| 摘要 |
662,660. Electrodeposition of copper. WESTINGHOUSE ELECTRIC INTERNATIONAL CO. March 17, 1949 [May 1, 1948; Feb. 18, 1949], Nos. 7328/49 and 7329/49. Drawings to Specification. Class 41. A process of electroplating copper on a base member from an aqueous cyanide electrolyte having copper dissolved therein, comprising applying a plating electric current to the base member while in contact with the electrolyte for a period of not more than 40 seconds, then applying a deplating current of a predetermined magnitude for a period of time to deliver at least 10 per cent of the coulombs delivered during the preceding plating period to effect removal of a part of the previously plated copper, and continuing the alternating plating and deplating process until a desired thickness of copper has been deposited, is characterized in that the electrolyte contains dissolved zinc, the concentration of which is maintained between 0.004 and 0.57 ozs. per U.S.A. gallon (0.03 and 4.27 grams per litre) of the electrolyte. The duration of each deplating period is preferably not longer than 10 seconds. The zinc may be derived from an anode consisting mainly of copper but containing between 5 per cent and 0.1 per cent by weight of zinc. The electrolyte may contain as additions agent a betaine having at least one non-cyclic hydrocarbon' radical which contains from 10 to 20 carbon atoms, the betaine being present in a concentration of 0.01 to 1.0 oz. per gallon. The electrolyte may also contain thiocyanate in a concentration of 0.1 to 10 ozs. per gallon. |
