Regeneration of etching solution used in the production of printed circuit boards

Abstract

Some waste waters containing copper are formed during the production of printed circuit boards. When these effluents are discharged into the reservoir, they must be diluted 140,000 times, and the treatment of these copper-containing effluents causes the copper loosing. The paper presents the results obtained during the study of electrochemical processing of copper-containing effluents formed at the stage of PCBs etching. The spent solution processing was realized in a membrane electrolytic cell. An increase in current density results in an increase in process speed. Along with a decrease in copper concentration in the solution, the hydrochloric acid was concentrated. It is shown that it is possible to regenerate the etching solution and obtain a metallic copper.