Electrode foil for aluminum electrolytic capacitor and method of manufacturing same

Abstract

Sub pits are suppressed from branching in a surface layer of an aluminum foil, and an electrode foil for an aluminum electrolytic capacitor with a large electrostatic capacitance and a method of manufacturing the same are provided. A large number of main pits are formed by etching on both surfaces of the aluminum foil to extend from the surfaces in a thickness direction of the foil, sub pits are formed to branch away from the main pits for a range from a vicinity of a surface layer portion of each main pits excluding the surface layer portion, to inner ends of the main pits. Since the sub pits are not formed in the surface layer of the aluminum foil, the sub pits can be increased in density effectively to the electrostatic capacitance, allowing the electrode foil for the aluminum electrolytic capacitor to have high mechanical strength and high electrostatic capacitance.