JPH11140165A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition useful as a semiconductor encapsulating material at an increased curing rate and to suppress the generation of chlorine ions and the like which cause insulation failure and circuit corrosion. . SOLUTION: An epoxy resin, a phenol resin, and 2-aryl-4, represented by the following general formula as a curing accelerator,
A 5-diphenylimidazole compound and an inorganic filler are essential components, and the curing accelerator is blended at 0.002 to 2.0% by weight with respect to the entire resin composition. (In the formula, Ar represents a phenyl group, a lower alkyl-substituted phenyl group, a naphthyl group, a lower alkyl-substituted naphthyl group, an anthranyl group or a lower alkyl-substituted anthranyl group.)

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention has excellent curability,
The present invention relates to an epoxy resin composition for a semiconductor encapsulant in which generation of ionic impurities such as chlorine ions in a cured product is small.

[0002]

2. Description of the Related Art In general, semiconductor devices are encapsulated by transfer molding using an epoxy resin. In particular, a system using a novolak type epoxy resin and a novolak type phenol resin is mainly used. In this case, as a curing accelerator, triphenylphosphine, 2-methylimidazole or 1,8-diazabicyclo [5.4.0] undecene (D
BU) is often used. Such an epoxy resin composition for a semiconductor encapsulant is required to have a shorter molding step, that is, to have a faster curing property in view of improving productivity. In addition, the cured product is required to be free from ionic impurities such as chlorine ions which cause poor insulation and cause corrosion of circuits.

[0003]

An epoxy comprising a conventional epoxy resin such as a novolak type epoxy resin, a phenol resin such as a novolak type phenol, a curing accelerator such as triphenylphosphine, 2-methylimidazole or DBU, and an inorganic filler. The resin composition has a disadvantage that the curing speed is not sufficient, and further, there are many ionic impurities such as chlorine ions in the cured product, and a leak current due to poor insulation properties and a disconnection due to corrosion of the circuit are generated. With respect to the improvement of the curing speed, studies are mainly made on curing accelerators, and on the reduction of ionic impurities, studies are being made on epoxy resins, phenolic resins and curing accelerators.

For example, Japanese Patent Application Laid-Open No. 62-1 discloses a method for improving curability by using triphenylphosphine tetraphenylborate as a curing accelerator.
Japanese Patent No. 49721, JP-A-8-245762 discloses that an epoxy resin composition having a specific composition is used to improve the reliability of a cured product. It cannot be said that it has been improved. The present invention provides an epoxy resin composition which is excellent in curability and which can provide a cured product with less generation of ionic impurities such as chlorine ions which are harmful from the viewpoint of reliability, and which is useful as a semiconductor sealing material. It is.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object, and as a result, by using a specific curing accelerator, the curability is excellent and the chlorine in the cured product is high. The present inventors have found that an epoxy resin composition having a small generation amount of ionic impurities such as ions can be obtained, and have completed the present invention.

That is, the present invention relates to (A) an epoxy resin, (B) a phenolic resin, (C) a 2-aryl-4,5-diphenylimidazole compound represented by the formula (2) as a curing accelerator, and (D) an inorganic filler. Agent as an essential component,
The present invention relates to an epoxy resin composition characterized in that the curing accelerator (C) is blended at a ratio of 0.002 to 2.0% by weight with respect to the whole resin composition.

[0007]

Embedded image (Wherein, Ar represents a phenyl group, a lower alkyl-substituted phenyl group, a naphthyl group, a lower alkyl-substituted naphthyl group, an anthranyl group or a lower alkyl-substituted anthranyl group)

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION (A) used in the present invention
The epoxy resin may be any one as long as it is generally used as an epoxy resin. Examples of the epoxy resin include glycidyl ether type epoxy resins such as bisphenol A type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, biphenyl type epoxy resin; glycidyl ester type epoxy resin; glycidylamine type epoxy resin; Aliphatic epoxy resin; alicyclic epoxy resin;
Heterocyclic epoxy resin; an epoxy resin having two or more epoxy groups in one molecule, such as a halogenated epoxy resin, and one or two selected from the group consisting of epoxy resins;
More than one species is used. The epoxy resin preferably has a chlorine ion content of 0.1% by weight or less. Further, as the epoxy resin, it is preferable to use a glycidyl ether type epoxy resin, and in particular, by using a novolak type epoxy resin having an epoxy equivalent of 170 to 300, a cured product having excellent properties can be obtained. , Most preferred.

The phenolic resin (B) used in the present invention may be any one as long as it is generally used as a phenolic resin, but it is preferable to use a novolak type phenolic resin. Examples of the novolak type phenol resin include phenol novolak resin, cresol novolak resin, tert-butylphenol novolak resin, nonylphenol novolak resin and the like, and one or two or more selected from these are used. It is desirable that the amount of the phenolic resin is appropriately selected from the relationship with the epoxy group equivalent of the epoxy resin, and the equivalent ratio of the phenolic hydroxyl group to the epoxy group is preferably in the range of 0.5 to 1.5. . When the equivalent ratio is less than 0.5 or more than 1.5, the reaction does not proceed sufficiently, and the properties of the cured product deteriorate.

The curing accelerator used in the present invention comprises:
2-aryl-4,5- represented by the above general formula (2)
It is a diphenylimidazole compound. Specific compounds include, for example, 2,4,5-triphenylimidazole, 2- (2-methylphenyl) -4,5-diphenylimidazole, 2- (3-methylphenyl) -4,5-
Diphenylimidazole, 2- (4-methylphenyl)
-4,5-diphenylimidazole, 2- (4-ethylphenyl) -4,5-diphenylimidazole, 2-
(4-isopropylphenyl) -4,5-diphenylimidazole, 2- (4-tert-butylphenyl)-
4,5-diphenylimidazole, 2- (2,4-dimethylphenyl) -4,5-diphenylimidazole,
-(1-naphthyl) -4,5-diphenylimidazole, 2- (2-naphthyl) -4,5-diphenylimidazole, 2- (4-methyl-1-naphthyl) -4,5-
Diphenylimidazole, 2- (8-methyl-2-naphthyl) -4,5-diphenylimidazole, 2- (6-
Ethyl-1-naphthyl) -4,5-diphenylimidazole, 2- (9-anthryl) -4,5-diphenylimidazole, 2- (6-methyl-1-anthryl)-
4,5-diphenylimidazole and the like. These can be used alone or in combination of two or more. Further, conventionally known amine compounds such as imidazole compounds and DBU and phosphorus compounds such as triphenylphosphine may be used in combination.

[0011] The compounding ratio of the curing accelerator is in the range of 0.002 to 2.0% by weight based on the whole resin composition. If the compounding ratio is less than 0.002% by weight, it takes too much time to cure, which is not practical. If it exceeds 2.0% by weight, a large amount of chlorine ions is generated in the cured product, and the cured product has a stable moisture resistance. The physical properties of the cured product are reduced, for example, the properties are reduced.

Examples of the inorganic filler (D) used in the present invention include quartz glass powder, crystalline silica powder, glass fiber, talc, alumina powder, calcium silicate powder, calcium carbonate powder, barium sulfate powder, and magnesia. And the like. One or more powders selected from the group consisting of powders are used. Among these, it is preferable to use quartz glass powder and crystalline silica powder because they have high purity and low thermal expansion coefficient.

The amount of such an inorganic filler to be compounded must be appropriately selected depending on the type of the epoxy resin, phenolic resin and inorganic filler to be used. And about 1.5 to 4 times by weight based on the total amount of the phenol resin. In addition, the particle size of the inorganic filler may be appropriately selected and used, and the moldability can be improved by mixing and mixing coarse and fine particles.

The epoxy resin composition of the present invention comprises (A) an epoxy resin, (B) a phenolic resin, (C) a 2-aryl-4,5-diphenylimidazole compound as a curing accelerator, and (D) an inorganic filler. The agent is an essential component, and examples of the additive include release agents such as natural waxes, synthetic waxes, metal salts of linear fatty acids, acid amides, esters, and paraffins, chlorinated paraffins, and bromo. Examples include flame retardants such as toluene, hexabromobenzene, and antimony trioxide, and silane coupling agents. These may be appropriately added and blended according to the purpose.

[0015] The epoxy resin composition of the present invention can be prepared from the above-mentioned components using a conventional method. For example, after mixing each component of a predetermined blending amount with a mixer or the like, melt-mixing with a heating roll, a kneader or an extruder,
Then, it is cooled and solidified, and pulverized to an appropriate size to obtain a molding material.

[0016]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited to the following Examples. The composition ratio in each example is part by weight.

Examples 1 to 7, Comparative Examples 1 to 5 According to the composition shown in Table 1, each component was mixed at room temperature,
After kneading and cooling at １００100 ° C., the mixture was pulverized to prepare an epoxy resin composition. Novolak type epoxy resin (epoxy equivalent 190) as epoxy resin, novolak type phenol resin (hydroxyl equivalent 117) as phenol resin,
Fused silica powder was used as the inorganic filler. Comparative Example 1
In Nos. 1 to 3, triphenylphosphine and D
BU, 2-methylimidazole was used. In Comparative Examples 4 and 5, each of 0.0016% by weight of 2- (4-methylphenyl) -4,5-diphenylimidazole as a curing accelerator was added to 100 parts by weight of the epoxy resin composition.
And 2.2% by weight.

The gelation time and the amount of ionic impurities in the cured product of these epoxy resin compositions were measured. The results were as shown in Table 2. In addition,
The gelation time and the amount of ionic impurities in the cured product were measured by the following methods. (A) Gelation time The curability of the epoxy resin compositions of Examples and Comparative Examples was measured by a hot plate gelation method (150 ° C.). (B) Amount of ionic impurities in cured product The epoxy resin compositions of Examples and Comparative Examples were cured by heating at 170 ° C for 5 hours to obtain molded articles. After the compact was pulverized, it was classified with a 60-mesh sieve, and 4 g of the passed powder was mixed with 15 g of distilled water in a Teflon high-pressure container (capacity: 25 m).
1) and heated (at 180 ° C. for 20 hours) to extract ionic impurities in the molded body. The extracted water thus obtained was measured for electric conductivity and the amount of chloride ions by ion chromatography.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

The epoxy resin composition of the present invention has excellent curability and gives a cured product with less generation of ionic impurities such as chloride ions, so that it is very useful as an epoxy resin for semiconductor encapsulants. It is.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 63/00 C08L 63/00 C H01L 23/29 H01L 23/30 R 23/31

Claims (1)

[Claims] An essential component is (A) an epoxy resin, (B) a phenolic resin, (C) a 2-aryl-4,5-diphenylimidazole compound represented by the formula (1) as a curing accelerator, and (D) an inorganic filler. And the curing accelerator (C) is added to the entire resin composition in an amount of 0.002 to 2.0.
An epoxy resin composition characterized in that it is blended in a ratio of weight%. Embedded image (Wherein, Ar represents a phenyl group, a lower alkyl-substituted phenyl group, a naphthyl group, a lower alkyl-substituted naphthyl group, an anthranyl group or a lower alkyl-substituted anthranyl group)