| abstract |
An encapsulant for an optical semiconductor device that has no discoloration in a reflow process, has a high gas barrier property against a corrosive gas, and does not easily crack or peel even when used in a harsh environment. An encapsulant 4 for an optical semiconductor device includes a first organopolysiloxane having an alkenyl group bonded to a silicon atom and an aryl group bonded to a silicon atom (provided that an organo group having a hydrogen atom bonded to a silicon atom). 2), a second organopolysiloxane having a hydrogen atom bonded to a silicon atom and an aryl group bonded to a silicon atom, and a platinum catalyst. The platinum catalyst is a mixture of a platinum alkenyl complex and a phosphorus compound. [Selection] Figure 1 |