JPS6162511A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain a low-stress epoxy resin having excellent moldability and moisture resistance, and high crack resistance caused by thermal shock, by compounding an epoxy resin with a small amount of a synthetic rubber containing epoxy group at the terminal or in the molecular chain. CONSTITUTION:The objective composition can be produced by compounding (A) an epoxy resin (e.g. bisphenol-type epoxy resin) with (B) 0.1-5wt synthetic rubber having preferably 3-10 epoxy groups at the terminal (preferably at both terminals) or in the molecular chain (a diene polymer having a molecular weight of preferably 700-3,000) and if necessary (C) a curing agent (preferably phenol novolac resin).

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a low stress epoxy resin composition that has excellent crack resistance when subjected to thermal shock and moisture resistance.
Its feature lies in the addition of synthetic rubber containing epoxy groups at the ends or within the molecule.

[Prior art]

Various low-stress epoxy resin compositions using synthetic rubber have been studied in the past, but both when adding synthetic rubber and when using synthetic rubber-modified epoxy resin, moldability (especially curability, parity) , mold releasability), etc. For example, when a carboxyl group-containing diene-based rubbery polymer is added [JP-A-58-176958]
In this case, not only did the rubber elute and formability was problematic, but it also contained a hydrophilic carboxyl group, resulting in significantly poor moisture resistance. Further, even when a carboxyl group-containing diene-based rubbery polymer is pre-reacted with an epoxy resin, it tends to be thermally decomposed and has the same drawback as addition.

Various low stress resin compositions that do not use synthetic rubber are also being studied. For example, a method of adding silicone [using a silicone-modified resin], a method of adding silicone [JP-A-56-129]
No. 246, JP-A No. 58-47014, etc.), but they not only have the same drawbacks as rubber-modified epoxy resins, but also have the problem of being expensive, that is, lacking in versatility.

Epoxy resin compositions have superior moisture resistance compared to phenolic resin compositions and polyester resin compositions. For example, it is used in circuit boards, semiconductor sealing materials, and the like. Currently, there is a strong demand for lower stress in these applications, especially in connection with sealing materials. This is to internationalize the final product, allowing it to be used at any time and place.

In other words, because it is used in many different ways and by many people,
They are required to be resistant to rough handling and rapid temperature changes.

[Purpose of the invention]

The present invention improves the shortcomings of low stress epoxy resin compositions used to make synthetic rubber, which conventionally had problems with moldability and could not be applied at the market level, and is suitable for application at the industrial level, that is, practical use. As a result of research for the purpose of developing products for the purpose of achieving the desired moldability, moisture resistance, and heat resistance by adding synthetic rubber containing epoxy groups at the ends or within the molecule to epoxy resin compositions, It has been discovered that a low stress epoxy resin composition can be obtained which has excellent crack resistance when subjected to impact.

[Structure of the Invention] The present invention provides an epoxy resin, a curing agent, a curing accelerator, a filler, and a mold release characterized by containing 0.1 to 5% by weight of synthetic rubber containing an epoxy group at the end or within the molecule. It is an epoxy resin composition composed of a surface treatment agent, a surface treatment agent, etc.

Synthetic rubber containing an epoxy group at one end is a diene rubbery polymer having an epoxy group at one or both ends that can react with a curing agent, preferably having epoxy groups at both ends. In addition, synthetic rubber containing epoxy groups in the molecule refers to diene-based rubbery polymers having one or more epoxy groups that can react with a curing agent in the molecule, and - the number of epoxy groups per molecule. The number is preferably 2 to 15, particularly preferably 3 to 10. The molecular weight of epoxy group-containing synthetic rubber is 500.
~l0QOOO is preferably SOO~I QOOOOl, particularly preferably 700-aooo. Examples of commercially available synthetic rubbers containing epoxy groups include R-4.
5EPI, EFT (Idemitsu Petrochemical), NI SSO
-PB -BF resin (Japan V), E1 stone ho IJ 7
'Tadien E series (Japan Petrochemicals) etc.

Synthetic rubbers containing epoxy groups at the ends or within the molecule not only have excellent compatibility with epoxy resins and curing agents and are easily dispersed evenly, but also react quickly with the curing agent during curing, resulting in poor moldability and It is possible to provide a low-stress epoxy resin composition that has excellent moisture resistance and excellent crack resistance when subjected to thermal shock.

The curing agent mentioned here is preferably phenol novolacs, but may also include acid anhydrides and amines. These may be used alone or in combination. Phenol novolacs refer to all those containing a phenolic hydroxyl group or a rust conductor in the novolak skeleton. Phenols (phenol, alkylphenol, resorcinol, etc.)
It includes not only single-component novolaks, but also co-condensed novolacs with any combination of phenols, and co-condensed novolaks with phenols and other resins.

Moreover, the epoxy resin referred to herein refers to all resins having an epoxy group. For example, it refers to a bisphenol type epoxy resin, a novolac type epoxy resin, a triazide/nuclear-containing epoxy resin, etc.

A feature of the present invention is that 0.1 to 5% by weight of epoxy group-containing synthetic rubber is added to the epoxy resin composition. It has been found that crack resistance is poor when the amount of epoxy group-containing synthetic rubber added is less than 0.1% by weight, and when the amount added is greater than 5% by weight, moldability is poor. Furthermore, even if synthetic rubber containing functional groups other than epoxy groups (e.g. carboxyl group, amine group, hydroxyl group, thiol group, incyanate group) is added, the same effect cannot be obtained, and moisture resistance and moldability may deteriorate. Significantly inferior scratch resistance and poor durability.

〔Effect of the invention〕

According to the method of the present invention, it is possible to obtain a low-stress epoxy resin composition that has excellent moldability, moisture resistance, and crack resistance when subjected to thermal shock. especially,
In today's world, where it is expected that plastic packaging will increasingly be used in semiconductor encapsulation applications, and where plastics are required to have lower stress, the present invention will play an extremely important role in industry.

〔Example〕

The following is an explanation using a study example of a molding material for semiconductor encapsulation. All parts used in the examples are parts by weight. The examples according to the present invention are superior in moldability, moisture resistance, and crack resistance compared to comparative examples according to the prior art, and have high added value that can be used industrially.

The epoxy-containing synthetic rubber used in this example is as follows.

Synthetic rubber A1 containing epoxy groups at both ends 114? Synthetic rubber B: 1,4 trans-type polybutadiene containing epoxy groups in the molecule (000 to number average molecular weight, epoxy equivalent 200) Synthetic rubber C: 1,2 vinyl type polybutadiene containing epoxy groups in the molecule (Number average molecular weight 700, epoxy equivalent weight 220) Homare synthesis 1"0" molecule contains "'#' group 1.2'"
'-''' Ibu polybutadiene (a average molecular weight 'LO00, epoxy equivalent weight 190) Synthetic rubber E: 1,2 vinyl type polybutadiene containing epoxy groups in the molecule (number average molecular weight Lsoo, epoxy equivalent weight 220) Examples 1 to 7 70 parts of fused silica (manufactured by Tatsumori), 0.4 part of a surface treatment agent (Nippon Unicar A-186), and synthetic rubbers A and B.

C, D, and E were added in the weight parts shown in the table and mixed using a mixer. Furthermore, epoxy resin (Asahi Ciba: ECN-1273)
20 parts, phenol novolac (manufactured by Sumitomo Bakelite)
10 parts, curing accelerator (Cape Kasei PP-360/Shikoku Kasei 2MZ = 9/1') 0.2 parts, pigment (Mitsubishi Kasei) 0.5 parts, ill type agent (Kiss Hoechst Japan)
After adding and mixing 0.4 part of OP/hex) S = 1/1), seven types of epoxy resin compositions were obtained by kneading in a co-kneader.

As a result of measuring the moldability and crack resistance of these molding materials, it was found that they were superior to the comparative examples as shown in the table. Furthermore, the more synthetic rubber there is, the better the crack resistance is, but when it is too much, the moldability is poor. j Comparative Example 1 70 parts of fused silica, 0.4 parts of surface treatment agent, terminal carboxyl group polyisoprene (Clan: LIR-403) 2
20 parts of epoxy resin, 10 parts of phenol novolak, 0.5 part of pigment, 0.2 part of curing accelerator, and 0.4 part of mold release agent (all the same raw materials as in Example) were made into materials in the same manner as in Example. did. As shown in the table, the moldability, crack resistance, and moisture resistance of this material are significantly inferior to those of the Examples.

Comparative Example 2 70 parts of fused silica, 0.4 parts of surface treatment agent, 2 parts of carboxyl group-containing acrylonitrile-butadiene copolymer (Hiker CTBN1300
Materials were prepared using 0.2 parts of a curing accelerator and 0.4 parts of a mold release agent in the same manner as in the examples. As shown in the table, the moldability, scratch resistance, and moisture resistance of this material are significantly inferior to those of the Examples.

Comparative Example 3 70 parts of fused silica, 20 parts of epoxy resin, 10 parts of phenol novolac, 0.2 parts of curing accelerator, 0.2 parts of surface treatment agent.
4 parts of pigment, 0.5 part of pigment, and 0.4 part of mold release agent (all the same raw materials as in the example) were made into materials in the same manner as in the example. As shown in the table, the moldability, crack resistance, and moisture resistance of this material are significantly inferior to those of the Examples.

*1.16 Determine the degree of occurrence of paris on the lead bin when molding pin DIP When the distance to a part of the tie bar is below the heat A1 duty ~ work time B1 h ~ % C1 grade or more (9 beyond the tie bar) D
30 minutes) Room ← Temperature (5 minutes) Apply 200 cycles of thermal shock at 150℃ (30 minutes) and judge by number of cracks/total number *3TST, 16 pin DIP sealed with a simulated element of 4 mm x 6 aa size. -165℃ (2 minutes)
Apply 200 cycles of thermal shock at 150'C (2 minutes) Number of cracks generated/F; Determined by number *4 Moisture resistance, 16 pln sealed with aluminum simulated element
DIP was stored at 135℃ and 100% condition for 1000 hours and judged by defective rate/total number due to aluminum corrosion.

Claims (1)

[Claims] Synthetic rubber containing epoxy groups at the end or within the molecule is 0.
．． An epoxy resin composition containing 1 to 5% by weight.