| 摘要 |
PURPOSE:To manufacture a stem which is economical and abounds in corrosion resistance by coating the surface of a metallic section of the stem for a semiconductor with a plating layer of silver containing gold. CONSTITUTION:The surface of a metallic section of a stem 1 consisting of a metallic bottom plate 2 to which a semiconductor element is fastened and lead terminals 4 insulated and sealed with glass 3 is coated with a plating layer 5 of silver containing gold. The plating layer of silver is obtained in such a manner that the surface of the metallic section of the stem is plated with 0.5-2.0mum thick silver, an upper section of a silver plated layer is plated with 0.1-2.0mum thick gold, the whole is thermally treated and gold on the surface of silver is diffused into silver. Thus, since mobility due to an electric field of silver is suppressed, silver can be used for the metallic section of the stem, and the stem for a semiconductor device, which is cheap and has strong corrosion resistance, can be manufactured. |
