JPS6258647B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric double layer capacitor.

An electric double layer capacitor is a large capacitance capacitor that utilizes an electric double layer formed at the interface between a polarizable electrode and an electrolyte (liquid). As shown in Fig. 1, the main body consists of polarizable electrodes 1 mainly made of activated carbon facing each other with a separator 2 (electrolyte 3) in between, metal cases 5 and 6 that also serve as current collector plates, and a sealing body 4. It has a sealed coin- or button-shaped structure.

However, the withstand voltage of this main body 7 is as low as 0.8V when using an aqueous electrolyte and 2V when using an anhydrous electrolyte (allowable voltage considering reliability).
MOS IC (complementary metal oxide semiconductor integrated circuit)
Typical driving voltage for RAM (Random Access Memory) used for power outage backup
In order to adapt to 5V, three to seven electric double layer capacitor bodies 7 are connected in series. Conventionally, the laminated structure for realizing this series connection is as shown in FIG. 2, in which several electric double layer capacitor bodies 7 are stacked on a shallow cylindrical metal case 8 with an insulator 12 on the side. Furthermore, a metal plate 10 having an external terminal of one pole, an insulating plate 11, and a metal plate 9 having an external terminal of the other pole are sequentially inserted, and finally the opening is drawn.

However, the laminated structure of the electric double layer capacitor 13 has disadvantages in that the contact resistance between the capacitor body and the external terminal is large, and round-shaped external terminals cannot be used.

Therefore, an object of the present invention is to reduce the contact resistance and enable the use of a terminal with a round cross section.
Moreover, it is an object of the present invention to provide an electric double layer capacitor that can be made smaller.

A first embodiment of the invention is shown in FIGS. 3 and 4. That is, this electric double layer capacitor has a small-diameter bottom opening 16b formed in the center of the bottom 16a of a shallow cylindrical metal case 16,
The external terminal 14 is attached to the inside of the mouth edge of the bottom portion 16a by welding, and its tip protrudes from the opening 16b. The insulating plate 17 has a recess 17a in which the round external terminal 14 is positioned, a recess 17b in which another round external terminal 15 described later is positioned, and a through hole 17c.
c is inserted into the bottom portion 16a. The external terminal 15 is welded in advance to the electrode plate on the insulating plate 17 side of the first electric double layer capacitor body 7 to be inserted first. This capacitor body 7 is inserted through the upper end opening 16c of the metal case 16, and the terminal 15 is inserted into the bottom opening 1
6b, the remaining electric double layer capacitor main body 7 is further inserted and laminated, and the insulator 12 is arranged on the inner surface, and then the opening 16c is drawn and swaged to the outer main body 7 so as to be pressurized. be integrated.

With this configuration, the upper end opening 16c is located on the opposite side of the external terminals 14 and 15, contrary to the conventional example. Also, if the case (electrode plate) 5 in Fig. 1 is used as the case (electrode plate) 6,
External terminal 15 in FIG. 3 (example) on the positive side
The metal plate 10 and the case 5 are welded together in FIG. In addition, the external terminal 14 on the negative side is welded to the case 16, and the case 16 is pressure-welded to the case 6, whereas the metal plate 9 and the case 8, and the case 8 and the case 6
Since both are pressure-welded, this embodiment has the advantage of reducing electrical resistance.
Further, in this embodiment, all the press-contact parts are structured so that they come into contact with each other at the sharp edges of the constricted parts, so that the contact resistance is greatly reduced compared to the conventional type including other press-contact parts. Furthermore, external terminals 14,1
No. 5 has the advantage that any shape other than a round shape, such as a square shape, a metal of a different material, or a metal with a surface treatment can be attached by welding. Moreover, the conventional metal plate 9,
Since there is no stack of 10 layers, the size is small.

A second embodiment of the invention is shown in FIG. That is, in the first embodiment, this electric double layer capacitor can be temporarily fixed by simply bending the external terminals 14' and 15' into a dogleg shape and inserting them into a printed circuit board. The rest is the same as the first embodiment.

As described above, the electric double layer capacitor of the present invention has a small-diameter opening formed at the bottom of the metal case, a first external terminal welded to the edge of the opening, and an insulating plate supported at the bottom. Since the second external terminal is welded to the capacitor body through the capacitor body, the contact resistance can be reduced compared to the conventional case, a round terminal can be used, and the capacitor can be made smaller.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the electric double layer capacitor body.
FIG. 2 is a sectional view of the conventional example, FIG. 3 is a sectional view of the first embodiment of the present invention, FIG. 4 is a bottom view thereof, and FIG.
The figure is a sectional view of the second embodiment. 7... Electric double layer capacitor body, 14, 15...
External terminal, 16...Metal case, 16a...Bottom, 1
6b...Bottom opening, 16c...Top opening, 17...Insulating plate.

Claims (1)

[Scope of Claims] 1. A cylindrical metal case with a shallow bottom and a small diameter bottom opening, and a first cylinder welded to the inner surface of the bottom of the metal case and protruding from the bottom opening.
an insulating plate inserted into the upper opening of the metal case and placed on the bottom; an opening edge of the upper opening that is inserted into the upper opening of the metal case and stacked on the insulating plate; a plurality of crimped electric double layer capacitor bodies; a second electrode which is welded to a pole plate in contact with the insulating plate of the electric double layer capacitor bodies, penetrates the insulating plate and protrudes from the bottom opening; Electric double layer capacitor with external terminal. 2. The electric double layer capacitor according to claim 1, wherein the first and second external terminals are made of a solderable metal having a round or square cross section or a surface-treated metal. 3. The electric double layer capacitor according to claim 1 or 2, wherein the first and second external terminals are snap-in type.