JPH0614465Y2 - Solid electrolytic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a solid electrolytic capacitor using a polymer of a heterocyclic compound as an electrolyte, and more particularly to a high voltage solid electrolytic capacitor.

[Prior art]

A dielectric oxide film such as aluminum oxide (Al ₂ O ₃ ) is formed on the surface of a metal plate capable of forming a dielectric oxide film such as aluminum, and pyrrole, furan, or an electrolyte is formed on the dielectric oxide film.
Forming a polymer layer of a heterocyclic compound such as thiophene,
There is known a solid electrolytic capacitor provided with a capacitor element having a conductive layer such as a graphite layer and a silver paste layer formed thereon (for example, JP-A-61-2315).

[Problems to be solved by the device]

However, the solid electrolytic capacitor using the polymer layer of the above heterocyclic compound as an electrolyte has a problem that it is difficult to increase the withstand voltage of the capacitor and a high withstand voltage cannot be obtained.

The present invention has been made in view of the above points, and an object of the present invention is to eliminate the above problems and provide a high-voltage solid electrolytic capacitor.

[Means for Solving the Problems]

The present invention for solving the above-mentioned problems is to provide a solid electrolytic capacitor, as shown in FIG. 1, on a metal plate (11) on which a dielectric oxide film can be formed. A metal oxide plate (11a) is attached and a dielectric oxide film layer is formed on the other surface, and an insulating strip layer (12) having a predetermined width is formed on the peripheral edge of the dielectric oxide film layer, and a portion surrounded by the insulating strip layer (12). A heterocyclic compound polymer layer (13) and a conductor layer (14 and 15) are sequentially formed on the above to form a capacitor element plate (10), and the capacitor element plate (10) is formed on one side of the metal plate (11). Dissimilar metal attached to (11
The conductor layer surface (1) surrounded by the surface a) and the insulating band layer (12)
5) are joined together to laminate a plurality of sheets, and a second layer is formed on the conductor layers (14, 15) and the dissimilar metal plate (11a) of the laminate (16).
As shown in the figure, the electrode element (17, 18) is attached to the capacitor element.

Further, in the solid electrolytic capacitor, as shown in FIG. 5, a dielectric oxide film layer is formed on the surface of a metal plate (21) on which a dielectric oxide film can be formed, and an insulating strip layer (22) is formed on the surface at a predetermined position. To divide the surface of the metal plate (21) into two parts, and sequentially form the polymer layer (23) of the heterocyclic compound and the conductor layers (24, 25) on one of the divided parts to form a capacitor element plate. (20) is formed, and the conductor layer (2
5) An insulating layer (26) is formed on the entire surface except for one surface, and the other metal plate (21) divided by the insulating strip layer (22) has a different type from the metal plate (21) such as solder. A dissimilar metal plate (30) that can be attached to the capacitor element plate (2
0) is formed, and the conductor layer (25) and the insulating layer (26) of the capacitor element plate (20) are joined to each other as shown in FIG. 3, and the dissimilar metal plate (30) and the conductor layer (25) are formed. )
Are connected to each other to laminate a plurality of sheets, and the dissimilar metal plates (3
0) and a conductor layer (25) with electrode terminals (27, 28) attached to the capacitor element.

[Action]

By configuring the solid electrolytic capacitor as described above,
A plurality of capacitor element plates (10, 20) are electrically connected in series, and the withstand voltage is equal to the number of stacked layers of the withstand voltage of each capacitor element plate. Therefore, a high withstand voltage solid electrolytic capacitor can be obtained. To be

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. First
1A and 1B are views showing a configuration of a capacitor element portion of a solid electrolytic capacitor according to the present invention. FIG. 1A is a partially cutaway sectional perspective view, and FIG. 1B is a partial sectional view of a capacitor element plate.

In this embodiment, an aluminum foil whose surface is roughened by etching is used as a metal plate on which a dielectric oxide film serving as a capacitor substrate can be formed. On one surface of the aluminum foil 11, for example, a different type of solderable metal 11a different from aluminum is welded, and an aluminum oxide (Al ₂ O ₃ ) film is formed on the other surface of the aluminum foil 11 to form a chemical foil. An insulating resin agent is applied to the peripheral edge portion to form an insulating strip layer 12, and a pyrrole polymer layer (polypyrrole) as a polymer layer of a heterocyclic compound serving as an electrolyte is formed on an aluminum foil 11 surrounded by the insulating strip layer 12. The layer 13), the graphite layer 14 and the silver paste layer 15 as conductor layers for electrode extraction are sequentially formed to form the capacitor element plate 10. The dissimilar metal plate 11
The connection of a may be performed with a conductive adhesive such as silver paste.

A plurality of (four in the figure) capacitor element plates 10 are laminated so that the surface of the dissimilar metal plate 11a and the surface of the silver paste layer 15 surrounded by the insulating band layer 12 are joined to form a laminate 16. To do.

Silver paste layer 15 and aluminum foil 1 of the laminate 16
As shown in FIG. 2, electrode terminals 17 and 18 are attached to each of them to form a solid electrolytic capacitor capacitor element.

A solid electrolytic capacitor is obtained by applying an exterior to the capacitor element.

By configuring the capacitor element as described above, the capacitors of each capacitor element plate 10 are connected in series, and the withstand voltage of this capacitor element is the number of laminated layers of the withstand voltage of each capacitor element plate 10 (4 in the figure). Times).

As a specific example, four capacitor element plates 10 having a withstand voltage of 16 V and a capacity of 1.9 μF are stacked to form a capacitor element having a withstand voltage of 63 V and a capacity of 0.47 μF. Since the thickness of the capacitor element is about 0.8 mm, a compact solid electrolytic capacitor having a high withstand voltage can be obtained in this embodiment.

In the above example, an aluminum foil was used as a metal plate capable of forming a dielectric oxide film, an aluminum oxide film was formed as a dielectric oxide film on the surface of the aluminum foil, and an insulating strip layer 12 was formed on the peripheral portion thereof. However, it goes without saying that the insulating band layer 12 may be formed on the peripheral edge of the aluminum foil 11 before the aluminum oxide film is formed, and the aluminum oxide may be formed on the portion surrounded by the insulating band layer 12. . In short, instead of using a metal plate on which a dielectric oxide film is formed in advance, an insulating band layer 12 is formed on the peripheral portion of a metal plate on which a dielectric oxide film is not formed, and a portion surrounded by the insulating band layer 12 is formed. A dielectric oxide film may be formed on. Further, the dissimilar metal 11a is an aluminum foil 11
The aluminum oxide film may be formed on the entire surface of the above and then joined by welding.

Further, the metal capable of forming the dielectric oxide film is not limited to aluminum, and for example, tantalum,
Of course, titanium or the like may be used.

FIG. 6 is a view for explaining the method of manufacturing the capacitor element plate 10 described above. The aluminum foil 11 is a chemical conversion foil having an aluminum oxide layer formed on one surface, and an insulating resin agent is printed on the grid to form a resin foil. It is applied by means to form an insulating strip layer 12 having a predetermined width. A polypyrrole layer 13, a graphite layer 14, and a silver paste layer 15 are sequentially formed on the portion of the aluminum foil 11 on which the lattice-shaped insulating strip layer 12 is surrounded by the insulating strip layer 12 by electrolytic oxidation polymerization. In addition,
Although not shown, the dissimilar metal plate 11a is an aluminum foil 11
1 may be preliminarily joined to one side thereof, or may be joined to the individual capacitor element plates 10 as described later.

The method for forming the polypyrrole layer 13, the graphite layer 14 and the silver paste layer 15 is described in detail in Japanese Patent Application No. 62-227647 filed by the applicant of the present invention, and is the subject matter of the present invention. Since it is not directly related, its details are omitted.

As described above, the polypyrrole layer 13 and the graphite layer 14
And aluminum foil 11 on which the silver paste layer 15 is formed
Are cut at the central portion of the insulating strip layer 12 as shown by lines AA and BB in FIG. 6 to form individual capacitor element plates 10.

FIG. 3 is a sectional view of a capacitor element of another solid electrolytic capacitor according to the present invention, and FIGS. 4 and 5 are views for explaining a manufacturing process of a capacitor element plate.

In this embodiment, an aluminum foil whose surface is roughened by etching is used as a metal plate capable of forming a dielectric oxide film serving as a capacitor substrate as in the above embodiments. Aluminum oxide (Al ₂ O ₂ ) on the surface of the aluminum foil
Around the entire circumference of the predetermined position of the chemical conversion foil 21 on which the film is formed, a fourth
As shown in the figure, an insulating resin agent is applied to form an insulating strip layer 22, and a pyrrole polymer as a polymer layer of a heterocyclic compound serving as an electrolyte is formed on the entire surface of the chemical conversion foil 21 divided by the insulating strip layer 22. A layer (polypyrrole layer 23), a graphite layer 24 and a silver paste layer 25 as conductor layers for extracting electrodes are sequentially formed.

Next, as shown in FIG. 5, an insulating resin agent is applied to the entire surface except one surface of the silver paste layer 25 to form an insulating layer 26. On the other hand, on the surface of the other formed foil 21 divided by the insulator layer 22, for example, a dissimilar metal plate 30 which can be soldered is attached to manufacture the capacitor element plate 20.

In the capacitor element plate 20, the silver paste layer 25 on which the insulating layer 26 is not formed and the insulating layer 26 are bonded to each other, and the other portion divided by the insulating strip layer 22 and the silver paste layer 25 are made of a conductive material such as silver paste. A plurality of sheets are laminated by connecting using the body 29. The capacitor element of the solid electrolytic capacitor of the present invention is completed by attaching the electrode terminals 27 and 28 to the dissimilar metal plate 30 and the silver paste layer 25 of the laminated body, respectively.

The solid electrolytic capacitor of the present invention is obtained by applying an exterior to the capacitor element.

In the above examples, a metal foil capable of forming a dielectric oxide film was an aluminum foil whose surface was roughened by etching, and a chemical conversion foil 11 having an aluminum oxide layer formed as a dielectric oxide film on the surface of the aluminum foil was used. However, an insulating strip layer 22 is formed on the entire peripheral surface of a predetermined position of an etched aluminum foil on which an aluminum oxide layer is not formed, and aluminum oxide is formed on one portion divided by the insulating strip layer 22. It goes without saying that the structure may be formed. In short, instead of using a metal plate on which a dielectric oxide film is formed in advance, an insulating band layer 22 is formed on the entire circumferential surface at a predetermined position of the metal plate on which the dielectric oxide film is not formed, and the insulating band layer 22 is used for division. Then, a dielectric oxide film may be formed on one portion.

Further, the metal capable of forming the dielectric oxide film is not limited to aluminum as in the above embodiment,
For example, tantalum, titanium or the like may be used.

By configuring the solid electrolytic capacitor element as described above, the withstand voltage of the solid electrolytic capacitor is double the number of stacked layers of the withstand voltage of the individual capacitor element plates 20 (four times in the embodiment). Moreover, in this embodiment, since the polypyrrole layer 23 is formed on both surfaces of the chemical conversion foil 21, the capacity of the capacitor is increased and the size can be reduced.

In each of the above examples, a pyrrole polymer layer was used as the polymer layer of the heterocyclic compound serving as the electrolyte, but the heterocyclic compound is not limited to pyrrole, and may be, for example, furan or thieophene. Alternatively, polymer layers of these heterocyclic compounds may be used.

[Effect of device]

As described above, according to the present invention, the following excellent effects can be obtained.

Since a plurality of capacitor element plates are electrically connected in series, and the breakdown voltage thereof is twice the breakdown voltage of each capacitor element plate in the number of laminated layers, a small solid electrolytic capacitor having a high breakdown voltage is obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a capacitor element portion of a solid electrolytic capacitor according to the present invention. FIG. 1 (a) is a partially cut perspective view, FIG. 1 (b) is a partial sectional view of a capacitor element plate, Two
FIG. 3 is a perspective view of a capacitor element of a solid electrolytic capacitor according to the present invention, FIG. 3 is a sectional view of a capacitor element of another solid electrolytic capacitor according to the present invention, and FIGS. FIG. 6 is a diagram for explaining the steps, and FIG. 6 is a diagram for explaining the method for manufacturing the capacitor element plate. In the figure, 10 ... Capacitor element plate, 11 ... Chemical foil, 1
2 ... Insulation strip layer, 13 ... Polypyrrole layer, 14 ... Graphite layer, 15 ... Silver paste layer, 16 ... Laminated body, 17, 18 ... Electrode terminals, 20 ... Capacitor element plate, 21 ... Formed foil, 22 ... Insulating strip layer, 23 ... Polypyrrole layer, 24 ... Graphite layer, 25 ... Silver paste layer, 26 ... Insulating layer, 27, 28 ... Electrode terminals.

Claims (4)

[Scope of utility model registration request] 1. A dielectric oxide film layer is formed by attaching a different kind of metal plate different from the metal plate to one surface of a metal plate on which a dielectric oxide film can be formed and forming a dielectric oxide film layer on the other surface. An insulating strip layer having a predetermined width is formed on the peripheral edge of the surface on which is formed, and a polymer layer of a heterocyclic compound and a conductive layer are sequentially formed in the portion surrounded by the insulating strip layer to form a capacitor element plate. , A plurality of the capacitor element plates are laminated by joining the dissimilar metal plate surface and a conductor layer surface surrounded by an insulating strip layer, and electrode terminals are attached to the conductor layer and the dissimilar metal plate of the laminate. A solid electrolytic capacitor comprising a capacitor element comprising 2. The dielectric oxide film layer formed on the surface of the metal plate is formed on the surface of the metal plate surrounded by an insulating strip layer. Solid electrolytic capacitor. 3. A dielectric oxide film layer is formed on the surface of a metal plate on which a dielectric oxide film can be formed, and an insulating band layer is formed on the surface at a predetermined position to divide the surface of the metal plate into two parts. A polymer layer of a heterocyclic compound and a conductor layer are sequentially formed on one of the divided sections, and an insulating layer is further formed on the other surface of the conductor layer except one surface thereof, and the other is divided by the insulating band layer. A different type of metal plate different from the metal plate is adhered to the surface of the metal plate to form a capacitor element plate, and a plurality of the capacitor element plates are joined to each other to form a conductive layer and an insulating layer surface. And a surface of the dissimilar metal plate and the surface of the conductor layer are joined together to laminate a plurality of sheets, and a capacitor element is formed by attaching electrode terminals to the dissimilar metal plate and the conductor layer of the laminated body. Solid electrolytic capacitor. 4. The dielectric oxide film layer formed on the surface of the metal plate is formed on the surface of the metal plate in one part divided by an insulating strip layer. The solid electrolytic capacitor described.