Method for selective removal of contaminants co-activator ber aqueous solutions containing palladium and tin

摘要

A method is provided for selective removal of copper contaminants from aqueous activator solutions which also contain palladium and tin. It comprises placement of insoluble electrodes in the aqeuous solution and application of a low voltage, preferably ranging from between 0.05 to 5.0 volts across the electrodes, whereby metallic copper is selectively deposited upon the cathode, with palladium and tin remaining in the aqueous solutions. Typically, the soluble copper ions are present as contaminants in activator solutions utilized in various electroless metal plating processes.