JPH0263283B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to the improvement of electrolytic capacitors,
In particular, the present invention relates to a terminal structure of an electrolytic capacitor compatible with surface mounting on a substrate.

[Conventional technology]

BACKGROUND ART In recent years, with the automation and higher integration of electronic component mounting processes, there has been a demand for leadless electronic components that can be surface mounted on substrates.

Generally, when an electrolytic capacitor is made leadless, there is a method described in Japanese Patent Laid-Open No. 59-211213 and shown in FIG. 2. That is, an insulating plate 16 is placed on the end face of the electrolytic capacitor 1, and the leads 8 are inserted through holes 17 provided in the insulating plate 16. The leads 8 protruding from the back surface of the insulating plate 16
is bent along the back surface of the insulating plate 16 to form a substantially flat surface on the back surface of the insulating plate 16.

Such a conventional leadless electrolytic capacitor can be surface mounted on the substrate 18 without changing the structure of the normal electrolytic capacitor 1.

[Problem to be solved]

However, in a leadless electrolytic capacitor having a conventional structure, only the lead 8 led from the main body of the electrolytic capacitor 1 makes electrical contact with the conductor portion 19 of the substrate 18. Therefore, the contact area between electrolytic capacitor 1 and conductor portion 19 has to be narrow. Alternatively, it is possible to form the tips of the leads 8 into a flat shape, but it has been difficult to provide a sufficient contact area. Therefore,
The contact area between the lead 8 and the conductor portion 19 of the substrate 18 is narrow, making it difficult to obtain a highly reliable connection.

Further, when electronic components are generally surface mounted by reflow soldering, the portion where the lead 8 and the conductor portion 19 of the board 18 are connected by the solder 20 is as follows.
As shown in FIG. 2, it is often the end face of the lead 8. That is, since the back surfaces of the leads 8 are in contact with the substrate 18, the molten solder 20 hardly penetrates into the back surfaces of the leads 8 and is fused so as to creep up onto the end surfaces of the leads 8. Therefore,
If the area of the end face of the lead 8 is small, the electrical connection between the conductor portion 19 of the substrate 18 and the lead 8 may be insufficient. Also, depending on the state of soldering, the leads 8 may separate from the solder 20 after surface mounting due to vibration of the board 18, swelling of the sealing body 6 due to an increase in internal pressure in the electrolytic capacitor 1 body due to temperature rise, etc. There was a risk that it would be lost.

Further, the insulating plate 16 and the main body of the electrolytic capacitor 1 are simply connected by bending the leads 8 and anchoring them. Therefore, the electrolytic capacitor 1 main body and the insulating plate 16 may be separated from each other during the mounting process on the board 18 due to mechanical weakness.

An object of the present invention is to realize a leadless electrolytic capacitor that can be surface mounted on a substrate without changing the structure of a conventional electrolytic capacitor.

[Means to solve problems]

This invention includes an electrode plate in which a pair of terminals made of solderable metal pieces are integrally molded on a pair of opposing sides of an insulating plate made of a heat-resistant synthetic resin, and an exterior housing in which a capacitor element is housed. It consists of an electrolytic capacitor with a sealing body attached to the opening of the case, and the outer surface of the sealing body and the top surface of the electrode plate face each other substantially parallel to each other, and the leads led from the capacitor element and the terminals of the electrode plate are electrically connected at a part of the upper surface of the terminal.

Further, the electrode plate is characterized in that a cutout portion extending toward the center of the electrode plate is formed on the same side surface where a pair of terminals are adjacent to each other.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial sectional view showing a first embodiment of the present invention, and FIG. 3 is a perspective view illustrating the connection state between an electrode plate and a lead. FIG. 4 is a perspective view showing a second embodiment of the invention.

In FIG. 1, an electrolytic capacitor 1 includes an electrode foil 3
A capacitor element 2 formed by winding a capacitor and an electrolytic paper 4 is housed in a bottomed cylindrical outer case 5 made of aluminum or the like. A sealing body 6 made of elastic rubber or the like is placed in the opening of the exterior case 5.

The lead 8 is electrically connected to the electrode foil 3, penetrates the sealing body 6, and projects from the end surface of the sealing body 6 to the outside.

On the outer surface of the sealing body 6, an electrode plate 9 as shown in FIG. 3 is arranged. This electrode plate 9 consists of an insulating plate 11 made of a heat-resistant synthetic resin such as polyethylene terephthalate or epoxy, and a terminal 10 made of a solderable metal piece such as copper or iron.
Terminals 10 are integrally formed on both sides facing an insulating plate 11.

The connection between this electrode plate 9 and the electrolytic capacitor 1 is as follows:
As shown in Figure 3, first, electrolytic capacitor 1
and the upper surface of the electrode plate 9 are arranged so as to contact each other in a perpendicular direction, and the leads 8 led from the electrolytic capacitor 1 are brought into contact with the terminals 10 of the electrode plate 9. Next, the leads 8 and the terminals 10 are electrically connected from the upper direction A of the electrode plate 9 using means such as spot welding or ultrasonic welding.

Furthermore, after connecting the lead 8 and the terminal 10,
The lead 8 of the electrolytic capacitor 1 is bent perpendicularly at the welded portion, so that the outer end surface of the electrolytic capacitor 1 and the upper surface of the electrode plate 9 face each other substantially in parallel, as shown in FIG.

Insulation between the outer case 5 and the terminals 10 of the electrode plate 9 is ensured by an outer sleeve 7 covering the outer surface of the outer case 5. This exterior sleeve 7 is made of synthetic resin such as vinyl chloride, and is in close contact with the surface of the exterior case 5.

Further, the insulation between the outer case 5 and the electrode plate 9 can be achieved by means other than the outer sleeve 7 as shown in the first embodiment, for example, by applying a synthetic resin to the upper surface of the electrode plate 9. Good too.

FIG. 4 is a perspective view showing a second embodiment of the present invention, in which an ordinary electrolytic capacitor 1 is used as the electrolytic capacitor 1, as in the first embodiment.

Further, the electrode plate 12 disposed on the end face of the electrolytic capacitor 1 can also be soldered to the insulating plate 14 made of heat-resistant synthetic resin, as in the first embodiment.
It consists of a terminal 13 made of a piece of metal such as copper or iron.

In the case of the second embodiment, a notch 15 extending from the side surface of the electrode plate 12 toward the center is provided on the side surface of the electrode plate 12 adjacent to which a pair of terminals 13 are adjacent. The longitudinal dimension of this notch 15 is approximately the same as or slightly longer than the diameter of the electrolytic capacitor 1. The electrolytic capacitor 1 has this notch 1
5 and comes into contact with the electrode plate 12. The lead 8 and the terminal 13 of the electrode 12 are welded from above B of the electrode plate 12, as in the first embodiment.

After the lead 8 and the terminal 13 are electrically connected, the lead 8 is bent at a substantially right angle so that the end surface of the electrolytic capacitor 1 and the upper surface of the electrode plate 12 face each other in parallel.

In the case of the second embodiment, the leads 8 can be formed shorter than in the first embodiment. Therefore, the process of bending the leads 8 after connecting the leads 8 and the electrode plate 12 becomes easy.

〔Effect of the invention〕

As described above, the present invention includes an electrode plate in which a pair of terminals made of solderable metal pieces are integrally molded on a pair of opposing sides of an insulating plate made of a heat-resistant synthetic resin, and a capacitor element. It consists of an electrolytic capacitor in which a sealing body is attached to the opening of an exterior case in which the capacitor is housed, and the outer surface of the sealing body and the upper surface of the electrode plate face each other in substantially parallel manner, and the leads led from the capacitor element and the terminal of the electrode plate are electrically connected at a part of the upper surface of the terminal, so that the lead of the electrolytic capacitor holds the electrode plate and allows the electrolytic capacitor itself to stand on its own. A flat surface is formed on the back surface of the electrode plate. Therefore, it is possible to surface-mount the electrolytic capacitor on a substrate without changing the structure of the conventional electrolytic capacitor.

Furthermore, when the electrolytic capacitor obtained by this invention is mounted on a board, the area of the terminal electrically connected to the lead of the electrolytic capacitor is larger than that of a conventional leadless electrolytic capacitor. has been done. Therefore, the solder creeps up over a wide area on the side surface of the terminal of the electrode plate, thereby ensuring reliable electrical connection between the electrolytic capacitor and the wiring on the board.

As described above, this invention is a useful invention that provides an electrolytic capacitor compatible with surface mounting on a substrate without changing the structure of a conventional electrolytic capacitor.

[Brief explanation of drawings]

FIG. 1 is a partially sectional view showing a first embodiment of the invention. FIG. 2 is a partial cross-sectional view showing the structure of a conventional leadless electrolytic capacitor, and FIG. 3 is a perspective view illustrating the state of connection between the leads led from the electrolytic capacitor and the terminals of the electrode plate. Fourth
The figure is a perspective view showing a second embodiment of the invention. DESCRIPTION OF SYMBOLS 1... Electrolytic capacitor, 2... Capacitor element, 3... Electrode foil, 4... Electrolytic paper, 5... Exterior case, 6... Sealing body, 7... Exterior sleeve, 8...
... Lead, 9, 12 ... Electrode plate, 10, 13 ...
Terminal, 11, 14, 16... Insulating plate, 15... Notch, 17... Through hole, 18... Substrate, 19... Conductor portion, 20... Solder.

Claims (1)

[Claims] 1. An electrode plate in which a pair of terminals made of solderable metal pieces are integrally molded on a pair of opposing sides of an insulating plate made of a heat-resistant synthetic resin, and a capacitor element are housed therein. The capacitor consists of an electrolytic capacitor with a sealing body attached to the opening of an external case, and the outer surface of the sealing body and the top surface of the electrode plate face each other almost parallel to each other, and the leads and electrodes led from the capacitor element An electrolytic capacitor characterized in that a terminal on a plate is electrically connected to a part of the upper surface of the terminal. 2. The electrolytic capacitor according to claim 1, wherein the electrode plate has a notch extending toward the center of the electrode plate on the same side surface where a pair of terminals are adjacent to each other.