JPS6412087B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to aluminum electrolytic capacitors, and more particularly to chip-type aluminum electrolytic capacitors.

Structure of conventional example and its problems In this type of conventional chip-type aluminum electrolytic capacitor, as shown in Fig. 1A, capacitor element 1
is housed in a bottomed cylindrical metal case 3 having a lead wire 2 and sealed with a sealing material 4, and this is used as an internal unit of a chip-type capacitor, and the lead wire 2 and the sealing material 4 are penetrated. The other lead wires 5 were welded to metal terminals 6 prepared in advance, and then the internal unit and the welded parts were molded with exterior resin 7 to complete the process. In addition, as shown in FIG. 1B, the capacitor element 1 is housed in a bottomed cylindrical metal case 8 without lead wires, sealed with a sealing material 4, and is assembled into an internal unit of a chip-type aluminum electrolytic capacitor. do. Both lead wires pass through the sealant 4, one is welded to a metal terminal 6 near the outside of the sealant, and the other wire is connected to the top surface of the sealant 4, the side surface, and the bottomed cylindrical metal case 8. It was bent along the side and bottom surfaces and stretched from the sealing material 4 to the other end and welded to the metal terminal 6, and then the internal unit and the welded portion were molded with an exterior resin 7 to complete the product.

In this case, since resin molding is performed, the molding time requires 30 seconds to 5 minutes, and approximately 10 hours of after-cure is required after molding, so there is a problem that the process cannot be continuous, which causes cost increases. It was also getting old. Furthermore, it is necessary to weld the metal terminals before molding and to bend the metal terminals after molding, complicating the process, resulting in an increase in process defects and a decrease in workability.

Purpose of the Invention The present invention eliminates the drawbacks of the conventional method, makes the lead wire into a flat shape by press processing, bends it along a heat-resistant insulating plate, and enables reflow soldering in place of the electrode plate of the terminal plate, simplifying the process, The purpose of this is to improve productivity, reduce costs, and reduce size.

Structure of the Invention The present invention stores a capacitor element together with an electrolyte in a metal case with a bottom, and uses heat-resistant Teflon resin.
The opening is sealed with a sealing body made of a sheet with a thickness of 0.4 mm or more and a rubber sealing material, and circular positive and cathode lead wires are configured to protrude in one direction from the sealing body,
A heat-resistant insulating plate having the same shape and size as the bottomed metal case is placed on the outer surface of the sealing body, and the heat-resistant insulating plate is provided with holes through which the circular positive and cathode lead wires pass through, and the capacitor element is connected to the capacitor element. The positive and negative electrode lead wires are passed through upwardly and bent on the upper surface of the heat-resistant insulating plate to form a flat external electrode.

DESCRIPTION OF EMBODIMENTS FIG. 2 shows a sectional view of a metal case with a cylindrical bottom according to an embodiment of the present invention. In the figure, parts that are the same as those in FIG. 1 are given the same reference numerals.

In the figure, 1 is a capacitor element formed by winding electrode foil and electrolytic paper, which is housed together with an electrolyte in a bottomed cylindrical metal case 8, and sealed with two layers of Teflon resin sheet with a thickness of 0.4 mm or more and rubber sealing material. A capacitor unit is constructed by sealing the opening with a heat-resistant sealing body 10 made of a heat-resistant material and having circular anode and cathode lead wires 2 and 5 protruding from the sealing body 10 in one direction.

After that, the lead wires 2,
Insert the capacitor unit and the heat-resistant insulating plate 9.
and assemble. Next, the circular lead wires 2 and 5 drawn out from the heat-resistant insulating plate 9 are pressed into a flat shape from the vicinity of the heat-resistant insulating plate 9.
These are referred to as external electrode portions 2-1 and 5-1. Cut and remove the excess lead wire that remains after bending to create a chip-type aluminum electrolytic capacitor.

The effects of Teflon resin sheets are to prevent softening and deterioration of the sealant due to high heat during the reflow soldering process, to improve life performance by suppressing the diffusion of the electrolyte impregnated inside the capacitor, and to prevent deterioration of the sealant due to board cleaning agents. There is prevention. It is necessary to determine the thickness of this Teflon resin sheet in search of the best economy while maintaining many of the above-mentioned merits.

(1) Formability...Multiple pieces of rubber are molded on the Teflon resin sheet surface, the Teflon resin sheet and the rubber are joined, and after the molding is completed, they are punched into individual pieces.In this case, the Teflon sheet is 0.3 mm or less. If there is, the Teflon sheet will stretch and be difficult to cut. If it is 0.4mm or more, hardness and stiffness can be obtained,
This eliminates elongation and allows efficient punching with a die.

(2) Diffusion of electrolyte... Diffusion of electrolyte greatly affects the thickness of the Teflon resin sheet, but experimentally the thinnest thickness at which the diffusion suppression effect can be obtained is 0.4.
mm.

The present invention has the above configuration, that is, the disk shape is arranged on the upper outer surface of the sealing plate, and the heat-resistant electrolyte is
Because it uses a heat-resistant sealing material, it has a structure that can withstand reflow soldering, and since the entire internal unit as a chip-type aluminum electrolytic capacitor is not molded with resin, it is small in size and easy to process. is extremely simplified.

Effects of the Invention With the above configuration, the present invention eliminates the need to configure external electrodes on the heat-resistant insulating plate, eliminates the need for resin molding, and at the same time reduces the size and simplifies the process. This has great effects such as improving productivity and reducing costs at the same time.

[Brief explanation of drawings]

1A and 1B are cross-sectional views of a conventional chip-type aluminum electrolytic capacitor, and FIG. 2 is a cross-sectional perspective view of a cylindrical bottomed metal case according to an embodiment of the present invention. 1: Capacitor element, 2, 5: Lead wire, 5-
1, 5-2: External electrode part, 8: Bottomed cylindrical metal case, 9: Heat-resistant insulating plate, 9-1, 9-2: Lead wire through hole, 10: Heat-resistant two-layer sealing body.

Claims (1)

[Claims] 1 The capacitor element is stored in a bottomed metal case together with an electrolyte, the opening is sealed with a sealing body made of a heat-resistant Teflon resin sheet with a thickness of 0.4 mm or more and a rubber sealing material, and the opening is sealed from the sealing body. A heat-resistant insulating plate having the same shape and size as the bottomed metal case is placed on the outer surface of the sealing body, and the heat-resistant insulating plate has circular positive and cathode lead wires protruding in the direction. Holes are provided to penetrate the positive and cathode lead wires of the capacitor element, and the positive and cathode lead wires of the capacitor element are penetrated upward, and the positive and cathode lead wires are bent into a flat shape on the upper surface of the heat-resistant insulating plate to provide external electrodes. A chip-type aluminum electrolytic capacitor characterized by: