JPS6312124A - Electrolytic capacitor - 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 Field of Industrial Application The present invention relates to an electrolytic capacitor used in various electronic devices.

2. Description of the Related Art Conventionally, as shown in Figure 6, this type of electrolytic capacitor consists of an anode foil made by roughening a valve metal foil and then forming a dielectric film by anodization, and a cathode foil serving as a counter electrode. and are wound through a separator to form capacitor element 1.
The capacitor element 1 is impregnated with a driving electrolyte and stored in a metal case 2. The lead wire 4 drawn out from the capacitor element 1 is connected to the opening of the case 2, and the bed 5 is connected to the opening of the case 2. A sealing body 3 formed by pasting an elastic body 3b on a hard insulator 3a to be penetrated is sealed to prevent the driving electrolyte inside 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 electrode surface, which is intricately penetrated, 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 drive electrolyte is contained inside, it tends to evaporate at high temperatures and solidify at low temperatures. Performance depends on the 4 drive electrolyte. On the other hand, what determines the life of an electrolytic capacitor is the internal sealing body that prevents the driving electrolyte from evaporating.The material of this sealing body 3 determines the reactivity and solubility of the driving electrolyte with the constituent materials. is determined and subject to restrictions.

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 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 sealing body 3 of the electrolytic capacitor is cleaned with a rogen-based organic core material, etc. to remove stains such as flux.
The elastic body 3b such as rubber, which is a part of the capacitor, comes into contact with the rogen-based organic solvent, swells, and over time penetrates into the electrolytic capacitor, corroding the capacitor element 1 and internal lead wires 4, etc. This can significantly deteriorate the electrical characteristics of electrolytic capacitors. Furthermore, the driving electrolyte and the like inside the electrolytic capacitor evaporate to the outside through the elastic body 3b, such as rubber, formed in the sealing body 3, significantly shortening the life of the electrolytic capacitor.

Therefore, the present invention provides an electrolytic capacitor that reduces the intrusion of halogen-based organic solvents into the capacitor, prevents the driving electrolyte from evaporating to the outside, and improves the electrical characteristics and life of the capacitor.

Means for Solving the Problems In order to solve these problems, the present invention provides a structure in which a surface area of The structure uses a sealing body on which an elastic layer having a surface area of 40% or less is formed.

Function: With this configuration, it is possible to reduce the intrusion of halogen-based organic solvents and the like from the outside into the electrolytic capacitor, and it is also possible to prevent the driving electrolyte inside the electrolytic capacitor from evaporating to the outside.

Embodiment Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings. In Figures 1 to 3, 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, lipeno) 10
A lug terminal 11 is connected to the upper part of the terminal.

The sealing body 9 includes a sealing body 9a formed by molding a hard insulator such as phenol resin, and a sealing body 92.
A groove 9b is formed in the upper surface of L so that the peripheral edge and the periphery of the part where the rivet 100 penetrates are continuous, and an elastic body 9C such as rubber is placed flush with the upper surface of the sealing body 9a within this groove 9b. It is formed to be. This elastic body 9C
The surface area of the sealing body 9a is set to be 40% or less of the surface area of the sealing body 9, and is molded by pouring a liquid elastic material through one gate while the sealing body body 9a is set in a molding die. .

As shown in Figure 4, if the surface area of the elastic body 9C exceeds 40%, 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 in width, corrodes the capacitor element 6 and leads 8, and significantly deteriorates the electrical characteristics.

Therefore, the surface area of the elastic body 9C with respect to the sealing body 9 is 4
It is important to keep the VC below 0%.

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

Because of the effects of the invention, it is possible to seal the hard insulator with a strong airtight seal without deforming or warping the sealing body itself, which is the main body, and it is also possible to use halogen organic solvents etc. when cleaning solder flux. Since the surface area of the elastic body is less than 40%, it is possible to suppress the infiltration of the electrolyte into the interior of the capacitor, preventing corrosion of the capacitor's wife and leads and stabilizing the characteristics.Moreover, the evaporation of the driving electrolyte can be reduced and the product can last for a long time. It has the advantage of being able to extend its service life and is of great industrial value.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional front view of essential parts showing an embodiment of the electrolytic capacitor of the present invention, Fig. 2 is a perspective view of a sealing body used in the capacitor, Fig. 3 is a sectional view of the same, and Fig. 4 is a cross-sectional view of the same sealing body. Figure 5 is a characteristic diagram showing the relationship between the surface area of the elastic body and the amount of solvent infiltration. Figure 5 is a characteristic diagram showing the weight reduction of the driving electrolyte of the present invention and the conventional electrolytic capacitor. Figure 6 is the main points of the conventional electrolytic capacitor. It is a partial cross-sectional front view. 6... Capacitor element, 7... Metal case, 8... Lead, 9... Sealing body,
9 &... Sealing body body, 9b... Groove, 9
C...Elastic body, 10...Rivet, 11
...Lug terminal. Name of agent: Patent attorney Toshio Nakao and one other name
1 Figure 2! b Figure 3 Figure 4

Claims (1)

[Claims] A capacitor element made by winding an anode foil and a cathode foil through a separator and impregnated with a driving electrolyte is housed in a case, and at least the periphery of the upper surface of the hard insulating sealing body is inserted into the opening of the case. An electrolytic electrolytic device formed by sealing a sealing body in which an elastic body is formed in a groove provided around the lead-out part of the lead of the capacitor element, and the surface area of this elastic body is 40% or less of the surface area of the sealing body. capacitor.