| 摘要 |
PURPOSE:To weaken attack on a substrate and to improve the adhesion of a plating film to it by using specified org. sulfonic acid, tin and lead salts thereof, sodium hypophosphite as a reducing agent and thiourea as a complexing agent for essential components of the plating bath. CONSTITUTION:This electroless tin-lead alloy plating bath contains org. sulfonic acid selected among alkanesulfonic acid, alkanosulfonic acid and arom. sulfonic acid, bivalent tin and lead salts thereof, sodium hypophosphite as a reducing agent and thiourea as a complexing agent as essential components or further contains a pH adjusting agent such as citric acid, tartaric acid or malic acid, a surfactant such as lauryl pyridinium chloride or sodium laurylsulfate and a brightener as required. When electroless plating is carried out with the plating bath, a uniform, smooth tin-lead alloy plating film can be formed with high work efficiency. |
