| 摘要 |
<p>A process is provided for regenerating a spent electroless copper plating bath which contains alkali metal salts resulting from the reduction of a water soluble copper salt under copper plating and reducing conditions. The regeneration is effected by means of the electrodialytic transfer of at least a portion of the anions in the spent plating bath through an anionic permselective membrane (18) into the anode compartment (12) of an electrodialytic cell (10). in the preferred embodiment, hydroxyl ions from the cathode compartment (16) of the electrodialytic cell (10) are concurrently transferred through a second anionic permselective membrane (20) to replace the transferred anions, the replacement taking place in a compartment (14) of the electrodialytic cell (10) located between the two anionic permselective membranes (18, 20). E.g., the spent solution to be regenerated is an aqueous solution containing Cu<+><+>, Na<+>, OH<->, HCOO<->, SO4<-><->, HCHO and the sodium salt of EDTA.</p> |
