Patent ID: 6989289

Claim:
A method of producing an electrolytic capacitor comprising: an anode layer formed of a valve metal foil having through holes formed therethrough and a coarsened surface, a dielectric layer of an oxide film formed by anodizing a part of the surface of the valve metal foil, and a cathode conductive polymer layer formed on the dielectric layer, and an electric collector, wherein the method comprises steps of: forming the through holes through the valve metal foil; attaching one electrolyzing electrode to one side surface of the valve metal foil; immersing the valve metal foil in a conductive monomer solution where an another electrolyzing electrode is disposed in the solution apart from the opposite side of the valve metal foil with respect to the one electrolyzing electrode; electrolyzing the solution between the one electrolyzing electrode and the another electrolyzing electrode to polymerize the monomer; generating an electrolytically-formed conductive polymer, starting on the one electrolyzing electrode side; making the electrolytically-formed conductive polymer grow through the through hole in the thickness direction of the valve metal foil thereby forming a cathode; and covering the surface of the another electrolyzing electrode side of the oxide film on the valve metal foil by the electrolytically-formed conductive polymer, as the cathode conductive polymer layer and said electric collector being a metal foil formed on one side of the anode layer via the cathode-side conductive polymer layer.