Electrolytic capacitor and method for manufacturing same

A method of manufacturing an electrolytic capacitor, comprising:

• providing an anode foil made of valve metal and a first oxide film provided on a surface of the anode foil which contains phosphorus;
• connecting an anode terminal to the anode foil;
• forming a capacitor element by stacking the anode foil, a cathode foil, and a separator such that the separator is provided between the anode foil and the cathode foil;
• forming a second oxide film on the surface of the anode terminal by anodizing the anode terminal with at least one of electrolysis solution containing adipate or borate as electrolyte and electrolysis solution consisting of boric acid aqueous solution;
• providing π-conjugated conductive polymer dispersing solution containing water and particles of conductive polymer;
• and
• after said providing the π-conjugated conductive polymer dispersing solution, impregnating the capacitor element with the π-conjugated conductive polymer dispersing solution.

An electrolytic capacitor comprising:

• a capacitor element including:
• an anode foil having a surface,
• a first oxide film provided on the surface of the anode foil;
• a solid electrolyte layer made of solid electrolyte provided on the first oxide film, the solid electrolyte layer being formed using π-conjugated conductive polymer dispersing material containing water and particles of conductive polymer, and
• a cathode foil provided on the solid electrolyte layer, the cathode foil facing the first oxide film across the solid electrolyte layer;
• an anode terminal connected to the anode foil;
• and
• a second oxide film provided on a surface of the anode terminal,
• wherein the first oxide film contains 6 ppm or more phosphorus, and
• wherein phosphorus is contained in the second oxide film at a concentration lower than about 1 ppm.

An electrolytic capacitor comprising:

• a capacitor element including:
• an anode foil having a surface,
• a first oxide film provided on the surface of the anode foil;
• a solid electrolyte layer made of solid electrolyte provided on the first oxide film, the solid electrolyte layer being formed using t-conjugated conductive polymer dispersing material containing water and particles of conductive polymer, and
• a cathode foil provided on the solid electrolyte layer, the cathode foil facing the first oxide film across the solid electrolyte layer;
• an anode terminal connected to the anode foil;
• and
• a second oxide film provided on a surface of the anode terminal,
• wherein the anode foil has a surface having pores provided therein,
• wherein the anode terminal has a surface having holes provided therein,
• wherein a mode value of diameters of the pores of the anode foil is larger than a mode value of diameters of the particles of the conductive polymer, and
• wherein a mode value of opening diameters of the holes of the anode terminal is smaller than the mode value of the diameters of the particles of the conductive polymer.