METHOD FOR MANUFACTURING ANODE FOIL OF ALUMINIUM ELECTROLYTIC CAPACITOR

摘要

The present invention provides a method of manufacturing anode foil for aluminum electrolytic capacitors with high capacitance and decreased leakage current. The method has the following steps: dipping etched aluminum foil into pure water having a temperature of 90° C. or higher so as to form a hydrated film on the foil; attaching organic acid to the surface of the hydrated film; performing main chemical conversion on the aluminum foil with application of formation voltage after the attaching step; performing depolarization on the aluminum foil after the main chemical conversion step; and performing follow-up chemical conversion on the aluminum foil after the main chemical conversion step. The main chemical conversion treatment has two-or-more stages. In the first stage of the treatment, the foil is dipped into a phosphate aqueous solution, and in the last stage, it is dipped into an aqueous solution different from the phosphate aqueous solution.