| 摘要 |
PROBLEM TO BE SOLVED: To prevent the plating spreading, abnormal deposition, unequal deposition, etc., at the time of applying gold plating and extend the life of a substituted gold plating bath. SOLUTION: This plating bath contains a soluble gold salt, a complexing agent consisting of sulfite and thiosulfite, a concealing complexing agent consisting of oxycarboxylic acid, such as tartaric acid, an amine compound, such as aminoacetic acid or ethylenediamine and ammonium compd., a pH control agent, an amphoteric surfactant or a mixture composed of the amphoteric surfactant and a nonionic surfactant. The plating bath is characterized in that the sulfite and the thiosulfite are combined as the complexing agent, that the concealing complexing agent is used and that the kind of the surfactant is limited to the mixture of the amphoteric or amphoteric and nonionic system. The stabilization of the gold ions in the plating bath and the suppression of the plating spreading, etc., at the time of gold plating may be simultaneously achieved by the synergistic effect based on the constitution.
|
