| 摘要 |
PURPOSE:To efficiently remove ions accumulated in a chemical copper plating soln. by adding an anionic chelating agent forming a chelate compound with a cuprous ion to a soln. in a cathode chamber when impurities are removed from the plating soln. by electrodialysis. CONSTITUTION:An electrodialytic cell is divided into a chamber for regenerating a plating soln., anode and cathode chambers with two anion exchange resin membranes. An anionic chelating agent forming a chelate compound with a cuprous ion is added to a soln. in the cathode chamber. The regenerating is filled with a chemical copper plating soln. contg. copper ions, a copper ion chelating agent, a copper ion reducing agent, and a pH adjusting agent as essential components. DC voltage is then applied between the cathode and anode placed in the cathode and anode chambers, respectively. Counter anions to copper ions and ions of an oxidation reaction product of the reducing agent are selectively removed from the plating soln. by electrodialysis. |
