Silver plating solution and silver plating process and pretreatment solution therefor

摘要

A cyclic thion compound is incorporated as an anti-immersion agent into a cyanide-containing silver plating solution for use in silver plating onto a copper or copper alloy surface or into a pre-dipping solution for use in treating the copper or copper alloy surface before the silver plating using a cyanide-containing silver plating solution. Immersion deposition of silver on the copper or copper alloy surface is prevented, and a plated article free of defects and having good plating properties is obtained even if cyanogen is contained at a relatively high concentration in the plating solution.