Patent ID: 8048969

Claim:
An epoxy resin composition used for encapsulation of a semiconductor device comprising a resin substrate or a metal substrate, and a semiconductor member mounted solely on one surface of the resin substrate or one surface of the metal substrate, wherein the semiconductor member is encapsulated with a cured product of an epoxy resin composition solely on the one surface of the resin substrate or metal substrate, said composition comprising (A) a naphthalene ring-containing epoxy resin having the general formula (1): wherein m and n are 0 or 1, R is hydrogen, C 1 -C 4 alkyl or phenyl, and G is a glycidyl-containing organic group, wherein 35 to 85 parts by weight of the resin wherein m=0 and n=0 and 1 to 35 parts by weight of the resin wherein m=1 and n=1 are included per 100 parts by weight of the resin of formula (1), (B) a phenolic resin curing agent comprising a phenolic resin having the general formula (3): wherein R 5 and R 6 are each independently hydrogen, C 1 -C 4 alkyl or aryl, and p is an integer of 0 to 10 and wherein the phenolic resin of formula (3) constitutes 25 to 100 weight-% of phenolic resin curing agent component (B), wherein said phenolic resin curing agent is present in an amount such that the molar ratio of phenolic hydroxyl groups therein to epoxy groups in the epoxy resin (A) is from 0.5 to 1.5, (C) an inorganic filler in an amount of 200 to 1100 parts by weight per 100 parts by weight of epoxy resin (A) and curing agent (B) combined, and (D) a phosphazene compound having the average compositional formula (2): wherein X is a single bond or a group selected from among CH 2 , C(CH 3 ) 2 , SO 2 , S, O, and O(CO)O; Y is OH, SH or NH 2 ; R 1 is a group selected from among C 1 -C 4 alkyl and alkoxy, NH 2 , NR 2 R 3 , and SR 4 ; R 2 , R 3 and R 4 each are hydrogen or C 1 -C 4 alkyl; d, e, f and n are numbers satisfying 0≦d≦0.25n, 0≦e≦2n, 0≦f≦2n, 2d+e+f=2n, and 3≦n≦1,000 in an amount of 1 to 50% by weight based on the total weight of components (A) and (B).