PHOTOSEMICONDUCTOR DEVICE

摘要

PURPOSE:To provide a photosemiconductor device having excellent phototransmission and capable of preventing its sealing resin parts from discoloring, even under conditions of being left in a high-temperature environ ment for a long time. CONSTITUTION:This photosemiconductor device is an element sealed using an epoxy resin formation containing components (A)-(D) mentioned below. (A) epoxy resin (B) acid anhydride based hardener (C) hardening accelerator (D) phosphorous acid.