SURFACE-SMOOTHENED COPPER FOIL, AND ITS PRODUCTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method for producing surface-smoothened copper foil where the pattern of the stripes in the marks of bubbles is less liable to be generated on the surface of electrolytic copper foil, productivity is high because of short electrolytic polishing time, and further, the load of wastewater treatment for a polishing liquid is reduced. SOLUTION: Regarding the method for producing surface-smoothened copper foil where the surface of copper foil is electrolytically polished using a phosphoric acid aqueous solution, the electrolytic polishing is performed under the condition where the current efficiency at the time of continuously performing the electrolytic polishing to the surface of the copper foil at a fixed current density reaches 62 to 90%. The concentration of phosphoric acid in the phosphoric acid aqueous solution is preferably controlled to 380 to 470 g/l. Further, the current density in the electrolytic polishing is preferably controlled to 20 to 50 A/dm2. Also, the quantity of electric charges required for the electrolytic polishing is preferably controlled to 100 to 2,000 C/dm2. Further, it is preferable that the phosphoric acid used for the phosphoric acid aqueous solution is H3PO4, and the temperature of the phosphoric acid aqueous solution is 20 to 40°C. COPYRIGHT: (C)2005,JPO&NCIPI