JPH0668006B2 - Sealing resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a resin composition for encapsulating an electronic / electrical component, which has low stress, excellent moisture resistance, and excellent cold-heat cycle characteristics.

(Prior Art) Conventionally, for electronic parts such as diodes, transistors, and integrated circuits, a method of sealing with a thermosetting resin has been performed. This resin encapsulation has been widely put into practical use because it is economically advantageous as compared with the hermetic sealing method using glass, metal, or ceramic. As a sealing resin composition, an epoxy resin composition is most commonly used among thermosetting resin compositions. Curing agents such as acid anhydrides, aromatic amines and novolac type phenolic resins are used in the epoxy resin composition. Among these, the epoxy resin composition using a novolac type phenolic resin as a curing agent is superior in moldability and moisture resistance, nontoxic, and inexpensive as compared with those using other curing agents, and thus semiconductor encapsulation. Widely used as a material.

However, in recent years, in the field of semiconductor integrated circuits, high integration of elements and large-sized pellets have progressed, and conventional epoxy resins using novolac-type phenolic resin as a curing agent shrink during molding and curing into semiconductor elements. Stressed,
It had the drawback of being less reliable. When a molded product (sealed product) using such a resin is subjected to a hot and cold cycle test, there is a drawback that the bonding wire is opened, resin cracks and pellet cracks occur, and the function as an electronic component cannot be achieved.

(Problems to be Solved by the Invention) The present invention has been made in order to solve the above-mentioned drawbacks, and has the advantages of a conventional epoxy resin composition with low stress, excellent humidity resistance, and excellent cold-heat cycle property. It is an object of the present invention to provide a retained and highly reliable sealing resin composition.

[Structure of the Invention] (Means and Actions for Solving the Problem) As a result of intensive studies aimed at achieving the above-mentioned object, the present inventors have found that when a hydrogenated polyisoprene rubber is blended, it has low stress and moisture resistance. It has been found that
The present invention has been completed.

That is, in the present invention, (A) epoxy resin (B) novolac type phenol resin (C) hydrogenated polyisoprene rubber having a hydrogenation rate of 60% or more and (D) an inorganic filler are essential components,
The hydrogenated polyisoprene rubber (C) is used in an amount of 0.1 to 10% by weight, and the inorganic filler (D) is used in an amount of 25% by weight based on the resin composition.
The resin composition for encapsulation is characterized in that each of the resin compositions is contained in a proportion of from 90 to 90% by weight.

As the epoxy resin (A) used in the present invention, as long as it is a compound having at least two epoxy groups in its molecule, there are no particular restrictions on the molecular structure, molecular weight, etc. Can be broadly included. Examples thereof include bisphenol type aromatic resins, alicyclic resins such as cyclohexane derivatives, and epoxy novolac resins represented by the following general formula.

(In the formula, R ¹ represents a hydrogen atom, a halogen atom or an alkyl group, R ² represents a hydrogen atom or an alkyl group, and n represents an integer of 1 or more.) These epoxy resins are used alone or in combination of two or more. Used.

Examples of the (B) novolak type phenolic resin used in the present invention include novolak type phenolic resins obtained by reacting phenols such as phenol and alkylphenol with formaldehyde or paraformaldehyde, and modified resins thereof, for example, epoxidized or butylated novolaks. Examples include type phenol resins. The mixing ratio of the novolac type phenol resin is such that the molar ratio [(a) / (b)] of the epoxy group (a) of the (A) epoxy resin and the phenolic hydroxyl group (b) of the (B) novolac type phenol resin is It is desirable to be in the range of 0.1 to 10. If this molar ratio is less than 0.1 or exceeds 10,
Moisture resistance, molding workability, and electrical properties of the cured product deteriorate, which is not preferable in any case. Therefore, it is limited within the above range.

The hydrogenated polyisoprene rubber (C) used in the present invention is represented by the following formula.

However, the hydrogenation ratio [x / (x + y)] is arbitrary, but is preferably 60% or more.

Specifically, Kuraprene LIR-290 (Kuraray Isoprene Chemical Co., Ltd. product name, hydrogenation ratio of about 90%)
And the like, and they can be used alone or in combination of two or more. The hydrogenated polyisoprene rubber is preferably blended in an amount of 0.1 to 10% by weight based on the resin composition. If the proportion is less than 0.1% by weight, the effect of low stress and hot and cold cycle is ineffective, and if it exceeds 10% by weight, the moldability is deteriorated and it is not suitable for practical use.

Examples of the inorganic filler (D) used in the present invention include silica powder, alumina, antimony trioxide, talc, calcium carbonate, titanium white, clay, asbestos, mica,
Red iron oxide, glass fiber, carbon fiber and the like can be mentioned, and they can be used alone or in admixture of two or more. Of these, silica powder and alumina are particularly preferable. The blending ratio of the inorganic filler needs to be 25 to 90% by weight of the resin composition. If the blending amount is less than 25% by weight, the moisture resistance, heat resistance, mechanical properties and moldability are not effective, and if it exceeds 90% by weight, the bulkiness becomes large and the moldability is poor and it is not suitable for practical use.

The encapsulating resin composition of the present invention contains an epoxy resin, a novolac-type phenol resin, a hydrogenated polyisoprene rubber, and an inorganic filler as essential components, but if necessary, for example, natural waxes, synthetic waxes, Metal salts of linear fatty acids, acid amides, esters, release agents such as paraffins, chlorinated paraffin, bromtoluene, hexabromobenzene, flame retardants such as antimony trioxide, colorants such as carbon black and red iron oxide, silanes A coupling agent, various curing accelerators, and the like can also be appropriately added and blended.

A general method for producing the encapsulating resin composition of the present invention as a molding material is epoxy resin, novolac type phenolic resin, hydrogenated polyisoprene rubber, inorganic filler and other, selected to a predetermined composition ratio. After the raw material components are sufficiently and uniformly mixed by a mixer or the like, they are further melt-mixed by a hot roll or mixed by a kneader or the like, then cooled and solidified, and pulverized to an appropriate size to obtain a molding material. The molding material thus obtained can be applied to sealing, covering, insulating, etc. of electronic parts or electric parts.

(Examples) Next, the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples. In the following Examples and Comparative Examples, "%" means "% by weight"
Means

Example 1 Cresol novolac epoxy resin (epoxy equivalent 21
5) 18%, novolac type phenol resin (phenol equivalent 107) 9%, hydrogenated polyisoprene rubber Kuraprene LIR-290 (Kuraray Isoprene Chemical Co.,
3% of trade name) and 70% of fused silica powder were mixed at room temperature, further kneaded at 90 to 95 ° C., cooled, and then pulverized to obtain a molding material. The obtained molding material was transfer-injected into a mold heated to 170 ° C. and cured to obtain a molded product (sealed product). About this molded product, stress, warm and cold cycle,
The moisture resistance and other properties were tested, and the results are shown in Table 1. The remarkable effects of the present invention were recognized.

Example 2 Cresol novolac epoxy resin (epoxy equivalent 21
5) 16%, novolac type phenol resin (phenol equivalent 107) 8%, hydrogenated polyisoprene rubber 6% and silica powder 70% were mixed, kneaded and pulverized in the same manner as in Example 1 to obtain a molding material. .

Next, molded products were obtained in the same manner, and stress, hot and cold cycle property, moisture resistance and other properties were tested on these molded products in the same manner as in Example 1. The results are shown in Table 1. The remarkable effect of the present invention was recognized.

Comparative Example Cresol novolac epoxy resin (epoxy equivalent 21
5) 20%, novolac type phenol resin (phenol equivalent 107) 10%, and silica powder 70% were mixed, kneaded and pulverized in the same manner as in Example 1 to obtain a molding material. Using this molding material, a molded product was made, and various characteristics of the molded product were tested in the same manner as in Example 1. The results are shown in Table 1.

[Effects of the Invention] As is clear from the above description and Table 1, the encapsulating resin composition of the present invention has a low stress, a high humidity resistance, and a low temperature due to a specific composition containing a hydrogenated polyisoprene rubber. Since it has excellent cycleability, there are no open bonding wires, resin cracks, or pellet cracks.
In addition, since the stress due to shrinkage during curing is low, the use of this composition makes it possible to obtain highly reliable electronic and electric parts.

Claims (2)

[Claims] 1. A resin composition comprising (A) an epoxy resin, (B) a novolac type phenol resin, (C) a hydrogenated polyisoprene rubber having a hydrogenation rate of 60% or more and (D) an inorganic filler as essential components. 0.1 to 10% by weight of the hydrogenated polyisoprene rubber of (C), and (D)
A resin composition for encapsulation, which comprises an inorganic filler in a proportion of 25 to 90% by weight, respectively. 2. The equivalent ratio [(a) / (b)] of the epoxy group (a) of the epoxy resin and the phenolic hydroxyl group (b) of the novolac type phenol resin is in the range of 0.1 to 10. The encapsulating resin composition according to claim 1.