JP2811645B2 - Manufacturing method of electrolytic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electrolytic capacitor impregnated with an organic semiconductor material, and more particularly to an improvement in an organic semiconductor material impregnating method.

[0002]

2. Description of the Related Art In general, in a dry-type foil electrolytic capacitor, a pair of lead terminals also made of aluminum are connected to a pair of anode and cathode foils made of high-purity aluminum foil. And a capacitor element wound with a spacer interposed therebetween.
As an electrolytic capacitor using such a capacitor element, for example, there is an electrolytic capacitor in which a capacitor element is impregnated with a driving electrolyte and stored in a case, and the case opening is sealed or the like. doing.

However, since the driving electrolyte uses an organic carboxylate such as ammonium adipate in an organic solvent such as ethylene glycol, there is a limit in improving the tan δ characteristic. Since the specific resistance is increased and the low-temperature characteristics are extremely deteriorated, the reliability is poor when used in a wide temperature range. Therefore, it is impossible for an electrolytic capacitor using a driving electrolyte to satisfy market requirements. Therefore, in recent years, various electrolytic capacitors using an organic semiconductor comprising a TCNQ complex instead of the driving electrolyte have been proposed, and some of them have been put to practical use.

As described above, the TCNQ is used for the capacitor element.
As a method for impregnating an organic semiconductor composed of a complex, there are generally a solution impregnation method, a dispersion impregnation method, and a vacuum evaporation method, but the TCNQ complex changes its properties under various conditions and is extremely difficult to handle. Therefore, various ideas have been devised for use. In particular, as the condition of the solid electrolyte, it is important that the resistance value itself affecting tan δ as a capacitor characteristic and the equivalent series resistance is small, and that there is a stable specific resistance value even in a wide temperature range. is there. When impregnating the capacitor element with the organic semiconductor comprising the TCNQ complex,
It is required that the required amount be uniformly penetrated into the capacitor element.

As a method for impregnating such a capacitor element with an organic semiconductor comprising a TCNQ complex, a heat-melt liquefaction treatment is considered to be promising, as conventionally proposed in patent publications and technical documents. As a specific method of this heat-melt liquefaction treatment, generally, put in an outer case,
A method in which a preheated capacitor element is housed in an organic semiconductor liquid composed of a desired TCNQ complex that has been heated and melted, and the capacitor element is impregnated with fine insulating pits of insulating paper fibers and electrode foil constituting the element. Has been adopted. In this case, in the heating and melting treatment of the organic semiconductor comprising the TCNQ complex, a kind of organic semiconductor that does not change much even when it is melted and solidified is housed in a cylindrical case for housing the capacitor element.

[0006]

However, organic semiconductors have a small particle size and a low bulk specific gravity. As a result, a necessary amount of organic semiconductor cannot be stored in a case. To solve this problem, a method that has been conventionally adopted is
The required amount of organic semiconductor is divided into halves, once housed in a case, and then pressed (compacted) with a round bar having a diameter slightly smaller than the inner diameter of the case to increase the density of the powder. There is a method in which after being put in, the material is heated and melted again by pressing with a round bar or the like.

However, such a conventional manufacturing method has poor workability, and there is a problem that the working environment is deteriorated due to scattering of the organic semiconductor powder. In addition, when the method of pressurizing with a round bar is employed as described above, variations in the pressure applied to the powder by the round bar cause variations in the heat conduction characteristics of the powder during heating and melting. Occurs. Due to the variation of the heating and melting time, further, the impregnation rate of the capacitor element becomes uneven, and
As the required impregnation cannot be obtained, as a result,
The capacitance and loss (tan) of the manufactured electrolytic capacitor
δ) and other characteristics are varied or deteriorated. In addition, when an automatic machine is used for the impregnation process,
Since the operation is performed for a fixed time (cycle), if the time until the melting varies, this greatly impairs the impregnation.

As described above, the conventional method for manufacturing an electrolytic capacitor has poor workability, and the impregnation of the capacitor element with the organic semiconductor is uneven and insufficient. There is a drawback that various characteristics are varied or deteriorated.

The present invention has been proposed to solve such problems of the prior art, and an object of the present invention is to improve the impregnation process of an organic semiconductor into a capacitor element by improving an organic semiconductor impregnation process. The present invention provides a method of manufacturing an electrolytic capacitor which is capable of uniformizing various characteristics such as capacitance and loss at a high level, and which is excellent in workability and work environment, and excellent in workability and work environment. That is.

[0010]

A method of manufacturing an electrolytic capacitor according to the present invention comprises forming a capacitor element by winding a capacitor element between an anode foil and a cathode foil made of a valve action metal with a spacer interposed therebetween. Inside and
In a method of manufacturing an electrolytic capacitor by impregnating a capacitor element with an organic semiconductor material, the organic semiconductor material may be used in an amount of 20 to
It is characterized in that it is made into granules having an average particle size of 70 mesh, stored in a case, heated and melted, and impregnated into a capacitor element. In this case, the size of the organic semiconductor material is more preferably in the range of 30 to 60 mesh.

[0011]

The operation of the present invention having the above configuration is as follows. That is, since the organic semiconductor is stored in a case in the form of granules of 20 to 70 mesh, the bulk specific gravity is significantly higher than in the case of using a powdery organic semiconductor, and there is no need to pressurize the organic semiconductor. A necessary amount of the organic semiconductor can be stored in the case. Therefore, the workability is good, and there is no problem of powder scattering, and the work environment is good.

As described above, since there is no need to pressurize the organic semiconductor, there is no variation in the heat conduction characteristics due to the variation in the pressing force. And the heating and melting time can be made uniform. As a result, the impregnation of the capacitor element with the organic semiconductor can be made uniform at a high level, so that various characteristics such as capacitance and loss of the completed electrolytic capacitor can be made uniform at a high level.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for manufacturing an electrolytic capacitor according to the present invention will be described below in detail with reference to FIGS. In this case, FIG. 1 is a sectional view showing an electrolytic capacitor manufactured according to one embodiment of the present invention, and FIG.
FIG. 3 is an exploded perspective view showing the structure of the capacitor element formed in the same embodiment. FIG. 3 is a schematic cross-sectional view showing a step (a) of storing an organic semiconductor in a case and a step (b) of heating and melting in the same embodiment. FIG.

First, as shown in FIG. 2, the surface of the aluminum foil is roughened with an etching solution to increase the surface area.
An anodic oxide film is formed to prepare an anode foil 1. Similarly,
The cathode foil 2 is prepared by roughening the surface of the aluminum foil with an etchant to increase the surface area. A spacer 3 made of kraft paper, manila paper, or the like is interposed between the anode foil 1 and the cathode foil 2, and the anode terminal 4 and the cathode terminal 5 are attached to arbitrary portions of the anode foil 1 and the cathode foil 2, respectively. To form a capacitor element 6.

Next, as shown in FIG. 3A, a predetermined amount of a granular organic semiconductor 8 made of a TCNQ complex is housed in an upper opening type case 7 made of, for example, aluminum or the like. . In this case, the size of the granules of the organic semiconductor 8 is in the range of 30 to 60 mesh.
Further, as shown in FIG. 3B, the granular organic semiconductor 8 is heated and melted to form a molten liquid organic semiconductor 9, and then,
As shown in FIG. 1, the capacitor element 6 is stored in a preheated state, and the organic semiconductor 9 in a molten liquid is impregnated in the capacitor element 6. After a sufficient impregnation time, the organic semiconductor 9 is cooled and solidified to obtain a solidified organic semiconductor 10. Finally, the opening of the case 7 is sealed with the sealing body 11 to complete the electrolytic capacitor.

In the above steps, the granular organic semiconductor 8 is used. Since the bulk specific gravity of the organic semiconductor 8 is much higher than that of the powdery organic semiconductor conventionally used, the impregnation of the capacitor element 6 is not performed. The required constant amount can be sufficiently stored in the case 7. Therefore, unlike the conventional case, it is not necessary to pressurize the organic semiconductor, so that the workability can be remarkably improved, and there is no problem of powder scattering, and the work environment is good.

As described above, in this embodiment in which it is not necessary to pressurize the organic semiconductor, there is no variation in the heat conduction characteristics due to the variation in the pressing force.
The heat conduction characteristics of the stored organic semiconductor can be made uniform, and the heating and melting time can be made uniform. As a result, the impregnation of the capacitor element with the organic semiconductor can be made uniform at a higher level than in the past, so that various factors such as capacitance and loss of the electrolytic capacitor of the present embodiment completed in the above steps are obtained. The characteristics can be made uniform at a much higher level than the electrolytic capacitor completed by the conventional technology.

Subsequently, actually, based on the above-described steps,
Electrolytic capacitor according to the manufacturing method of the present invention (product A of the present invention)
And an electrolytic capacitor (conventional product B) was produced by a conventional production method using a powdery organic semiconductor. That is, both the present invention and the conventional example use an anode foil having a width of 5 mm and a length of 25 mm and a cathode foil having a width of 5 mm and a length of 35 mm, and a width of 6 mm between these anode foil and cathode foil.
A capacitor element was formed by winding manila paper having a thickness of 50 μm as a spacer and winding it.

Next, as the organic semiconductor material, a TCNQ complex of N-methyl-3-n-propylimidazole was prepared for both the present invention and the conventional example. In this case, in the present invention, a 30-mesh to 60-mesh granular TCNQ complex was used by rolling once and then pulverized. On the other hand, in the conventional example, a powdery TCN having an average particle size of 100 mesh was used.
The Q complex was used. In these conditions, the bulk specific gravity of the conventional powdery TCNQ complex was 0.25 g /
While was cm ^3, and bulk density of the granular TCNQ complexes of the present invention, an average 0.5 g / cm ^3, it exhibited a multiple of the conventional example.

In the present invention and the conventional example, the diameter is 5 m.
m, an aluminum case with a height of 10 mm is prepared, and a certain amount (about 90 mg) of TCNQ required for impregnation into the capacitor element
The complexes were each stored. In this case, the granular TCNQ
In the present invention using the complex, the bulk specific gravity was large, so that the entire necessary amount could be stored as it was. On the other hand, in the conventional example, since the bulk specific gravity is small and the whole amount cannot be stored at once, about 6
0 mg of the TCNQ complex was once stored in the case, pressurized with a round bar smaller than the inner diameter of the case, and then the remaining TCNQ complex was additionally stored. Thereafter, both of the present invention and the conventional example were heated and melted on a heater, the preheated capacitor element was stored, impregnated, and cooled and solidified to complete an electrolytic capacitor rated at 16 V-10 μF.

The capacitance distribution and the loss distribution of the thus completed electrolytic capacitor according to the present invention (product A of the present invention) and the electrolytic capacitor according to the prior art (comparative product B) were investigated. FIG. 4 and FIG. The results shown were obtained. As is clear from FIGS. 4 and 5, both the capacitance characteristic and the loss characteristic of the product A of the present invention are made uniform at a higher level than the conventional product B.

The present invention is not limited to the above-described embodiment. For example, the type of the organic semiconductor is not limited to the TCNQ complex of N-methyl-3-n-propylimidazole, n amyl isoquinolinium TCN
Q complex, Nnbutylisoquinolinium TCNQ complex,
Alternatively, other organic semiconductors can be used, and in this case, the same excellent operational effects as those of the above-described embodiment can be obtained. Further, the present invention is not limited to the electrolytic capacitors having the dimensions and ratings of the above-described embodiment, but is applicable to various electrolytic capacitors having various dimensions and ratings. The same excellent operational effects as those described above can be obtained. Further, the present invention is characterized in that the organic semiconductor material is stored in a case in the form of granules having a particle size of 20 to 70 mesh in the impregnation step of the organic semiconductor material. As long as the method is used, specific configurations of the other various steps can be freely selected, and the same excellent operational effects as those of the above embodiment can be obtained regardless of the configuration of the other steps.

[0023]

As described above, in the present invention,
In the step of impregnating the organic semiconductor material, the organic semiconductor material is stored in the case in the form of granules having a particle size of 20 to 70 mesh, so that the impregnation of the capacitor element with the organic semiconductor can be performed at a higher level than before. It is possible to equalize and uniformize various characteristics such as capacitance and loss at a high level.
An excellent method for manufacturing an electrolytic capacitor can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an electrolytic capacitor manufactured by one embodiment of a method for manufacturing an electrolytic capacitor according to the present invention.

FIG. 2 is an exploded perspective view showing the structure of the capacitor element formed in the manufacturing method of FIG.

FIG. 3 is a schematic cross-sectional view showing a step (a) of storing an organic semiconductor in a case and a step (b) of heating and melting in the manufacturing method of FIG.

FIG. 4 is a characteristic diagram showing capacitance distributions of an electrolytic capacitor (product A of the present invention) according to a manufacturing method of the present invention and an electrolytic capacitor (conventional product B) of a conventional manufacturing method.

FIG. 5 is a characteristic diagram showing a loss distribution in an electrolytic capacitor (product A of the present invention) according to a manufacturing method of the present invention and an electrolytic capacitor (conventional product B) according to a conventional manufacturing method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Anode foil 2 ... Cathode foil 3 ... Spacer 4 ... Anode terminal 6 ... Cathode terminal 6 ... Capacitor element 7 ... Case 8 ... Granular organic semiconductor 9 ... Molten liquid organic semiconductor 10 ... Solid state organic semiconductor 11 ... Sealing body

Claims (1)

(57) [Claims] 1. A capacitor element formed by winding a valve metal between an anode foil and a cathode foil with a spacer interposed therebetween to form a capacitor element.
A method for producing an electrolytic capacitor by accommodating the capacitor element in a case and impregnating the capacitor element with an organic semiconductor material, wherein the organic semiconductor material is formed into granules having an average particle diameter of 20 to 70 mesh. A method for producing an electrolytic capacitor, comprising: heating, melting, and impregnating a capacitor element.