JPH0645203A - Solid electrolytic capacitor - Google Patents

Abstract

PURPOSE:To obtain a solid electrolytic capacitor capable of miniatuarizing a structure and increasing capacitance. CONSTITUTION:An anode body is constituted of an aluminum fine wire 20, and by winding this aluminum fine wire in a plane form through a winding core projecting part 22 on an insulation substrate 24, the aluminum fine wire is formed as a plate-like winding wire anode body 26, and next a solid electrolyte layer and a conductive layer 28 are produced on a part of this winding wire anode body and also connected with external connection terminals 30, 32, and finally an insulation coated plate 34 is placed on the projecting part 22 so as to coat the winding wire anode body and external connection terminals, and a gap between the insulation substrate and insulation coated plate is sealed with heatproof plastics 36.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid electrolytic capacitor, and more particularly to a solid electrolytic capacitor which can be downsized and have an increased capacity.

[0002]

2. Description of the Related Art As electrolytic capacitors, there are known a liquid type capacitor in which a liquid electrolyte (electrolyte solution) is interposed between an anode and a cathode and a solid type capacitor in which a solid electrolyte is interposed. However, it is generally known that the latter is remarkably excellent especially in the characteristics in a high frequency region.

Next, such a solid electrolytic capacitor will be briefly described below with reference to FIG. 2. A capacitor of this type is generally first shown in FIG. 2 (A) by an anode body (usually aluminum). Plate body 10 constituting the
An oxide film layer 12 is formed in the concave portion by chemical conversion treatment. Then, in FIG. 2B, the oxide film layer 12 is formed.
First, a conductive solid electrolyte (preferably polypyrrole) film 14 is formed on the top by chemical polymerization, and then a voltage is applied to the polypyrrole film 14 via a current-carrying pin 16 in FIG. As shown in FIG. 2D, a capacitor is formed by electrolytically polymerizing the polypyrrole film 14 and growing it to the surface of the recess. Note that this capacitor is completed by subsequently connecting an external connection terminal (not shown) using a conductive paste or the like and covering the exterior 18 with an epoxy resin or the like.

[0004]

However, the above-mentioned conventional solid electrolytic capacitor has the following basic drawbacks.

That is, in the conventional solid electrolytic capacitor, as is clear from FIG. 2, the anode body is composed of a thick plate body in which a recess is formed over the entire central portion. At the same time that the structure of
Reduced capacity (especially in comparison to the larger structures)
It had a basic difficulty. In addition, this difficulty (that is, increase in size of the structure) is to prevent the solid electrolyte layer (polypyrrole) film from being damaged by twisting, bending, etc. It is due to what must be done.

Therefore, an object of the present invention is to provide a solid electrolytic capacitor which can be downsized and have an increased capacity.

[0007]

In order to achieve the above object, a solid electrolytic capacitor according to the present invention is a solid electrolytic capacitor in which a solid electrolyte layer is formed on an anode body whose surface is formed with an oxide film. The body is made of aluminum fine wire, and the aluminum fine wire is flatly wound on an insulating substrate having a protrusion serving as a winding core at the center to form a flat-plate winding anode body. After a solid electrolyte layer and a conductive layer are partially formed and external connection terminals are connected, an insulating coating plate is placed on the protrusions so as to cover the winding anode body and the external connection terminals, and the insulating substrate. And a gap between the insulating cover plate and the insulating cover plate is sealed with a heat resistant synthetic resin.

[0008]

According to the present invention, the anode body is formed as a flat plate-shaped winding anode body made of aluminum fine wire, and this winding anode body is formed on the insulating substrate after forming the solid electrolyte layer and the conductive layer. It is protected by resin-sealing between the insulating cover plate. As a result, the structure of the entire capacitor (anode body, insulating substrate, and insulating cover plate) is downsized, and the capacity is increased. Moreover, the solid electrolyte layer is not damaged.

[0009]

Embodiments of the solid electrolytic capacitor according to the present invention will be described below in detail with reference to the accompanying drawings.

In FIG. 1, in the solid electrolytic capacitor according to the present invention, first, the anode body is composed of an aluminum fine wire 20 (see FIG. 1B) having an oxide film formed on its surface by chemical conversion treatment. And this aluminum thin wire 2
As shown in FIG. 1 (B), 0 is wound in a plane shape on an insulating substrate 24 having a projecting portion 22 serving as a winding core in the center as shown in FIG. 1 (A). Is formed as a flat plate-shaped wound anode body 26. In addition, this winding anode body 26
In the formation of, the number of windings of the aluminum thin wire 20 is sufficient as one stage, but the number of stages may be two or more. Next, as shown in FIG. 1C, a solid electrolyte layer and a conductive layer 28 are formed on a part of the wound anode body 26, and external connection terminals 30 and 32 are connected. The solid electrolyte layer 28 is formed by a usual method, that is, on the oxide film of the winding anode body 26 (aluminum thin wire 20), first, a conductive solid electrolyte (preferably polypyrrole) film is formed by chemical polymerization. Then, a voltage may be applied to electropolymerize the polypyrrole film to produce the polypyrrole film. In this case, in the producing step, the winding anode body 2
It is preferable to mask the area other than the generated portion 6 with an epoxy resin or the like. The negative terminal 30 and the positive terminal 32 for external connection are each made of a solderable metal, for example, copper, copper-aluminum clad, and the like.
The conductive portion and the non-generated portion of the solid electrolyte layer and the conductive layer 28 are connected by a conductive adhesive or the like. And finally, as shown in FIG.
Also, an insulating cover plate 34 is placed on the protrusion 22 so as to cover the external connection terminals 30 and 32, and a gap between the insulating substrate 24 and the insulating cover plate 34 is made into a heat resistant synthetic resin 36 made of epoxy resin or the like. Seal with. External connection terminal 3
0 and 32 are finally bent and formed as shown by the chain line.

As described above, the solid electrolytic capacitor of the present invention is constructed as a flat plate-shaped winding anode body in which the anode body is made of fine aluminum wire, and this winding anode body produces the solid electrolyte layer and the conductive layer. After that, the space between the insulating substrate and the insulating cover plate is protected by resin sealing. Therefore, the capacitor (anode body, insulating substrate, and insulating cover plate) can be reduced in size as a whole, and at the same time, the capacitance can be increased. Further, the solid electrolyte layer is not damaged at least after the winding, because the winding anode body is not twisted.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and many design changes can be made without departing from the spirit thereof.

[0013]

As described above, in the solid electrolytic capacitor according to the present invention, the anode body is constructed as a flat plate-shaped wound anode body made of aluminum fine wire wound around the winding core protrusion on the insulating substrate. In addition, the winding anode body is structured such that a solid electrolyte layer is formed on a part of the wound anode body, and then the space between the insulating substrate and the insulating coating plate is sealed with resin to protect the capacitor (anode body). , The insulating substrate and the insulating coated plate) can consequently increase the capacity while the overall structure is downsized. Further, in this case, the solid electrolyte layer is not damaged at least after the winding, because the winding anode body is not twisted.

[Brief description of drawings]

1A to 1D are process explanatory views showing an embodiment of a manufacturing process of a solid electrolytic capacitor according to the present invention.

FIG. 2A to FIG. 2D are process explanatory views showing a manufacturing process of a conventional solid electrolytic capacitor.

[Explanation of symbols]

 20 Aluminum Fine Wire 22 Protrusions 24 Insulating Substrate 26 Winding Anode Body 28 Solid Electrolyte Layer and Conductive Layer 30, 32 External Connection Terminal 34 Insulation Cover Plate 36 Heat Resistant Synthetic Resin

Claims (1)

[Claims] 1. In a solid electrolytic capacitor in which a solid electrolyte layer is formed on an anode body whose surface is formed with an oxide film, the anode body is made of thin aluminum wire, and the thin aluminum wire is provided with a protrusion serving as a winding core at the center. After winding in a flat shape on an insulating substrate provided to form a flat-plate winding anode body, a solid electrolyte layer and a conductive layer are formed on a part of this winding anode body, and external connection terminals are connected. An insulating coating plate is placed on the protrusion so as to cover the winding anode body and the external connection terminal, and a gap between the insulating substrate and the insulating coating plate is sealed with a heat resistant synthetic resin. Solid electrolytic capacitor.