JP2845010B2 - Solid electrolytic capacitors - Google Patents

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 an element structure of a microminiature capacitor.

[0002]

2. Description of the Related Art In recent years, demands for lighter, thinner, and smaller electronic devices have been increasing, and the competition for miniaturization of electronic components has been unavoidable. Also for solid electrolytic capacitors, small-sized products have been actively developed due to similar needs, and are particularly remarkable for chip components.

A conventional solid electrolytic capacitor is shown in FIG.
The following description will be made using the chip-shaped solid electrolytic capacitor described above. After the insulating resin layer 4 is formed at the base of the anode lead 2 for the purpose of preventing the formation of the solid electrolyte layer 5 on the anode body 1 on which the anode lead 2 has been implanted. An oxide film 3 is formed by a known means, a solid electrolyte layer 5, a current collector layer 6 such as graphite, and a cathode layer 6 such as a silver paste are formed. After being removed thermally or thermally, the anode lead terminal 9 is connected by welding, the cathode layer 6 and the cathode lead terminal 10 are connected by a conductive adhesive 8, and a part of the positive / negative lead terminal 9, 10 is connected. Except for covering with the exterior resin 11, and furthermore, the positive and negative lead terminals 9,1
No. 0 was bent along the peripheral surface of the exterior resin 11 to form a chip-shaped solid electrolytic capacitor.

[0004]

In the conventional solid electrolytic capacitor, when a solid electrolyte layer 5, a current collector layer 6, and a cathode layer 7 are formed on the peripheral surface of the anode lead 2 in FIG.
Contact with the anode lead terminal 9 causes an increase in leakage current, or in an extreme case, short-circuiting and the function as a capacitor is lost.

For this reason, in forming each of the above-mentioned layers on the anode body 1, it is very important to level out the layers, and it is necessary to prevent the rising phenomenon due to surface tension and the adhesion due to scattering.

As a means for achieving this object, an insulating resin layer 4 is formed at the base of the anode lead 2. However, as the size of the capacitor becomes smaller, it becomes more difficult to make the coating amount and the coating level uniform, so that a large amount is required. It takes time for coating. Further, in order to prevent the rising, it is necessary to apply a certain amount or more of the coating amount, but in order to secure this coating amount, the interval between the anode lead terminal 9 and the anode body 1 must be made longer than a certain amount. Therefore, the shape of the anode body 1 is shortened by that much, which is an obstacle to downsizing and increasing the capacity.

SUMMARY OF THE INVENTION An object of the present invention is to provide a solid electrolytic capacitor capable of easily controlling the formation level of each layer of the solid electrolytic capacitor, simplifying the process, and achieving a small size and a large capacity.

[0008]

A solid electrolytic capacitor according to the present invention is a capacitor having an oxide film, a solid electrolyte layer, a current collector layer, and a cathode layer formed on an anode body made of a valve metal having an anode lead implanted thereon. A solid electrolytic capacitor comprising an element, an anode / cathode lead terminal respectively derived from the anode lead and the cathode layer, and an exterior resin covering the capacitor element except for a part of the anode / cathode terminal; And a tomographically formed insulating resin layer, solid electrolyte layer, current collector layer, and cathode layer on the peripheral surface of the anode lead between the connection portion of the anode lead terminal and the anode body.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a chip-shaped solid electrolytic capacitor according to one embodiment of the present invention, FIG. 1 (a) is an overall sectional view, and FIG. 1 (b) is a partial sectional view of an anode lead.

After an insulating resin layer 4 is formed at the base of the anode lead 2 of the anode body 1 on which the anode lead 2 is implanted, the oxide film 3, the solid electrolyte layer 5, the current collector layer 6, and the cathode are formed by known means. A layer 7 is sequentially formed on the anode body 1 and the anode lead 2, and then an oxide film 3, an insulating resin layer 4, a solid electrolyte layer 5, a current collector layer 6, and a cathode layer 7 After removal by means such as sandblasting,
After connecting to the anode lead terminal 9 by welding, and then connecting the cathode layer 7 of the anode body 1 and the cathode lead terminal 10 with a conductive adhesive 8, transfer is performed except for a part of the positive and negative lead terminals 9, 10. The exterior is covered with the exterior resin 11 by a molding means, and the positive / negative lead terminals 9 and 10 are further exposed to the exterior resin 1.
1 was bent along the peripheral surface to form a chip-shaped solid electrolytic capacitor.

In this embodiment, the solid electrolyte layer 5, the current collector layer 6, and the cathode layer 7 formed on the anode lead 2 are basically insulated by the insulating resin layer 4, and are connected to the anode lead terminal 9. A structure in which the oxide film 3, insulating resin layer 4, solid electrolyte layer 5, current collector layer 6, and cathode layer 7 are tomographically removed by means such as sandblasting with the minimum dimensions so that the anode body 1 can be as close as possible. It has become.

Therefore, the dimensional control in forming the capacitor element 12 is very easy, and there is no problem in the structure of the present invention even if the immersion level is slightly shifted or a rising phenomenon occurs. .

Further, the shape of the anode body 1 can be lengthened in the length direction, and the volume can be increased by about 20% as compared with the conventional case. As a result, a smaller and larger-capacity capacitor was obtained.

Next, a second embodiment will be described with reference to FIG. FIG. 2 is a sectional view of a resin dip type solid electrolytic capacitor. Capacitor element 12 in which oxide film 3, insulating resin layer 4, solid electrolyte layer 5, current collector layer 6, and cathode layer 7 are formed on anode lead 2 tomographically in the same manner as in Example 1.
Of the anode lead 2 and the anode lead terminal 9
And the cathode lead terminal 10 are covered with solder 13 and fixed, and the capacitor element 12 is immersed in the exterior resin 11 except for a part of the positive / negative lead terminals 9 and 10 and then dried and cured to form a solid electrolytic capacitor. did.

In this embodiment, the same effects as those of the chip-shaped solid electrolytic capacitor of the first embodiment were obtained.

[0016]

As described above, according to the present invention, the solid electrolyte layer and the cathode, which have not been formed on the anode lead, are intentionally formed via an insulating resin layer and then removed. Since the structure is insulated, the following effects can be obtained. (1) It is easy to control the formation level of each layer including the insulating resin layer and the solid electrolyte layer, and the process can be simplified. (2) The connection between the anode lead and the anode lead terminal can be brought close to the anode body, and the volume of the anode body can be increased, so that a small and large-capacity solid electrolytic capacitor can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, in which FIG. 1 (a) is an overall view and FIG. 1 (b) is an enlarged view of a main part.

FIG. 2 is a cross-sectional view of a resin dip type solid electrolytic capacitor according to another embodiment of the present invention.

FIG. 3 is a cross-sectional view of an example of a conventional chip-shaped solid electrolytic capacitor. FIG. 3 (a) is an overall view, and FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anode body 2 Anode lead 3 Oxide film 4 Insulating resin layer 5 Solid electrolyte layer 6 Current collector layer 7 Cathode layer 8 Conductive adhesive 9 Anode lead terminal 10 Cathode lead terminal 11 Exterior resin 12 Capacitor element 13 Solder

Claims (1)

(57) [Claims] 1. A capacitor element in which an oxide film, a solid electrolyte layer, a current collector layer, and a cathode layer are formed on an anode body made of a valve metal on which an anode lead is implanted, and are respectively derived from the anode lead and the cathode layer. Positive and negative lead terminals,
In a solid electrolytic capacitor made of an exterior resin that covers the capacitor element except for a part of the positive / negative terminal, a connection portion between the anode lead and the anode lead terminal and an anode lead peripheral surface between the anode bodies, A solid electrolytic capacitor having a tomographically formed insulating resin layer, solid electrolyte layer, current collector layer and cathode layer.