| abstract |
(57) [Abstract] [Purpose] To provide an optical semiconductor device in which stress on an encapsulation element is small and which is excellent in transparency, heat resistance, and moisture resistance. [Structure] (A) Epoxy resin, (B) acid anhydride curing agent, (C) curing accelerator, and (D) a molecular weight of 500 to 5000 having a functional group that reacts with at least one glycidyl group in one molecule. A copolymer of the organopolysiloxane and the polybutadiene epoxide is used as an essential component. |