Electrolytic gold plating solution

Abstract

An objective of the present invention is to provide an electrolytic gold plating solution that stably exhibits good selective gold deposition properties during gold plating. An electrolytic gold plating solution according to the present invention contains a gold source, and an oxidizing agent (specific oxidizing agent) that exhibits a reaction potential equal to or greater than a specific value when linear sweep voltammetry is performed under specific conditions. Furthermore, concentrations of copper ions and lead ions in the electrolytic gold plating solution are less than a specific value. The specific oxidizing agent acts to improve selective gold deposition in the electrolytic gold plating solution. However, if copper ions or lead ions are present in the electrolytic gold plating solution, the effect of the specific oxidizing agent in improving selective gold deposition is inhibited. In the electrolytic gold plating solution of the present invention, concentrations of copper ions and lead ions are kept low, allowing the effect of the specific oxidizing agent in selective gold deposition to be realized without being inhibited.