ALUMINUM FOIL FOR ELECTROLYTIC CAPACITOR CAPABLE OF ENSURING CAPACITANCE CHARACTERISTICS AND ESTIMATION METHOD OF CAPACITANCE CHARACTERISTICS OF ALUMINUM FOIL FOR ELECTROLYTIC CAPACITOR

摘要

PROBLEM TO BE SOLVED: To provide an aluminum foil which can ensure capacitance characteristics of an Al foil for an electrolytic capacitor and moreover is superior in capacitance characteristics, and an evaluation method of the capacitance characteristics of the Al foil. ;SOLUTION: In an Al film for an electrolytic capacitor, an oxide film is formed on the Al foil surface. For the Al foil prior to electrolytic etching, the interface impedance of the Al foil/the oxide film of the Al film/aqueous solution which is measured by an interface impedance method is made to satisfy such that a maximum value Aa of the real axis component in an impedance locus A developed on a complex plane is in the range of 500-1500 . The Al foil prior to electrolytic etching is used as an anode electrode, the interface impedance of the Al foil/the oxide film of the Al foil/aqueous solution is measured under a specified conditions, thereby capacitance characteristics of the Al foil ate evaluated.;COPYRIGHT: (C)1999,JPO