| 摘要 |
PROBLEM TO BE SOLVED: To improve solution stability by specifying the gold concentration and chelating agent concentration in a noncyanide gold electroplating liquid containing a tervalent gold compound, such as gold hydroxide salt and/or chloroaurate, a chelating agent of a hydantoin base compound, a buffer agent and a conductive salt and the pH thereof. SOLUTION: The gold concentration is 0.5 to 30 g/l, the concentration of the chelating agent is 0.1 to 2.5 M/l and the pH is 5.0 to 10.0. The hydantoin base compound is preferably any among imidazoline dion, 5,5-dimethyl hydantoin and hydantoic acid. Any one kind of any among hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid or their salts or >=2 kinds thereof are preferably used as the conductive salt. There is no settlement of gold and the gold plating treatment may be carried out continuously for a long time. The plating treatment may be carried out without the dissolution of photoresist even in the presence of the coating thereof. A hardness value is high and the plating is suitable as a pump deposit for IC packaging.
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