PROCESS AND APPARATUS FOR REGENERATING A COPPER-CONTAINING ETCHING SOLUTION

• Main Authors: REITH, HERIBERT, OTT, RUDI
• Format: Patent
• Language: English; German
• Published: 01.06.1988
• Edition: 4
• Subjects: APPARATUS THEREFOR; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTIONOF COMPOUNDS OR NON-METALS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; METALLURGY; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLICMATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASSC23 AND AT LEAST ONEPROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25; NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; PRINTED CIRCUITS; PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY ORREFINING OF METALS

A method and apparatus for the regeneration of a copper-containing etching solution which contains copper (II) chloride as well as alkali chloride as a sequestering agent, wherein the cathode is operated at a current density of 40-400 A/dm2 and the anode is operated at a current density of 1-100 A/dm2. Copper forms at the cathode as a powdered slurry while chlorine forms at the anode which oxidizes copper (I) chloride to copper (II) chloride. With this method one can process etching solutions which contain not only copper but also base metals including zinc from etching brass or tombac, and obtain a powdered mixture of copper and base metal. The apparatus features a rotating disk-shaped cathode from whose outer face the metal powder is stripped by a scraper.