TREATMENT OF TIN-LEAD ALLOY FILM ON COPPER ALLOY BAR

摘要

PURPOSE:To prevent the deterioration of a plated film due to an org. additive in the film by electroplating a pretreated Cu alloy bar with an Sn-Pb alloy having a specified composition, melting the resulting plated film by heating to remove the org. additive and solidifying the film by cooling. CONSTITUTION:A Cu alloy bar pretreated by alkali electrolytic degreasing and pickling is electroplated with an Sn-Pb alloy consisting of 95-55% Sn and 5-45% Pb to 0.7-1.5mum thickness in a plating soln. contg. an org. additive added to enhance luster. The resulting plated film is melted by heating to decompose and volatilize the org. additive in the film and the film is solidified by cooling. Thus, a stable thin plated film having high luster and almost free from pinholes is formed.