Patent ID: 9441104
Filing Date: 2016-09-13
CPC Classification: C08K,C08L,H01L

Claim Text:
1. A heat-curable epoxy resin composition for optical semiconductor element encapsulation, comprising: (A) a prepolymer obtained by a reaction of components (A-1), (A-2), (A-3) and (A-4) at an epoxy group equivalent/acid anhydride group equivalent ratio of 0.6 to 2.0, (B) a curing accelerator comprised of an onium salt represented by the following formula 1: (A-2) is added in an amount of 11 to 100 parts by mass with respect to 100 parts by mass of (A-1); (A-4) is added in an amount of 2 to 20 parts by mass with respect to 100 parts by mass of a total sum of (A-1), (A-2) and (A-3); and the component (B) is added in an amount of 0.05 to 5 parts by mass with respect to 100 parts by mass of a total sum of (A-1), (A-2), (A-3) and (A-4).