JPS63299317A - Electrolytic capacitor - Google Patents

Abstract

PURPOSE:To enable the tight hermetic hole-sealing, and stabilize characteristics, by using hole-sealing body wherein rubber-type elastic bodies are arranged on the peripheral part of a rigid insulating plate, that of a lead lead-out part, and the side part of the rigid insulating plate. CONSTITUTION:An anode foil and a cathode foil are wound via a separator to form a capacitor element 6, which is impregnated with electrolyte for driving and accommodated in a case 7. A hole-sealing body 9 is stuck to seal the aperture part of the case 2. The hole-sealing body 9 has the peripheral part of a rigid insulating plate 9a and that of the lead-out part, and the side part of the insulating plate 9a has rubber type elastic bodies 9c, 9d. Under the pressing force applied to the elastic bodies by the end-portion of the case 7, the elastic bodies 9c, 9d are pushed in a curling part, and the tight hole-sealing is enabled. Thereby, characteristics are stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electrolytic capacitor used in various electronic devices.

Conventionally, as shown in Figure 5, this type of electrolytic capacitor has been made by roughening a valve metal foil and then forming a dielectric film by anodizing it as an anode foil, and a cathode foil as a counter electrode. are wound through a separator to make a capacitor element 1, and the capacitor element 1 is impregnated with a driving electrolyte and stored in a metal case 2. A sealing body 3a is sealed, through which a rivet 5 connected to the lead wire 4 to be drawn out passes through, and is constructed by pasting an elastic body 3b on a hard insulator 3a.
It is configured to prevent the internal driving electrolyte from evaporating to dryness.

In such electrolytic capacitors, the surface area of the electrode is expanded, the dielectric film is extremely thin, the dielectric constant is high, and the driving electrolyte penetrates into the intricately inserted electrode part and adheres closely to the cathode body. By working as a capacitor, it is possible to obtain a capacitor that is smaller and has a larger capacity than other types of capacitors. In addition, since the driving electrolyte is contained inside, it easily evaporates at high temperatures (and solidifies at low temperatures, and the operability of the capacitor is significantly degraded when it evaporates or solidifies). The performance of the capacitor depends on the driving electrolyte.On the other hand, the life of the electrolytic capacitor is determined by the sealing body 3 that prevents the internal driving electrolyte from evaporating. Reactivity, solubility, evaporation rate, etc. with the constituent materials of the electrolyte are determined and subject to limitations.

In other words, the characteristics of the driving electrolyte are determined by the sealing body 3, and furthermore, the sealing body 3
Therefore, it is no exaggeration to say that the sealing body 3 determines the performance of the capacitor.

Problems to be Solved by the Invention However, the conventional electrolytic capacitor sealing body 3 as described above
In this structure, when the electrolytic capacitor is mounted on a printed circuit board etc., the rubber that is part of the sealing body 3 of the electrolytic capacitor is When a halogen-based organic solvent or the like comes into contact with the elastic body 3b, it swells, and over time, it enters the inside of the electrolytic capacitor, corroding the capacitor element 1, internal lead wires 4, etc., and causing damage to the electrolytic capacitor. Those that significantly reduce the electrical characteristics.Also, the driving electrolyte, etc. inside the electrolytic capacitor evaporates to the outside through the elastic body 3b, such as rubber, formed on the sealing body 3, and significantly shortens the life of the electrolytic capacitor. In addition, the elastic body 3 of the sealing body attached to the opening of the metal case 2 by drawing or curling was cut due to variations in the drawing or curling of the metal case 2, and the cut portion The internal driving electrolyte etc. evaporated to the outside, reducing the lifespan.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an electrolytic capacitor that prevents halogenated organic solvents from entering the interior and prevents driving electrolyte from evaporating to the outside, thereby improving electrical characteristics and service life. be.

Means for Solving the Problems In order to solve these problems, the present invention provides a sealing structure in which a rubber-like elastic body is provided on the peripheral edge of the upper surface of the hard insulating plate, the side portion of the lead extraction layer, and the side portions. The seal is sealed using a sealing body disposed such that the rubber-like elastic body at the peripheral edge of the body, especially the upper surface, protrudes.

Effect With this configuration, when the open end of the metal case of an electrolytic capacitor is curled, the elastic body is pushed into the curling part by the pressure of the elastic body from the case edge, and there is no place for the elastic body to escape. This enables strong sealing, prevents evaporation of the electrolyte, and prevents halogenated organic solvents from entering the interior of the capacitor.

Embodiment Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings. In Figures 1 and 2, reference numeral 6 denotes an anode foil made by roughening a valve metal foil such as aluminum and then forming a dielectric film by anodizing the anode foil, and a separator between the anode foil and the counter cathode foil. This capacitor element 6 is impregnated with a driving electrolyte and housed in a metal case 7 made of aluminum or the like. Also, a lead 8Q ( ) is drawn out from this capacitor element 6, and drawn into the opening of the metal case 7.
A lead 8 is connected to the lower end of a rivet 10 inserted so as to penetrate through the sealing body 9 attached by curling, and a lug terminal 11 is connected to the upper part of the rivet IO.

The sealing body 9 has a sealing body 9a formed by molding a hard insulator such as phenol resin, and on the upper surface of the sealing body 9a, the peripheral edge and the periphery of the portion where the rivet 10 penetrates are respectively formed. An elastic body 9c made of rubber or the like is formed continuously, and an elastic body 9d made of rubber or the like is formed on the side surface of the sealing body 9a so as to be connected to the elastic body 9c on the upper surface. Furthermore, the peripheral edge of the upper elastic body 9c is formed into a convex shape 9b, and is fitted so that the upper and side surfaces of the sealing body 9a are covered with the elastic body 9c made of rubber or the like. The surface area of the upper surface of this elastic body 9c is set to be 40% or less of the surface area of the upper surface of the sealing body, and when the sealing body body 9a is set in the mold, one portion of the liquid elastic body is
It is formed by pouring through two gates.

- If the surface area of the elastic body 9c exceeds 40% as shown in Figure 3, the halogen-based organic solvent that is used to clean the electrolytic capacitor after mounting it on a printed circuit board to remove stains such as flux will enter the electrolytic capacitor. This significantly increases the amount of carbon dioxide, corroding the capacitor element 6 and leads 8, and significantly reducing the electrical characteristics.Therefore, it is important that the surface area of the elastic body 9C that is exposed to the sealing body 9 is 40% or less. .

Furthermore, the elastic body 9c is formed in the convex shape 9b on the peripheral edge and the elastic body 9d on the side surface, and as shown in FIG. This prevents the elastic body 9C19d from being cut due to. Furthermore, since the elastic body 9C19d is molded on the convex shape 9b on the peripheral edge and on the side surface, there is no place for the elastic body to escape into the case during curling or cresting, and a strong airtight seal is possible. .

Furthermore, when considering the evaporation of the driving electrolyte in the electrolytic capacitor with the above structure and the electrolytic capacitor with the conventional structure, as shown in FIG. As a result, the weight can be reduced by about half, resulting in a longer life.

Effects of the Invention As described above, the electrolytic capacitor of the present invention is composed of a hard insulator and an elastic body, and the main body of the sealing body is made of a hard insulator. This allows for a strong airtight seal.Furthermore, the thickness of the elastic material at the periphery is approximately twice as thick, which prevents halogenated organic solvents from entering the interior when cleaning solder flux. Since the surface area of the elastic body is less than 40%, corrosion of the capacitor elements and leads can be prevented and the characteristics stabilized, and the evaporation of the driving electrolyte is also reduced (which results in a longer life). It has the advantage of being able to do a lot of things, and is of great industrial value.

[Brief explanation of drawings]

FIG. 1 is a sectional front view of essential parts showing an embodiment of the electrolytic capacitor of the present invention, FIGS. 2 a and 2 b are a top view of a sealing body used in the capacitor, and a sectional view taken along line A-A'. Fig. 3 is a characteristic diagram showing the relationship between the surface area of the elastic body of the sealing body and the amount of solvent infiltration, Fig. 4 is a characteristic diagram showing the weight reduction of the driving electrolyte of the present invention and the conventional electrolytic capacitor, and Fig. 5 1 is a sectional front view of a main part of a conventional electrolytic capacitor. 6... Capacitor element, 7... Metal case, 8... Lead, 9... Sealing body,
9a...Sealing body body, 9b...Convex shape,
9c, 9d...Elastic body, lO...Rivet, 11...Lug terminal. Name of agent: Patent attorney Toshio Nakao and 1 other person @ 1 Figure 6 - Conte, Suoko Kyu Figure 2

Claims (2)

[Claims] (1) Constructed by storing a capacitor element made by winding a positive electrode foil and a negative electrode foil with a separator in between, impregnated with a driving electrolyte in a case, and sealing a sealing body to the opening of the case. 1. An electrolytic capacitor in which a rubber-like elastic body is provided on a peripheral edge of a hard insulating plate, a periphery of a lead extraction part, and a side part of the hard insulating plate to form a sealing body. (2) The electrolytic capacitor according to claim 1, wherein the rubber-like elastic body disposed on the peripheral edge of the hard insulating plate projects outward.