| 摘要 |
PURPOSE:To obtain the electroless gold plating soln. capable of obtaining a thick plating especially at low temp. and in the vicinity of neutrality and having low toxicity from an aq. soln. contg. chloroauric acid (salt), Na2SO3, an alkali metal thiosulfate, ascorbic acid (salt), and a buffer as the components. CONSTITUTION:An electroless gold plating soln. is formed from an aq. soln. contg. chloroauric acid or its salt (e.g., Nasalt), Na2SO3, an alkali metal thiosulfate (e.g., Na salt), ascorbic acid or its salt (e.g., Na salt), and a buffer (e.g., NH4Cl). A soln. contg. 0.001-0.10mol/l sodium chloroaurate, 0.05-1.0mol/l Na2SO3, 0.05-2.0mol/l Na2S2O3, 0.001-0.10mol/l ascorbic acid, and 0.01-1.0mol/l NH4Cl is preferably used as the gold plating soln. By such a plating soln., electroless gold plating can be continuously and stably carried out in the vicinity of neutrality, at the low temp. of 50-60 deg.C, and at a practically available plating rate. |
