JPS609655B2 - Manufacturing method of electrolytic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an electrolytic capacitor using a resin case.

FIGS. 1 and 2 show cross-sectional views of a small electrolytic capacitor using a general aluminum case.

In the figure, 1 is a lead terminal drawn out from the electrode foil, 2 is a capacitor element formed by winding the anode and cathode electrode foils with electrolytic paper interposed therebetween, and 3 is a gate part of a cylindrical case 4 made of aluminum. It is an elastic sealing body such as rubber that is inserted and sealed. In the structure described above, the seal ○
Since the cord terminal 1 is passed through the center of the body 3 and the case 4 is tightened and sealed together with the sealing body 3, there is a limit to the thickness of the sealing body 3, and it cannot be made into a thin shape.

There are many ideas for electrolytic capacitors using plastic cases, such as embedding the lead terminals in a resin sealing plate in advance and molding them at the same time, but there are dimensional limitations, and their external dimensions are inevitably limited. Small electrolytic capacitors were not covered.

The main reason for this is the airtightness of the sealing part, which has the drawback that it is difficult to maintain airtightness at the external lead terminal part of the small electrolytic capacitor. The present invention eliminates the above-mentioned drawbacks and provides a method for manufacturing an electrolytic capacitor that is compact, can be reliably kept airtight, and can be manufactured at low cost.

The present invention will be described below with reference to the embodiments shown in FIGS. 3 and 4.

1 is a lead terminal drawn out from the electrolytic foil of the anode and cathode, 2 is a capacitor element wound around the electrode foil through electrolytic paper, 5 is a cylindrical resin case, and 6 is a resin lid; An elastic body 7 made of rubber or the like with a convex annular band 7a provided at the bottom is embedded by resin molding, and the sealing body consists of a resin lid 6 and an elastic body 7 and is integrally formed.

Further, an insertion hole in the shape of a lead terminal 1 is provided in the center of the elastic body 7, and the diameter of the hole is designed to be 4 mm smaller than the outer diameter of the lead terminal 1. The lead terminal drawn out from the capacitor element 2 is inserted into the insertion hole provided in the elastic body 7 of the sealing body, and the resin case and the resin cover are bonded to seal the capacitor element, thereby completing the electrolytic capacitor. Reference numeral 6a denotes a protrusion provided on the resin lid 6 in order to fix the capacitor element 2 and maintain the breathing action of the capacitor.

The upper part of the entrance of the resin case 5 and the resin lid 6 may be adhered by ultrasonic melting, thermocompression bonding, etc., or may be adhered by using a bonding agent. Since the electrolytic capacitor manufactured by the method of the present invention is constructed as described above, when the resin lid 6 is molded, an elastic body 7 made of rubber or the like provided with a convex annular band 7a is buried in the center. Since the resin lid 6 and the elastic body 7 are integrally formed, airtightness between the resin lid 6 and the elastic body 7 is ensured. The movement of the elastic body 7 can be mechanically prevented by the convex annular band 7a. Further, the lead terminal 1 is connected to the elastic body 7.
Since the outer diameter of the elastic body 7 can be designed to be small and thin, the elastic body 7 can be designed to have a small outer diameter and a thin wall. There is no need to tighten, assembly is easy, the outer diameter and thickness of the sealing part can be reduced, and airtightness can be ensured. For this reason, in the type 4 electrolytic capacitor with lead terminals drawn out in opposite directions as shown in Fig. 4, the outer diameter of the case is 5.
In addition, since the resin case 6 is used, there is no need to cover with an insulating sleeve, and the product can be manufactured at low cost. Figure 6 shows an electrolytic capacitor manufactured by the conventional manufacturing method and an electrolytic capacitor manufactured by the manufacturing method of the present invention housed in an aluminum case with the same rating, 10 μF, 50 W.
In the 85oo continuous high temperature load life characteristic diagram comparing V, A shows the capacitance one hour characteristic diagram, the opening shows the loss (tan6) one hour characteristic diagram, and C shows the leakage current one hour characteristic diagram. There was almost no difference in airtightness and life characteristics compared to the one using the same method, and the cost was reduced by about 30%.

As described above, according to the manufacturing method of the present invention, it is possible to provide an electrolytic capacitor that is small, has high airtightness, and can be mass-produced at low cost, and is of great industrial and practical value.

[Brief explanation of drawings]

1 and 2 are cross-sectional views of an electrolytic capacitor housed in an aluminum case manufactured by a conventional manufacturing method, FIGS. 3 and 4 are cross-sectional views of an embodiment of an electrolytic capacitor manufactured by the manufacturing method of the present invention, and FIG. 5 is a high-temperature load life characteristic diagram comparing an electrolytic capacitor manufactured by the conventional manufacturing method and an electrolytic capacitor manufactured by the manufacturing method of the present invention housed in an aluminum case; A is a capacitance one-hour characteristic diagram;
tan6) One-hour characteristic diagram, C shows a one-hour characteristic diagram of leakage current. 1: Lead terminal, 2: Capacitor element, 5: Resin case, 6: Resin lid, 7: Elastic body, 7a: Convex annular band. 1st koji 2nd figure 3rd figure 4th younger brother S figure (A) (〇) (C)

Claims (1)

[Claims] 1. A capacitor element, a resin case housing the capacitor element, and a convex annular band provided on the outer periphery of the elastic body,
It is equipped with a sealing body that is embedded during molding of the resin lid and integrally forms the elastic body and the resin lid, and the lead terminal drawn out from the capacitor element is inserted into the hole provided in the center of the elastic body, and the resin case is closed. A method for manufacturing an electrolytic capacitor, which comprises sealing a capacitor element by bonding a resin lid and a resin lid.