Matsushita Electric Industrial Co., Ltd.

Takahiro Hamada

Masakazu Tanahashi

Emiko Igaki

Chiharu Hayashi

Yasunobu Tsuji

Yoshihiko Tsujikawa

A solid electrolyte capacitor includes an anode made of a valve metal on whose surface a dielectric oxide film layer is formed, a solid electrolyte layer formed on the dielectric oxide film, a cathode layer formed on the solid electrolyte layer, a cathode contact terminal electrically connected to the cathode layer, and an anode contact terminal electrically connected to the anode layer. The cathode layer includes a carbon layer containing carbon particles, and a conductive paste layer containing conductive metal particles and having numerous pores, formed in that order from the solid electrolyte layer side. The solid electrolyte capacitor further includes a conductive polymer layer formed through the numerous pores of the conductive paste layer and connecting the carbon particles of the carbon layer and the conductive metal particles of the conductive paste layer. Thus, the interface resistance between the carbon layer and the conductive paste layer is lowered, and a solid electrolyte capacitor with small equivalent series resistance can be provided.

Solid electrolyte capacitor and method for manufacturing the same

The present invention provides a method of producing an electrolytic capacitor including a porous anode and a solid electrolyte made of a conductive polymer, which can improve coating properties of the conductive polymer on an external surface of the porous anode and productivity. By controlling a polymerization rate, it is possible to sufficiently coat the external surface of the porous anode and fill inner spaces of a lot of pores of the porous anode with the conductive polymer with less numbers of polymerization in comparison with a method of the prior art, thereby obtaining an electrolytic capacitor with small leak current and high reliability.

Method of producing electrolytic capacitor

The present invention provides a method for producing an electrolytic capacitor including a porous body of a valve metal, an oxide film on a surface of the valve metal, and a conductive polymer layer on a surface of the oxide film. The step of forming the conductive polymer layer on the surface of the oxide film includes the steps of dipping the porous body in a monomer solution; lifting the porous body from the monomer solution and dipping the porous body in an oxidizing solution; and lifting the porous body from the oxidizing solution and allowing the porous body to stand. In the step of dipping the porous body in the oxidizing solution, a period for which the porous body is dipped in the oxidizing solution is equal to or shorter than a period in which 30% of the monomer contained in pores of the porous body diffuses and flows into the oxidizing solution. Alternatively, the volume of the oxidizing solution can be less than three times that of the porous body. The above method can be performed by replacing the monomer solution and the oxidizing solution with each other. Furthermore, a temperature of the porous body is maintained at a low temperature (e.g., 10.degree. C. or less) in the step of dipping the porous body in the oxidizing solution.

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Hirakata, Japan

Takahiro Hamada