JPH0312766B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a chip-type electrolytic capacitor, and in particular to simplifying the step of impregnating an electrolyte.

Generally, in chip-type electrolytic capacitors, a case made of a thermoplastic synthetic resin, a thermosetting synthetic resin, or a lamination of both is used as an exterior member that covers an electrolytic capacitor element.

Conventionally, in such a chip-type electrolytic capacitor, an injection hole for injecting an electrolyte is formed in the case, and after the electrolyte is injected into the case through the injection hole, the injection hole is closed.

When going through such a process, the manufacturing process becomes complicated, and it is difficult to maintain the airtightness of the case. If the sealing is insufficient, the electrolyte may evaporate or moisture may enter, causing the electrolytic capacitor's electricity to deteriorate. This will damage the physical characteristics of the product and shorten its lifespan.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for manufacturing a chip-type electrolytic capacitor, which increases manufacturing efficiency by simplifying the electrolyte impregnation process and also manufactures a highly reliable chip-type electrolytic capacitor.

That is, the method for manufacturing a chip-type electrolytic capacitor of the present invention includes a pair of parallel band-shaped outer lead parts 2A and 2B, and a vertical lead part 4 that stands opposite to the edge of this outer lead part. , element leads (tabs 18, 20) provided on this vertical lead part.
A step of forming a lead frame 2 consisting of a connecting portion 8 to be connected to the lead frame, passing the vertical lead portion on the lead frame, exposing the connecting portion on the upper surface, and forming a recess between the connecting portions. 12, a step of forming the first case piece 10A with a synthetic resin, a step of injecting the electrolytic solution 14 into the recess of the first case piece, and a step of forming the electrode foils on the anode side and the cathode side with a separator. The electrolytic capacitor element 16 with the element leads interposed therebetween and connected to each electrode foil drawn out to the end face is housed in the recess of the first case piece, and the element leads are connected to the connection parts. and the first step.
The second case piece 10B is joined to the case piece 10B to seal the electrolytic solution and the electrolytic capacitor element in the recess.

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

1 and 2 show an embodiment of the method for manufacturing a chip electrolytic capacitor according to the present invention.

In FIG. 1, a lead frame 2 is formed by molding a highly conductive metal plate, and the lead frame 2 has outer lead portions 2A, 2B formed in a band shape at regular intervals. In each of the outer lead parts 2A, 2B, vertical lead parts 4 are formed at regular intervals at opposite positions on the edges thereof, and sprocket holes 6 are formed at regular intervals within the spaces, and vertical lead parts 4 are formed at regular intervals within the intervals. At the top of the lead part 4, a connecting part 8 is formed by bending the end at a right angle to the opposite side.
is formed. This lead frame 2 is placed inside a synthetic resin mold.

Next, on the upper surface of the lead frame 2, a first case piece 10A is formed from thermoplastic synthetic resin on the center line of the vertical lead part 4. In this case, in the first case piece 10A, each vertical lead part 4 formed on the lead frame 2 is passed through to expose the connecting part 8 on the upper surface, and a recessed part 12 is formed between each connecting part 8. Ru. That is, the first case piece 10A is formed at the same height as the vertical lead portions 4 of the outer lead portions 2A, 2B.

Next, the recess 12 of the first case piece 10A is filled with the electrolytic solution 14, and the electrolytic capacitor element 16 is inserted, and the tabs 18 and 20 as the element leads pulled out from the end face are attached by ultrasonic welding or the like. It is connected to each connection part 8 by a connection means. The electrolytic capacitor element 16 is impregnated with the electrolytic solution 14 filled in the recess 12 .

In this case, the electrolytic capacitor element 16 is wound with an anode foil and a cathode foil together with a separator interposed therebetween, and each electrode foil has a connecting tab 18,
20 shall be connected and placed.

Next, on the top surface of the first case piece 10A, a second
As shown in the figure, the second case piece 10B that covers the electrolytic capacitor element 16 is integrally joined by ultrasonic welding or the like. The second case piece 10B is made of thermoplastic synthetic resin in the same way as the first case piece 10A, or is integrally molded in advance from a metal plate with good thermal conductivity such as aluminum.

Next, for the chip electrolytic capacitor formed on the lead frame 2, the outer lead parts 2A and 2B are cut off along the wall surface of the first case piece 10A, and
A chip type electrolytic capacitor as shown in FIG. 3 can be manufactured.

According to this manufacturing method, unlike conventional methods, an injection hole for impregnating the electrolyte is not formed in the case member, so the impregnation is easy, and there is no need for steps such as blocking the injection hole. This simplifies the electrolyte impregnation process and improves the airtightness of the case. Furthermore, by simplifying the impregnation process, it is expected that the yield will be improved and the manufacturing cost will be reduced.

Therefore, an electrolytic capacitor manufactured by such a manufacturing method has high reliability and can maintain stable electrical characteristics over a long period of time.

In this embodiment, the lead frame 2 is separated in the final step, but the same effect can be expected even if the lead frame 2 is separated before the case piece 10B is joined or before the electrolyte is injected into the case piece 10B.

Further, the present invention can be practiced not only when forming an electrolytic capacitor not only on a continuous lead member but also on individually separated lead members, and similar effects can be expected.

As explained above, according to the present invention, it is possible to simplify the electrolyte impregnation process, thereby improving manufacturing efficiency and reducing manufacturing costs, and further improving the airtightness of the outer case. This makes it possible to manufacture highly reliable electrolytic capacitors with stable electrical characteristics.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing the method for manufacturing a chip-type electrolytic capacitor of the present invention, FIG. 2 is a vertical cross-sectional view showing the final manufacturing process, and FIG. FIG. 2... Lead frame, 2A, 2B... Outer lead part, 4... Vertical lead part, 8... Connection part, 10A... First case piece, 10B... Second case piece, 12...
Recessed portion, 14... Electrolyte, 16... Electrolytic capacitor element, 18, 20... Tab (element lead).

Claims (1)

[Claims] 1. A pair of parallel belt-shaped outer lead portions, a vertical lead portion that stands opposite to the edge of the outer lead portion, and an element lead provided on the vertical lead portion. a step of forming a lead frame comprising a connecting portion to be connected to the lead frame; passing the vertical lead portion on the lead frame, exposing the connecting portion on the upper surface, and providing a recess between the connecting portions; forming a first case piece made of synthetic resin; injecting an electrolytic solution into the recess of the first case piece; and interposing electrode foils on the anode side and the cathode side with a separator between each electrode. accommodating an electrolytic capacitor element with the element lead connected to the foil pulled out to the end face in the recess of the first case piece, and connecting the element lead to the connection part; A method for manufacturing a chip-type electrolytic capacitor, comprising the steps of: joining a second case piece to the case piece to seal the electrolytic solution and the electrolytic capacitor element in the recess. 2 The outer lead portion is connected to the first and second
The chip-type electrolytic device according to claim 1, further comprising the step of separating the first case piece from the lead frame before or after joining, and forming an external connection terminal on the first case piece. Method of manufacturing capacitors.