Abstract: The present invention is a package for optical semiconductor devices, and an optical semiconductor device using the package, which can prevent discoloration of a plating layer formed on a lead frame even when a silicone resin is used as a sealing resin for an optical semiconductor device, and which enables high luminous efficiency for a long time. Specifically, in the package for semiconductor devices, a plating laminate 15, wherein a pure Ag plating layer 4, a thin reflective plating layer 6 serving as the uppermost layer for improving the light reflection ratio, and a resistant plating layer 5 serving as an intermediate layer therebetween and having chemical resistance against at least either metal chlorides or metal sulfides are laminated, is formed on at least the surface of a lead electrode. The reflective plating layer 4 is composed of a pure Ag thin film, and the resistant plating layer 5 is composed of a complete solid solution Au—Ag alloy plating layer.

Abstract: The present invention is a package for optical semiconductor devices, and an optical semiconductor device using the package, which can prevent discoloration of a plating layer formed on a lead frame even when a silicone resin is used as a sealing resin for an optical semiconductor device, and which enables high luminous efficiency for a long time. Specifically, in the package for semiconductor devices, a plating laminate 15, wherein a pure Ag plating layer 4, a thin reflective plating layer 6 serving as the uppermost layer for improving the light reflection ratio, and a resistant plating layer 5 serving as an intermediate layer therebetween and having chemical resistance against at least either metal chlorides or metal sulfides are laminated, is formed on at least the surface of a lead electrode. The reflective plating layer 4 is composed of a pure Ag thin film, and the resistant plating layer 5 is composed of a complete solid solution Au—Ag alloy plating layer.

Abstract: There is provided a lead frame for an optical semiconductor device, an optical semiconductor device using such lead frame, and a manufacturing method for these, where the optical semiconductor device exhibits favorable brightness over a long period of time by preventing discoloration and degeneration of a plating layer provide on the lead frame and a resulting reduction in a reflection coefficient for light emitted from a light emitting element, even when using silicone resin as a sealing resin. An Ag—Au alloy plating layer 22 is formed on the surface of a pure Ag plating layer 21 on a lead frame 10 sealed chloroplatinic acid-containing silicon resin, so as to prevent direct contact between the layer 21 and the silicone resin. This suppresses the formation of AgCl due to a reaction with a hardening catalyst of the silicon resin, thereby preventing the Ag plating layer from turning a blackish-brown color.