JPH08301987A - Epoxy resin composition - Google Patents

Abstract

PURPOSE: To prevent the formation of fog on molds upon continuous molding by incorporating an epoxy resin, a curing agent, a filler composed mainly of silica, a specific silicon modifier, and an organic peroxide. CONSTITUTION: This epoxy resin composition is prepared by mixing uniformly an epoxy resin having at least two epoxy groups, a curing agent, a filler composed mainly of silica, a silicon modifier of the formula (wherein X and Y are each H, alkyl, phenyl or vinyl; n is 10-1,000) which has vinyl groups at the ends, and an organic free radical initiator made of an organic peroxide, followed by kneading, cooling/solidifying, and grinding the mixture.

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 used for encapsulation of printed wiring boards, electronic parts and semiconductor elements.

[0002]

2. Description of the Related Art An epoxy resin composition is known as a sealing material for physically and chemically protecting and fixing electronic parts and semiconductor elements. In recent years, as the wiring density has increased, the chip size has become larger. However, when the large chip is sealed with an epoxy resin composition, the internal stress of the cured product in the epoxy resin composition causes aluminum wiring. There are problems such as gap (sliding) and generation of cracks in the passivation layer.

Therefore, in order to bring the coefficient of thermal expansion of the epoxy resin composition close to that of the chip, the content of silica is increased and the coefficient of thermal expansion is reduced by adding a silicone modifier to relieve the internal stress. Is being attempted. As this silicon modifier, a silicon modifier having vinyl groups at both ends is often used.

[0004]

However, although a decrease in internal stress is observed when a silicone modifier is added,
When molding is continuously carried out, the molding die is liable to fog, and the molded product is liable to have a poor appearance.

The present invention has been made in view of the above facts, and an object of the present invention is to provide an epoxy resin composition which does not cause clouding in a molding die even when continuous molding is performed.

[0006]

The epoxy resin composition according to claim 1 of the present invention is an epoxy resin having two or more epoxy groups, a curing agent, a filler containing silica, and the following general formula: 1] An epoxy resin composition containing a silicone modifier having vinyl groups at both ends, represented by 1], characterized in that the composition contains an organic radical initiator composed of an organic peroxide. Epoxy resin composition.

[0007]

Embedded image

[In the formula, X and Y represent hydrogen, an alkyl group, a phenyl group or a vinyl group, and n = 10 to 1000 is represented. The epoxy resin composition according to claim 2 of the present invention is the epoxy resin composition according to claim 1, wherein the organic peroxide is an acyl peroxide, hydroperoxide, ketone peroxide, or t-butyl. It is characterized in that it is at least one kind of a peroxide having a group and a peroxide having a cumyl group.

An epoxy resin composition according to a third aspect of the present invention is represented by an epoxy resin having two or more epoxy groups, a curing agent, a filler containing silica, and the general formula [1]. An epoxy resin composition containing a silicone modifier having vinyl groups at both ends, wherein the composition contains an organic radical initiator composed of an azo compound.

An epoxy resin composition according to a fourth aspect of the present invention is the epoxy resin composition according to the third aspect, wherein the azo compound is 2,2'-azobis (4-methoxy-).
2,4-dimethylpentanenitrile), 2,2'-azobis (2,4-dimethylpentanenitrile), 2,2 '
-Azobis (isobutyronitrile), 2,2'-azobis (2-methylbutanenitrile), 4,4'-azobis (4-cyanopentanoic acid), 1,1'-azobis (cyclohexanecarbonitrile), 2 , 2'-azobis (2
-Acetoxypropane), 2- (tert-butylazo)-
4-methoxy-2,4-dimethylpentanenitrile, 2
-(Tert-butylazo) -2,4-dimethylpentanenitrile, 2- (tert-butylazo) -4-cyanopentanoic acid, 2- (tert-butylazo) isobutyronitrile,
At least one of 2- (tert-butylazo) -2-methylbutanenitrile, 1- (tert-amylazo) cyclohexanecarbonitrile, 1- (tert-butylazo) cyclohexanecarbonitrile, and 1- (tert-butylazo) formamide It is characterized by being more than one species.

The present invention will be described in detail below. The epoxy resin composition according to claim 1 of the present invention is an epoxy resin,
It contains a curing agent, a filler containing silica as a component, and a silicon modifier.

The above-mentioned epoxy resin is not particularly limited as long as it has two or more epoxy groups per molecule, and examples thereof include cresol novolac type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin and naphthalene type. , A biphenyl type or an alicyclic epoxy resin, a highly flame-retardant brominated epoxy resin, and the like. These may be used alone or in combination of two or more.

Examples of the curing agent include phenol novolac resin, acid anhydrides, amines and the like.
These may be used alone or in combination of two or more. The curing agent is not limited, but a phenol novolac resin is preferable from the viewpoint of good moisture resistance of the cured product.

A filler containing the above silica as a component is contained. Examples of the filler containing the above-mentioned silica include, for example,
Examples thereof include silica powder and glass fiber. In addition, it is preferable to subject the filler containing silica to a surface treatment with a silane coupling agent because the moisture resistance reliability of the molded product is improved.

The silicon modifier which constitutes the epoxy resin composition of the present invention has the above-mentioned general formula [1] as an essential constituent material.
It contains a silicone modifier having vinyl groups at both ends. The silicon modifier having vinyl groups at both ends has two or more vinyl groups as is clear from the structural formula. In addition, the said epoxy resin composition may use together another silicon modifier as needed. Examples of the other silicon modifier include epoxy / polyether silicone.

The present invention is characterized by using an organic peroxide as a constituent material. The organic peroxide is an organic radical initiator having a function of initiating a radical polymerization reaction with respect to the silicon modifier having vinyl groups at both ends. When the organic peroxide is contained, heat-dissociated oxygen ions act on the vinyl group to cause a polymerization reaction.
As a result, the molecular weight of the silicon modifier increases,
The amount of volatilization is reduced during molding of the mold, which prevents fogging of the mold.

Examples of the organic peroxides include acyl peroxides, hydroperoxides, ketone peroxides, peroxides having a t-butyl group, and peroxides having a cumyl group. Further, specifically, the acyl peroxide includes benzoyl peroxide, t-butyl perbenzoate, lauroyl peroxide, and the like, and the hydroperoxide is cumene hydroperoxide,
Examples of the above-mentioned ketone peroxide include methyl ethyl ketone peroxide and cyclohexanone peroxide, and examples of the above-mentioned peroxide having a t-butyl group include di-t-butyl peroxide. Examples of the above-mentioned peroxides having a cumyl group include dikurumi peroxide. These are either alone or 2
Used in combination with more than one species.

The above-mentioned epoxy resin composition may contain, together with the above-mentioned components, a curing accelerator, a flame retardant, a release agent, if necessary.
A colorant or the like is appropriately contained. Examples of the curing accelerator include tertiary amines, imidazoles, organic phosphorus compounds and the like, examples of the flame retardant include antimony trioxide, hydrated alumina and the like, and examples of the releasing agent include: Examples thereof include carnauba wax, stearic acid, and stearic acid salts, and examples of the colorant include pigments such as carbon black and metal oxides.

After the above-mentioned components are uniformly mixed by using a mixer, a blender or the like, they are kneaded by using a kneader, a roll or the like to obtain an epoxy resin composition. After kneading, it is cooled and solidified if necessary, and pulverized into powder or granules for use.

Next, the epoxy resin composition according to claim 3 of the present invention will be described. The epoxy resin composition of the present invention contains an epoxy resin, a curing agent, a filler containing silica as a component, and a silicon modifier. Examples of these materials include those similar to the above-mentioned epoxy resin composition.

The present invention is characterized by using an azo compound as a constituent material. The azo compound is an organic radical initiator having a function of initiating a radical polymerization reaction with respect to the silicon modifier having vinyl groups at both ends. When the azo compound is contained, the dissociated azo compound acts on the vinyl group to cause a polymerization reaction. As a result, the molecular weight of the silicon modifier becomes large, so that the amount of volatilization at the time of molding the mold becomes small, and the mold is prevented from fogging.

Examples of the azo compound include 2,
2'-azobis (4-methoxy-2,4-dimethylpentanenitrile), 2,2'-azobis (2,4-dimethylpentanenitrile), 2,2'-azobis (isobutyronitrile), 2,2 '-Azobis (2-methylbutanenitrile), 4,4'-azobis (4-cyanopentanoic acid), 1,1'-azobis (cyclohexanecarbonitrile), 2,2'-azobis (2-acetoxypropane), 2- (tert-butylazo) -4-methoxy-2,
4-dimethylpentanenitrile, 2- (tert-butylazo) -2,4-dimethylpentanenitrile, 2- (tert
-Butylazo) -4-cyanopentanoic acid, 2- (tert-
Butylazo) isobutyronitrile, 2- (tert-butylazo) -2-methylbutanenitrile, 1- (tert-amylazo) cyclohexanecarbonitrile, 1- (tert-
Butylazo) cyclohexanecarbonitrile, and 1
-(Tert-butylazo) formamide. These may be used alone or in combination of two or more.

The above-mentioned epoxy resin composition contains, together with the above-mentioned components, a curing accelerator, a flame retardant, a release agent, if necessary.
A colorant or the like is appropriately contained. Examples of these materials include those similar to the above-mentioned epoxy resin composition.

After the above-mentioned blending components are uniformly mixed using a mixer, a blender or the like, they are kneaded using a kneader, a roll or the like to obtain an epoxy resin composition. After kneading, it is cooled and solidified if necessary, and pulverized into powder or granules for use.

[0025]

Since the epoxy resin composition according to claim 1 or 2 of the present invention contains an organic radical initiator composed of an organic peroxide, oxygen ions dissociated by heat act on the vinyl group to polymerize. Since the reaction occurs, the molecular weight of the silicon modifier increases.

Since the epoxy resin composition according to claim 3 or 4 of the present invention contains an organic radical initiator composed of an azo compound, the dissociated azo compound acts on a vinyl group to cause a polymerization reaction. However, the molecular weight of the silicon modifier increases.

[0027]

【Example】

Example 1 17.2 parts by weight of cresol novolac type epoxy resin (Sumitomo Chemical Co., Ltd .: ESCN195: epoxy equivalent 197) as epoxy resin (hereinafter referred to as "part") and bisphenol A type epoxy resin as flame retardant epoxy resin 1.5 parts of brominated brominated epoxy resin (ESB400 manufactured by Yuka Shell Co., Ltd.) and phenol novolac resin as a curing agent (PSM6 manufactured by Arakawa Chemical Co., Ltd.)
200) in an amount of 8.0 parts, silica powder as a filler in an amount of 70.0 parts, and a silica modifier as a silicon modifier, wherein X and Y in the general formula [1] have a vinyl group at both ends. Vinyl-modified silicone having an average polymerization degree of 35
0) and 0.095 parts by weight of epoxy-polyether-modified silicone (Toray Silicone Co., Ltd .: SF8421)
0.1 part, di-t-butyl peroxide as an organic peroxide 0.005 part, 2-ethylimidazole as a curing accelerator 0.4 part, and antimony trioxide 1.5 parts as a flame retardant. , 0.5 parts of natural carnauba wax as a release agent, 0.5 parts of carbon black as a colorant,
0.2 part of a silane coupling agent was used as a surface treatment agent.

The silica powder was surface-treated with a silane coupling agent, the components were uniformly mixed with a mixer and then kneaded with a kneader to obtain an epoxy resin composition.

Example 2 An epoxy resin composition was obtained in the same manner as in Example 1 except that 0.005 parts of t-butylperbenzoate was used as the organic peroxide instead of the organic peroxide of Example 1. .

Example 3 An epoxy resin composition was obtained in the same manner as in Example 1 except that 0.005 parts of dikurumiper oxide was used as the organic peroxide instead of the organic peroxide of Example 1.

Example 4 As an epoxy resin, 17.2 parts of cresol novolac type epoxy resin (Sumitomo Chemical Co., Ltd .: ESCN195: epoxy equivalent 197) and as a flame retardant epoxy resin, bisphenol A type epoxy resin was brominated. Epoxy resin (ESB40 manufactured by Yuka Shell Co., Ltd.)
0) and 1.5 parts of phenol novolak resin (Arakawa Chemical Co., Ltd .: PSM6200) as a curing agent.
Part, silica powder 7 as a filler containing silica as a component.
0.0 part of a vinyl-modified silicone (average polymerization degree 350) having vinyl groups at both ends, wherein X and Y have a methyl group in the general formula [1], is used as a silicon modifier.
Parts, 0.1 part of epoxy-polyether-modified silicon (Toray Silicone Co., Ltd .: SF8421), 0.005 parts of 2,2′-azobis (isobutyronitrile) as an azo compound, and 2 parts as a curing accelerator. -0.4 parts of ethylimidazole, 1.5 parts of antimony trioxide as a flame retardant, 0.5 parts of natural carnauba wax as a release agent, 0.5 parts of carbon black as a coloring agent,
0.2 part of a silane coupling agent was used as a surface treatment agent.

The silica powder was surface-treated with a silane coupling agent, the components were uniformly mixed with a mixer and then kneaded with a kneader to obtain an epoxy resin composition.

Example 5 Instead of the azo compound of Example 4, as an azo compound,
An epoxy resin composition was obtained in the same manner as in Example 4 except that 0.005 part of 1'-azobis (cyclohexanecarbonitrile) was used.

Example 6 Instead of the azo compound of Example 4, as the azo compound, 1-
An epoxy resin composition was obtained in the same manner as in Example 4 except that 0.005 parts of (tert-butylazo) formamide was used.

Comparative Example 1 17.2 parts of a cresol novolac type epoxy resin (ESCN195: epoxy equivalent 197, manufactured by Sumitomo Chemical Co., Ltd.) as an epoxy resin, and a bisphenol A type epoxy resin brominated as a flame retardant epoxy resin. Epoxy resin (ESB40 manufactured by Yuka Shell Co., Ltd.)
0) and 1.5 parts of phenol novolak resin (Arakawa Chemical Co., Ltd .: PSM6200) as a curing agent.
Part, silica powder 7 as a filler containing silica as a component.
0.0 part of a vinyl-modified silicone (average polymerization degree 350) having vinyl groups at both ends, wherein X and Y have a methyl group in the general formula [1], is used as a silicon modifier.
Parts, 0.1 part of epoxy-polyether-modified silicone (SF8421 manufactured by Toray Silicone Co., Ltd.), 0.4 part of 2-ethylimidazole as a curing accelerator, and 1.5 parts of antimony trioxide as a flame retardant. Parts, 0.5 parts of natural carnauba wax as a release agent, 0.5 parts of carbon black as a colorant, and 0.2 parts of a silane coupling agent as a surface treatment agent.

The silica powder was surface-treated with a silane coupling agent, the above components were uniformly mixed with a mixer, and then kneaded with a kneader to obtain an epoxy resin composition.

Using the obtained epoxy resin compositions of Examples 1 to 6 and Comparative Example 1, continuous molding was evaluated. Using the above epoxy resin composition, a pressure of 50 kg / cm ² ,
Continuous molding was performed at a temperature of 150 ° C. for 3 minutes using a molding die up to 1000 times. The appearance of the molded product was visually inspected every 100 times, and the presence or absence of a defective product due to the occurrence of fogging was inspected. As shown in Table 1, in each of Examples 1 to 6, there was no defective product due to fogging up to 1000 times, but in Comparative Example 1, defective product due to fogging occurred after 100 times.

[0038]

[Table 1]

[0039]

Since the epoxy resin composition according to claim 1 or 2 of the present invention contains an organic radical initiator composed of an organic peroxide, the organic peroxide is a vinyl group of a silicon modifier. To increase the molecular weight. As a result, the epoxy resin composition of the present invention does not cause clouding in the molding die even when continuous molding is performed.

Since the epoxy resin composition according to claim 3 or 4 of the present invention contains an organic radical initiator composed of an azo compound, the azo compound acts on the vinyl group of the silicon modifier, and the molecular weight is changed. Enlarge. As a result, the epoxy resin composition of the present invention does not cause clouding in the molding die even when continuous molding is performed.

Claims (4)

[Claims] 1. An epoxy resin having two or more epoxy groups, a curing agent, a filler containing silica as a component, and a silicone modifier having vinyl groups at both ends represented by the following general formula [1]. An epoxy resin composition containing, wherein the composition contains an organic radical initiator comprising an organic peroxide. Embedded image [In formula, X and Y show hydrogen, an alkyl group, a phenyl group, and a vinyl group, and n = 10-1000 is shown. ] 2. The organic peroxide is an acyl peroxide,
The epoxy resin composition according to claim 1, wherein the epoxy resin composition is at least one of hydroperoxide, a ketone peroxide, a t-butyl group-containing peroxide, and a cumyl group-containing peroxide. 3. An epoxy resin having two or more epoxy groups, a curing agent, a filler containing silica, and a silicone modifier having vinyl groups at both ends represented by the following general formula [1]. An epoxy resin composition containing, wherein the composition contains an organic radical initiator comprising an azo compound. Embedded image [In formula, X and Y show hydrogen, an alkyl group, a phenyl group, and a vinyl group, and n = 10-1000 is shown. ] 4. The azo compound is 2,2′-azobis (4-methoxy-2,4-dimethylpentanenitrile), 2,2′-azobis (2,4-dimethylpentanenitrile), 2,2 ′. -Azobis (isobutyronitrile), 2,2'-azobis (2-methylbutanenitrile), 4,4'-azobis (4-cyanopentanoic acid),
1,1′-azobis (cyclohexanecarbonitrile), 2,2′-azobis (2-acetoxypropane), 2- (tert-butylazo) -4-methoxy-2,4
-Dimethylpentanenitrile, 2- (tert-butylazo) -2,4-dimethylpentanenitrile, 2- (tert
-Butylazo) -4-cyanopentanoic acid, 2- (tert-
Butylazo) isobutyronitrile, 2- (tert-butylazo) -2-methylbutanenitrile, 1- (tert-amylazo) cyclohexanecarbonitrile, 1- (tert-
Butylazo) cyclohexanecarbonitrile, and 1
The epoxy resin composition according to claim 3, which is at least one kind of-(tert-butylazo) formamide.