Epoxy resin composition for encapsulating semiconductor devices and semiconductor devices encapsulated therewith

Abstract

An epoxy resin composition comprising: (A) an epoxy resin having at least three epoxy groups per molecule and an epoxy equivalent of 170 or lower;(B) an epoxy resin having a phenolic nucleus and two epoxy groups in such an amount that a weight ratio of the epoxy resin (B) to the epoxy resin (A) ranges from 35/65 to 65/35;(C) a phenolic curing agent in such an amount that a molar ratio of phenolic hydroxyl groups to the whole epoxy groups in the composition ranges from 0.5 to 1.5; and(D) an inorganic filler in an amount of from 86 to 92 wt %, based on a total weight of the composition.

Description

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a temperature profile chart of an IR reflow furnace used in the present Example.

Claims

1. An epoxy resin composition comprising: (A) an epoxy resin having at least three epoxy groups per molecule and an epoxy equivalent of 170 or lower;(B) an epoxy resin having a phenolic nucleus and two epoxy groups in such an amount that a weight ratio of the epoxy resin (B) to the epoxy resin (A) ranges from 35/65 to 65/35;(C) a phenolic curing agent in such an amount that a molar ratio of phenolic hydroxyl groups to the whole epoxy groups in the composition ranges from 0.5 to 1.5; and(D) an inorganic filler in an amount of from 86 to 92 wt %, based on a total weight of the composition.

2. The epoxy composition according to claim 1, wherein the epoxy resin (B) has a viscosity measured with an ICI cone/plate viscometer according to ASTM D4287 at 150° C. of from 0.005 to 0.01 Pa·s.

3. The epoxy composition according to claim 1, wherein the epoxy resin (B) is represented by the following formula (1).

4. The epoxy composition according to claim 1, wherein the epoxy resin (A) has an epoxy equivalent of from 120 to 170.

5. The epoxy composition according to claim 1, wherein the phenolic curing agent (C) is selected from the group consisting of cresol novolac resins, phenolic resins containing naphthalenic backbone, and aralykyl type phenolic resins containing biphenyl backbone.

6. The epoxy composition according to claim 1, wherein the inorganic filler is spherical fused silica.

7. A semiconductor device encapsulated with the epoxy resin composition according to any one of claims 1 to 6.

8. The semiconductor device according to claim 7, wherein the semiconductor device is surface mounted on a substrate.