Abstract: In the present invention, provided are i) an encapsulant composition comprising an epoxy resin, a curing agent, an inorganic filler, an adduct of triphenylphosphine with benzoquinone, and a hydrous bismuth nitrate oxide; the inorganic filler being mixed in an amount of from 70% by volume to 85% by volume based on the total weight of the encapsulant composition, and the hydrous bismuth nitrate oxide being mixed in an amount of from 2.5 parts by weight to 20 parts by weight based on 100 parts by weight of the epoxy resin, and ii) an electronic device having an encapsulating member comprising a cured product of this encapsulant composition.

Abstract: An LOC structure semiconductor device having a good solder heat resistance without electrical characteristic failures due to damages to the passivation film and the diffusion layer thereunder attributing to the filler can be obtained by encapsulating an LOC structure semiconductor chip with an encapsulating material comprising an epoxy resin, a curing agent, a curing promoter, and an inorganic filler, the filler having a smaller particle size than the distance between a inner lead and a semiconductor chip and being in an amount of 80 to 95% by weight based on the total weight of the encapsulating material.