JPS6163012A - Electrolytic condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrolytic capacitor with an improved sealing part.

Conventional electrolytic capacitors are shown in Figure 1 (A) or (+1).
As shown in FIG. 2, a lead wire 4 led out from a capacitor element 2 is inserted through an elastic body 3 such as rubber and housed in a case 1, and the opening of the case 1 is sealed.

That is, since the elastic body 3 such as rubber is used to seal the opening of the case 1, the elastic body hardens during a long-term life test in a high-temperature atmosphere, and the airtightness deteriorates, causing leakage of the electrolyte. There were drawbacks such as deterioration of characteristics. Furthermore, when cleaning with a solvent etc. after soldering to a printed circuit board, some capacitors have a resin such as epoxy applied to the sealing part and hardened to protect it, in order to prevent the cleaning liquid from penetrating into the inside of the capacitor. However, this method had the disadvantage of increasing the cost of parts, materials, and manufacturing man-hours, making the product expensive.

The present invention aims to eliminate the above-mentioned drawbacks and provide an electrolytic capacitor that can withstand high temperatures and is highly reliable.

The present invention will be described below with reference to the embodiments shown in FIGS. 2 and 3.

Figures 2 (a) and (Iff) are cross-sectional views of electrolytic capacitors,
(C) and (D) are cross-sectional views of the case, where the case 7 is made of cylindrical aluminum or thermoplastic resin, and a thin wall portion 7b is provided at a position less than the diameter A of the case 7 from the open end, and the capacitor is After storing the element 8, the open end 7a of the case 7 is inserted through the resin sheet 5 such as polypropylene.
is bent at the thin wall portion 7b to cover the sealing portion,
The bent portion is filled with resin 6. When the case 7 is made of thermoplastic resin, it is preferable to preheat it in advance and bend the end portion 7a.

Further, the filling resin is preferably one such as acrylic, phenol, epoxy, or urethane, which polymerizes and hardens in a short period of time. 9 is a lead wire led out from the capacitor element 8.

Note that the resin sheet 5 may be an elastic body.

FIG. 3 is a plan view of an electrolytic capacitor, showing an example in which the opening end 7a of the case 7 is modified, and (A) is a thin walled portion 7b.
The part extending from to the opening end is formed into a tongue shape, and the shape is trapezoidal, (17) is fan-shaped, and (c) is round.

The electrolytic capacitor of the present invention is manufactured as described above.

Therefore, since the case 7 is provided with the thin wall portion 7b,
The open end 7a of the case 7 can be easily bent. When voltage is applied to the capacitor, under normal conditions, the bent part of the case 7 protects the fixation of the resin 6, resulting in a marked increase in airtightness, and the sealing body will not deteriorate even if used for a long time in a high temperature atmosphere. Therefore, leakage of electrolyte and deterioration of characteristics hardly occur.

On the other hand, when an abnormal voltage or a reverse voltage is applied to the capacitor and the internal pressure of the capacitor increases, since the thin wall portion 7b is provided at the bent portion of the open end 7a, the thin wall portion 7b is pushed outward by the resin 6. As a result, gas can be released and the explosion-proof function can be achieved. Furthermore, the lead wire 9 is connected to the resin 6
Since it is fixed to the case 7, many effects can be obtained, such as being able to prevent the generation of electrical noise even in response to physical impact.

In the above embodiment, the case 7 is cylindrical and has an open end 7a at both ends, but a case with a bottom at one end may also be used, and the thin part 7b is formed on the inner surface of the case 7 or It may be formed continuously or intermittently on the outer surface. The bending angle of the opening end 7a is not limited to a right angle.
Any structure may be used as long as it covers the sealing part.

As described above, the present invention provides an electrolytic capacitor with significantly improved airtightness and high reliability, which is of great practical value.

[Brief explanation of the drawing]

Figures 1 (A) and (II+) are cross-sectional views of conventional electrolytic capacitors, Figures 2 and 3 are embodiments of the present invention, and (A) and (U) are cross-sectional views of electrolytic capacitors; ), (d) are cross-sectional views of the electrolytic capacitor case, and Figure 3 (a), (
0) and (c) are plan views of electrolytic capacitors. 6: Resin 7: Cylindrical case 7a: Open end 7b = Thin wall portion 8: Capacitor element

Claims (1)

[Claims] A thin wall portion is provided at a position less than 1/2 the diameter of the case from the open end of a cylindrical bottomed or bottomless case, and a portion from the thin wall portion to the open end is formed into a tongue shape, A capacitor element is housed, a resin sheet is disposed between the capacitor element and the open end of the case, and the thin wall part is configured to bend the open end of the case to cover the sealing part, and the bent part An electrolytic capacitor characterized by being filled with resin.