JPS627143A - Epoxy resin molding material for sealing semiconductor - Google Patents

Abstract

PURPOSE:To obtain a semiconductor sealing epoxy resin molding material having excellent crack resistance and moisture resistance by hydrophobically treating the surface of a silica with alkoxysilane, and further reducing filler particle diameter to displace the equivalent ratio of epoxy resin and hardener as compared with the normal one. CONSTITUTION:Silica which is hydrophobically treated in advance on the surface with alkoxysilanes in mean particle diameter of 15 microns or less and in the maximum particle diameter of 100 micron or less is used as a filler, and the equivalent ratio of epoxy resin and a hardener is set to a range of 1.1-1.5. A surfactant uses alkoxysilanes, is mixed in advance with silica, heat treated as required to form a hydrophobic film on the surface of the silica. If the equivalent ratio is lower than the specified range, low stress effect cannot be obtained to deteriorate the moisture resistance. If the silica is excessively rough, the filling property is improper, and the particle diameter is further reduced for the use wherein severe packing property is required.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an Eixy resin molding material for semiconductor encapsulation that has excellent crack resistance and moisture resistance when subjected to thermal shock. Its characteristics include using silica whose surface has been made hydrophobic as a filler, changing the balance between the epoxy resin and hardening agent, and reducing the particle size of the filler to achieve high moisture resistance and low stress.

[Prior art]

Conventionally, a coupling agent is used in a 2-oxy resin molding material for semiconductor encapsulation to bond silica and resin as a filler and a binder. The main purpose of this is to connect the filler/resin interface and increase the strength of the composition, and the silane coupling agent (epoxysilane, aminosilane,
(vinyl silane, etc.) are mainly used.

However, recently there has been a strong demand for lower stress in all applications. This is because final products are becoming more international and used for a wide variety of purposes, so they are required to withstand rough handling and storage more than ever before. Also, the conventional technology is to make the epoxy resin and curing agent have an equivalent ratio of epoxy groups to hydroxyl groups of 1:1, but in this case, the filler/resin in the molding material is too tightly bonded. As a result, the final product becomes hard and brittle, making it impossible to satisfy these requirements.

For example, it has been pointed out that there are drawbacks such as resin cracks that occur when thermal shock is applied, and moisture resistance becomes extremely poor.

[Purpose of the invention]

The present invention was developed as a result of research aimed at developing a practical product by fundamentally improving the Eixy resin molding material for semiconductor encapsulation, which previously had problems with crack resistance and moisture resistance when subjected to thermal shock. The surface of the resin is hydrophobized with alkoxysilanes, the filler particle size is further reduced, and the equivalent ratio of Eixy resin and hardening agent (Eyxy resin/hardening agent) is increased to achieve the desired resistance. It has been discovered that an epixy resin molding material for semiconductor encapsulation having excellent crack resistance and moisture resistance can be obtained.

(Structure of the Invention) The present invention has an average particle diameter of 15 microns or less and a maximum particle diameter of
Silica of 0 micron or less is used as a filler and the equivalence ratio of epoxy resin and curing agent (epoxy resin/curing agent) is L.
This is an Eixy resin molding material for semiconductor encapsulation, characterized in that it has a molecular weight within the range of 1 to 1.5.

Generally, an epoxy resin molding material for semiconductor encapsulation is composed of an epixy resin, silica, a processing agent, a curing agent, a curing accelerator, a mold release agent, a flame retardant, a pigment, and the like. In particular, the materials currently in general use are cresol novolak epixy resin, phenol novolac (curing agent), tertiary amine (curing accelerator), silica (filler), and silane coupling agent (
processing agent), etc., and the amount of silica is 50 to 80.
wt% is normal.

In the present invention, it is essential to use alkoxysilanes as a surface treatment agent and to mix this with silica in advance and, if necessary, to perform a treatment such as heating to form a hydrophobic film on the silica surface. Also, the amount added is 1 to 1 for silica.
3 wt% is preferred.

If it is too small, the water repellent effect and low stress effect may not be obtained, and if it is too large, it may not be compatible with the molding material and may ooze out. Furthermore, it is essential that the equivalent ratio of (Eixy resin/curing agent) be within the range of 1.1 to 1.5. Below this range, the low stress effect cannot be obtained (0.9 to 1.l
) has poor moisture resistance.

Moreover, if it exceeds this range, moldability (hardenability/paris) may become a problem.

The silica needs to have a weight average particle size of 15 microns or less and a maximum particle size of 100 microns or less.

If it is too rough, it will cause problems with filling properties, etc. Further, for applications such as flat 72 cages that require strict filling properties, particles with even smaller particle sizes, such as those with an average particle size of 10 microns or less and a maximum particle size of 50 microns or less, are preferable. Furthermore, for sensitive semiconductor encapsulation applications where characteristic fluctuations are a problem, particles with an average particle size of 5 microns or less and a maximum particle size of 20 microns or less are preferable.

〔Effect of the invention〕

As described above, according to the present invention, an Eixy resin molding material for semiconductor encapsulation having excellent crack resistance and moisture resistance can be obtained. Particularly in today's world, where it is expected that more and more plastic packaging will be used in the future, and where plastics are required to have lower stress and higher moisture resistance, the present invention will play an extremely important role in industry.

〔Example〕

The following is an explanation using a study example of an epoxy resin molding material.

All parts used in the examples are parts by weight.

The raw materials used in the present invention are as follows.

Epixy resin Nippon Kayaku EOCN-10
20 Curing agent Sumitomo Bakler-F) Phenol novolac curing accelerator Guai Kasei/Shikoku Kasei PP-360/2MZ=% Mold release agent Hoechst Jano ξn Hoechst OP/A, Kist S=butt silica FS-891 crushed Average particle size 20 microns (Denki Kagaku Kogyo) Maximum particle size 1
50 microns (B) FS-90 Crushed average particle size 15 microns Maximum particle size 100 microns Silane coupling agent Chisso GPS-M surface treatment agent Toray Silicone 5Z-60
70 Manufacturing method ■ Put silica, silane cassilling agent, and surface treatment agent into a heating kneader and mix at 120°C with 30 molecules. The thus obtained silica and other raw materials are further mixed and then kneaded for 5 minutes using heated rolls at 120°C.

(2) All raw materials are mixed at the same time and then kneaded for 5 minutes using heated rolls at 120°C.

[Example of consideration]

70 parts of silica, 0.3 part of silane cassilling agent, 0.3 part of surface treatment agent, 30 parts in total of engineered resin and curing agent, 0.2 part of curing accelerator, and 0.5 part of mold release agent. silica particle size,
Trial production was carried out as shown in Table 1, with the manufacturing method and the equivalent ratio of (epoxy resin/curing agent) being adjusted. As a result of planning the characteristics of these 10 types of materials and the characteristics of the simulated IC (Table 1), it was possible to obtain excellent results in both crack resistance and moisture resistance by using the method of the present invention.

Claims (1)

[Claims] Silica whose surface has been hydrophobized with alkoxysilanes and has a weight average particle size of 15 microns or less and a maximum particle size of 100 microns or less is used as a filler, and the equivalent ratio of novolac-type epoxy resin and phenol novolac curing agent (
An epoxy resin molding material for semiconductor encapsulation, characterized in that the ratio (epoxy resin/curing agent) is within the range of 1.1 to 1.5.