| 摘要 |
PURPOSE:To prevent simply the formation of tin whiskers at a low cost without depriving tin plating of its effect, by forming a thin lead film on the surface of the tin plating formed on a base metal. CONSTITUTION:A tin film 11 is formed on a base metal 13 by plating after forming an under film 12 on the metal 13 by plating, and a thin lead film 31 is formed on the film 11. Thus, the formation of tin whiskers can be prevented without deteriorating the advantages of the tin plating such as improved rust and corrosion preventing properties and solderability. The lead film 31 is formed by electroless plating, vapor deposition, sputtering or other method. A region having high lead concn. may be formed in place of the lead film 31 by ion implantation, diffusion or other method, or a thin film of a lead-tin alloy contg. >=5% lead may be formed and the same effect is obtd. |
