JPH05234827A - Electrolytic capacitor - Google Patents

Abstract

PURPOSE:To provide an electrolytic capacitor wherein the size of a capacitor element does not become large as a whole as well as an anode lead member and a cathode lead member can be extracted effectively from the capacitor element. CONSTITUTION:An anode foil 21 in which a cutout part 21a has been formed at one corner part, a separator 23 and a cathode foil 22 in which a cutout part 22a has been formed at one corner part are laminated sequentially in such a way that the cutout part 21a in the anode foil 21 does not correspond to the cutout part 22a in the cathode foil 22. Thereby, a capacitor element 25 is constituted. In addition, the capacitor element is constituted in the following manner: a cathode lead member 26 is connected to an exposed part 22b, in the cathode foil 22, which corresponds to the cutout part 21a in the anode foil 21; and an anode lead member 27 is connected to an exposed part 21b, in the anode foil 21, which corresponds to the cutout part 22a in the cathode foil 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic capacitor used in various electronic devices.

[0002]

2. Description of the Related Art In a conventional aluminum electrolytic capacitor, a valve action metal foil is roughened by etching, and then an anode foil having a dielectric oxide film formed by anodic oxidation and a cathode foil opposite thereto are interposed by a separator. A capacitor element is formed by winding the capacitor element, and the capacitor element is impregnated with a driving electrolytic solution, and the capacitor element is housed in a bottomed cylindrical metal case made of an aluminum material. A sealing member is attached to the opening of one end of the metal case so that the driving electrolyte solution inside does not evaporate.

In various electronic devices, which generally tend to be miniaturized by making ICs, this type of aluminum electrolytic capacitor occupies a large volume and is required to have a small size and a large capacity. Therefore, the capacitor element is miniaturized by forming the electrode foil thin to improve the winding density and by strongly performing the etching treatment to increase the surface area of the electrode foil. However, in the case of this winding type capacitor element, since the anode foil and the cathode foil are wound with a separator interposed, a reactance component is generated, the impedance at high frequencies becomes high, and the frequency characteristics deteriorate. Has the problem.

In addition, attempts have been made to make the electrolytic capacitor a flat type in order to improve the mounting efficiency in the housing of electronic equipment. However, in this case, since the cylindrical wound-type capacitor element is processed into a flat shape by compression molding, the lamination characteristics of the electrode foil become nonuniform, and the electrical characteristics are generally lower than those of the cylindrical shape. It is a thing.

Therefore, in order to solve such a problem, a flat plate type electrolytic capacitor as shown in FIGS. 3 and 4 has been proposed. That is, in the flat plate type electrolytic capacitor shown in FIG. 3, the anode foil 1 and the cathode foil 2 formed in a rectangular shape are laterally offset and alternately stacked with the separator 3 interposed between the two. The capacitor element 5 is formed by stacking together and fixing with the fixing tape 4, and the anode lead member 6 and the edge portion of the anode foil 1 and the cathode foil 2 in the laminated state exposed from the separator 3 The cathode lead member 7 is connected by welding.

The flat electrolytic capacitor shown in FIG. 4 is formed in a rectangular shape and has a protruding portion 8 protruding outward.
an anode foil 8 having a and a cathode foil 9 having a protruding portion 9a which is similarly formed in a rectangular shape and protrudes outward, together with a separator 10 interposed between the two, and each protruding portion 8a, 9a are alternately superposed and laminated so that they do not correspond to each other, and fixed by a fixing tape 11 to form the capacitor element 12, and the anode foil 8 in a laminated state.
The anode lead member 13 and the cathode lead member 14 are connected by welding to the protruding portion 8a and the protruding portion 9a of the cathode foil 9.

[0007]

However, in the flat plate type electrolytic capacitor shown in FIG. 3, the anode lead member 6 is used.
When the cathode lead member 7 and the cathode lead member 7 are led out from the capacitor element 5, the anode foil 1 and the cathode foil 2 formed in a rectangular shape are laterally displaced to form the edge portions exposed from the separator 3, respectively. Since the anode lead member 6 and the cathode lead member 7 are connected to each other, the total area of the capacitor element 5 is increased by the amount of lateral displacement of the anode foil 1 and the cathode foil 2. Therefore, there is a problem that the electrolytic capacitor itself becomes large.

Further, in the flat plate type electrolytic capacitor shown in FIG. 4, when the anode lead member 13 and the cathode lead member 14 are led out from the capacitor element 12, the anode foil 8 and the cathode foil 9 which are formed in a rectangular shape respectively are externally mounted. Projecting portion 8 projecting in one direction
a and 9a are formed, and the anode lead member 13 and the cathode lead member 14 are connected to these protrusions 8a and 9a, the overall size of the capacitor element 12 is the protrusion of the protrusions 8a and 9a. There is a problem in that the size is increased by the size, and thereby the electrolytic capacitor itself is increased in size.

The present invention solves such a problem and an electrolytic capacitor in which the anode lead member and the cathode lead member can be effectively led out from the capacitor element without increasing the size of the entire capacitor element. It is intended to provide.

[0010]

In order to achieve the above object, an electrolytic capacitor of the present invention is provided with an anode foil and a cathode foil each having a notch at one corner, and between the anode foil and the cathode foil. And a separator provided with notches at two corners, and the anode foil, the separator, and the cathode foil are sequentially arranged so that the notches of the anode foil and the notches of the cathode foil do not correspond to each other. A capacitor element is formed by stacking layers, a cathode lead member is connected to the exposed portion of the cathode foil corresponding to the cutout portion of the anode foil, and the anode is exposed to the exposed portion of the anode foil corresponding to the cutout portion of the cathode foil. The lead member is connected.

[0011]

According to the electrolytic capacitor having the above structure, an anode foil and a cathode foil each having a notch at one corner,
A separator interposed between the anode foil and the cathode foil and having cutouts at two corners, and the anode foil, the separator, and the cathode foil are provided with the cutouts of the anode foil and the cathode foil. A capacitor element is constructed by stacking so that the cutouts do not correspond to each other, and the exposed portion of the cathode foil corresponding to the cutout portion of the anode foil and the exposed portion of the anode foil corresponding to the cutout portion of the cathode foil. Since the cathode lead member and the anode lead member are connected to each other, as the size of the entire capacitor element, the conventional anode foil and the cathode foil are laterally displaced, or the anode foil and the cathode foil are externally separated. It does not become as large as the one provided with a protruding portion toward one side, and this makes it possible to miniaturize the electrolytic capacitor itself, and at the same time, to conduct the anode lead member and the cathode lead member from the capacitor element. There without increase in cost, in which support efficient.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. 1 (a), (b), (c), (d),
(E) shows components of the capacitor element in the electrolytic capacitor of one embodiment of the present invention.
In (a), (b), (c), (d), and (e), 2
Reference numeral 1 is a rectangular shaped anode foil, and this anode foil 21 is obtained by roughening an aluminum foil which is a valve metal by etching and then forming a dielectric oxide film by anodic oxidation. As shown in (a), a notch 21a is provided at one corner.

Reference numeral 22 is a cathode foil made of an aluminum foil opposite to the anode foil 21. The cathode foil 22 is formed into a rectangular shape having the same size as the anode foil 21 as shown in FIG. Notches 22a are provided at the corners. Two
3 is interposed between the anode foil 21 and the cathode foil 22 to be the anode foil 2
1 and the cathode foil 22 serve as an insulator that prevents direct contact between the cathode foil 22 and the cathode foil 22.
As shown in (b), it is formed into a rectangular shape having the same size as the anode foil 21 and the cathode foil 22, and the cutout portions 21a of the anode foil 21 and the cutout portions 22 of the cathode foil 22 are formed at two corners.
Notches 23a and 23b having the same size as a are provided.

These anode foil 21, cathode foil 22,
When the capacitor element is formed by using the separator 23, the anode foil 21, the separator 23, and the cathode foil 22 are replaced with those shown in FIG.
As shown in (d), the anode foil 21 and the cathode foil 22 are sequentially laminated so that the cutout portion 21a and the cutout portion 22a of the cathode foil 22 do not correspond to each other, and then fixed with a fixing tape 24 as shown in FIG. 4E. By doing so, the capacitor element 25 is formed, and thereafter, the cathode foil 22 corresponding to the cutout portion 21a of the anode foil 21 is formed.
The cathode lead member 26 is connected to the exposed portion 22b of the anode by welding, and the anode lead member 27 is connected to the exposed portion 21b of the anode foil 21 corresponding to the cutout portion 22a of the cathode foil 22 by welding.

Further, the capacitor element 25 is mounted in an exterior member 28 as shown in FIG. 2 after impregnated with a driving electrolytic solution, and the edge portion is sealed with a welding 29 to form a flat plate type electrolytic cell. It constitutes a capacitor.

According to the above-described embodiment of the present invention, the anode foil 21 having the notch 21a at one corner, the cathode foil 22 having the notch 22a at one corner, and And a separator 23 interposed between the anode foil 21 and the cathode foil 22 and provided with notches 23a and 23b at two corners, and the anode foil 21, the separator 23 and the cathode foil 22 are
Notch 21a of anode foil 21 and notch 2 of cathode foil 22
The capacitor element 25 is formed by sequentially stacking so that the two 2a do not correspond, and the cutout portion 2 of the anode foil 21 is formed.
The cathode lead member 26 is connected to the exposed portion 22b of the cathode foil 22 corresponding to 1a, and the cutout portion 2 of the cathode foil 22 is connected.
Since the anode lead member 27 is connected to the exposed portion 21b of the anode foil 21 corresponding to 2a, the size of the entire capacitor element 25 is a conventional one in which the anode foil and the cathode foil are laterally displaced, Alternatively, the anode foil and the cathode foil do not become larger than those provided with protruding portions that protrude outward, respectively, which allows the electrolytic capacitor itself to be downsized and the anode lead member 2
7 and the cathode lead member 26 can be effectively derived from the capacitor element 25 without increasing the cost. Further, unlike the conventional winding method, no reactance component is generated, so that the impedance at high frequency is low and the frequency characteristic is good.

[0017]

As described above, according to the electrolytic capacitor of the present invention, an anode foil and a cathode foil each provided with a notch at one corner, and an anode foil and a cathode foil interposed between the anode foil and the cathode foil, and It has a separator with a notch at one corner,
A capacitor element is formed by sequentially stacking the anode foil, the separator, and the cathode foil so that the notch portion of the anode foil and the notch portion of the cathode foil do not correspond to each other, and the cathode corresponding to the notch portion of the anode foil. Since the cathode lead member and the anode lead member are connected to the exposed portion of the foil and the exposed portion of the anode foil corresponding to the cutout portion of the cathode foil, the size of the entire capacitor element is the same as the conventional anode foil. And the cathode foil are laterally offset, or the anode foil and the cathode foil do not have to be as large as the ones that have protrusions that project outwards, respectively, which allows the electrolytic capacitor itself to be downsized. At the same time, it is possible to effectively derive the anode lead member and the cathode lead member from the capacitor element without increasing the cost.

[Brief description of drawings]

1A is a perspective view showing an anode foil of an electrolytic capacitor according to an embodiment of the present invention, FIG. 1B is a perspective view showing a separator of the electrolytic capacitor, and FIG. 1C is a perspective view showing a cathode foil of the electrolytic capacitor. ) A perspective view showing a state in which an anode foil, a separator and a cathode foil of the same electrolytic capacitor are laminated (e) A perspective view showing a capacitor element of the same electrolytic capacitor

FIG. 2 is a perspective view showing the appearance of the electrolytic capacitor.

FIG. 3 is a perspective view of a capacitor element of an electrolytic capacitor showing a conventional example.

FIG. 4 is a perspective view of a capacitor element of an electrolytic capacitor showing another conventional example.

[Explanation of symbols]

 21 Anode Foil 21a Notch 21b Exposed Part 22 Cathode Foil 22a Notch 22b Exposed 23 Separator 23a, 23b Notch 25 Capacitor Element 26 Cathode Lead Member 27 Anode Lead Member

Claims (1)

[Claims] 1. An anode foil and a cathode foil each having a notch at one corner, and a separator interposed between the anode foil and the cathode foil and having notches at two corners. Having the anode foil, the separator, the cathode foil, the capacitor element is formed by sequentially laminating the notch portion of the anode foil and the notch portion of the cathode foil so as not to correspond to each other, and in the notch portion of the anode foil. An electrolytic capacitor in which a cathode lead member is connected to an exposed portion of a corresponding cathode foil, and an anode lead member is further connected to an exposed portion of an anode foil corresponding to a cutout portion of the cathode foil.