JPH07211594A - Capacitor and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a capacitor whose wettability is enhanced and which enhances the impregnating property of an electrolytic solution by a method wherein a corona discharge treatment is conducted to both faces, one face or a required part of an electrode foil for an anode, an electrode foil for a cathode or a sheet of isolation paper. CONSTITUTION:An Al foil 12 is arranged and installed between both end parts 5a, 6a, and a voltage at about 70kV is applied across both end parts 5a, 6a. An ionization action is generated around a first electrode 5 and a second electrode 6, and a corona discharge is generated. Embossed parts are worked physically by the action of the corona discharge onto the surface 12a and the back 12b of the Al foil 12 which is passed between both end parts 5a, 6a, and uneven faces 12c are formed. In addition, the surface 12a and the back 12b are activated chemically by the action of ozone or active oxygen, they are oxidized, and aluminum oxide is formed on the surface 12a and the back 12b of the Al foil. Thereby, the Al foil is reformed, its wettability is enhanced, and its leakage current is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor and a method for manufacturing the same, and in particular, after performing corona discharge treatment on both sides, one side or a required part of an electrode foil for anode, electrode foil for cathode or separator paper, By alternately laminating the anode electrode foil, the cathode electrode foil and the separator paper and winding them up, and in the case of an electrolytic capacitor, impregnating with an electrolytic solution to form a capacitor element,
A capacitor and its capacitor which are improved in wettability of the anode electrode foil, the cathode electrode foil and the separator paper to drastically shorten the impregnation time of the electrolytic solution and to reduce the leakage current to improve the electrical characteristics. It relates to a manufacturing method.

[0002]

2. Description of the Related Art A conventional capacitor, particularly an electrolytic capacitor, is an aluminum foil having a purity of about 99.99%, an etching foil obtained by etching the aluminum foil by an electrochemical treatment to roughen it to increase its surface area, and the etching. A compound foil having a dielectric oxide film formed on its surface by further anodizing the foil is used as an electrode foil for an anode and an electrode foil for a cathode, and a tab for electrode extraction is fixed to the electrode foil for an anode and the electrode foil for a cathode. Electrode foil, cathode electrode foil and separator paper are alternately stacked and rolled up into a cylindrical or elliptical flat shape, and then impregnated with an electrolytic solution to manufacture a capacitor element, and the capacitor element is made of metal. After storing in a cylindrical case with a bottom,
It was manufactured by sealing the open end of the case with a sealing material such as rubber having elasticity.

As a combination of the electrode foil for the anode and the electrode foil for the cathode, a combination of an aluminum foil and a chemical foil, an etching foil and a chemical foil, a chemical foil and a chemical foil, and the like are used. In any combination, The anode electrode foil, the cathode electrode foil, and the separator paper are alternately laminated and rolled up into a cylindrical shape, and then impregnated with an electrolytic solution.

The impregnation of the electrolytic solution is carried out by utilizing the capillary phenomenon and the permeation phenomenon, and in order to promote the impregnation, the capacitor element is put in a vacuum chamber, a pressurizing chamber or a heating chamber to form a vacuum and then the pressure is applied. Alternatively, various measures have been taken to rapidly and completely impregnate by heating or shorten the time required for impregnation.

However, the wider the foil of the capacitor element, the larger the diameter of the capacitor element, and the larger the capacitor element, and the harder the anode electrode foil, the cathode electrode foil, and the separator paper are wound up with the electrolyte solution. It is difficult to do so, and the impregnation requires a long time, which is an obstacle to improvement of productivity, and improvement of the impregnation step of the electrolytic solution has been desired.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above-mentioned drawbacks of the prior art. The purpose of the present invention is to make an electrode foil for an anode, an electrode foil for a cathode or a separator paper. Corona discharge treatment on both sides, one side or a required part activates the surface of the electrode foil for anode, electrode foil for cathode or separator paper to further improve the wettability, and thereby electrolytic treatment The purpose is to improve the impregnation property of the liquid so that the impregnation time of the electrolytic solution can be shortened, and to improve the productivity.

Still another object is to roughen the surface of the anode electrode foil, the cathode electrode foil or the separator paper to increase the surface area by the above-mentioned constitution, and to improve the electrical performance by the same. It is possible to manufacture a high-performance electrolytic capacitor in a smaller size, improve reliability, and extend the life of the electrolytic capacitor.

Still another object is the thickness, width, degree of etching, thickness of chemical film formation, type of anode electrode foil of aluminum foil which is selected according to electric capacity such as electrostatic capacity and voltage of electrolytic capacitor. Depending on the type of cathode electrode foil and the type of separator paper, the predetermined electrical characteristics can be obtained by applying corona discharge treatment to both sides, one side or a required part of the anode electrode foil, cathode electrode foil or separator paper. It is to make it easy to manufacture an electrolytic capacitor that has.

Still another object is to form a capacitor element by alternately laminating and winding up on both sides, one side or a required part of the electrode foil for anode, electrode foil for cathode or separator paper while continuously performing corona discharge treatment. By doing so, the productivity of the capacitor element is significantly improved.

Still another object is to perform corona discharge treatment on both sides, one side or a required part of the electrode foil for the anode, the electrode foil for the cathode or the separator paper in advance, and then roll it up to form a capacitor element. Another object of the present invention is to make it possible to relatively easily produce a high-performance electrolytic capacitor that has been subjected to corona discharge treatment without requiring a large and expensive device capable of continuously performing discharge treatment and winding treatment at the same time.

[0011]

SUMMARY OF THE INVENTION In summary, a capacitor according to the present invention (Claim 1) has corona discharge treatment on both sides, one side or a required part of an electrode foil for an anode, an electrode foil for a cathode or a separator paper. After that, the anode electrode foil, the cathode electrode foil, and the separator paper are alternately superposed and rolled up to form a capacitor element.

In the method of the present invention (claim 2), the anode electrode foil, the cathode electrode foil or the separator paper is continuously subjected to corona discharge treatment on both sides, one side or a required part of the anode electrode foil. The cathode electrode foil and the separator paper are alternately stacked and rolled up to form a capacitor element.

Further, in the method of the present invention (claim 3), the anode electrode foil, the cathode electrode foil or the separator paper is subjected to corona discharge treatment in advance on both sides, one side or a required part thereof, and the anode electrode foil is obtained. The cathode electrode foil and the separator paper are alternately stacked and rolled up to form a capacitor element.

In the electrolytic capacitor according to the present invention (claim 4), the corona discharge treatment is applied to both sides, one side or a required part of the aluminum foil, the chemical conversion foil having the oxide film formed on the surface of the aluminum foil or the separator paper. After that, the aluminum foil, the chemical conversion foil, and the separator paper are alternately superposed and rolled up, and a capacitor element impregnated with an electrolytic solution is included.

In the method of the present invention (claim 5), corona discharge treatment is continuously applied to both sides, one side or a required part of an aluminum foil, a chemical conversion foil having an oxide film formed on the surface of the aluminum foil or a separator paper. On the other hand, the aluminum foil, the chemical conversion foil, and the separator paper are alternately laminated and rolled up to form a capacitor element.

In the method of the present invention (claim 6), corona discharge treatment is applied to both sides, one side or a required part of an aluminum foil, a chemical conversion foil having an oxide film formed on the surface of the aluminum foil or a separator paper in advance. The aluminum foil, the chemical conversion foil, and the separator paper are alternately laminated and rolled up to form a capacitor element.

The electrolytic capacitor according to the present invention (claim 7) is a chemical conversion foil in which an oxide film is formed on the surface of an aluminum foil, an etching foil obtained by electrochemically etching the surface of the aluminum foil, or both sides of a separator. It is characterized in that it includes a capacitor element in which the chemical conversion foil, the etching foil and the separator paper are alternately superposed and rolled up and impregnated with an electrolytic solution after corona discharge treatment is applied to one surface or a required part thereof. Is.

Further, the method of the present invention (claim 8) is a chemical conversion foil in which an oxide film is formed on the surface of an aluminum foil, an etching foil obtained by electrochemically etching the surface of an aluminum foil, or a separator paper. While continuously performing corona discharge treatment on a part of the above, the chemical conversion foil, the etching foil, and the separator paper are alternately superposed and rolled up to form a capacitor element.

In the method of the present invention (claim 9), the chemical conversion foil in which an oxide film is formed on the surface of the aluminum foil, the etching foil obtained by electrochemically etching the surface of the aluminum foil or the separator paper is used on both sides, one side or as required. A part of the above is subjected to corona discharge treatment in advance, and the chemical conversion foil, the etching foil and the separator paper are alternately superposed and rolled up to form a capacitor element.

In the electrolytic capacitor according to the present invention (claim 10), after the corona discharge treatment is applied to both surfaces, one surface or a required part of the chemical conversion foil or the separator paper having the oxide film formed on the surface of the aluminum foil, It is characterized in that it includes a capacitor element in which two sheets of the chemical conversion foil and the separator paper are alternately superposed and rolled up to impregnate the electrolytic solution.

In the method of the present invention (claim 11), two or more sheets of chemical conversion foil or separator paper having an oxide film formed on the surface of aluminum foil are continuously corona-discharge-treated on both sides, one side or a required part thereof. The compound foil and the separator are alternately stacked and wound up to form a capacitor element.

Further, according to the method of the present invention (claim 12), the corona discharge treatment is applied in advance to both sides, one side or a required part of the chemical conversion foil or the separator paper having the oxide film formed on the surface of the aluminum foil, and then two sheets are formed. The compound foil and the separator are alternately stacked and wound up to form a capacitor element.

[0023]

Function: In air, the applied voltage between the electrodes is about 70k
When the voltage is increased to about V / cm, an ionization action occurs around the electrode, and light is emitted to the end portion of the electrode to 1 to 100 μm.
It is well known that corona discharge in which a weak current of about A flows is generated.

By subjecting the aluminum foil to corona discharge (hereinafter referred to as corona discharge treatment), the surface of the aluminum foil is physically embossed by the action of light, current and ozone or active oxygen as ionization products. Chemically, aluminum oxide is not generated.For example, the cut surface of the aluminum foil by a slitter, the lead tab, etc. are activated to activate the surface, and aluminum oxide is generated to prevent leakage current. Reduction is achieved.

By performing corona discharge treatment on a separator (separation paper) such as insulating paper and film or non-woven fabric made of kraft paper, Manila paper, etc., not only the surface area is increased by the embossing mentioned above, but also the surface area is increased. By activation, wettability is improved, the impregnation time of the electrolytic solution is significantly shortened, and in the insulating paper, a carbonyl group is generated from a hydroxyl group to combine with a metal ion to reduce a leakage current.

As described above, the corona discharge treatment of the anode electrode foil, the cathode electrode foil or the separator paper improves the wettability and greatly shortens the impregnation time of the electrolytic solution, thereby caulking the tab of the electrolytic capacitor. The time balance among the steps, the winding step, the electrolytic solution impregnating step, the assembling step and the aging step can be made uniform, and automation is facilitated, so that the productivity can be greatly improved.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings. 1 to 5, a capacitor element 1 according to the present invention includes an electrode foil 2 for anode, an electrode foil 3 for cathode, and a separator 4 which have been subjected to corona discharge treatment on both sides, one side or a required part thereof. ing.

For example, a method of subjecting the front surface 12a and the back surface 12b of the aluminum foil 12 as an example of the anode electrode foil 2 to corona discharge treatment will be described. In FIGS. 1 and 2, the end portions 5a and 6a are made to facilitate discharge. A first electrode 5 and a second electrode 6, which are formed in an acute angle, are arranged with a space of about 1 cm, and a high voltage power supply is provided between the first electrode 5 and the second electrode 6. 8 are connected by an electric wire 9 so that an AC high voltage can be applied between both ends 5a, 6a.

The aluminum foil 12 is disposed between the both ends 5a and 6a, and the applied voltage between the both ends 5a and 6a is set to about 7.
When the voltage is increased to about 0 kV, an ionization action occurs around the first electrode 5 and the second electrode 6, and a weak current of about 1 to 100 μA flows between both ends 5a and 6a to start corona discharge.

The aluminum foil 12, which is placed between the first electrode 5 and the second electrode 6 which are corona-discharging and runs in the direction of the arrow A, has light, current and ionization products such as ozone or active oxygen by corona-discharging. Acts to physically emboss the front surface 12a and the back surface 12b of the aluminum foil 12 to form the uneven surface 12c on the front surface 12a and the back surface 12b, and roughens the surface area to increase the surface area. Specifically, the surfaces 12a, 12 are affected by the action of ozone or active oxygen.
b is activated, the surfaces 12a and 12b of the aluminum foil 12 are oxidized to produce aluminum oxide, and a dielectric oxide film is formed.

The above-mentioned corona discharge treatment is continuously performed, and the aluminum foil 12 is modified by the corona discharge treatment to improve the wettability and reduce the leakage current.

Only on the surface 12a of the aluminum foil 12,
In order to perform the corona discharge treatment, in FIG. 3, the first electrode 5 and the cylindrical second electrode 6 each having the end 5a formed in an acute angle so as to face the surface 12a of the aluminum foil 12 traveling in the direction of arrow A are formed. And a high voltage power source 8 connected by an electric wire 9 between the first electrode 5 and the second electrode 6, and an alternating current of about 70 kV between the first electrode 5 and the second electrode 6. By applying a high voltage, the surface 12a of the aluminum foil 12 is subjected to corona discharge treatment and embossed to increase the surface area to improve wettability as in FIG. 2, and a dielectric oxide film is formed to prevent leakage current. Is configured to be modified.

In the above-described embodiments, the aluminum foil 12 was treated as corona discharge as an example of the anode electrode foil 2, but the cathode electrode foil 3 and the separator paper 4 were used.
The same can be applied to the case of corona discharge treatment.

In order to manufacture the capacitor element 1 while continuously performing corona discharge treatment on the anode electrode foil 2, the cathode electrode foil 3 and the separator paper 4, the coil element was wound in FIGS. 4 and 5. The anode electrode foil coil, the cathode electrode foil coil, and the separator paper coil (not shown) are fed out in the direction of arrow A while guiding the anode electrode foil 2, the cathode electrode foil 3 and the separator paper 4 respectively with the guide roller 10. During the feeding, the tab with the lead wire is subjected to a sharpening process (not shown) and fixed to the electrode foil 2 for anode and the electrode foil 3 for cathode.

Further, between the first electrode 5 and the second electrode 6 which are spaced from each other by about 1 cm and are arranged to face each other and to which high voltage is applied, the electrode foil 2 for anode, the electrode foil 3 for cathode and the isolation are provided. The paper 4 is run, and the corona discharge treatment is performed on both sides of the anode electrode foil 2, the cathode electrode foil 3 and the separator paper 4, and they are alternately superposed on each other and rolled up on the winding shaft 11 in a cylindrical or elliptical flat shape. To manufacture the capacitor element 1.

As the anode electrode foil 2, the cathode electrode foil 3 and the separator paper 4, aluminum foil, a chemical conversion foil in which an oxide film is formed on the surface of the aluminum foil or an aluminum foil whose surface is electrochemically etched is etched. A foil or the like can be used in an appropriate combination according to the required electrical performance.

The manufacturing method according to the present invention is characterized in that the anode electrode foil 2, the cathode electrode foil 3 or the separator paper 4 is continuously subjected to corona discharge treatment on both sides, one side or a required part of the anode electrode foil. 2. A method for manufacturing the capacitor element 1 by alternately stacking the electrode foil 3 for cathode and the separator paper 4 and winding them up.

In another manufacturing method according to the present invention, the anode electrode foil 2, the cathode electrode foil 3 or the separator paper 4 is subjected to a corona discharge treatment in advance on both sides, one side or a required part of the anode foil, In this manufacturing method, the electrode foil 2, the electrode foil 3 for the cathode, and the separator paper 4 are alternately superposed and rolled up to form the capacitor element 1.

The present invention is configured as described above,
The operation will be described below. 1 to 5, the anode electrode foil 2, the cathode electrode foil 3 and the separator 4 are disposed between the first electrode 5 and the second electrode 6 which are disposed opposite to each other and are subjected to a high voltage to cause corona discharge. The corona discharge is applied to the surface of the anode electrode foil 2, the cathode electrode foil 3 and the separator paper 4, and light and current are physically applied to the surfaces of the anode electrode foil 2, the cathode electrode foil 3 and the separator paper 4 to form an uneven surface. The surface of the anode electrode foil 2, the cathode electrode foil 3 and the separator paper 4 is activated by roughening the surface area to increase the surface area thereof, and by making ozone or active oxygen as an ionization product act on the anode electrode foil. 2. When the cathode electrode foil 3 is an aluminum foil 12, the surface thereof is oxidized to form a dielectric oxide film to improve wettability and reduce leakage current, thereby making the anode electrode foil 2 and the cathode electrode. Foil 3
Also, the separator 4 is modified.

The capacitor element 1 produced by rolling up the above-mentioned modified anode electrode foil 2, cathode electrode foil 3 and separator paper 4 has improved wettability, so that the electrolytic solution can be removed in a short time. Impregnation can be performed, productivity can be significantly improved, leakage current can be reduced, electrical characteristics can be improved, reliability can be improved, and a capacitor with a long life can be manufactured. it can.

In the above embodiment, the capacitor element is described as being wound on the anode electrode foil, the cathode electrode foil, or the separator paper while continuously performing the corona discharge treatment, but the capacitor element is continuously corona. It is not limited to winding up while performing discharge processing,
You may wind using the electrode foil for anodes, the electrode foil for cathodes, or separator paper which were previously subjected to corona discharge treatment.

[0042]

As described above, the present invention provides an electrode foil for an anode,
Corona discharge treatment was applied to both sides, one side or required part of the cathode electrode foil or separator paper, so that the surface of the anode electrode foil, cathode electrode foil or separator paper is activated and the wettability is further improved. As a result, the impregnation property of the electrolytic solution can be improved, and the impregnation time of the electrolytic solution can be shortened, so that the productivity of the capacitor can be improved.

Further, with the above structure, the surface of the anode electrode foil, the cathode electrode foil or the separator paper can be roughened to increase the surface area, and as a result, the electrical performance is improved and the electrolytic capacitor having the same performance is obtained. Can be manufactured in a smaller size, reliability can be improved, and the life of the electrolytic capacitor can be extended.

Furthermore, the thickness of the aluminum foil selected according to the electric capacity of the electrolytic capacitor, the electric voltage and the like,
Width, degree of etching, thickness of chemical film formation, type of electrode foil for anode, type of electrode foil for cathode, type of separator paper, anode electrode foil, both sides of cathode electrode foil or separator paper, one side Alternatively, since corona discharge treatment is applied to a required part, there is an effect that an electrolytic capacitor having predetermined electric characteristics can be easily manufactured.

Further, since the anode electrode foil, the cathode electrode foil or the separator paper is subjected to corona discharge treatment continuously on both sides, one side or a required part of the foil, the layers are alternately superposed and rolled up to form a capacitor element. There is an effect that the productivity of can be greatly improved.

Furthermore, since the corona discharge treatment is applied in advance to both sides, one side or a required part of the electrode foil for the anode, the electrode foil for the cathode or the separator paper, it is rolled up to form a capacitor element.
There is an effect that a high-performance electrolytic capacitor subjected to corona discharge treatment can be relatively easily manufactured without requiring a large and expensive device capable of continuously performing the corona discharge treatment and the winding treatment at the same time.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which corona discharge treatment is applied to both surfaces of an anode electrode foil, a cathode electrode foil, or separator paper.

FIG. 2 is a vertical cross-sectional view showing a state in which an anode electrode foil, a cathode electrode foil or a separator paper is subjected to corona discharge treatment.

FIG. 3 is a perspective view showing a state in which a corona discharge treatment is applied to one surface of an electrode foil for an anode, an electrode foil for a cathode or a separator.

FIG. 4 is a front view showing a state in which an anode electrode foil, a cathode electrode foil, and a separator paper are continuously wound while being corona-discharge treated to manufacture a capacitor element.

FIG. 5 is a perspective view of a completed capacitor element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Capacitor element 2 Electrode foil for anode 3 Electrode foil for cathode 4 Separation paper 12 Aluminum foil as an example of electrode foil for anode

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location // C25F 3/04 Z

Claims (12)

[Claims] 1. Anode electrode foil, cathode electrode foil or separator paper after corona discharge treatment on both surfaces, one surface or a required part of the anode electrode foil, cathode electrode foil and separator paper. A capacitor characterized by including a capacitor element formed by alternately stacking and winding up. 2. The anode electrode foil, the cathode electrode foil and the separator while continuously performing corona discharge treatment on both surfaces, one surface or a required part of the anode electrode foil, the cathode electrode foil or the separator paper. A method for manufacturing a capacitor, characterized in that paper is alternately stacked and rolled up to form a capacitor element. 3. The anode electrode foil, the cathode electrode foil or the separator paper is previously subjected to corona discharge treatment on both sides, one side or a required part thereof, and the anode electrode foil, the cathode electrode foil and the separator. A method for manufacturing a capacitor, characterized in that paper is alternately stacked and rolled up to form a capacitor element. 4. The aluminum foil, the chemical conversion foil having an oxide film formed on the surface of the aluminum foil or the separator paper, which is subjected to corona discharge treatment on both sides, one side or a required part thereof, and then the aluminum foil, the chemical conversion foil and the above An electrolytic capacitor comprising a capacitor element in which separators are alternately superposed and rolled up to impregnate an electrolytic solution. 5. The aluminum foil, the chemical conversion foil in which an oxide film is formed on the surface of the aluminum foil, or both sides, one side or a required part of a separator paper is continuously subjected to corona discharge treatment, and the aluminum foil, the chemical conversion foil, and A method of manufacturing a capacitor, characterized in that the separators are alternately stacked and rolled up to form a capacitor element. 6. An aluminum foil, a chemical conversion foil in which an oxide film is formed on the surface of the aluminum foil, or a separator paper is previously subjected to corona discharge treatment on both sides, one side or a required part of the aluminum foil, the chemical conversion foil and A method of manufacturing a capacitor, characterized in that the separators are alternately stacked and rolled up to form a capacitor element. 7. A corona discharge treatment is applied to both sides, one side or a required part of a chemical conversion foil in which an oxide film is formed on the surface of an aluminum foil, an etching foil obtained by electrochemically etching the surface of an aluminum foil or a separator paper. After that, the formed foil,
An electrolytic capacitor comprising a capacitor element in which the etching foil and the separator are alternately stacked and rolled up and impregnated with an electrolytic solution. 8. A corona discharge continuously formed on both surfaces, one surface or a required part of a chemical conversion foil in which an oxide film is formed on the surface of an aluminum foil, an etching foil obtained by electrochemically etching the surface of an aluminum foil or a separator paper. A method for manufacturing a capacitor, characterized in that the chemical conversion foil, the etching foil, and the separator paper are alternately superposed while being treated and rolled up to form a capacitor element. 9. A corona discharge treatment is applied to both sides, one side or a required part of a chemical conversion foil in which an oxide film is formed on the surface of an aluminum foil, an etching foil obtained by electrochemically etching the surface of an aluminum foil or a separator paper. A method of manufacturing a capacitor, wherein the chemical conversion foil, the etching foil, and the separator paper are alternately laminated and rolled up to form a capacitor element. 10. A chemical conversion foil or separator having an oxide film formed on the surface of an aluminum foil is subjected to corona discharge treatment on both sides, one side or a required part thereof, and then two chemical conversion foils and the separator are separated. An electrolytic capacitor comprising a capacitor element in which the electrolytic solution is impregnated by alternately laminating and winding up. 11. Two sheets of the chemical conversion foil and the isolation paper while continuously performing corona discharge treatment on both sides, one side or a required part of the chemical conversion foil or the isolation paper having an oxide film formed on the surface of an aluminum foil. A method for manufacturing a capacitor, which comprises alternately stacking and winding up to form a capacitor element. 12. A corona discharge treatment is applied in advance to both sides, one side or a required part of a chemical conversion foil or separator paper having an oxide film formed on the surface of an aluminum foil, and two chemical conversion foils and the separator paper are provided. A method for manufacturing a capacitor, which comprises alternately stacking and winding up to form a capacitor element.