METHOD FOR PREPARING TIN/SILVER ALLOY PLATING SOLUTION

摘要

The present invention relates to a method for preparing a tin/silver alloy plating solution comprising methane sulfonic acid tin, methane sulfonic acid silver, methane sulfonic acid, a nonionic surfactant, and additives. The method comprises: a first step of removing extricated anion metal impurities existing in the methane sulfonic acid and nonionic surfactant; a second step of dissolving, by means of an electrolysis method, tin and silver in the methane sulfonic acid from which the impurities have been removed, respectively, so as to produce methane sulfonic acid tin and methane sulfonic acid silver; a third step of combining the methane sulfonic acid, methane sulfonic acid tin, methane sulfonic acid silver, nonionic surfactant, and additives so as to produce a mixture solution; and a fourth step of filtering the mixture solution. Thus, the method of the present invention may enable the anion metal impurities of each raw material for preparing a plating solution to be removed, and a plating solution to be prepared from refined materials, thus providing a plating solution which enables the production of a uniformly plated film even in high-speed plating and which has a constant silver precipitate content.