JPH07183172A - Manufacture of solid electrolytic capacitor - Google Patents

Abstract

PURPOSE:To uniformly melt an powdery organic semiconducting material filling up a capacitor case in a short time by heating and melting the material after pressing and shaping the material to have a recessed cross section. CONSTITUTION:An aluminum capacitor case 2 is filled up with an organic semiconductor composed of TCNQ complex salt as an electrolyte in a 90-% powder state. After filling, the complex salt is pressed and shaped to have a recessed cross section by using a stamp 41 having a V-shaped tip. Then the case 2 is put in a high-frequency coil and the case 2 is caused to generate heat with an induced current and the powdery TCNQ is melted by energizing the coil. Finally, a solid electrolytic capacitor is obtained by dipping capacitor elements in the molten TCNQ complex salt. Therefore, the characteristic deterioration of the TCNQ complex salt can be suppressed and the characteristics of the solid electrolytic capacitor can be improved, because the complex salt can be heated and melted in a short time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a solid electrolytic capacitor used as a component of various electronic devices.

[0002]

2. Description of the Related Art A solid electrolytic capacitor using an organic semiconductor as an electrolyte is disclosed in Japanese Patent Publication No. 3-76573.

A cross-sectional structure of the solid electrolytic capacitor is shown in FIG.
Shown in. In FIG. 4, 2 is a case made of aluminum and having a bottomed cylindrical shape, 1 is a capacitor element in which a positive side electrode plate 10, a separator paper 12 and a negative side electrode plate 11 are stacked and wound, and 9 is an electrolyte. And 13 is a sealing member.

Here, as a typical organic semiconductor,
A complex salt of 7,7,8,8-tetracyanoquinodimethane (hereinafter abbreviated as TCNQ complex salt) can be mentioned.

The organic semiconductor as the electrolyte is shown in FIG.
After being filled in the aluminum case 2 in the state of powder 90 as shown in (a) and pressed and shaped as shown in FIG. 5 (c) using a flat punch 45 as shown in FIG. 5 (b), By immersing the capacitor element in a place where it is heated and melted, the separator paper of the capacitor element is impregnated.

In the impregnation step, it is necessary to perform heating, melting and impregnation treatments in a short time in order to prevent deterioration of the characteristics of the organic semiconductor as an electrolyte. However, since the organic semiconductor materials such as the TCNQ complex salt have poor thermal conductivity, as shown in FIG.
Even if the portion 91 near the wall surface of the case 2 is in a molten state,
An incompletely melted portion 99 may remain in the center.

[0007]

DISCLOSURE OF THE INVENTION The present invention clarifies a method for producing a solid electrolytic capacitor capable of uniformly melting an organic semiconductor material by heating for a short time.

[0008]

In the method of manufacturing a solid electrolytic capacitor according to the present invention, a powdery organic semiconductor material filled in a capacitor case is pressed and shaped to have a concave vertical section, and then heated and melted. It is a feature.

[0009]

According to the above manufacturing method, the heat from the case is transferred substantially uniformly to the powdery organic semiconductor material pressed and shaped to form a layer having a substantially uniform thickness along the wall surface of the case. The organic semiconductor material is heated and melted substantially uniformly so that no unmelted portion remains in the central portion.

[0010]

EXAMPLES Examples of the present invention will be described below.

In the method for producing a solid electrolytic capacitor according to the present invention, a TCNQ complex salt as an electrolyte is used as shown in FIG.
As shown in FIG. 1 (a), powder 90 is filled in a capacitor case 2 made of aluminum, and vertical cutting is performed as shown in FIG. 1 (c) using a V-shaped tip 41 as shown in FIG. 1 (b). It is pressed into a concave shape, heat-melted and impregnated into a wound-type capacitor element.

As a heating method in the impregnation step,
An induction heating method capable of rapid heating and cooling is suitable. That is, FIG.
As shown in FIG. 3, the aluminum case 2 filled with the powdery TCNQ complex salt 90 in a concave shape in the vertical cross section is housed in the holder 5 and placed inside the high frequency coil 6, and when the high frequency coil is energized. The aluminum case self-heats due to the induced current, and this heat generation causes the powdery TCNQ complex salt to rise in temperature and melt.

As shown in FIG. 3, the heater 8 may be used to indirectly heat the aluminum case 2 housed in the holder 7.

Then, the wound capacitor element is dipped in the molten TCNQ complex salt to impregnate the separator paper of the capacitor element with the TCNQ complex salt, and after solidification by cooling, sealing treatment is performed, as shown in FIG. A solid electrolytic capacitor can be obtained.

Here, according to the manufacturing method of the present invention and the conventional manufacturing method, the case size is φ8 mm, and the rating is 16V10.
Table 1 shows a summary of the results obtained by making 30 prototypes of 0 μF solid electrolytic capacitors and measuring the equivalent series resistance (hereinafter abbreviated as ESR) of each sample at a frequency of 100 kHz.

[0016]

[Table 1]

As can be seen from Table 1, the solid electrolytic capacitor according to the present invention generally has a small ESR value and its variation is small.

[0018]

According to the present invention, in the step of heating and melting the organic semiconductor to impregnate the capacitor element, the organic semiconductor is heated and melted substantially uniformly, so that the time required for the step is shortened and the organic semiconductor is reduced. The deterioration of the characteristics is suppressed, and the characteristics of the solid electrolytic capacitor using the organic semiconductor become excellent.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of (a) capacitor case, (b) V-shaped punch, and (c) capacitor case for explaining an embodiment of the present invention.

FIG. 2 is a cross-sectional view of an induction heating system for explaining an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a heater heating system for explaining an embodiment of the present invention.

FIG. 4 is a cross-sectional view of a solid electrolytic capacitor for explaining an example of the present invention and a conventional example.

FIG. 5 is a cross-sectional view of (a) capacitor case, (b) flat punch, and (c) capacitor case for explaining a conventional example.

FIG. 6 is a cross-sectional view of a capacitor case for explaining the problems of the conventional example.

[Explanation of symbols]

 1 Capacitor element 2 Capacitor case 41 V-shaped punch 9 Electrolyte consisting of organic semiconductor 90 Powdery organic semiconductor

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[Procedure amendment]

[Submission date] February 9, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

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[Figure 1]

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 5

[Correction method] Change

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[Figure 5]

Claims (2)

[Claims] 1. A method for producing a solid electrolytic capacitor, comprising a step of filling a cylindrical case having a bottom with a powdery organic semiconductor material, heating and melting the organic semiconductor material to impregnate the capacitor element, and then cooling and solidifying. In the method for producing a solid electrolytic capacitor, the powdery organic semiconductor material filled in the case is pressed and shaped so as to have a concave vertical section, and then heated and melted. 2. The method for producing a solid electrolytic capacitor according to claim 1, wherein the organic semiconductor is a complex salt of 7,7,8,8-tetracyanoquinodimethane.