JPS61296052A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain a low-stress epoxy resin composition having excellent moldability, moisture-resistance and crack-resistance, by adding a specific amount of a solid synthetic rubber surface coated with an alkoxysilane. CONSTITUTION:An epoxy resin is compounded with 0.5-5wt% solid synthetic rubber (e.g. SBR, BR, etc.) having a volume-average particle diameter of 1-50mum and the maximum particle diameter of <=100mum and surface-treated with an alkoxysilane.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a low-stress epoxy resin composition that has excellent moldability, moisture resistance, and crack resistance. This is where the solid synthetic rubber is added.

[Prior art]

As a technique related to conventional low-resistance carboxy resin compositions, a method of adding liquid synthetic rubber or a modified product thereof is known (for example, Japanese Patent Application Laid-Open No. 53-144958, Japanese Patent Application Laid-open No. 57-180626, 58-174416)
Also known are methods of adding silicones or modified products thereof (eg, JP-A-56-129246, JP-A-58-47014). However, all of these methods had serious problems in moldability and moisture resistance. Furthermore, when silicones are used, there is a problem that they are too expensive and cannot be used for general purposes.

Now, most of the synthetic rubbers and silicones conventionally used are in the form of viscous liquids or semi-solids, and it is difficult to completely uniformly disperse these substances on an industrial mass production scale. As a result, the composition may become non-uniform, resulting in moldability problems such as unevenness during final processing by the user.

It also has the drawbacks of non-uniform composition and poor moisture resistance due to melting by heating. This is because moisture can easily pass through the non-uniform parts, and large cavities can be formed during high temperature tests, allowing water to pass through.

For this reason, modification of synthetic rubbers and silicones has been considered, but these also have major problems. Take as an example the most common modification method - modification with epoxy resin. In the case of simple melt-mixing, the uniformity is improved, but the fact that the material essentially melts due to heating is not improved, and there is a problem of deterioration of moisture resistance due to the formation of small cavities. Furthermore, even when the resin is fixed with an epoxy resin by reaction, the reactivity of the cyedexy resin with a large amount of epoxy resin becomes extremely low, resulting in a problem that the processing time becomes longer and the crosslinking density becomes lower. That is, moldability and moisture resistance deteriorate.

[Purpose of the invention]

As a result of research aimed at improving the drawbacks of conventional synthetic rubber-based low-stress Axi resin compositions that had problems with moldability and moisture resistance, the present invention was developed to solve the above problems by using solid synthetic rubber that has been surface-treated. We discovered that this problem could be completely solved and created an industrial product. Another object of the present invention is to provide a high-quality, inexpensive plastic that can be used throughout the world, that is, a general-purpose epoxy resin composition that has good productivity and excellent moisture resistance and crack resistance.

[Structure of the invention]

The present invention provides: (1) an epoxy resin composition containing 0.5 to 5% by weight of a solid synthetic rubber whose surface is coated with an alkoxysilane; (2) a particle size distribution of the solid synthetic rubber having a volume average particle size; Diameter 1-50
The epoxy resin composition according to item (1), wherein the maximum particle size in μm is 100 μm or less.

The epoxy resin composition referred to in the present invention includes an epoxy resin, a curing accelerator, and a surface-treated solid synthetic rubber, and generally includes a curing agent, a filler, a surface treatment agent, and a mold release agent.・Pigments, flame retardants, etc. are often added. Polypoxy resin is bisphenol type: Phenol novolac type:
Cresol novolac type: Refers to all epoxy resins such as heterocyclic epoxy. Also, for semiconductor encapsulation, a sample with few impurities, for example, 5 tons of sample, is heated to 125°C and 20°C with 451% pure water.
It is preferable that the extracted water mist conductivity at the time of hr extraction is 10μ8/tan or less.

The curing accelerator refers to catalysts for curing the epoxy resin, and includes, for example, imidazoles, tertiary amines, organic phosphines, and organic aluminum chelates.

The composition of the present invention contains a solid synthetic rubber whose surface has been subjected to a hydrophobic treatment, that is, whose surface has been coated with an alkoxysilane.
It is essential to contain 5 to 5% by weight.

The alkoxysilanes mentioned here refer to silanes containing alkoxy groups such as methoxy and ethoxy groups and silanol groups, and are commonly referred to as silane surface treatment agents, silane coupling agents, silane coating agents, etc. This is what is happening. For example, A-162, A-174, A-1
89 (Japan Unicar), SR-6020-SH-604
0.5H-6072()-Le Silicone), KBM
-22-KBM-103/KBE-402 (Shin-Etsu Chemical), CPS-M-EES-M-AAS-M (f
), TSL-8122・TSL-8123
・TSL-8127 (Toshiba Silico-y), MI'S
-33・PTS -32・RT-168E (Otona Kagaku Kogyo), IMEO-cut 0・TRIAMO (Dynam
it).

Solid synthetic rubbers also include commercially available products called SBR (styrene/butadiene), BR (butadiene), IR (isoprene), etc., and those obtained by crosslinking and solidifying liquid rubbers.

Surface treatment with alkoxysilanes is essential; if untreated, moisture resistance will deteriorate significantly. Further, the surface treatment is preferably such that the surface of the solid synthetic rubber is coated in one to three layers.

The amount of surface-treated solid synthetic rubber added is 0.5 to 5% by weight. If it is too small, the stress-lowering effect will not be exhibited, and if it is too large, problems such as deterioration of moisture resistance will occur. (This brings out the drawbacks of synthetic rubber.) In addition, the particle size of solid synthetic rubber is 1 to 5.
It is preferable that the maximum particle size is 100 μm or less at 0 μm. If it is coarse, the composition may become non-uniform, causing problems such as local stress generation and deterioration of moisture resistance.

Also, if it is too fine, fluidity and filling properties may deteriorate.

= 6- Furthermore, an anti-aggregation agent such as Carplex, walnut powder, finely powdered alumina, etc. may be added as necessary.

〔Effect of the invention〕

According to the present invention, a low stress epoxy resin composition having excellent moldability, moisture resistance and crack resistance can be obtained. In addition, since the additive is a stable substance in solid form and the surface is subjected to surface protection treatment against moisture, an extremely stable epoxy resin composition can be obtained. As a result, the final product using the composition of the invention is suitable for use anywhere in the world.

Moreover, since it uses inexpensive additives, it is versatile.

〔Example〕

The following is an explanation based on a study example of a low-pressure encapsulation molding material for semiconductor encapsulation. All parts used in the study examples are parts by weight.

The raw materials used in the study examples are as follows.

Niboxy resin: ESCN-20O8 (Sumitomo Chemical) Curing agent: Phenol novolak (Sumitomo Bakelite) Curing accelerator: Sumikier〇 (Sumitomo Chemical) Filler: Fused silica (Sumitomo Sekiwa)
Silane coupling agent: GLYMO (Dynamit
) Mold release agent: Hoechst Wax S (Hoechst Wax S) Low stress additive: I Synthetic rubber CTBN 13
00X13 (Ube Industries) (prior technology) ■Rubber-modified niboxy ZX-836 (Tobu Kasei) ■Silicone oil KF-383 (Shin-Etsu Chemical) ■Liquid silicone rubber KE-41 (Shin-Etsu Chemical) Solid synthetic rubber knee below 25℃ The cooled solid inzolene rubber IR-10 is pulverized under a stream of liquid nitrogen. At this time, a trace amount (1 tre or less) of ultrafine silica Aerosilna 200 is added to prevent caking.

Synthesis of 93 types to improve the crushed particle size Got the rubber.

■Average particle size 0.8μm Maximum particle size 5μm■ 1
15μm ' 100μm ■ l 70
μm l 200 μm Furthermore, after spraying and adding a silane surface treatment agent AZ-6LO1 according to the specific surface area, the surface treatment is completed using a fluidized bed dryer.

Study Example: 20 parts of epoxy resin, 10 parts of curing agent, 70 parts of filler, 0.5 part of silane coupling agent, 0.5 part of mold release agent, and 0.2 part of curing accelerator are mixed for 10 minutes in a Henschel mixer. In addition, χ parts of solid synthetic rubber or y parts of low stress additives are added.
of water and mix for an additional 5 minutes.

At this time, a total of 11 types of formulations were made, taking into account the types and amounts of solid synthetic rubber and low stress additives, as well as the presence or absence of surface treatment in the case of solid synthetic rubber. These formulations were heated at a temperature of 40°C at the tip.
A molding material was prepared using a co-kneader whose end temperature was set to 90°C. Table 1 shows the contents and measurement results of the molding material obtained. Examination Examples 1 to 4 according to the present invention are outstandingly excellent in terms of moldability, moisture resistance, and low stress properties.

O Snow ε Air flow; E 47-1-66 method / Percoll hardness i JIS method Curing time 90 seconds, 175°C ・Mold stain resistance: 500 shots Number of stains in the cavity of the molding ridge n pieces / parameter = 60 pieces O Moisture resistance Characteristic: 1 monitor IC with aluminum simulating element enclosed
Number of defects when left at 21°C 100% for 1000 hours n pieces/parameter = 20 pieces 0 Characteristic variation; Resistance value change that occurs when the same monitor IC as humidity resistance is immersed in a 260°C solder bath for 10 seconds Number of defects n pieces / Parameter = 20 pieces O Crack resistance; 96 monitor ICs with the same moisture resistance
Number of defects when a thermal shock of ℃←150℃ is applied from 500 to n/parameter -20 Patent applicant Sumitomo Bakelite Co., Ltd. II -

Claims (2)

[Claims] (1) An epoxy resin composition containing 0.5 to 5% by weight of solid synthetic rubber whose surface is coated with alkoxysilanes. (2) The particle size distribution of the solid synthetic rubber is a volume average particle size of 1 to 50.
The epoxy resin composition according to claim 1, wherein the maximum particle size in μm is 100 μm or less.