Epoxy resin composition and semiconductor devices encapsulated therewith

Claim 1

An epoxy resin composition comprising (A) a naphthalene ring-containing epoxy resin of the following general formula (1): ##STR29## wherein R 1 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, OG is ##STR30## letter k is an integer of from 0 t 5, l is an integer of from 0 to 3, m is an integer of from 0 to 2, and n is equal to 1 or 2, and the OG groups may be attached to either one ring or both rings of the naphthalene ring, (B) a biphenyl-containing epoxy resin of the following formula (2): ##STR31## wherein R 2 is a hydrogen atom, a halogen atom or a monovalent hydrocarbon group having 1 to 5 carbon atoms, and letter q is an integer of from 0 to 5, (C) a phenolic resin of the following formula (3): ##STR32## wherein R 3 is selected from the group consisting of ##STR33## and substituted derivatives thereof in which some or all of the hydrogen atoms in the phenyl ring or rings in R 3 are replaced by alkyl groups having 1 to 5 carbon atoms, R 4 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and letter r is an integer of from 0 to 5, and (D) an inorganic filler present in an amount of 100 to 1,000 parts by weight of filler per 100 parts by weight of components (A), (B) and (C) combined, wherein components (A) and (B) are present in a weight ratio of 1/1 to 9/1 and wherein components (A), (B) and (C) contain epoxy and phenolic hydroxyl groups in such quantities that the molar ratio of epoxy groups to hydroxyl groups in said composition ranges from 1/2 to 3/2.