Epoxy resin compositions and semiconductor devices encapsulated therewith.

摘要

An epoxy resin composition comprising (A) a naphthalene ring-containing epoxy resin, (B) a phenolic resin comprising a phenolic resin of the general formula (1): wherein R is selected from the group consisting of and substituted ones thereof in which some or all of the hydrogen atoms are replaced by alkyl groups having 1 to 5 carbon atoms, R<1> is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is an integer of from 0 to 5, and (C) an inorganic filler. The compositions have good flow and cure to products having low modulus of elasticity, a low coefficient of expansion, high Tg irrespective of low stresses, and low water absorption. Semiconductor devices encapsulated with the present composition are highly reliable even after being subject to thermal shocks upon surface mounting.