| 摘要 |
PROBLEM TO BE SOLVED: To reduce the size of a solid-state electrolytic capacitor and to increase the capacitance of the capacitor and, at the same time, to improve the tanδand high-frequency characteristics of the capacitor by forming a manganese dioxide layer, containing at least one kinds of ions selected out of sulfuric acid ions and hydrogen sulfate ions on an anodically oxidizes film formed on a porous electrode body of a valve metal. SOLUTION: A tantalum electrode body 1 is prepared by subjecting a sintered body of pulverizes powder to formation in a phosphoric acid solution and by forming an oxidizes film 2 on the surface of the formed body. On the surface of the film 2, a manganese dioxide layer 3 is formed by repeatedly dipping the body 1 in a manganese nitrate solution containing an added sulfuric acid solution and thermally decomposing the body 1 five times successively, repeatedly impregnating the body 1 with the manganese nitrate solution containing an added sulfuric acid solution and thermally decomposing the body 1 four times repeatedly. Thereafter, a cathode extraction electrode 4 composed of a carbon layer and conductive silver-resin layer is provided. In addition, aluminum, titanium, or niobium may be used as a valve metal.
|
