Continuously electropolishing copper or copper alloys - by passing as anode through two electrolysers contg. phosphoric acid and copper ions one at const. temp

摘要

Cu or Cu materials, esp. cylindrical materials, e.g. wire or tubes, for electronics and other industrial uses, are continuously electro-polished to obtain very smooth surfaces by passing through 2 consecutive electrolysers filled with an electrolyte soln. contg. 70-90 wt. % H3PO4, Cu ions in concn. of 0.05-2 g ion/1 H3PO4 and org. additives. In 1st electrolyser, (I) is passivated at a const. soln. temp. of 70-100 degrees C, using an anodic current density of 0.1-2 mA/cm2 of (I). In 2nd electrolyser, temp. is 10-30 degrees C at inlet and 60-140 degrees C at outlet, and voltage between (I) as anode and the cathode is 1.5-2.5 v. depending on type of additives. Pref. org. additives consist of 1-100 g/l tert. aliphatic amines and/or 1-5 mg/l alkyl ammonium cpds.