Chip-formed solid electrolytic capacitor without an anode lead projecting from anode member

• US 5,654,869 A
• Filed: 12/08/1995
• Issued: 08/05/1997
• Est. Priority Date: 12/12/1994
• Status: Expired due to Term

• Current Assignee: NEC Tokin Corporation (Yageo Corporation)
• Original Assignee: NEC Corporation
• Inventors: Kobayashi, Atushi, Ohi, Masashi, Taniguchi, Hiromichi
• Primary Examiner(s): Ledynh, Bot L.
• Application Number:
  US08/569,304
• Time in Patent Office: 606 Days
• Field of Search: 361/523, 361/524-525, 361/528-529, 361/532-536, 361/537-540, 29/25.03
• US Class Current: 361/540
• CPC Class Codes: H01G 9/012 specially adapted for solid capacitors

Abstract

A chip-formed solid electrolytic capacitor having a structure wherein a projecting anode lead is not provided for an anode member. The solid electrolytic capacitor is fabricated by the following manner: First, an electrically insulating resin such as a fluororesin is impregnated into an end face of a porous electrode member to form an insulating resin impregnated portion, and an electrode lead member is bonded to the anode member at the insulating resin impregnated portion. An anodic oxidation film, a solid electrolyte layer and a cathode layer successively are formed on the anode member. Then, an electrically insulating outer package is applied so that the cathode layer on a face of the anode member opposing to the face on which the electrode lead member is mounted is exposed. After removing the electrode lead member, an anode outer electrode layer is formed on the insulating resin impregnated portion, and a cathode outer electrode layer which electrically connects to the cathode layer is formed on the end face of the anode member opposing to the anode outer electrode layer.

Claims

1. A solid electrolytic capacitor in the form of a chip, comprising a porous anode member made of a valve metal, an oxide film layer formed on the anode member, a cathode layer formed from a conductive material, a solid electrolyte layer held between the oxide film layer and the cathode layer, an anode outer electrode layer disposed on one of a pair of end faces of the anode member, a cathode outer electrode layer disposed on the other end face of the anode member and electrically connected to the cathode layer, and an outer packaging resin layer for covering over a region in which the anode outer electrode layer and the cathode outer electrode layer are not formed to isolate both outer electrode layers from each other,

the one of the end faces of the anode member having an insulating resin impregnated portion where an electrically insulating resin is impregnated in the anode member, the anode member and the anode outer electrode layer being electrically connected to each other at the insulating resin impregnated portion.

2. The solid electrolytic capacitor according to claim 1, wherein the anode member and the anode outer electrode layer are connected to each other by way of a plated layer.

3. The solid electrolytic capacitor according to claim 2, wherein the electrically insulating resin is a fluororesin.

4. The solid electrolytic capacitor according to claim 1, wherein the electrically insulating resin is a water repellent resin.

5. The solid electrolytic capacitor according to claim 4, wherein the anode member and the anode outer electrode layer are connected to each other by way of a plated layer.

6. The solid electrolytic capacitor according to claim 5, wherein the cathode layer and the cathode outer electrode layer are connected to each other by way of another plated layer.

7. The solid electrolytic capacitor according to claim 1, wherein the solid electrolyte layer is formed from manganese dioxide.

8. The solid electrolytic capacitor according to claim 1, wherein the solid electrolyte layer is formed from a conductive polymer material.

9. A chip-type solid electrolytic capacitor comprising:

a porous anode member made of a valve metal;

an oxide film layer formed on the anode member;

a cathode layer of conductive material;

a solid electrolyte layer held between the oxide film layer and the cathode layer;

an anode outer electrode layer disposed on a first end face of the anode member;

a cathode outer electrode layer disposed on a second end face of the anode member and electrically connected to the cathode layer;

an outer packaging resin layer formed over a part of said cathode layer not covered by one of the anode outer electrode layer and the cathode outer electrode layer, said outer packaging resin layer isolating said anode and cathode outer electrode layers from each other;

the first end face of the anode member having an insulating resin-impregnated portion where an electrically insulating resin is impregnated in the anode member, the anode member and the anode outer electrode layer being electrically connected to each other via the insulating resin-impregnated portion;

said porous anode member being free of implanted anode leads; and

said anode outer electrode layer only being disposed over the first end face of said anode member.