Patent ID: 7612458

Claim:
An epoxy resin composition for use in semiconductor encapsulating comprising: an epoxy resin (A); a phenol resin (B); a curing accelerator (C); and an inorganic filler (D), wherein the inorganic filler (D) contains a eutectic mixture (d3) of silicon dioxide and alumina which is a spherical inorganic filler formed by: (a) adding aluminum powder to silica material and then thermofusing them; or (b) mixing metallic silicon with metallic aluminum and then reacting them with oxygen, wherein a content ratio of the silicon dioxide in the eutectic mixture (d3) is not less than 80 weight percent and not more than 99.8 weight percent, a content ratio of the alumina in the eutectic mixture (d3) is not less than 0.2 weight percent and not more than 20 weight percent, and an extract of the eutectic mixture (d3) has a pH value no less than 3 and no more than 5.