JPH05152464A - Epoxy resin composition for photosemiconductor sealing - Google Patents

Abstract

PURPOSE:To improve heat resistance and suppress deterioration of light transmittance in a high-temperature and high-moisture atmosphere by permitting the composition to contain a prescribed epoxy resin with 20-100wt.% of the total epoxy resin and permitting the composition to contain hardening agent and hardening accelerator. CONSTITUTION:The composition contains epoxy resin expressed by a formula I and II with 20-100wt.% of the total epoxy resin. The composition also contains hardening agent and hardening accelerator. When the (m) of the formula I is less than three, heat resistance is not sufficient and when the (m) is over 30, the softening point becomes too high to manufacture the resin composition. When the (l) of the formula II is less than two, heat resistance is not sufficiently high and when the (l) is over 20, the softening point becomes too high to manufacture a resin composition. The epoxy resin which satisfies the formulas I and II improves the heat resistance by its multifunctional molecule structure, deterioration of moisture absorption is suppressed in the high-temperature high- moisture atmosphere at 100-125 deg.C with the moisture of 85-100% and the deterioration of light transmittance is suppressed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an epoxy resin composition for encapsulating an optical semiconductor, which is excellent in light transmittance.

[0002]

2. Description of the Related Art In the field of optoelectronics, an acid anhydride-curable epoxy resin composition has excellent transparency and transmittance in the near-infrared light region of wavelength 900 to 1000 nm, and is therefore suitable for photosensors and the like. It is used. However, the conventional acid anhydride curing type epoxy resin composition has a temperature of 100 to 125 ° C. and a humidity of 85 to 100.
% In a high temperature and high humidity atmosphere, there is a drawback in moisture resistance and there is a drawback that the light transmittance is significantly lowered. To improve these drawbacks, a method of adding silicone oil to improve the moisture resistance (JP-A-61-127723) and a method of adding a coupling agent to improve the moisture resistance (JP-A-61-12).
No. 7724) was tried, but it was not yet satisfactory. Therefore, optical semiconductors hermetically sealed using glass are used for applications such as area sensors where moisture resistance is required. However, there is a drawback that the assembling cost is high, and development of an epoxy molding material excellent in productivity and moisture resistance has been desired.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides an epoxy resin composition for optical semiconductor encapsulation, in which the light transmittance does not deteriorate in a high temperature and high humidity atmosphere.

[0004]

The present invention comprises (A) an epoxy resin represented by the following formulas (1) and (2) in an amount of 20 to 100% by weight based on the total amount of the epoxy resin, and (B) a curing agent. And (C) an epoxy resin composition for optical semiconductor encapsulation, which comprises a curing accelerator.

[0005]

[Chemical 3]

[0006]

[Chemical 4]

When the epoxy resin of the formula (1) and the formula (2) of the present invention is used, the heat resistance is increased due to the polyfunctional molecular structure, and the temperature is 100 to 125 ° C. and the humidity is 85 to 100%. Deterioration of moisture absorption under the condition is reduced, and deterioration of light transmittance is suppressed. In the formula (1), m is in the range of 4 to 30.
Is less than 3, the heat resistance is not sufficient, and the reduction of the light transmittance under high temperature and high humidity cannot be suppressed. Further, when m exceeds 30, the softening point becomes too high, which makes it difficult to manufacture the resin composition.

In the formula (2), l is in the range of 3 to 20, and if l is less than 2, the heat resistance is not sufficiently improved and the deterioration of the light transmittance in a high temperature and high humidity atmosphere cannot be suppressed. Further, when 1 exceeds 20, the softening point increases and it becomes difficult to produce a resin composition. Examples of the epoxy resin to be added to the formulas (1) and (2) include a bisphenol A type epoxy resin, a novolac type epoxy resin, and an alicyclic epoxy resin. The total amount of the epoxy resin of the formula (1) and the formula (2) is 20 to 100% by weight of the total amount of the epoxy resin,
It is preferably 50% by weight or more. If it is less than 20% by weight, the heat resistance is not sufficiently improved, and the reduction of the light transmittance under a high temperature and high humidity atmosphere cannot be suppressed. The weight blending ratio of the formula (1) and the formula (2) is as follows: formula (1) / formula (2) = 80/20 to 20
/ 80, preferably 70/30 to 30/70.

As the curing agent, polybasic carboxylic acid anhydride,
Examples include phenol type novolac resins. Examples of polybasic carboxylic acid anhydrides include phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, maleic anhydride and nadic acid anhydride. Phenol type novolac resins include phenol type, cresol type and bisphenol A type. These may be used alone or in combination of two or more. The mixing ratio of the curing agent and the epoxy resin is preferably 0.5 to 1.2 equivalents relative to 1 epoxy equivalent, and if it is out of this range, moldability may be deteriorated.

Examples of the curing accelerator include tertiary amines such as trimethylamine and triethanolamine, organic phosphine compounds such as triphenylphosphine and tricyclohexylphosphine, and imidazoles such as 2-methylimidazole. Further, one or more known azo or quinone dyes may be added to the invention. Further, a fatty acid ester, stearic acid or the like can be added as a release agent. In the production of the composition of the present invention, the respective components are mixed, kneaded at 50 to 90 ° C. using a heating roll, cooled and solidified, and then pulverized into a powder form.

[0011]

EXAMPLES The present invention will be specifically described below with reference to examples.

Examples 1 to 4 and Comparative Examples 1 to 3 Tetrahexaphthalic anhydride was added to 100 parts by weight of the epoxy resin shown in Table 1 in an amount of 0.9 equivalent to 1 equivalent of epoxy, and 1 part by weight of 2-methylimidazole and glycerin were added. 3 parts by weight of fatty acid ester was blended, heated and kneaded with a heating roll at 70 to 90 ° C., cooled and solidified, and then pulverized to obtain a resin composition powder. Using a low-pressure transfer molding machine, the resin composition was molded into a test piece having a thickness of 1 mm at a temperature of 150 ° C., and post-cured at 150 ° C. for 4 hours. This test piece was used to evaluate the light transmittance of untreated and after moisture absorption. The results are shown in Table 1.

* Light transmittance The test piece was boiled in pure water at 100 ° C for 200 hours, and the light transmittance at a wavelength of 950 nm was measured using a spectrophotometer. Light transmittance ◎: 90% or more ○: 85 to 90% ×: less than 85% * Measured by heating a test piece with a glass transition temperature of 15 mm × 3 mm × 4 mm from room temperature to 260 ° C using a TMA tester.

[0014]

[Table 1]

A: Epoxy resin of formula (1) (epoxy equivalent 190, softening point 73 ° C., m = 15) B: Epoxy resin of formula (2) (epoxy equivalent 110, softening point 61 ° C., l = 10) C : Bisphenol A type epoxy resin (epoxy equivalent 4
90, softening point 68 ° C) D: Cresol novolac type epoxy resin (epoxy equivalent 220, softening point 70 ° C)

[0016]

When the epoxy resin composition of the present invention is used, the transparency and moisture resistance are excellent, and the deterioration of the light transmittance in the near-infrared light region is suppressed, and the moisture resistance of an area sensor or the like is suppressed. It can be expanded to the required applications of. Moreover, there is an effect that the assembly cost can be reduced as compared with the hermetic sealing using glass.

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Claims (1)

[Claims] 1. An epoxy resin represented by the following formula (1) and (2): (A) 20 to 100% of the total amount of epoxy resin.
An epoxy resin composition for semiconductor encapsulation, which is contained by weight and comprises (B) a curing agent and (C) a curing accelerator. [Chemical 1] [Chemical 2]