US 5,473,503 AGranted

Solid electrolytic capacitor and method for manufacturing the same

AssigneeNEC Corporation

InventorsKoji Sakata, Atsushi Kobayashi, Takashi Fukaumi, Toshihiko Nishiyama, Satoshi Arai

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Abstract

A solid electrolytic capacitor using a conductive polymeric compound as a solid electrolyte is disclosed, wherein a powder is dispersed in the conductive polymer to provide unevenness on the surface of the solid electrolyte, thereby increasing the surface area, whereby a mechanical adhesion between the solid electrolyte and a cathode conductor layer is increased. The conductive polymer comprises a first conductive polymer layer which contacts a dielectric layer at an anode body side, and a second conductive polymer layer which contacts the cathode conductor layer side, and the powder is dispersed in the second conductive polymer layer. By this constitution, tan .delta. and an equivalent series resistance (ESR) of the solid electrolytic capacitor are decreased.

Claims10

Dependent claims

A solid electrolytic capacitor comprising:

an anode body of valve metal,
an oxide layer of the valve metal formed on the anode body,
a first electrically conductive polymer layer formed on the oxide layer,
a second electrically conductive polymer layer formed on the first electrically conductive polymer layer,
a plurality of electrically conductive powders dispersed within the second electrically conductive polymer layer to cause a surface of the second electrically conductive polymer layer to be an uneven surface that includes a plurality of convex portions and a plurality of concave portions, each of the convex portions being formed along an associated one of the electrically conductive powders and each of the concave portions being formed between adjacent ones of the electrically conductive powders to intervene therebetween, and
a cathode conductor layer formed on the second electrically conductive polymer layer with an adhesiveness enhanced by the uneven surface of the second electrically conductive polymer layer.

3 more elements

Dependencies are inferred from the claim text.