JPS59129251A - Epoxy resin molding material - Google Patents

Abstract

PURPOSE:To provide an epoxy resin molding material which is suitable for use in the sealing of electronic parts and in which stress is lowered without lowering moisture resistance, by adding a specified epoxy compd. and a silicone intermediate. CONSTITUTION:An epoxy compd. having at least three epoxy groups per molecule and a silicon intermediate are added to an epoxy resin molding material. As the principal ingredient for the epoxy resin molding material, novolak or bisphenol type epoxy resin is used as the resin component and, optionally, additives such as hardener, filler, pigment, parting agent, reinforcing agent, etc. are blended. The epoxy compd. and the silicone intermediate are added at any stage of the production of the molding material. As the epoxy compd., epoxidized trioxyphenyl-methane is preferred. As the silicone intermediate, an amino- modified silicone intermediate is preferred.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an epoxy resin molding material suitable for sealing electronic components such as semiconductor devices.

[Background technology]

Capacitors, diodes, transistors, thyristors,
Individual semiconductors such as Hall elements or integrated circuits such as ICs and LSIs are often sealed with an epoxy resin molding compound to mechanically and electrically protect the semiconductors from the external environment. As sealing methods, hermetic sealing, ceramic sealing, and plastic sealing are used, but plastic sealing is currently the mainstream because it is easy to mass produce and is inexpensive.

Regarding the types of plastics, there are epoxy resins and silicone resins, but silicone resins are expensive and have poor adhesion to metals, so epoxy resin encapsulation is the mainstream of plastic encapsulation. However, there are also problems with epoxy resins. That is, first of all, reliability against moisture is poor. Furthermore, due to the large difference in coefficient of linear expansion between silicon chips and lead frames, internal stress is generated after molding, and this stress increases during heat cycle tests and solder heat resistance tests, causing scratches and cracks on the semiconductor element protective film. This will eventually lead to cracks in the semiconductor element, resulting in defective products.

It is known that internal stress is generally proportional to the product of linear expansion coefficient, flexural modulus, and glass transition temperature. Inorganic fillers are added to reduce the coefficient of linear expansion. However, if a large amount is added to reduce the coefficient of linear expansion, not only will the flexural modulus increase, but also the moisture resistance will decrease.

) When a certain kind of flexibility imparting agent is added to the arrow to lower the bending Jiff property, the glass transition point decreases, the coefficient of linear expansion increases, and even moisture resistance increases without sufficient crosslinking density being obtained. There was a problem of a decrease in moisture resistance, and if an attempt was made to achieve low stress, the moisture resistance inevitably decreased. In short, there is currently no low stress gray IS that is highly moisture resistant.

[Purpose of the invention]

In view of these circumstances, it is an object of the present invention to reduce stress in an epoxy resin molding material for sealing, while avoiding deterioration in moisture resistance and maintaining the conventional level.

[Disclosure of the invention]

Such an object is achieved by adding an epoxy compound having 3 or more epoxy groups per molecule (hereinafter referred to as "epoxy compound A") and a silicon intermediate to an epoxy resin molding material.

Therefore, the gist of the present invention is an epoxy resin molding material characterized in that a silicone intermediate is added to an epoxy compound. This will be explained in detail below.

The structure of the epoxy resin molding material as the main material is the same as the conventional one. That is, an epoxy resin such as a novolac type or bisphenol type is used as the resin component, and a curing agent, a filler, a pigment, a molding agent, a reinforcing material, etc. are added as necessary. Kneading.

Grinding and the like are performed in the same manner as before. The epoxy compound A and the silicon intermediate are added at some stage in the production of the molding material in this manner.

As the epoxy compound A used in this invention, epoxidized trioxyphenylmethane is preferably used, and as the silicon intermediate, compounds modified with alicyclic epoxy, epoxy modified, carbitol modified, epoxy polyether modified, amine modified, etc. are used. However, 73-modified silicon intermediates are preferred.

Epoxidized trioxyphenylmethane is represented by R=CH in the following structural formula.

Epoxidized trioxyphenylpropane represented by R=CHCH7C112 is also used in this invention.

As the amino-modified silicone intermediate, those represented by the following general formula are preferably used.

The amino-modified silicone intermediate has an amino acid i of 60
A value in the range of 0 to 3000 is preferred.

If it is less than 600, moisture resistance will decrease and curing behavior will change due to an increase in the amount of amine, and if it exceeds 3,000, unevenness will easily occur on the surface of the molded product, depending on the relationship with the amount added. This is because the decrease in elastic modulus is also unsatisfactory. As the amount of epoxy compound A such as epoxidized trioxyphenylmethane is increased, the glass transition point increases, but on the other hand, it becomes brittle. On the other hand, when the amount of silicon intermediate added increases, the appearance of the molded product becomes uneven. Furthermore, depending on the amount added, there is also a concern that the glass transition point and volume resistivity at heat may decrease slightly. Coniboxylated trioxyphenylmethanepropane is a trifunctional poxy compound, and while it increases the crosslinking density and forms a three-dimensionally strong bond, it lowers the flexural modulus due to the free vibration of the phenyl group. On the other hand, the silicon intermediate is incorporated into the reaction framework during curing, imparting flexibility and lowering the flexural modulus. In this way, the epoxy compound A and the silicon intermediate have their own advantages and disadvantages. However, when both are used in combination as in this invention, a high degree of stress reduction can be achieved due to their complementary and synergistic effects, and iI4i! No deterioration in physical properties or thermal properties occurs. There is a problem with compatibility between epoxy resins and epoxy compounds such as epoxidized trioxyphenylmethane, which causes a thin firmness like oozing of the resin during molding, but by using a silicone intermediate in combination, There is no occurrence of firmness, and moldability is also improved. This silicone intermediate has the advantage of preventing thinning and firmness even for orthocresol type epoxy resins.

In view of the above circumstances, the amount of both added is 1/1 of the epoxy resin.
Preferably, the amount of the epoxy compound A is 5 to 100 parts by weight and the amount of the silicon intermediate is 1.00 parts by weight to 15 parts by weight.

〔Effect of the invention〕

Since the epoxy resin molding material according to the present invention blends the silicone intermediate into the epoxy compound in this way, the moisture resistance does not change (deteriorate), and
We were able to achieve a reduction in the flexural modulus without changing the linear expansion coefficient, glass transition point, or molding shrinkage rate. Furthermore, the bending strength could be maintained high, and thin firmness could not be caused during molding.

Examples will be described below along with comparative examples.

[Example, comparative example]

(Margins below) The blended products in Table 1 were kneaded on a heated roll at 80 to 110°C, and the resulting Sea 1~ was cooled, crushed, and subjected to testing. The results are shown in Table 2, and all of the Examples were not inferior in other physical properties and were lower in flexural modulus and thermal stress than the Comparative Examples.

(Hereafter, extra white)

Claims (4)

[Claims] (1) An epoxy resin molding material characterized in that an epoxy compound having three or more epoxy groups per molecule and a silicone intermediate are added. (2) The amount added to 100 parts by weight of epoxy resin is 1
The epoxy resin molding material according to claim 1, wherein the epoxy compound having 3 or more epoxy groups per molecule is 5 to 100 parts by weight, and the silicone intermediate is 1 to 15 parts by weight. (3) The epoxy resin molding material according to claim 1 or 2, wherein the epoxy compound having 3 or more epoxy groups per molecule is epoxidized trioxyphenylmethane. (4) The silicon intermediate has an amine equivalent of 600 to 3°0.
The epoxy resin molding material according to claim 1, 2 or 3, which is an amino-modified silicone intermediate of 0.