Etching of chromium alloys

Claim 1

THE PROCESS OF FORMING A PREDETERMINED PATTERN OF ELECTRICAL CONDUCTORS ON AN ELECTRICAL INSULATING MEMBER WHICH COMPRISES THE STEPS OF FORMING A LAYER OF A FERROUS ALLOY CONTAINING SUFFICIENT CHROMIUM TO RENDER THE ALLOY STAINLESS OVER THE ENTIRE SURFACE PORTION OF THE MEMBER, SUBJECTING THE EXPOSED SURFACE OF THE LAYER OF THE FERROUS ALLOY TO AN ANODIC ACID ELECTROETCHING ACTION TO REMOVE OXIDES AND OTHER IMPURITIES FROM SAID EXPOSED SURFACE TO PROVIDE AN ETCHED SURFACE, ELECTRPOLATING SAID ETCHED SURFACE OF THE FERROUS ALLOY WITH A COATING SELECTED FROM THE CLASS; NICKEL, IRON, COBALT, ZINC, NICKELIRON AND NICKEL-COBALT TO PROVIDE AN ELECTROPLATED COATING, FORMING ON DISCRETE PORTIONS OF THE EXPOSED SURFACE OF SAID ELECTROPLATED COATING AN ETCHANT RESIST COMPOSITION WHICH COINCIDES WITH SAID PREDETERMINED PATTERN OF ELECTRICAL CONDUCTORS TO PROVIDE A RESIST COMPOSITION BEARING SURFACE, AND APPLYING TO SAID RESIST-COMPOSITION-BEARING SURFACE AN ETCHANT FOR REMOVING ALL OF THE ELECTROPLATED COATING AND FERROUS ALLOY NOT UNDERLYING THE SAID PREDETERMINED PATTERN OF RESIST COMPOSITION.