PURPOSE: To reduce an initial tanδ value and its irregularity and to reduce a change in a tanδ value at a humidity-resistant test by a method wherein a cathode extraction part is constituted in such a way that a second carbon layer which is composed of a thermoplastic resin and of a powder having a specific particle size and a nickel oxide cathode layer are formed sequentially on a first carbon layer.
CONSTITUTION: A tantalum anodic-oxidation film layer 13 is formed on the surface of a tantalum porous electrode body 12 provided with a tantalum anode extraction wire 11; a solid electrolyte layer 14 composed of a manganese dioxide layer and a first carbon layer 15 are formed sequentially; a coating film as a second carbon layer 16 which is composed of a carbon powder having an average particle size of 1 to 30μm and an acrylic resin is formed on them; in addition, a coating film as a cathode layer 17 which is composed of a nickel oxide powder having an average particle size of 10 to 60μm and an acrylic resin is formed on it. Thereby, a capacitor element is obtained. Then, an external cathode terminal 19 is arranged and installed at the cathode layer 17 via a silver adhesive 18; the anode extraction wire 11 is welded to an external anode terminal 20; after that, an outer-package resin 21 is executed. When the particle size of carbon is outside said range, a tanδ value becomes large. When the particle size of nickel oxide is at 10μm or lower, the tanδ value becomes large. When the size is at 60μm or higher, the surface state of the coating film becomes worse.
SAKURAI WATARU
HASEGAWA NOBUO
OBA TAKESHI
