invention has conventionally been problematic in moldability, moisture resistance, etc., and improved these drawbacks of the low stress epoxy resin composition by silicone which could not be applied at the market level, and applied at the industrial level, that is, As a result of research for the purpose of developing a practical product, an epoxy resin, which is a glycidyl ether of styrene-modified O-cresol novolac obtained by condensation of O-cresol, formalin and styrene under an acidic catalyst, is reacted with a hydrogen group-containing organopolysiloxane. It has been found that a low stress epoxy resin composition having excellent crack resistance and moisture resistance when subjected to a thermal shock can be obtained by using the epoxy resin obtained from the above.

[Structure of Invention]

The present invention relates to an epoxy resin obtained by reacting an epoxy resin, which is a glycidyl ether of styrene-modified O-cresol novolac obtained by condensation of O-cresol, formalin, and styrene under an acidic catalyst, with a hydrogen group-containing organopolysiloxane. An epoxy resin composition for semiconductor encapsulation, which is used as a part or all of a curing agent, a curing accelerator, a silica filler, and the like.

The hydrogen group-containing organopolysiloxane used in the present invention refers to an organopolysiloxane having a Si—H bond at the side chain or at the terminal, and has the general formula End (R is an alkyl group, a phenyl group) or the like. The molecular weight is arbitrary, and anything from a silicone oil type generally called H oil to a high molecular weight silicone raw rubber can be used.

The reaction between the hydrogen group-containing organopolysiloxane and the vinyl group in the resin derived from styrene is a hydrosilylation reaction and can be easily performed by using a platinum-based catalyst or the like (for example, chloroplatinic acid).

By carrying out this reaction, bleeding of silicon from the cured product can be prevented, and a low stress epoxy resin composition in which silicone is evenly dispersed in the cured product can be obtained in terms of morphology.

Such an epoxy resin is an epoxy resin having a sea-island structure in which the organopolysiloxane component is dispersed as fine particles of 1 μm or less in the resin, and not only is it excellent in crack resistance against thermal shock, but also the organopolysiloxane component is Since it is bonded, it does not bleed from the resin, so it has excellent moldability and moisture resistance.

The modified epoxy resin thus obtained can be used as all or part of the epoxy resin. However, it is desirable to add the organopolysiloxane component in the cured product in an amount of 1% by weight or more, and if the amount is less than this, stress characteristics may be deteriorated. Further, if the organopolysiloxane component is added to ½ or more of the total weight of the resin components (epoxy resin and curing agent) in the cured product, the curing characteristics will be significantly deteriorated.

Examples of the epoxy resin used in combination in the present invention include bisphenol A type epoxy resin, novolac type epoxy resin, alicyclic epoxy resin and the like. These epoxy resins may be used alone or in combination of two or more. You may use it.

As the curing agent, polybasic carboxylic acid anhydrides may be used alone or in combination of two or more. Examples of these are phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, succinic anhydride, maleic anhydride and the like. Alternatively, a phenol novolac resin may be used as the curing agent. Further, the amount of the curing agent blended in the epoxy resin is preferably 0.5 to 1.2 equivalents per one epoxy equivalent, and other than that, serious defects may occur in moldability.

As a curing accelerator, a tertiary amine or its derivative trimethylamine, triethylamine, 2, 3, 4,
6,7,8,9,10-octahydro-pyramide (1,2
-A) Azepine or the like or a quaternary ammonium salt thereof Organic phosphine compound (a) First, second and third phosphines: octylphosphine
Amine, diphenylphosphine, butylphenylphosphine
, Tricyclohexylphosphine, triphenylphos
Fin, etc., (b) Solid of compound having π bond with organic third phosphine
In-type adduct: maleic anhydride-triphenylphosphine
Adduct, thioisocyanate-triphenylphosphine
Adduct, diazodiphenylmethane-triphenylphos
Fin addition product, etc. (c) Organic borophonium salt: [φ_ThreePCH_Twoφ] Cl ,
(Φ_ThreePEt] I , [Φ_ThreePEt] Br etc Organoaluminum compound (a) Al (OR)_Three[R: H, alkyl group, aryl group, ant
Group-containing hydrocarbon group]: Aluminum isopropoxy
Aluminum, aluminum n-butoxide, aluminum tert-
Butoxide, aluminum sec-butyrate, aluminum
(B) β-diketone complex of aluminum (aluminum
): Aluminum acetylacetonate, aluminum
Mutrifluoroacetylacetonate, aluminum pen
Examples thereof include tafluoroacetylacetonato and the like, titanium compound butyl titanate, titanium white and the like, acids paratoluenesulfonic acid and the like.

〔The invention's effect〕

As described above, according to the present invention, it is possible to obtain a low stress epoxy resin composition which is excellent in moldability and moisture resistance and is excellent in crack resistance and the like when subjected to thermal shock. In particular, in semiconductor encapsulation applications, plastic packaging is expected to become more and more in the future, and the stress reduction of plastics is required for that purpose. Therefore, the industrial significance of the present invention is very large.

〔Example〕

Hereinafter, description will be made on a study example of a molding material for semiconductor encapsulation. All parts used in the examples are parts by weight. The examples according to the present invention are superior in moldability, moisture resistance, and crack resistance as compared with the prior art, and have high added value that can be industrially used.

The hydrogen group-containing organopolysiloxane used in the examples is as follows.

Organopolysiloxane a: average structural formula Organopolysiloxane b: average structural formula The reaction products of the epoxy resin, which is a glycidyl ether of styrene-modified o-cresol novolac used in the examples, and the hydrogen group-containing organopolysiloxane are as follows.

Reactant (epoxy resin) o-cresol, formaldehyde and styrene (molar ratio 0.7: 0.75: 0.3) were reacted under sulfuric acid catalyst and purified, and styrene-modified o-cresol novolac was added with epichlorohydrin at a molar ratio of 1: 3. After purification by addition reaction using a caustic soda catalyst, an epoxy resin, which is a glycidyl ether of styrene-modified o-cresol novolac, was obtained. Organopolysiloxane a20 against 80 parts of this epoxy resin
Reaction product obtained by reacting a part with a chloroplatinic acid catalyst and purifying, softening point 63 ° C.

Reactant (epoxy resin) A reaction obtained by reacting 80 parts of an epoxy resin, which is a glycidyl ether of styrene-modified o-cresol novolac obtained in the same manner as above, with 20 parts of organopolysiloxane b under a chloroplatinic acid catalyst and purification. Material, softening point 65 ℃ Adaptation example As an epoxy resin, / = 1/1, /
= 1/1 for 5 levels, and hardener and epoxy group / phenolic acid hydroxyl group = 1/1 (molar ratio)
The mixture was charged to 30 parts, further 0.2 parts of a curing accelerator, 70 parts of a filler, 0.5 part of a surface treating material and 0.4 part of a release agent were added and mixed, and then kneaded using a twin-screw extruder to form a material. As a result of a comparative examination of a total of five types of moldability, crack resistance, and moisture resistance, when the resin composition according to the present invention was used, the characteristics were all better than when the conventional o-cresol novolac epoxy resin was used alone. It turned out to be extremely good. The results are summarized in Table-1.

The raw materials used in the examples are as follows.

-Orthocresol novolac type epoxy resin: Nippon Kayaku EOCN-1025-65 (epoxy resin) -Curing agent / phenol novolac: Gunei Chemical MP-120-Curing accelerator: KAEI Kasei PP-360 / Shikoku Kasei 2MZ = 9 / 1-Filling material: Tatsumori Mori fused silica-Surface treatment agent: Nippon Unicar A-186-Release agent: Hoechst Japan Hoechst OP / Hoechst S = 1/1

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 59-30820 (JP, A) JP 58-21417 (JP, A) JP 62-7723 (JP, A) JP 62- 136860 (JP, A)

Claims (1)

[Claims] 1. An epoxy resin and a curing agent obtained by reacting an epoxy resin, which is a glycidyl ether of styrene-modified O-cresol novolac, which is obtained by condensing O-cresol, formalin, and styrene under an acidic catalyst, with a hydrogen group-containing organopolysiloxane. An epoxy resin composition for semiconductor encapsulation, comprising a curing accelerator, and a silica filler as essential components.