| 摘要 |
PURPOSE:To make a mold release agent unnecessary by preventing resin and a mold by a gold coating from adhering to each other, by providing the gold coating on the surface of a cavity in a molding mold. CONSTITUTION:A gold coating 5 is formed on a mold surface including recessed parts 3a, 4a of both a top and bottom forces 3, 4 with an electroplating method. The gold coating 5a, 5b and their surfaces are formed by adjusting plating conditions so that surface roughness becomes 0.1mum or less and mirror surfaces respectively. In addition, the gold surface is smoothened and cleaned by performing grinding and degreasing treatment of the mold surfaces of both the top and bottom molds 3, 4, to form the gold coatings 5a, 5b. The gold coatings 5a, 5b are formed on the mold surface by electrolyzing gold into an electrolytic bath obtained by dissolving gold cyanide into, for example, excessive potassium cyanide by making both the molds 3, 4 and the gold respectively the cathode and anode after that. Although sealing resin is stuck firmly to a semiconductor element 1 and lead frame 2, it shows nonadhesion to the gold coating 5a, 5b. |
