PURPOSE: To prevent decrease in strength of aluminum electrode foil by a method wherein a dielectric film, on which the dielectric fine particles of high dielectric constant are mingled, is formed on the surface of aluminum foil.
CONSTITUTION: A sheet of aluminum foil 3, of which the surface area is enlarged by forming a number of etch pits by etching, is delivered to a chemically forming bath 7 through a roller 6. A chemically forming solution, consisting of an adipic acid ammonium solution containing titanium oxide grains, is poured into the chemically forming bath 7, and an aluminum foil is formed by applying voltage from a chemically forming power source 8. The manufactured aluminum foil 3 is heat-treated in a heat treatment furnace 9, then it is depolarized in a deporarization treatment bath 10, subsequently a post-treatment is conducted in a chemically forming bath 13, and finally, it is dried up by a heat treatment furnace 14, and the aluminum foil is formed. As a result, electrostatic capacitance can be increased without decreasing strength, and a small electrolytic capacitor can be manufactured.
KAMIMOTO KOJI
KURAMASU KEIZABURO
TANAHASHI MASAKAZU
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