Patent ID: 7090895

Claim:
A process for producing a resin encapsulated semiconductor device comprising a semiconductor device and a cured product of a flame retardant epoxy resin composition, comprising the steps of: molding on said semiconductor device a flame retardant epoxy resin composition comprising (A) a halogen-free epoxy resin with at least 2 epoxy groups within each molecule, (B) a curing agent having at least two phenolic hydroxyl groups within the curing molecule, and (C) a foaming agent which decomposes at a temperature of at least 180° C.; and curing the molded composition to form said cured product to encapsulate the semiconductor device within the cured product, wherein: (i) the quantity of gas that is generated from said foaming agent (C) is at least 40 ml/g, (ii) said curing agent (B) is present in a quantity which produces a ratio of the hydroxyl group equivalence of component (B) relative to the epoxy equivalence of the epoxy resin of component (A) which falls within the range of approximately 0.5 to 2.0, (iii) said foaming agent (C) is present in a quantity ranging from 0.01 to 50% by weight based on the whole composition, and the temperature for molding and curing the composition is lower than the decomposition temperature of said foaming agent (C).