JPH0483325A - Chip-type solid electrolytic capacitor - Google Patents

Abstract

PURPOSE:To enable piled-up capacitors to be connected in parallel and obtain a desired electrostatic capacity with an installation space for one piece by providing a pair of lead-out pieces at each leading side edge part of an anode lead terminal and a cathode lead terminal in bifurcated shape and by allowing each of the lead-out pieces to be directed toward mutually opposing side wall surfaces of an armor case for folding in opposite direction. CONSTITUTION:A capacitor element 11 is provided with a flat-plate shaped electrode foil 12 which consists of a valve operation metal foil, an anode lead terminal 13 is mounted to a specified position, reformation treatment is performed, a solid electrolyte 14 which consists of a conductive macromolecule is formed around the electrode foil 12, and then a cathode lead-out layer 15 is formed on it and a cathode lead terminal 16 is mounted to it. A pair of lead-out pieces 13a, 13b, 16a, and 16b are formed in one piece at the each lead-out side edge part so that they are in bifurcated shape. With a capacitor 10, this capacitor element 11 is stored within an armor case 17, an epoxy resin 18 is filled into it, and each lead-out piece 13a, 13b, 16a, and 16b are directed toward the opposite side and are folded. Those which are adjacent each other up and down are folded in opposite direction and are connected in parallel by allowing the capacitor 10 to be laminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a chip-type solid electrolytic capacitor having a flat capacitor element.

[Conventional technology]

The capacitor element of a solid electrolytic capacitor is generally made of a foil-wound type or a metal powder sintered body, but in either case, it is said that it is difficult to make it thin because it has a certain diameter due to its shape. There is.

Therefore, flat capacitor elements are used to reduce the thickness. In other words, this capacitor element is made by attaching an anode lead terminal to the electrode foil by caulking, preferably by caulking, with a valve metal foil made of aluminum or the like that has been subjected to a predetermined etching treatment and chemical conversion treatment left in the form of a flat plate, and then preferably subjected to chemical conversion treatment again. A solid electrolyte made of a conductive polymer such as polypyrrole is formed around it, and a cathode extraction layer made of carbon and silver paste is further formed thereon. Thereafter, a cathode lead terminal is attached to the cathode surface using a conductive adhesive such as wetted silver. Next, this capacitor element is housed in a flat outer case in the shape of a rectangular cylinder with a bottom, and is temporarily fixed to the bottom of the case using a suitable fixing material such as adhesive silver or pitch, and then finally placed inside the outer case. is filled with resin for device encapsulation.

[Problem to be solved by the invention]

FIG. 6 shows an external perspective view of the chip type solid electrolytic capacitor 1 manufactured as described above. In this conventional example, since the capacitor 1 is surface mounted in a lying state (horizontal state M), each lead terminal 2a, 2b is bent along the same side wall surface (lower surface side in the figure) of the outer case 3. I have to.

According to this, the mounting height can be kept low, but since the element itself is a single piece of foil, the capacitance is small. To compensate for this, multiple capacitors 1 are mounted on the circuit board. They could be connected in parallel, but on the other hand, a large installation space would be required, which is not preferable in terms of miniaturization.

[Means to solve the problem]

The present invention has been made to solve the above-mentioned conventional problems, and its structural features are that the valve metal foil is plate-shaped,
A solid electrolyte made of conductive polymer is formed on the electrode foil to which an anode lead terminal is attached, a cathode lead layer is formed on the solid electrolyte, and a cathode lead terminal is attached to the cathode lead layer. In a chip-type solid electrolytic capacitor that is equipped with a capacitor element and an exterior case surrounding the capacitor element, a pair of drawer pieces are provided in a bifurcated shape at each drawer side end of the anode lead terminal and the cathode lead terminal. Each of the drawer pieces is bent in opposite directions toward the mutually opposing side wall surfaces of the outer case.

In this case, the pair of lead-out pieces may be formed in two pieces in a substantially U-shape at each end of the lead terminal, or one of the pair of lead-out pieces may be formed on the lead terminal itself. The other drawer piece may be a leg piece attached to the same lead terminal as a separate member.

[For production]

Since pull-out pieces for each lead terminal are provided on both opposing wall surfaces of the exterior case, that is, the top wall surface and the bottom wall surface facing the circuit board, each capacitor is connected in parallel by stacking them.

Capacitance can be increased in the installation space for one capacitor.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 5.

First, based on FIG. 1, the capacitor element 11 used in this chip type solid electrolytic capacitor lO (see FIG. 2)
The configuration of is explained. That is, the capacitor element 11 includes an electrode foil 12 made of a valve metal foil such as aluminum which has been subjected to a predetermined etching treatment and chemical conversion treatment. This electrode foil 12 is used in the form of a flat plate, and anode lead terminals 13 are attached to predetermined locations thereof by caulking or welding. Preferably, after reconversion treatment, a solid electrolyte 14 made of a conductive polymer 1 such as polypyrrole is formed around the electrode foil 12, and a cathode extraction layer 15 made of carbon and silver paste is further formed thereon. Then, a cathode lead terminal 16 is electrically and mechanically attached to this cathode lead-out layer 15 using a conductive adhesive such as adhesive silver (not shown).

A pair of drawer pieces 13a, 13b: 16a, 16b are provided at the drawer side end of each lead terminal 13.16, respectively. According to this example, each drawer piece 13a.

13b; 16a, 16b are lead terminals 13.1
6, it is integrally molded to form a substantially U-shape (bifurcated).

FIG. 2 shows a perspective view of this chip type solid electrolytic capacitor lO. That is, the capacitor IO is constructed by housing the capacitor element 11 in an exterior case 17 made of an electrically insulating material, for example, synthetic resin, and filling the case 17 with, for example, an epoxy resin 18 for encapsulating the element.
Each drawer piece 13a, 13b; 16a *16b
Fold each side toward the opposite side.

When placed horizontally in the figure, the lower side of the exterior case 17 is the bottom wall surface 17a, and the upper side opposite thereto is the top wall surface 17a.
7b, in this example one drawer piece L3a, 16
a is bent along the bottom wall surface 17a, and the other drawer pieces 13b and 16b are bent toward the top wall surface 17b on the contrary.

Therefore, according to this configuration, the capacitors 10 can be connected in parallel by stacking them as illustrated in FIG. In addition, in this embodiment, the drawer piece 1
The arrangement of 3a and 13b and 16a and 16b is shifted in the horizontal direction, and when stacked with their sides aligned, the drawer pieces may not be able to come into contact with each other. Therefore, as shown in FIG. 3, each drawer piece 13 is
a, 13b; 16a.

16b is bent in the opposite direction. That is, taking the drawer piece 13a as an example, for example, in a capacitor 10 placed below, the drawer piece 13a is bent toward the upper wall surface 17b of the outer case 17, and the capacitor 10 placed above is bent. The drawer pieces 13a are bent toward the bottom wall surface 17a so that even if they are stacked with their sides aligned, the drawer pieces 13a butt against each other.

4 and 5 show another embodiment using a lead terminal 20 different from the above embodiment.

In this lead terminal 20, its own drawer piece 2
A drawer piece 20b prepared as a separate member is attached to 0a in a bifurcated manner so as to overlap with it.

That is, by welding one end of the drawer piece 20b,
It is attached to a predetermined portion of the lead terminal 20 so that the other end is aligned with the length of the drawer piece 20a. According to this, each of the drawer pieces 20a and 20b is pulled out of the exterior case 17 from the same position, as shown in FIG.
In addition, since the drawer pieces are bent in opposite directions, they can be simply stacked without having to particularly consider the position of the drawer pieces as in the above embodiment. In this example, the same reference numerals are given to both the anode lead terminal and the cathode lead terminal.

〔Effect of the invention〕

As explained above, according to the present invention, each lead terminal is provided with a pull-out piece on each of both opposing wall surfaces of the outer case, that is, the bottom wall surface that faces the circuit board during mounting, and the top wall surface that faces the bottom wall surface. Each capacitor is connected in parallel by stacking a predetermined number of capacitors.
A desired capacitance can be obtained in the installation space for one capacitor.

[Brief explanation of the drawing]

1 to 5 relate to embodiments of the present invention,
Fig. 1 is a perspective view showing a broken capacitor element applied to the present invention, Fig. 2 is a perspective view of a chip-type solid electrolytic capacitor shown as an example, and Fig. 3 is a stacked state of the capacitor. FIG. 4 is an exploded perspective view of a modified example of the lead terminal, FIG. 5 is a perspective view of a chip type solid electrolytic capacitor as another example to which the lead terminal of FIG. 4 is applied, and FIG. The figure is a perspective view showing a conventional chip-type solid electrolytic capacitor. In the figure, 10 is a chip type solid electrolytic capacitor, 11 is a capacitor element, 12 is an electrode foil, 13.16.20 is a wire terminal, 13a, 13b, 16a, 16b
, 20a, 20b are drawer pieces, 17 is an exterior case, and 18 is a resin for encapsulating an element. Patent applicant Elnor Co., Ltd. Patent applicant Asahi Glass Co., Ltd. Agent Patent attorney Takuya Ohara Figure 2 Figure 4

Claims (3)

[Claims] (1) Valve metal foil is shaped into a plate, an anode lead terminal is attached to the electrode foil, a conductive polymer solid electrolyte is formed, and a cathode lead layer is formed on the solid electrolyte. In a chip type solid electrolytic capacitor comprising a flat capacitor element having a cathode lead terminal attached to the same cathode lead-out layer and an exterior case provided around the capacitor element, each drawer of the anode lead terminal and the cathode lead terminal A chip type solid electrolytic capacitor characterized in that a pair of drawer pieces are provided in a fork shape at a side end portion, and each of the drawer pieces is bent in opposite directions toward mutually opposing side wall surfaces of the outer case. (2) The chip type solid electrolytic capacitor according to claim 1, wherein the pair of drawer pieces are integrally molded in a substantially U-shape with each drawer side end of the lead terminal. (3) The chip-type solid electrolytic capacitor according to claim 1, wherein one of the pair of lead-out pieces is made of the lead terminal itself, and the other lead-out piece is a leg piece attached to the lead terminal as a separate member. .