Sanyo Electric Co., Ltd.

Other

Sanyo Electronic Components Co., Ltd.

Youichi Kojima

Takeshi Takamatsu

Hidenori Kamigawa

Yasuhiro Kishimoto

Yutaka Taketani

Kakusyo Yoshida

Hiroshi Yakui

Yasuhiko Ito

Yasutoshi Sugita

Tomohiro Nishio

This invention relates to solid electrolyte capacitors and is intended to decrease the contact resistance between the body of the capacitor and lead frames and the internal resistance of these components. The, invention provides a process for producing a solid electrolyte capacitor by forming a dielectric oxide film on an anode body of valve metal, forming a cathode layer of solid conductive substance on the oxide film to prepare a capacitor element, coating the cathode layer of the capacitor element with a carbon layer, coating the carbon layer with a silver paste layer to prepare a capacitor body, and bonding a lead frame to the silver paste layer of the. capacitor body with a silver adhesive. While the capacitor element coated with the carbon layer and a silver paste are being vibrated relative to each other, the capacitor element is dipped in the silver paste and withdrawn therefrom in the direction of the vibration, whereby the carbon layer is coated with the silver paste layer. The surface of the lead frame is partly or entirely formed with a high conductive layer of a material having a higher electric conductivity than the substrate of the lead frame, the high conductive layer extending from a connection to the capacitor body to a connection for an external circuit.

Solid electrolyte capacitor, and process and apparatus for producing same

The invention provides a process for producing solid electrolyte capacitors by forming a dielectric oxide film and a first cathode layer of solid conductive substance over the surface of an anode body of valve metal, and forming a second cathode layer of conductive high polymer on the first cathode layer by electrolytic oxidative polymerization. The second cathode layer is formed by immersing in the electrolyte the anode body formed over the surface thereof with the oxide film and the first cathode layer, feeding a positive voltage with an external electrode piece in contact with the first cathode layer in the electrolyte, and shifting the feeding point at a predetermined time interval.

Solid electrolyte capacitor

The invention provides a process for producing solid electrolyte capacitors by forming a dielectric oxide film and a first cathode layer of solid conductive substance over the surface of an anode body of valve metal, and forming a second cathode layer of conductive high polymer on the first cathode layer by electrolytic oxidative polymerization. In forming the second cathode layer, the pH of the electrolyte to be used for electrolytic oxidative polymerization is maintained within a predetermined range by adding an acid or alkali to the electrolyte. Since the pH of the electrolyte remains substantially unaltered by the polymerization according to the invention, the electrolyte is repeatedly usable while permitting the resulting second cathode layers to retain the desired electric conductivity. The second cathode layer is formed by immersing in the electrolyte the anode body formed over the surface thereof with the oxide film and the first cathode layer, feeding a positive voltage with an external electrode piece in contact with the first cathode layer in the electrolyte, and shifting the feeding point at a predetermined time interval. The feeding point where the electrode piece is in contact with the first cathode layer for feeding shifts during the step of electrolytic oxidative polymerization, so that the thickness of the second cathode layer formed as centered about the feeding point is made uniform to the greatest possible extent over the entire anode body without increasing locally.

The object of the invention is to provide a process for producing an organic solid electrolyte capacitor which is diminished in leakage current, and an apparatus for use in practicing the process. The process includes the steps of completing a capacitor element by forming a dielectric oxide film over an anode body of valve metal and subsequently forming a cathode layer of solid conductive organic material over the oxide film, subjecting the capacitor element to an aging treatment, and forming a shell around the capacitor element. The apparatus, which is an aging apparatus for such capacitor elements, comprises a box for accommodating a plurality of capacitor elements, a conductive buffer layer provided inside the box, a conductive holding member disposed on the box for attaching thereto the outer end of anode lead of each of the capacitor elements, with a silver paste layer of the element in contact with the buffer layer, a current limiter connected to the buffer layer for restricting the current to be passed through the capacitor element to not greater than a predetermined value, and a power source having positive and negative electrodes connected to the holding member and the current limiter, respectively.

Process and apparatus for producing organic solid electrolyte capacitor

This invention relates to solid electrolyte capacitors and is intended to decrease the contact resistance between the body of the capacitor and lead frames and the internal resistance of these components The invention provides a process for producing a solid electrolyte capacitor by forming a dielectric oxide film on an anode body of valve metal, forming a cathode layer of solid conductive substance on the oxide film to prepare a capacitor element, coating the cathode layer of the capacitor element with a carbon layer, coating the carbon layer with a silver paste layer to prepare a capacitor body, and bonding a lead frame to the silver paste layer of the capacitor body with a silver adhesive. While the capacitor element coated with the carbon layer and a silver paste are being vibrated relative to each other, the capacitor element is dipped in the silver paste and withdrawn therefrom in the direction of the vibration, whereby the carbon layer is coated with the silver paste layer. The surface of the lead frame is partly or entirely formed with a high conductive layer of a material having a higher electric conductivity than the substrate of the lead frame, the high conductive layer extending from a connection to the capacitor body to a connection for an external circuit.

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Daito, Japan

Youichi Kojima