JPS63299316A - Electrolytic capacitor - Google Patents

Abstract

PURPOSE:To enable the tight hermetic hole-sealing, and stabilize characteristics, by sealing the aperture part of a metal case with a hole-sealing body composed of a rigid insulating plate and an elastic body arranged on the upper surface of the rigid insulating plate. CONSTITUTION:An anode foil and a cathode foil are wound together with a separator, and impregnated with a driving electrolyte, to form a capacitor element 6, which is accommodated in a cylindrical metal case 7 having a bottom. The aperture of the case 7 is sealed with a hole-sealing body 9 composed of a rigid insulating plate 9a and an elastic body 9c arranged on the upper surface of the insulating plate 9a. The insulating plate 9a has recesses 9b on the peripheral part of the upper surface and that of lead lead-out parts, and has, on the peripheral part of the lower surface, protrusions 9d with the almost same size as the recesses 9b on the upper peripheral surface. Thereby, the tight hermetic hole-sealing is enabled, and the 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.

2. Description of the Related Art Conventionally, this type of electrolytic capacitor consists of an anode foil made by roughening a valve metal foil and then forming a dielectric film by anodizing, as shown in Fig. 6, and a cathode foil as a counter electrode. is 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, and the opening of this case 2 is filled with a capacitor element 1.
An elastic body 3 is placed on a hard insulator 3a passing through a rivet 5 connected to a lead wire 4 drawn out from a capacitor element 1.
The sealing body 3 configured by pasting b is sealed so that the internal driving electrolyte does not evaporate 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 body and adheres closely to the cathode body. In addition, since it contains a driving electrolyte inside, it easily evaporates at high temperatures, and when cooled to low temperatures. If it becomes, it will solidify easily (,
The performance of a capacitor is influenced by the driving electrolyte, as the operability of the capacitor is significantly degraded in evaporated or solidified states. On the other hand, what determines the life of an electrolytic capacitor is the sealing body that prevents the internal driving electrolyte from evaporating.The material and structure of this sealing body 3 determine the reactivity, solubility, and Evaporation rate etc. 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, in the structure of the conventional electrolytic capacitor sealing body as described above, the thickness of the hard insulating plate is only about 1/2 at the peripheral edge.
2, the hard insulating board may crack or even break when curling is performed. In such cases, the internal electrolyte leaks to the outside,
There are problems such as contamination of other parts under the printed curtain, infiltration of halogenated organic solvent for cleaning from the outside, corrosion of the internal leads, and failure to maintain the electrical characteristics of the electrolytic capacitor. Ta.

The present invention is an electrolyzer that prevents cracks in such hard insulating plates, prevents halogenated organic solvents from entering the interior, prevents drive electrolyte from evaporating to the outside, and improves electrical characteristics and service life. It provides capacitors.

Means for Solving the Problems In order to solve these problems, the present invention provides four parts on the periphery of the top surface and around the lead extraction part, and also makes the recess in the peripheral part deeper than the periphery of the lead extraction part. an insulating plate having a protrusion of approximately the same size as the concave portion of the circumferential edge on the upper surface, and a protrusion on the peripheral edge of the lower surface, and a convex portion on the upper surface of the hard insulating plate so as to be embedded in the concave portion; The opening of the metal case is sealed with a sealing body made of an elastic body.

Function: With this structure, when the open end of the metal case of an electrolytic capacitor is curled, the thickness of the hard insulating plate is maintained because a convex part is provided that corresponds to the concave part provided on the periphery. Therefore, a strong curling process can be performed without causing cracks, etc., thereby preventing evaporation of the electrolytic solution and preventing halogenated organic solvents from entering the inside of the capacitor.

Embodiment Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings. In Figures 1 to 5, reference numeral 6 denotes an anode foil made by roughening a valve metal foil such as aluminum and 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. A lead 8 is drawn out from the capacitor element 6, and the lead 8 is attached to the lower end of a rivet 10 that is inserted so as to penetrate a sealing body 9 that is sealed to the opening of the metal case 7 by drawing and curling. Connected and rivet l
A lug terminal 11 is connected to the upper part of O.

As shown in FIGS. 2 and 3, the sealing body 9 has a sealing body 9a formed of a hard insulator such as phenol resin, and a peripheral edge portion is formed on the upper surface of the sealing body 9a. and the periphery of the portion through which the rivet 10 passes, respectively, are continuous with each other.

9b' is formed, and the recess 9b at the peripheral edge is
+1i 'i'\It is formed to have a depth approximately twice as deep as that of the recessed portion 9b' of the portion through which it passes. This recess 9b.

9b'', an elastic body 9c made of rubber or the like is fitted so as to be flush with the upper surface of the sealing body 9a.

The surface area of the elastic body 9c is set to be 40% or less of the surface area of the sealing body 3, and the liquid elastic body is poured through one gate with the sealing body 9a set in the mold. It is formed.

If the surface area of the elastic body 9c exceeds 40% as shown in Figure 4, the amount of halogen-based organic solvent that is mounted on a printed circuit board, etc. and cleaned to remove stains such as flux will infiltrate into the electrolytic capacitor. increases significantly, corrodes the capacitor element 6 and leads 8, and significantly deteriorates the electrical characteristics. Therefore, it is important that the surface area of the elastic body 9C relative to the sealing body 9 be 40% or less.

Furthermore, the elastic body 9C has a recess 9b in the electrode rivet through hole.
' and the recess 9b at the peripheral edge are about twice as deep, so the elastic body 9c is formed thicker at the peripheral edge, and as shown in Figure 1, the opening of the metal case is This prevents the elastic body from being cut due to variations in the curling process. Furthermore, since the elastic body 9C is fitted into the recess 9b on the peripheral edge and has a protrusion 9d on the peripheral edge of the lower surface that is approximately the same size as the recess 9b on the upper peripheral edge, the elastic body 9C is a rigid insulator. The sealing body 9a, which is the body, will not break (and when curling is applied, there is no place for the elastic body 9C to escape, making it possible to seal with strong airtightness.

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. 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, when cleaning the solder flux, the infiltration of halogenated organic solvents into the interior can be suppressed because the thickness of the elastic body at the periphery is approximately twice as thick, and the surface area of the elastic body is less than 40%. It has the advantage of preventing corrosion of capacitor elements and leads, stabilizing the characteristics, and reducing evaporation of the driving electrolyte, resulting in a longer lifespan, and is of great industrial value. It is.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional front view of an aluminum 1-solution capacitor according to an embodiment of the present invention, Fig. 2 is a sectional view of the sealing body of the same capacitor, and Figs. 3A and B are front and back views of the same sealing body. figure,
Figure 4 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, Figure 5 is a comparison diagram of the characteristics of the uninvented product and the conventional product, and Figure 6 is a part of a conventional aluminum electrolytic capacitor. It is a cross-sectional front view. 6... Capacitor element, 7... Metal case, 9... Sealing body, 9a... Sealing body body, 9d, 9b'...・Concavity, 9C...
・Elastic body, 9d... Protrusion, name of agent Patent attorney Toshio Nakao and 1 other person 5 --- Rivet 6 --- Capacitor Shuko 7 --- Joint case 3 --- Lead 9 --- Ichimuraguchi) Rei 3 Figure 40 2040 Do θ 30/θθ

Claims (1)

[Claims] A capacitor element made by winding an anode foil and a cathode foil together with a separator and impregnating it with a driving electrolyte is housed in a cylindrical metal case with a bottom, and a recess is provided at the periphery of the top surface and around the lead extraction part. A hard insulating plate having a concave portion on the peripheral edge deeper than the periphery of the lead pull-out portion and a convex portion on the peripheral edge portion of the lower surface having approximately the same size as the concave portion on the peripheral edge of the upper surface, and this hard insulating plate. An electrolytic capacitor in which the opening of the metal case is sealed with a sealing body comprising an elastic body disposed on the upper surface of a plate so as to be embedded in the recess.