Baths for the chemical polishing of copper or copper alloy surfaces, comprising, in aqueous solution, hydrogen peroxide, chloride ions, phosphoric acid and phosphate and hydrogenphosphate ions, in quantities adjusted so as to impart a pH of between 1.25 and 3 to the bath....http://www.google.es/patents/US4981553?utm_source=gb-gplus-sharePatente US4981553 - Copper etching bath and method of using
