| 摘要 |
PURPOSE:To obtain a lead frame material which has an adquate strength and also, is superior in bending processability, wire-bonding characteristic and so on by a method wherein the surface layer and the central part side of the lead frame material are each constituted of a material different in composition and also, the surface layer is formed in such a way that the softening temperature of the material of the surface layer becomes lower than that of the material of the central part side. CONSTITUTION:A lead frame material is formed in a two-layer structure of a central part side and a surface layer and the surface layer is constituted in such a way as to be easy to soften faster than the central layer. this lead material can be manufacture by clading or an alloying treatment through surface diffusion, such as a method wherein the surface of a certain metal is coated with a metal of a composition different from that of the metal by plating, evaporation, ion-implantation and so on and this is subjected to a diffused heating. Thereby, the generation of abnormality in the surface due to bending is prevented and the wirebonding characteristic can be improve. |
