PASSIVAZIONE DI SUPERFICI DI APPARECCHIATURE METALLICHE IN PROCESSI PER DEPOSIZIONE DI RAME SENZA ELETTRICITA

The metallic surfaces of plating equipment in use during electroless copper deposition, such as vessels 2, racks 26 supporting substrates 24 to be plated, plumbing are rendered substantially resistant to electroless copper deposition for extended periods by initially imposing on such equipment surfaces an electrical potential via power supply 10 more positive than the mixed potential of the electroless copper deposition solution and sufficiently positive to resist electroless deposition. The workpiece substrate 24 is insulated from rack 26 by non-conductor 27. The electrical potential supplied by electrode 6 and the vessel walls 12a, 12b, is monitored during the electroless plating using reference electrode 22.