JPH0855762A - Electrolytic capacitor - Google Patents

Abstract

PURPOSE:To achieve miniaturization and height reduction by bringing a positive foil and a spacer or the width of the positive foil and the spacer into identical size and disposing a separator between at least the bottom surface of a case and a capacitor element. CONSTITUTION:Positive foil, negative foil and a spacer are wound to make a capacitor element 1 which has a rated voltage of 16V, a diameter of 16m and a length of 25m The lead terminals 2, 3 of the capacitor element 1 are inserted into a sealing plug 4 and a separator 6 is disposed between the capacitor element 1 and the bottom surface of a case 5 and contained and sealed into the case 5. Thus, the electrode foil and the width of the spacer are made to have identical size, and the separator 6 is disposed between the capacitor element 1 and the bottom surface of the case 5, thereby being able to prevent short-circuiting. Thereby, the miniaturization and the height reduction by the difference between the electrode foil and the width of the spacer can be made to be able to contribute to the miniaturization of an electric apparatus. The fraction defective of dielectric breakdown which is generated in an aging process exhibits an extremely low value.

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 electronic equipment and the like, and more particularly to an electrolytic capacitor which can be made compact and low in height.

[0002]

2. Description of the Related Art A foil-type dry electrolytic capacitor is constructed by sandwiching a spacer such as kraft paper or manila paper between an anode foil and a cathode foil to which lead wire terminals are attached and winding them to form a capacitor element. This was impregnated with a driving electrolytic solution, and the lead wire terminals were inserted into a sealing plug, housed in a case, and hermetically sealed.

Even in the electrolytic capacitor having such a structure, there is a strong demand for downsizing and height reduction as the downsizing of electronic equipments progresses.

[0004]

There are various methods for reducing the size or height of the electrolytic capacitor, such as using a high-magnification electrode foil and reducing the width difference between the electrode foil and the spacer. Is also a means. When the electrode foil and the spacer are wound, a winding deviation or the like occurs, and the electrode foil and the case or the electrode foils may come into contact with each other in the assembly process to cause a short circuit defect. For this reason, the width of the spacer has usually been wider than the width of the electrode foil by about 1 to 3 mm.
However, in recent years, the precision of the winder has been improved, and a high-precision machine with a mechanism for removing burrs generated on the end face of the electrode foil has been introduced.

In view of the above situation, the present invention sets the widths of the electrode foil and the spacer to be the same size in view of the demands for downsizing and height reduction and the improvement of the accuracy of the capacitor winding machine. It is an object of the present invention to provide a miniaturized or low-profile electrolytic capacitor by reducing the width difference between the foil and the spacer to zero.

[0006]

SUMMARY OF THE INVENTION An electrolytic capacitor according to the present invention includes a capacitor element wound between a positive electrode foil and a negative electrode foil, to which a lead wire terminal is attached, via a spacer, and a lead wire terminal of the capacitor element. In an electrolytic capacitor comprising a sealing plug having inserted therein, and a case that accommodates and seals the capacitor element and the sealing plug, the anode foil and the spacer, or the width of the anode foil and the cathode foil and the spacer have the same size, and at least the above. A separator is arranged between the bottom surface of the case and the capacitor element.

[0007]

According to the electrolytic capacitor having such a structure, the electrode foil and the spacer have the same width, and the separator can be disposed between the capacitor element and the bottom surface of the case to prevent a short circuit. It is possible to reduce the size and height by the difference in the width between the electrode foil and the spacer, and it is possible to greatly contribute to the downsizing of electronic devices.

[0008]

【Example】

Example 1 An anode foil, a cathode foil, and a spacer (capacitor paper) were wound under the conditions shown in Table 1 and Table 2 to produce a capacitor element 1 having a rated voltage of 16 V, a diameter of 16 mm and a length of 25 mm, as shown in FIG. did. The lead wire terminals 2 and 3 of the capacitor element 1 were inserted into the sealing plug 4, and the separator 6 was placed between the capacitor element 1 and the bottom surface of the case 5 and housed in the case 5 for sealing. The capacitance of this sample is as shown in Tables 1 and 2. In the conventional example, a separator was not provided between the capacitor element and the bottom surface of the case, and the same materials and parts as those of the example were used except for the conditions shown in Tables 1 and 2.

In addition, Table 3 shows the dielectric breakdown defect rate generated in the aging process for each of the 10,000 prototypes and the conventional example manufactured under the conditions shown in Tables 1 and 2.

[0010]

[Table 1]

[0011]

[Table 2]

[0012]

[Table 3]

As is clear from Tables 1 and 2 described above, first, by setting the widths of the anode foil and the spacer to be the same size, it is possible to increase the capacitance of about 40% with a capacitor element of the same size. it can.

Further, it is clear from Table 3 that the dielectric breakdown defect rate is small when the withstand voltage of the separator is larger than the withstand voltage of the spacer arranged between the anode foil and the cathode foil of the capacitor element. It was confirmed that the effect was further enhanced when the separator was provided on the inner surface of the case as in Example F.

Example 2 In Example 1, the width of the anode foil and the spacer were the same, but in Example 2, the width of the anode foil, the cathode foil and the spacer were the same. , Table 5 and Table 6.

[0016]

[Table 4]

[0017]

[Table 5]

[0018]

[Table 6]

In Examples G to L, since the width of the cathode foil was the same, the dielectric breakdown defect rate was slightly larger than that in Examples A to F.
Similar results were obtained as in the case of ~ F.

[0020]

As described above, according to the present invention, it is possible to meet a request from an electric equipment manufacturer for providing a downsized and low-profile electrolytic capacitor without lowering reliability.

[Brief description of drawings]

FIG. 1 is a front sectional view showing an electrolytic capacitor according to the present invention.

[Explanation of symbols]

 1 Capacitor element 2 Lead wire terminal 3 Lead wire terminal 4 Sealing cap 5 Case 6 Separator

Claims (5)

[Claims] 1. A capacitor element wound between a positive electrode foil and a negative electrode foil to which lead wire terminals are attached via a spacer,
A sealing plug into which a lead wire terminal of the capacitor element is inserted,
In an electrolytic capacitor provided with a case in which the capacitor element and a sealing plug are accommodated and sealed, the anode foil and the spacer, or the anode foil and the cathode foil and the spacer have the same width, and at least the bottom surface of the case and the capacitor element. An electrolytic capacitor having a separator interposed therebetween. 2. The electrolytic capacitor according to claim 1, wherein the electric insulation of the separator is higher than that of the spacer. 3. The electrolytic capacitor according to claim 1, wherein the separator is provided on the entire bottom surface of the case. 4. The separator according to claim 1, wherein the separator is provided on a bottom surface and a side surface of the case.
The electrolytic capacitor according to any one of 1. 5. The electrolytic capacitor according to claim 1, wherein the separator is electrolytic capacitor paper.