JPH05283297A - Chip-shaped solid electrolytic capacitor - Google Patents

Abstract

PURPOSE:To easily work and assemble a capacitor and to enhance the reliability and the yield of the capacitor by a method wherein an anode plate into which a sheetlike or fiber-reinforced member has been compounded is used for the capacitor. CONSTITUTION:An anode plate for a capacitor is manufactured in the following manner: in order to increase the rigidity of the anode plate, a sheetlike reinforcement material 2 (a stainless thin sheet, a copper sheet or the like) is put into the inside by a clad rolling operation, an explosion bonding operation, a press working operation or the like or a fiberlike reinforcement material 8 (a carbon fiber, a steel cord or the like) is mixed when an anode material is cast; and it is rolled or explosion-bonded by sandwiching a fiber between two anode plates. The anode plate 1 which has been worked in this manner is cut to a chip shape; an etching treatment and a chemical formation treatment are executed; after that, a cathode layer 3 which is composed of a solid electrolyte and a cathode conductive layer is formed; an element is formed. An anode lead 4 and a cathode lead 5 are extracted from the element; this assembly is covered with an outer-package resin 7; both leads are bent. Thereby, the operating property of the capacitor is improved in its manufacturing operation and the electrostatic capacity of the capacitor can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip type solid electrolytic capacitor.

[0002]

2. Description of the Related Art Tantalum electrolytic capacitors have been widely put into practical use as chip type solid electrolytic capacitors.
Tantalum powder is sintered and lead wires are attached to form internal elements. Therefore, the structure of the chip capacitor is also suitable for that, for example, as shown in FIG. 9, the anode inner lead 13 and the outer lead 4 taken out from the element 12 made of a tantalum sintered body are connected, and the cathode is the outside. The cathode lead 5 is formed along the element 12 and connected through a silver paste. In the case of an aluminum solid electrolytic capacitor, a sintered solid electrolytic capacitor has almost the same structure as a tantalum electrolytic capacitor.
At present, almost no sintered capacitors have been put to practical use.

In the case of an aluminum solid electrolytic capacitor, a flat aluminum plate is subjected to an etching treatment to increase the electrode area, and then an anodized film layer is formed, a solid electrolyte layer and a cathode conductive layer are sequentially formed, and a flat element or a wound element is formed. A capacitor product is constructed by using the inner lead as an outer electrode as it is as a rotating element. In the case of the flat element, the electrode plate is directly joined to the external electrode (lead frame) on the anode side without interposing the internal lead, or the cathode conductive layer is directly joined to the external electrode (lead frame) on the cathode side. For example, as shown in FIG. 10, one flat plate-shaped anode plate 14 is formed with a cathode layer 3 formed of a solid electrolyte layer and a cathode conductive layer after forming an anodized film layer after etching treatment, and the cathode side is External anode lead 4 at the tip of anode plate 14
The external cathode lead 5 is bonded to the external cathode lead 5 through silver paste by forming a shape along the outer peripheral surface of the element on the cathode side.
Connected with.

[0004]

The anode plate of the aluminum solid electrolytic capacitor has a uniform flat plate structure and a thin thickness of about 100 μm. Since the flat plate structure is used as shown in FIG. 10, the rigidity is insufficient. However, there is a problem in workability in the capacitor manufacturing process. For example, in most cases, transfer molding is performed to obtain a chip-type structure, and a uniform flat plate structure is not sufficient to withstand the stress applied to the anode plate during resin injection, especially the injection pressure. In addition, the stress applied to the anode plate also increases with respect to the resin stress, plate deformation occurs, and the stress is localized at the joint with the lead portion, resulting in poor reliability as a capacitor. Further, there is a drawback that the assembly process for forming the device into chips is very complicated. Further, the flat anode plate has a problem that the electrostatic capacity is lower than that of the conventional aluminum electrolytic capacitor having a wound structure.

Therefore, the present invention solves the problem of workability in capacitor manufacturing due to insufficient rigidity of the above-mentioned flat anode plate, and also increases the effective area of the capacitor to increase the capacitance. It is an object of the present invention to provide a chip-type solid electrolytic capacitor to which an anode plate that can realize an increase is applied.

[0006]

In order to achieve the above object, the present invention is characterized in that a plate in which a plate-shaped or fibrous reinforcing member is compounded is used as a capacitor anode plate in an anode plate of a chip type solid electrolytic capacitor. And Further, the present invention is
The cross section in the thickness direction of the anode plate of the chip-type solid electrolytic capacitor is a corrugated plate shape, which is an anode plate in which the rigidity of the anode plate is increased and the effective area of the capacitor is expanded. By using the capacitor of the present invention, it is possible to solve the conventional problem in manufacturing due to the lack of rigidity of the plate due to the uniform flat plate shape of the anode plate. Furthermore, in order to increase the capacitance of the present invention,
The cross-sectional shape of the plate is changed to a corrugated plate to increase rigidity and the capacity per unit area of the chip is increased, and the problem of increasing the capacity of the chip type solid electrolytic capacitor is solved.

[0007]

In general, it is often used in the field of thin plate structural design to increase the rigidity as compared with a plate before compounding by compounding the plate with a reinforcing material. The present invention applies the findings there to a capacitor anode material. The anode plate of this capacitor has a plate-like reinforcing material 2 (for example, stainless thin plate or copper plate) inside or a fibrous reinforcement to increase the rigidity of the anode plate by clad rolling, explosion-bonding, pressing, etc. The material 8 (for example, carbon fiber or steel cord) is mixed during casting of the anode material, or the fibers are sandwiched between two anode plates and rolled or explosively bonded. After the anode plate 1 processed as described above is cut into a chip shape, subjected to etching treatment and chemical conversion treatment, a cathode layer 3 composed of a solid electrolyte and a cathode conductive layer is formed to produce a device. The anode lead and the cathode lead are taken from the element, the exterior resin 7 is covered by molding, and both leads are bent to complete the solid electrolytic capacitor.

The reinforcing method of the anode plate can be achieved by adjusting the amount and shape of the reinforcing material so as to increase the rigidity of the anode plate, and further performing corrugated plate processing. A rectangular wave, a U-shape, a V-shape or a combination thereof is selected as the wave shape in order to satisfy the required predetermined capacity of the anode plate. Selected multiple times. When processing a corrugated plate, the wave pitch is 0.5 to 5 mm and the wave height is 0.5 to 5 mm.
For example, if the plate thickness is 100 μm and the wave pitch and height are 1.
By setting the thickness to 0 mm and 1.0 mm, the capacity per unit area of the chip doubled. As a result, the yield of the capacitor can be improved by increasing the rigidity of the anode plate, and the capacity per unit area of the chip can be increased.

[0009]

Embodiments of the present invention will be described with reference to the drawings. Examples of typical sectional views in the thickness direction of the present invention are shown in FIGS.
Shown in. In FIG. 1, reference numeral 1 denotes an aluminum alloy plate having a total thickness of 110 μm and including a stainless plate as a plate-like reinforcing member 2. The plate is subjected to etching treatment and chemical conversion treatment, and then impregnated with a solid electrolyte to form colloidal carbon. layer,
The cathode conductive layer 3 made of a silver paste layer is sequentially formed.
Reference numeral 4 is an anode lead made of aluminum drawn out by welding with an aluminum plate of the device, 5 is a cathode lead, and 6 is a masking resin for insulating the anode from the solid electrolyte layer and the cathode conductive layer. Then, the exterior resin 7 is covered by molding, and the anode lead 4 and the cathode lead 5 are completed by bending along the side surfaces.

In FIG. 2, reference numeral 8 is an element having a total thickness of 105 μm and made of an alloy plate of aluminum and zirconium, which is a valve metal containing carbon fiber, as the fibrous reinforcing member 9, and the plate was subjected to the same treatment as described above. Is. The capacitor is completed by the same method as above. As described above, according to the structure of FIGS. 1 and 2 of the present invention, the rigidity of the element is increased, and the element structure becomes extremely stable.

FIG. 3 shows a capacitor using an anode plate 10 reinforced by a flat plate-shaped reinforcing member 2 obtained by processing the anode plate into a V-shape. FIG. 4 shows a capacitor using an anode plate 11 reinforced with a fibrous reinforcing member 9 obtained by processing the anode plate into a V-shape. FIG. 5 shows a capacitor using an anode plate 10 reinforced with a flat plate-shaped reinforcing member 2 obtained by processing the anode plate into a U-shape.
FIG. 6 shows a capacitor using an anode plate 11 reinforced by a fibrous reinforcing member 9 obtained by processing the anode plate into a U-shape. Figure 7
Is a capacitor using the anode plate 10 reinforced by the flat plate-shaped reinforcing member 2 obtained by processing the anode plate into a rectangular wave shape. FIG. 8 shows a capacitor using an anode plate 11 reinforced by a fibrous reinforcing member 9 obtained by processing the anode plate into a rectangular wave shape. FIG. 3 of the present invention
The structure shown in FIG. 8 increases the rigidity of the element and increases the capacitance due to the increase of the effective area of the capacitor, resulting in an extremely stable element structure.

[0012]

According to the present invention, when a capacitor is manufactured by using an anode plate which is a composite of plate-like or fibrous reinforcing members, the rigidity is increased and the capacitor can be easily processed and assembled. Stable against upper stress. As a result, the reliability and yield of the capacitor were improved. Needless to say, the corrugated plate of the anode plate increases the effective surface area and thus the capacitance. As a result, productivity is improved and miniaturization is achieved, and its industrial and practical value is great.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an embodiment of a chip type solid electrolytic capacitor of the present invention.

FIG. 2 is a cross-sectional view of another embodiment of the chip type solid electrolytic capacitor of the present invention.

FIG. 3 is a sectional view of another embodiment of the chip type solid electrolytic capacitor of the present invention.

FIG. 4 is a sectional view of another embodiment of the chip-type solid electrolytic capacitor of the present invention.

FIG. 5 is a sectional view of another embodiment of the chip type solid electrolytic capacitor of the present invention.

FIG. 6 is a sectional view of another embodiment of the chip type solid electrolytic capacitor of the present invention.

FIG. 7 is a sectional view of another embodiment of the chip type solid electrolytic capacitor of the present invention.

FIG. 8 is a sectional view of another embodiment of the chip type solid electrolytic capacitor of the present invention.

FIG. 9 is a cross-sectional view of a conventional chip type tantalum electrolytic capacitor.

FIG. 10 is a cross-sectional view of a chip type solid electrolytic capacitor using a conventional element.

[Explanation of symbols]

1 Anode plate reinforced by a plate-like reinforcing member 2 Plate-like reinforcing member 3 Cathode layer composed of a solid electrolyte and a cathode conductive layer 4 Anode lead (external lead) 5 Cathode lead (external lead) 6 Masking part 7 Mold exterior insulating resin 8 Anode plate reinforced with fibrous reinforcing member 9 Fibrous reinforcing member 10 Anode plate reinforced with corrugated plate reinforced with plate-shaped reinforcing member 11 Anode plate reinforced with corrugated plate reinforced with fibrous reinforcing member 12 Tantalum sintered body Capacitor element composed of 13 Internal lead 14 Flat plate-shaped anode plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuichi Taniguchi 20-1 Shintomi, Futtsu City, Chiba Shin Nippon Steel Co., Ltd.Technology Development Division Nichicon Co., Ltd., 3rd floor, Uehara Building, 4th, 191 Nakabori

Claims (2)

[Claims] 1. A chip-type solid electrolytic capacitor in which an anode plate made of a valve metal or an alloy thereof is subjected to an etching treatment and a chemical conversion treatment to form a dielectric film, and then a solid electrolyte layer and a cathode conductive layer are sequentially formed. A chip-type solid electrolytic capacitor, characterized in that a plate in which a plate-shaped or fibrous reinforcing member is combined is used as a capacitor anode plate. 2. The anode plate, which has a corrugated plate-shaped cross section in the thickness direction, and which has an increased effective area as a capacitor while increasing the rigidity of the anode plate. Chip type solid electrolytic capacitor.