JPH0645205A - 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 on an insulation substrate 26 comprising cut-off winding guiding parts 22, 24 having an undercut, the aluminum fine wire is formed as two plate-like winding wire anode bodies 26, 30, and terminals 32, 34 for an external connection are respectively connected with end parts 28a, 30a on the projecting side reverse to each of the cut-off winding guiding parts of the both winding wire anode bodies. A solid electrolyte layer and a conductive layer 36 are produced on the remainders 28b, 30b excluding an end part on the projecting side of the both winding wire anode bodies to form a capacitor element 38, and thereby this capacitor element is sealed with heatproof plastics and also forming is performed by bending terminals for an exterminal connection.

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 thin aluminum wire, and the thin aluminum wire is flatly wound on both sides of an insulating substrate having stepped notch winding guides on opposite sides to form two flat-plate winding anode bodies, An external connection terminal is connected to each of the protruding side end portions of the two-winding anode body opposite to the cut-out winding guide portion, and the remaining portion of the both-winding anode body excluding the protruding side end portion is solid. It is characterized in that an electrolyte layer and a conductive layer are generated to form a capacitor element, and the capacitor element is resin-sealed and formed.

In this case, it is preferable that the two-winding anode body is constructed such that after the solid electrolyte layer and the conductive layer are formed, the space between them is further connected by a conductive paste.

[0009]

According to the present invention, the anode body is formed as two flat plate-shaped winding anode bodies made of aluminum fine wires wound on an insulating substrate, and these both winding anode bodies are solid electrolyte layers. And, after forming the conductive layer, resin-encapsulated on the insulating substrate. Therefore, as compared with the conventional capacitor of this type, the entire structure is downsized, and at the same time, the capacitance is increased. In this case, the solid electrolyte layer is protected from being deformed due to twisting by sealing the winding anode body with resin after its formation,
It will not be damaged.

Further, the present invention is characterized in that the anode body is formed in two pieces as described above, and the external connection terminals are connected to each of them, so that the solid electrolytic capacitor is constructed in a bipolar manner.

[0011]

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. 1 (B)] having an oxide film formed on its surface by chemical conversion treatment. And this aluminum thin wire 2
1 is wound flatly on an insulating substrate 26 having stepped notch winding guide portions 22 and 24 on opposite sides as shown in FIG. 1 (A). As shown, it is formed as two flat-plate wound anode bodies 28, 30. Then, the protruding side end portion 28 of each of the two winding anode bodies 28, 30 opposite to the cutout winding guide portions 22, 24.
External connection terminals 32 and 34 are respectively connected to a and 30a, and as shown in FIG. 1C, the remaining portions of the two-winding anode bodies 28 and 30 excluding the projecting side end portions 28a and 30a portions are respectively formed. , The solid electrolyte layer and the conductive layer 36 are formed to form the capacitor element 38. At this time, preferably, the both winding anode bodies 28 and 30 are electrically connected with a conductive paste. Then, as shown in FIG. 1D, the capacitor element 38 is sealed with a heat-resistant synthetic resin 46 made of epoxy resin or the like, and the external connection terminals 32 and 34 are bent and formed. The external connection terminals 32 and 34 are each made of a solderable metal such as copper or copper-aluminum clad, and are connected to the winding anode bodies 28 and 30 by a conductive adhesive or the like. To do. Further, the solid electrolyte layer and the conductive layer 36 are formed by a usual method, that is, by immersing a part of the winding anode bodies 28, 30 (aluminum fine wire 20) in a pyrrole solution, and then chemically polymerizing the oxide film on the oxide film. Conductive solid electrolyte (polypyrrole)
It can be produced by forming a film and then applying a voltage to electropolymerize the polypyrrole film. In this case, when dipping in the pyrrole solution, a portion 2 of the wound anode bodies 28, 30 other than the generated portion is formed.
Masking made of epoxy resin or the like is applied to 8b and 30b in advance. In addition, the sealing with resin and the exterior are
Any method such as molding or potting may be used.

As described above, the solid electrolytic capacitor of the present invention is constructed as two flat-plate winding anode bodies each having an anode body made of an aluminum thin wire wound on an insulating substrate, and these both-winding anode bodies. After forming the solid electrolyte layer and the conductive layer, the resin is resin-sealed on the insulating substrate. Therefore, as compared with the conventional capacitor of this type, the entire structure is downsized, and at the same time, the capacitance is increased. In this case, the solid electrolyte layer, after its formation,
Since the winding anode body is sealed with resin, the winding anode body is protected from deformation due to twisting and the like, so that it is not damaged.

Further, the present invention is characterized in that the anode body is formed in two pieces as described above, and the external connection terminal is connected to each of them, so that the solid electrolytic capacitor can be constructed in a bipolar manner.

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.

[0016]

As described above, in the solid electrolytic capacitor according to the present invention, the anode body is constructed as two flat plate-shaped winding anode bodies made of thin aluminum wires wound on the insulating substrate. These two-winding anode bodies are configured to have a solid electrolyte layer and a conductive layer formed on a part thereof and then resin-sealed on the insulating substrate. The structure can be downsized and the capacity can be increased at the same time. In addition,
In this case, the solid electrolyte layer is not damaged because the winding anode body is resin-sealed after its formation to protect the solid electrolyte layer from deformation due to twisting and the like.

Further, the present invention is characterized in that the anode body is formed in two pieces as described above, and the external connection terminal is connected to each of them, so that the solid electrolytic capacitor can be constructed in a bipolar manner.

[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, 24 Notch Winding Guide 26 Insulating Substrate 28, 30 Winding Anode Body 32, 34 External Connection Terminal 36 Solid Electrolyte Layer and Conductive Layer 38 Capacitor Element 40 Heat Resistant Synthetic Resin

Claims (1)

[Claims] 1. A solid electrolytic capacitor in which a solid electrolyte layer is formed on an anode body whose surface is formed with an oxide film, wherein the anode body is made of aluminum fine wire, and the aluminum fine wire is wound in a notched winding on both sides facing each other. Two flat-plate winding anode bodies are formed by winding them in a flat shape on both sides of an insulating substrate having a guide portion, and the two winding anode bodies are provided on the protruding side end portions on the opposite side of the notched winding guide portions. Each of them is connected to an external connection terminal, and a solid electrolyte layer and a conductive layer are formed in the remaining portion of the winding anode body excluding the protruding end portions to form a capacitor element, and the capacitor element is resin-sealed. Solid electrolytic capacitor characterized by being formed and formed.