JPS59221352A - Epoxy resin composition having low radioactivity - Google Patents

Abstract

PURPOSE:To provide the titled composition having excellent flame retardance, high moisture resistance, and low radioactivity, available at a low cost, and suitable as a plastic package of IC free fron soft error, by compounding a filler having extremely low content of radioactive impurities with a flame retardant. CONSTITUTION:An epoxy resin is compounded with (A) a filler containing <=0.005CPH/cm<2> of radioactive impurity in terms of alpha-ray dose, and (B) a flame retardant containing <=0.10CPH/cm<2> of impurities. The filler is preferably high-purity fused silica or high-purity alumina in an amount of 50-90wt%. The flame retardant is preferably a high-purity antimony trioxide, and its amount is 0.5-5wt%. The epoxy resin is preferably an o-cresol novolac epoxy resin, etc. having a softening point of <=80 deg.C, an epoxy equivalent of <=220, a total chlorine content of <=1000ppm, and an electrical conductivity (of the water obtained by treating the resin in a pressure cooker) of <=500muOMEGA/cm.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an Epoquine resin composition that emits extremely little radiation such as alpha rays, and is characterized by the use of fillers and flame retardants that contain extremely little radioactive impurities.

Recently, the general-purpose use of computers has been remarkable.

Small, convenient and inexpensive computers such as personal computers and microcomputers have come to be widely used by everyone from elementary school students to the elderly. Office computers are also becoming more compact and cost-effective.

These small comviators are functionally comparable to the large computers of a few years ago, but their prices have fallen from IAo to 1.4o. What supports this trend is
This is an effort to reduce the cost of semiconductors, that is, to rationalize combiator-related companies. One of the factors that cannot be overlooked in reducing semiconductor costs is the shift to plastic packaging. For a long time, combiators have been required to be reliable, that is, to not fail during long-term C crossings. For this reason, in the past, packages were only made of expensive octopus or ceramic. However, plastic packages with extremely high reliability have been developed and are rapidly changing.Currently, most consumer ICs and transistors, as well as some industrial ICs and LSIs, are inexpensive. The package is made of plastic.The trend is that plastic packages are being used more and more for consumer use, which requires relatively low reliability, and for industrial use, which requires high reliability, the use of plastic is also increasing.In the future. Although it is expected that the use of plastic packaging for industrial semiconductors will continue to advance, the problem that has surfaced at the moment is countermeasures against soft errors.For example, in memory applications where semiconductors are becoming highly integrated and multifunctional, The capacity progresses as IK → 4 → 16 → 64K... (=Therefore, radiation (α rays)
Malfunctions due to this = soft errors are more likely to occur. Therefore, packaging materials must also be made of materials that emit less radiation.

64th is already a transition period for plastic packaging, and plastic packaging products are about to be announced in 256th. The amount of radiation that causes malfunctions in these LSIs and VLSIs is expressed in terms of radioactive impurities (uranium, thorium, etc.) and alpha rays as follows.

The present invention provides a sealing material (molding material, paint, etc.) for circuits that are particularly problematic in the above 64 VLSIs, etc., where soft errors occur.The gist of the present invention is to (-Filling materials with radioactive impurities (uranium, thorium, etc.) at an alpha dose of 0.005 CPH/dl or less and 0
．． This is an epoxy resin composition characterized in that it contains a twist-retardant agent having a twist resistance of 10 CP)j/i or less.

Substances constituting the epoxy resin composition that may contain radioactive impurities are fillers and flame retardants, particularly inorganic fillers and flame retardants. For epoxy resin compositions for VLSIs, etc., it is essential that both of these components generate less radiation.

The required levels of radioactive impurities in fillers and flame retardants are as follows: Memory Capacity 16K (- General grade filler and aged fuel grade used).

As a patent related to the present invention, JP-A-57-195151
There is. The gist of this is to use low-radiation silica powder as a filler, but the desired low-radiation properties cannot be obtained in applications that require flame retardancy, that is, in compositions that use flame retardants.

Compositions (two flame retardants, e.g. U, 94V-0) are required.Currently, compositions that do not contain flame retardants have no use (they have extremely poor industrial utility and industrial utility).

In addition, common commercially available flame retardants that generate a lot of radiation, for example,
Ordinary antimony dioxide (alpha to, 3-0.8 cpa
When A) is used, even if flame retardation can be achieved, low radiation characteristics as an epoxy resin composition cannot be obtained.

In particular, flame retardants that generate high radiation (at first glance) are localized, and localized C2-alpha radiation generation may increase. Reliability C cannot be used.

The present invention is extremely useful in industry as it provides an epoxy resin composition that is flame retardant, has good moisture resistance, is inexpensive, and satisfies low radiation properties.

In addition, epoxy resin refers to all substances having an epoxy group, such as bisphenol A type epoxy resin (Shell 820, 1001, etc.), novolac type epoxy resin (
Examples include Nippon Kayaku EPPN-201, Dainippon Ink 5-Kagaku Kogyo Ebicuron N-673, etc.).

The curing agent refers to all substances that react with epoxy resins, such as phenol novolacs (Nippon Kayaku PN-
80, OCN-100, etc.), acid anhydrides (TCPA
, H) IPA etc.), amines (DDA%DIImV
) etc.

Examples of the filler include silica, alumina, calcium carbonate, mica, clay, glass, asbestos, and aluminum hydroxide.

In particular, high-purity fused silica and high-purity alumina having the characteristics shown in the following table are useful for achieving the objects of the present invention.

6- Examples of flame release agents include antimony (antimony trioxide, antimony tetraoxide, antimony trioxide), boron compounds (boric acid, antimony trioxide),
Zinc borate).

Among them, highly pure antimony trioxide, which has the characteristics shown in the following table, is a particularly desirable flame retardant.

Further, it is desirable that the amount of the inorganic filler and the inorganic flame retardant used be in the range of 50 to 90% by weight and 05 to 5% by weight, respectively. Outside these weight ranges, there may be defects in fluidity, thermal expansion characteristics, heat resistance, insert corrosion, etc.

In particular, in the application of molding materials for semiconductor encapsulation, fused silica is used as a filler among inorganic fillers at 5% by weight, and antimony trioxide is used as a flame retardant among inorganic fillers at 0% by weight.
Preferably, 5 to 5% by weight is used.

In addition, as the Epoquine resin, ortho-cresol novolak type epoxy resin special (: softening point is 80°C or less, Evoquine equivalent is 220 or less, total chlorine amount is 1000 ppm or less,
The electrical conductivity of Brenyar Cooker extract water is 500 μr.
S/x or less is preferable, and the curing agent is preferably a phenol novolak special (=softening point of 105° C. or less, electric conductivity of Brennyer cooker extract water of 100 μVα or less, and sacrificial acid amount of 50 ppm or less).

(Note) Total chlorine amount: Measured by sodium amalgam method. Under oil extraction for 20 hours, the present invention will be described in detail with reference to examples for molding materials for semiconductor pairs. All amounts shown below are parts by weight, abbreviated as 1 part.

Examples 20 parts of orthocresol novolak type epoxy resin (Sumitomo Chemical ESCN-195XI), 10 parts of phenol novolac (Nippon Kayaku PN-100), X part of fused silica, antimony trioxide part, silane coupling agent (Chisso EES) -M) 0.5 part, catalyst (K-I Kasei PP-360) 0.5 part, carbon (Mitsubishi Kasei)
0.5 part, mold release agent (Noda wax) 0.5 part at 100℃
A molding material was prepared by mixing for 3 minutes using a heating roll. At this time, we took two levels of fused silica and antimony dioxide and obtained several types of molding materials as shown in Table 1.The characteristics and soft error rate of these molding materials were investigated.The results are shown in the attached table. =For VLSI molding materials, fillers and flame retardants should both be low in radioactive impurities, with radioactive impurities for alpha rays below 0.005 cpH/crl and below 0.10 cpa/cII. It has been found that this is an essential condition.It has also been found that it is preferable that the amount of filler material for the molding material be 50 to 90% by weight, and the amount of flame retardant be 0.5 to 5% by weight.

10- ・Amount of radioactive impurities: Measured by neutron activation analysis, α-ray dose
= Measured with an α-ray counter (manufactured by Science Spectrum), soft error rate: ======; - 1 unit (%/10
00 device-hr), high-temperature properties Two-process C encapsulation molded products are stored at 200°C, 500 hv, and judgment is made based on whether or not property changes (leak defects) occur.Patent applicant: Sumitomo Bakelite Co., Ltd. 12-359-

Claims (1)

[Claims] Evokin resin (=radioactive impurities are 0.005C in alpha radiation dose)
P) A low radiation epoxy resin composition comprising a filler of k- or less and a flame retardant of 0.100 PI (/d or less).