PRODUCTION OF COPPER ALLOY MATERIAL FOR ELECTRONIC PARTS HAVING GOOD SILVER PLATING PROPERTY

摘要

PROBLEM TO BE SOLVED: To obtain a copper alloy material capable of being directly and excellently plated with silver without applying a substrate plating by pickling the copper alloy material contg. Fe with an aq. acidic soln. contg. sulfuric acid, an oxidizing agent and ethylene glycol in specified concn. at least after final annealing. ;SOLUTION: The oxide of Fe is completely dissolved in an aq. acidic soln. contg. sulfuric acid, an oxidizing agent and 1 to 100 g/l ethylene glycol, and its redeposition is effectively prevented by the soln. Hydrogen peroxide and a persulfate are preferably used as the oxidizing agent. When sulfuric acid is combined with hydrogen peroxide, the sulfuric acid concn. is controlled to 100 to 500 g/l and the hydrogen peroxide concn. to 5 to 100 g/l from the standpoint of etching power and economy. While both concns. are controlled in such a range, the molar ratio (sulfuric acid/hydrogen peroxide) is adjusted to ≥0.35. Meanwhile, pickling is preferably carried out in the aq. acidic soln. at 20 to 70°C for 1 to 300 sec to sufficiently improve the silver plating property.;COPYRIGHT: (C)1998,JPO