NON-CYANIDE DISPLACEMENT SILVER PLATING BATH

摘要

PROBLEM TO BE SOLVED: To obtain a plating bath in which a dense and uniform silver film can be precipitated on a tin plating film by properly determining the concn. of univalent silver ion and properly selecting acid radicals and complexing agent to stably maintain the silver ion. ;SOLUTION: This plating bath contains 0.01 to 50g/l univalent silver ion and one or more kinds of acid radicals or complexing agent to stabilize the silver ion in the bath so as to obtain a smooth and dense silver displacement precipitation film. These are ions of nitric or nitrous acid, sulfuric or sulfurous acid and hydrochloric acid, ammonium ion, acetic acid ion, ions of sulfonic acids expressed by formulae I to III, urea, thiourea or thioacetoamide expressed by formula IV or derivs. of these, hydantoin compds. expressed by formula V, specified imidosuccinate, imidomaleate or derivs. of these, specified amines or salts, specified thiocarboxylic acid, thiosulfuric acid, benztriazole, benzthiazole, etc.;COPYRIGHT: (C)1998,JPO