Patent ID: 8178599

Claim:
An epoxy resin composition for encapsulation of semiconductors which comprises (A) a spherical alumina; (B) an ultrafine silica having a specific surface area of 120-240 m 2 /g; (C) a polyorganosiloxane with a substituent having an oxygen, nitrogen or sulfur atom; (D) an epoxy resin; (E) a phenolic resin curing agent; and (F) a curing accelerator, said ultrafine silica being contained in an amount of 0.2-0.8% by weight based on the total weight of the resin composition, wherein said polyorganosiloxane is present in an amount of from 0.3 to 2.0% by weight based on the total weight of the resin composition, and the spherical alumina is present in an amount of from 85% to 92% by weight based on the total weight of the resin composition.