JPH0311538B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a leadless aluminum electrolytic capacitor.

Configuration of conventional example and its problems This is a conventional so-called leadless electronic component of this type. For example, a chip type electrolytic capacitor was constructed as shown in FIGS. 1a and 1b. That is,
An anode foil made by roughening aluminum foil and forming a dielectric oxide film through anodization, and a cathode foil made by roughening aluminum foil are wound through a separator and impregnated with a driving electrolyte. This capacitor element 1 constitutes a capacitor element 1.
is stored in a bottomed cylindrical metal case 2, and
The open end is sealed using a sealing material 3 having elasticity such as rubber to form an aluminum electrolytic capacitor, and the lead wire 4 drawn out from the aluminum electrolytic capacitor is welded to the comb-shaped terminal 5 by a method such as welding. Electrical and mechanical connections were made, and a molded resin sheath 6 was applied to the entire body except for the comb-shaped terminals 5, resulting in a completed product.

This type of chip-type aluminum electrolytic capacitor is
When mounting on a printed circuit board, the molded resin exterior 6 is applied as described above in order to provide solder heat resistance.Generally, the molded resin exterior 6 is heated at a temperature of 100℃ to 150℃ for about 10kg/5 minutes. ^cm2
Under such harsh conditions, the driving electrolyte of the electrolytic capacitor evaporates, causing characteristic deterioration such as a decrease in capacitance and an increase in tanδ, and the molded resin exterior 6 However, the problem was that it was extremely expensive.

Furthermore, since it is a horizontal type, when it is mounted on a printed circuit board, it occupies a large area of the printed circuit board, which is a factor that hinders miniaturization of various devices.

In order to solve the above problems, the present inventors previously proposed an aluminum electrolytic capacitor of the type shown in FIG. That is, the lead wire connected to the capacitor element is pulled out from the same end surface of the metal case 2 in the shape of a lead cylinder with a bottom, and the lead wire passes through so as to come into contact with the end surface of the opening of the metal case 2 from which the lead wire is pulled out. An insulating portion 8 with holes is provided, and a recess 9 is provided on the outer surface of the insulating plate 8, and the tip portion 4a of the lead wire is accommodated in the recess 9.

However, in the above-mentioned aluminum electrolytic capacitor, the tip 4a of the lead wire passing through the through hole of the insulating plate 8 is placed in the same direction as the recess 9 of the insulating plate 8 (hereinafter referred to as the lead wire). If an external force is applied to an aluminum electrolytic capacitor from a direction parallel to the lead wire (referred to as a direction parallel to the lead wire), the mounting strength against it is strong, but if an external force is applied to an aluminum electrolytic capacitor from a direction perpendicular to the direction parallel to the lead wire, There was a problem in that the mounting strength was weak.

OBJECTS OF THE INVENTION The present invention aims to eliminate such conventional problems and to provide an aluminum electrolytic capacitor with improved mounting strength.

Structure of the Invention In order to achieve the above object, the aluminum electrolytic capacitor of the present invention includes a capacitor element in which an anode foil and a cathode foil are wound with a separator in between, and a driving electrolyte is impregnated therein, and the capacitor element is housed therein. a cylindrical case with a bottom, a sealing member housed in an opening of the case through which the lead wire connected to the capacitor element is passed through in order to draw out the lead wire from the same end surface, and an opening of the case. a rectangular insulating plate disposed so as to be in contact with the end face and having a through hole through which the lead wire passes; , a recess connected to the through hole is provided on one diagonal line, the tip of the lead wire passing through the through hole is bent so as to be accommodated in the recess, and the tip of the lead wire is flattened. The rectangular insulating plate has a flat end face that protrudes from the rectangular insulating plate.

With this configuration, the shape of the tip of the lead wire is symmetrical with respect to the diagonal line of the insulating plate, so external forces are not applied to the aluminum electrolytic capacitor from directions parallel to and perpendicular to the lead wire. In either case, strong mounting strength can be obtained. Further, the tip of the lead wire housed in the recess of the insulating plate is configured to be flat, and the end surface of the flat part protrudes from the rectangular insulating plate, so the tip of the lead wire is printed. When an aluminum electrolytic capacitor is attached to a board by soldering, the solder wraps around to the upper surface of the flat part of the lead wire that protrudes from the rectangular insulating plate, further improving the mounting strength.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3 to 5. In FIGS. 3 to 5, the same parts as in FIGS. 1 and 2 are designated by the same numbers.

In Fig. 3, 1 is a capacitor element similar to the conventional one, and this capacitor element 1 is an anode foil made by electrochemically roughening a high-purity aluminum foil and then anodizing it to form a dielectric oxide film. ,
It is constructed by winding a roughened cathode aluminum foil with a separator in between, and impregnating the wound material with a driving electrolyte. This capacitor element 1 is housed in a cylindrical metal case 2 with a bottom. Further, a lead wire 4 is connected to the anode foil and the cathode foil of the capacitor element 1.

The opening of the metal case 2 is fitted with a sealing member 7 having a two-layer structure of a rubber-like elastic body 7a and a non-rubber-like elastic body 7b, and is sealed by drawing. Consists of aluminum electrolytic capacitors. Further, the lead wire 4 connected to the capacitor element 1 passes through the sealing member 7 and is drawn out from the same end surface.

Reference numeral 8 denotes a rectangular insulating plate disposed so as to come into contact with the end face of the opening from which the lead wire 4 is drawn out of the metal case 2, and this insulating plate 8 is provided with a through hole 8a through which the lead wire 4 passes. ing. Further, a recess 8b located on the outer surface of the insulating plate 8 and connected to the through hole 8a is provided on one of the diagonals of the rectangular insulating plate 8, as shown in FIG. The tip 4a of the lead wire 4 passing through the through hole 8a is bent so as to be accommodated in the recess 8b. In this case, Fig. 5 a, b
As shown in the figure, the round bar lead wire 4 may have its tip 4a flattened and bent, or may be left as a round bar lead wire, but it is preferable that the lead wire 4 It is better to flatten and bend the leading end 4a of the lead wire 4, and in one embodiment of the present invention, the leading end 4a of the lead wire 4 is made flat as shown in FIG. The end face of the flat part is made to protrude from the rectangular insulating plate 8. With this configuration, when the tip end 4a of the lead wire 4 is soldered to a printed circuit board and an aluminum electrolytic capacitor is mounted, the upper surface of the flat part of the lead wire 4 that protrudes from the rectangular insulating plate is covered. Since the solder wraps around, the attachment strength can be further improved.

Effects of the Invention As described above, in the aluminum electrolytic capacitor of the present invention, a rectangular insulating plate having a through hole through which a lead wire connected to a capacitor element passes is inserted into an opening of a bottomed cylindrical case that houses a capacitor element. A concave portion is disposed so as to be in contact with the end surface, is located on the outer surface of the insulating plate, and is connected to the through hole on one of the diagonals of the rectangular insulating plate, and extends through the through hole. Since the tip of the lead wire is bent so that it is stored in the recess, the shape of the tip of the lead wire is symmetrical with respect to the diagonal of the insulating plate. Even if an external force is applied to the aluminum electrolytic capacitor in parallel or perpendicular directions, strong mounting strength can be obtained in both cases.

Further, the tip of the lead wire housed in the recess of the insulating plate is configured to be flat, and the end surface of the flat part protrudes from the rectangular insulating plate. When an aluminum electrolytic capacitor is attached to a printed circuit board by soldering, the solder wraps around to the top surface of the flat part of the lead wire that protrudes from the rectangular insulating plate, further improving the mounting strength and further improving the strength of the installation. Even on the more protruding flat portion of the lead wire, the degree of solder adhesion can be visually observed.

[Brief explanation of the drawing]

Figures 1a and b are cross-sectional views and side views of conventional chip-type aluminum electrolytic capacitors, Figure 2 is a perspective view of a leadless aluminum electrolytic capacitor previously proposed by the present inventors, and Figure 3 is the invention of the present invention. FIG. 4 is a partially sectional front view of a leadless aluminum electrolytic capacitor showing one embodiment of the present invention, FIG. 4 is a perspective view thereof, and FIGS. 1...Capacitor element, 2...Metal case, 4
... Lead wire, 7 ... Sealing member, 8a ... Through hole, 8b ... Recess.

Claims (1)

[Scope of Claims] 1. A capacitor element in which an anode foil and a cathode foil are wound with a separator in between and impregnated with a driving electrolyte, a bottomed cylindrical case that houses the capacitor element, and the capacitor. The lead wire connected to the element is passed through the lead wire in order to be drawn out from the same end surface, and the sealing member is housed in the opening of the case, and the sealing member is disposed so as to come into contact with the end surface of the opening of the case, and the a rectangular insulating plate provided with a through hole through which a lead wire passes, a recess located on the outer surface of the insulating plate and connected to the through hole on one of the diagonals of the rectangular insulating plate; is provided, and the tip of the lead wire that has passed through the through hole is bent so as to be accommodated in the recess, and the tip of the lead wire is formed into a flat shape, and the end surface of the flat portion is shaped like the one described above. An aluminum electrolytic capacitor characterized by protruding from a rectangular insulating plate. 2. The aluminum electrolytic capacitor according to claim 1, wherein the sealing member is composed of a rubber-like elastic body and a non-rubber-like elastic body.