摘要 |
PURPOSE:To reduce the cost a lead frame by providing the first metal-plated layer on a part of the lead frame whereon an element is mounted, and the seccond metal-plated layer only on other part than the above. CONSTITUTION:Only a part of a lead 1 whereon a semiconductor element is mounted is plated with an Au film, and other part than the above is plated with an Ag film. By this constitution, the cost of the frame can be reduced while the adhesiveness of the element and the joining property of fine metal wires are maintained as usual, and in addition, since the metal films of different kinds are formed adjacently, the surface of the material of the frame is not exposed and thus the corrosion of the material is prevented. |