JPH0158857B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a chip-type electrolytic capacitor that simplifies the manufacturing process.

Electrolytic capacitors, like other electronic components, are becoming more and more chipped as electronic devices become lighter and smaller and wiring work becomes automated. In general, electrolytic capacitors are formed by winding electrode foils on the anode and cathode sides with separator paper interposed between them and impregnating the inside with electrolyte. Forming a resin coating and turning a wound electrolytic capacitor into a chip requires considerably advanced technology.

Conventionally, for this type of electrolytic capacitor, a tubular type with a solid anode body instead of an electrode foil on the anode side has been proposed, but even in such electrolytic capacitors, a separator paper is placed around the outer periphery of the anode body. At the same time, after winding the cathode foil, a process such as impregnating it with an electrolyte is required.

Therefore, the present invention has developed a chip-type electrolytic capacitor that simplifies the process of winding the separator paper, impregnating it with electrolyte, etc. by coating the surface of the anode body with separator paper powder together with a semi-solid electrolyte. The purpose is to provide a manufacturing method.

That is, in the method of manufacturing a chip electrolytic capacitor of the present invention, a block-shaped anode body is formed, a semi-solid electrolyte and separator paper powder are applied to the outer surface of the anode body, and the outer surface of the anode body is coated with separator paper powder. A plate-shaped cathode body sandwiching the electrolyte and the separator paper powder is bent and brought into contact with the anode body, covering the outer surface of the cathode body and the exposed portion of the anode body, and 1st on the anode body side
and a second terminal on the cathode body side are selectively exposed to form a synthetic resin coating, and the first and second terminals exposed from the synthetic resin coating are covered with a surface portion of the synthetic resin coating. It is constructed so that it can be bent and placed.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

1 to 6 show an embodiment of the method for manufacturing a chip-type electrolytic capacitor of the present invention, and FIGS. 1 to 5 show an electrode body or an electrolytic capacitor element in the manufacturing process, and FIG. 6 shows a chip-type electrolytic capacitor element. Electrolytic capacitor, FIG. 7 shows a cross section taken along the - line in FIG. 6.

As shown in FIG. 1, the anode body 2 is formed from a valve metal such as aluminum into a block shape such as a rectangular parallelepiped or a cube. The anode body 2 is made porous by etching to enlarge its surface, and the surface thereof is anodized to form a dielectric oxide film 4. On one end surface of this anode body 2, a terminal 6 formed in a plate shape with the same type of valve metal as the anode body 2 and having the same width as the end face width is attached so that a part of the terminal 6 protrudes. Connect electrically with fixing means. The dielectric oxide film 4 is formed on the portion of the terminal 6 that is fixed to the anode body 2 and the vicinity thereof by anodizing similarly to the anode body 2.

The formation of the dielectric oxide film 4 by anodizing the anode body 2 and the terminals 6 may be performed after the anode body 2 and the terminals 6 are fixed. In this case, in order to facilitate external connection, the portion of the terminal 6 protruding from the anode body 2 shall not be anodized, and a solderable metal may be welded or a solderable metal layer may be applied to the surface thereof. It is also possible to use a cladding material formed with .

As shown in FIG. 2, this anode body 2 is coated with separator paper powder 8 using a semi-solid electrolyte on the surface forming the capacitor. FIG. 3 shows a part of the anode body 2 which has been subjected to such treatment, and the surface of the dielectric oxide film 4 of the anode body 2 is coated with separator paper powder 8 using an electrolyte 10. That is, the separator paper powder 8 contains the electrolyte 1
It is applied to the surface of the dielectric oxide film 4 with the adhesive force of 0. In this embodiment, both sides and the bottom of the anode body 2 shown in the figure are used as capacitor surfaces, and the electrolyte 10 and separator paper powder 8 are coated on these surfaces. In this case, the entire surface of the anode body 2 and a part of the terminal 6 may be subjected to the above treatment.
The electrolyte 10 used is a highly viscous electrolyte prepared by dissolving ammonium adipate in ethylene glycol and dissolving a gelling agent, polyvinyl alcohol, etc. into a semi-solid state.

A plate-shaped cathode body 12 that matches the surface of the anode body 2 coated with the separator paper powder 8 is brought into contact with the surface of the anode body 2 coated with the separator paper powder 8 in this manner. In this embodiment, the cathode body 12 is made of the same kind of metal as the anode body 2, such as aluminum, processed into a plate shape such as a foil, and one side of the anode body 2 has a terminal on the cathode side in advance. 14 is electrically connected by a fixing means such as welding with a part thereof protruding. The cathode body 12 formed in this manner is bent along both side surfaces and the bottom surface of the anode body 2 and placed in opposition to form an electrolytic capacitor element 18, as shown by the arrow 16. Further, the terminal 14 is made of a part of valve metal such as aluminum treated to be solderable in the same manner as the terminal 6, or is formed of a clad material having a solderable metal formed on the surface layer.

On the outer surface of the cathode body 12 and the exposed portion of the anode body 2, which are the outer surfaces of the electrolytic capacitor element 18,
As shown in FIG. 5, a synthetic resin coating 20 is formed to serve as an exterior body for the electrolytic capacitor element 18. In this case, a portion of the terminals 6, 14 shall penetrate the synthetic resin coating 20 and protrude.

As shown in FIG. 6, the terminals 6 and 14 are bent in a right angle direction along the surface of the synthetic resin coating 20 to form a terminal surface that can be face bonded.

As shown in FIG. 7, the chip-type electrolytic capacitor manufactured through such a process has an electrolyte 10, separator paper powder 8, cathode body 12, and synthetic resin coating 20 laminated in sequence on the surface of the anode body 2. ing. In particular, since the separator paper powder 8 is used and the coating method utilizes the adhesive force of the semi-solid electrolyte 10, the electrolytic capacitor element 18 can be formed extremely quickly and easily.

Furthermore, regarding the formation of the exterior body with the synthetic resin coating 20, since the electrolyte is in a semi-solid state, the process of adhering the molten synthetic resin to the electrolytic capacitor element 18 can be easily performed, and the yield can be improved. can be achieved. Moreover, synthetic resin coating 2
0, sufficient airtightness can be obtained, and the thickness of the synthetic resin coating 20 can be formed relatively thin, which not only improves manufacturing efficiency but also reduces costs by saving materials and the like.

Next, FIGS. 8 to 10 show other embodiments of the method for manufacturing a chip-type electrolytic capacitor according to the present invention. In the embodiment described above, the end surface of the anode body 2 is not used as a capacitor surface, but as shown in FIG. Also, the electrode portion 22 that comes into contact with that surface is formed. In this way, the capacity can be increased with the same volume.

Furthermore, if the terminal 14 is fixed to the electrode portion 22 as shown in FIG. 9, the terminal 14 can be bent to face the anode side terminal 6, as shown in FIG. .

Note that the terminals 6 and 14 may be formed of a solderable metal such as copper or iron in addition to the valve metal. In this case, an electrolyte layer is not formed on the surface of the terminal 6 on the anode side, but a synthetic resin coating is formed on the surface of the terminal 6 on the anode side to ensure electrical insulation from the cathode side.

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

(a) Since the separator paper powder is applied between the anode body and the cathode body using a semi-solid electrolyte, the conventional steps of winding the separator paper and impregnating it with electrolyte solution can be performed at the same time. In addition to simplifying the process, the exterior with synthetic resin coating can be easily applied without inconveniences such as electrolyte leakage, and sufficient airtightness can be ensured, making it possible to create highly reliable chip-type electrolytic capacitors. It can be manufactured efficiently.

(b) In addition, if separator paper powder is used instead of separator paper, the separator paper powder can be reliably attached to the surface of the anode body, which has an arbitrary surface shape such as unevenness. Compared to other anode bodies, the degree of freedom in its shape can be increased.

[Brief explanation of drawings]

1 to 6 are diagrams showing an embodiment of the method for manufacturing a chip-type electrolytic capacitor according to the present invention, and FIG.
Line sectional views and FIGS. 8 to 10 are diagrams showing other embodiments of the method for manufacturing a chip-type electrolytic capacitor according to the present invention. 2... Anode body, 6, 14... Terminal, 8... Separator paper powder, 10... Electrolyte, 12... Cathode body, 20... Synthetic resin coating.

Claims (1)

[Claims] 1. Form an anode body in the form of a block, apply separator paper powder together with a semi-solid electrolyte to the outer surface of the anode body, and apply the following steps to the outer surface of the anode body:
A plate-shaped cathode body sandwiching the electrolyte and the separator paper powder is bent correspondingly to the anode body and brought into contact with the anode body, covering the outer surface of the cathode body and the exposed part of the anode body, and also covering the outer surface of the cathode body and the exposed part of the anode body, and 1 terminal and a second terminal on the cathode body side are selectively exposed to form a synthetic resin coating, and the first and second terminals exposed from the synthetic resin coating are covered with a surface of the synthetic resin coating. A method for manufacturing a chip-type electrolytic capacitor, which is characterized in that the capacitor is bent at a portion.