JP5408247B2 - Method and apparatus for manufacturing aluminum electrode plate for electrolytic capacitor - Google Patents

Description

  The present invention relates to a method and a manufacturing apparatus for manufacturing an aluminum electrode plate for electrolytic capacitors by AC etching of an aluminum plate.

  When an aluminum electrode used for an aluminum electrolytic capacitor is manufactured by alternating current etching, in principle, an aluminum foil is disposed between two electrodes disposed in an etching solution and an alternating current is applied between the two electrodes. (See Non-Patent Document 1).

Izaya Nagata, “Electrolytic Cathode Aluminum Electrolytic Capacitor”, Nippon Electric Storage Industrial Co., Ltd., February 24, 1997, 2nd edition, p. 226-227

  However, since the method described in Non-Patent Document 1 has only two electrodes, it can be etched only on one aluminum foil, and there is a problem that productivity is extremely low.

  Here, for the purpose of increasing productivity, the inventor of the present application arranges the aluminum foil 10x between the electrodes 20x facing each other in the three or more electrodes 20x, as shown in FIG. It is proposed to apply an alternating current to all of the three or more electrodes 20x.

  However, in order to apply an alternating current to all of the three or more electrodes 20x, it is necessary to connect the wires to all the electrodes 20x, which causes a problem that the device configuration is complicated. In addition, if wiring is connected to all the electrodes 20x, there is a problem that much labor is required for maintenance such as replacement of the electrodes 20x. Further, when the balance of the wiring resistance to each electrode 20x is lost, there is a problem that the etching current density for the aluminum foil 10x varies.

  In view of the above problems, an object of the present invention is to provide a method and a method for manufacturing an aluminum electrode plate for an electrolytic capacitor capable of simplifying the apparatus configuration and performing stable etching between any electrodes. To provide an apparatus.

In order to solve the above problems, in the present invention, in the method for producing an aluminum electrode plate for an electrolytic capacitor in which an aluminum plate is AC-etched in an etching solution stored in an etching tank, the etching solution contains the etching solution in the etching solution. Three or more electrodes that do not dissolve by electrolysis in the above are arranged so as to face each other, and a plurality of the aluminum plates are arranged in a state of being separated from each other between the electrodes facing each other in the three or more electrodes, Of the three or more electrodes, an AC current is applied only between the electrodes arranged at both ends, and AC etching is performed on both surfaces of the aluminum plate without energizing the electrodes other than the electrodes arranged at both ends. It is characterized by.

Further, in the present invention, in an apparatus for manufacturing an aluminum electrode plate for an electrolytic capacitor that AC-etches an aluminum plate in an etching solution stored in an etching bath, the aluminum electrode plate for an electrolytic capacitor is disposed so as to face each other in the etching solution. Among the three or more electrodes that do not dissolve by electrolysis in the above and the three or more electrodes, an alternating current is applied only between the electrodes arranged at both ends, and no electrode other than the electrodes arranged at both ends is energized And a plurality of the aluminum plates are arranged in a state of being divided from each other between the electrodes facing each other in the three or more electrodes.

  In the present invention, three or more electrodes are disposed in the etching solution so as to face each other, an aluminum plate is disposed between each of the electrodes facing each other in the three or more electrodes, and among the three or more electrodes, An alternating current is applied between the electrodes arranged at both ends. As a result, both surfaces of the aluminum plate are etched. In that case, it is not necessary to supply electric power to electrodes other than the electrodes arranged at both ends of the three or more electrodes and the aluminum plate arranged between the electrodes. For this reason, the apparatus configuration can be simplified such that only a part of the electrodes need to be connected by wiring. In addition, since it is only necessary to connect the wiring to only some of the electrodes, much labor is not required for maintenance such as electrode replacement. Furthermore, since it is only necessary to connect the wiring to only some of the electrodes, a situation where the balance of the wiring resistance to each electrode is not lost does not occur. Therefore, etching can be performed in a state where the etching current density for the aluminum plate is stable.

  In the present invention, the etching tank includes an electrode shielding part that blocks between the inner wall of the etching tank and the electrode, an aluminum plate shielding part that blocks between the inner wall of the etching tank and the aluminum plate, Is preferably provided. According to such a configuration, it is possible to prevent electrical influences between the plurality of etching chambers via the etching solution.

  In this case, the electrode shielding portion includes an electrode holding slit into which an end portion of the electrode is inserted, and the aluminum plate shielding portion includes an aluminum plate holding slit into which the end portion of the aluminum plate is inserted. It is preferable to become. That is, it is preferable to hold the end portion of the electrode using the electrode shielding portion and hold the end portion of the aluminum plate using the aluminum plate shielding portion.

  In the present invention, the etching tank is preferably provided with a plurality of etching solution supply ports for supplying the etching solution for each of a plurality of etching chambers partitioned by the electrode and the aluminum plate. With this configuration, it is possible to prevent electrical influences between the plurality of etching chambers via the etching solution.

  In the present invention, it is preferable that the plurality of etching solution supply ports communicate with a common etching solution supply path. With this configuration, even when a plurality of etching solution supply ports are provided, the configuration for supplying the etching solution can be simplified.

  In the present invention, the plurality of etching solution supply ports are opened at the wall surface of the etching tank, and the side opposite to the side where the electrodes are disposed with respect to the inner wall where the etching solution supply port opens in the etching tank. Preferably, the etching solution supply path is partitioned. With this configuration, even when a plurality of etching solution supply ports are provided, the configuration of the etching solution supply path can be simplified.

  In the present invention, it is preferable that the plurality of etching solution supply ports open at the bottom wall of the wall surface of the etching tank. According to such a configuration, since the etching solution can be efficiently stirred in the etching chamber, the composition and temperature of the etching solution in the etching chamber can be made uniform.

  The aluminum electrode plate for electrolytic capacitors to which the present invention is applied is used, for example, as an anode of an aluminum electrolytic capacitor in which a functional polymer is used as an electrolyte. That is, the aluminum electrode plate for electrolytic capacitors to which the present invention is applied is used for an electrolytic capacitor in which a dielectric film is formed on the surface and a functional polymer layer is formed on the dielectric film.

  In the present invention, three or more electrodes are disposed in the etching solution so as to face each other, an aluminum plate is disposed between each of the electrodes facing each other in the three or more electrodes, and among the three or more electrodes, An alternating current is applied between the electrodes arranged at both ends. As a result, both surfaces of the aluminum plate are etched. In that case, it is not necessary to supply electric power to electrodes other than the electrodes arranged at both ends of the three or more electrodes and the aluminum plate arranged between the electrodes. For this reason, the apparatus configuration can be simplified such that only a part of the electrodes need to be connected by wiring. In addition, since it is only necessary to connect the wiring to only some of the electrodes, much labor is not required for maintenance such as electrode replacement. Furthermore, since it is only necessary to connect the wiring to only some of the electrodes, a situation where the balance of the wiring resistance to each electrode is not lost does not occur. Therefore, etching can be performed in a state where the etching current density for the aluminum plate is stable.

It is explanatory drawing which shows typically the manufacturing method and manufacturing apparatus of the aluminum electrode plate for electrolytic capacitors to which this invention is applied. It is explanatory drawing which shows the principal part of the manufacturing apparatus of the aluminum electrode plate for electrolytic capacitors to which this invention is applied. It is explanatory drawing which shows the principal part of another manufacturing apparatus of the aluminum electrode plate for electrolytic capacitors to which this invention is applied. It is explanatory drawing which shows the principal part of another manufacturing apparatus of the aluminum electrode plate for electrolytic capacitors to which this invention is applied. It is a figure showing the cross-sectional photograph of the aluminum etched board for electrolytic capacitors to which this invention is applied. It is explanatory drawing when manufacturing an electrolytic capacitor using the aluminum etched plate for electrolytic capacitors to which this invention is applied. It is explanatory drawing which shows typically the manufacturing method and manufacturing apparatus of the aluminum electrode plate for electrolytic capacitors which concern on the reference example of this invention.

  Embodiments of the present invention will be described with reference to the drawings.

(Configuration of manufacturing equipment for aluminum electrode plates for electrolytic capacitors)
FIG. 1 is an explanatory view schematically showing a manufacturing method and manufacturing apparatus (etching apparatus) of an aluminum electrode plate for electrolytic capacitors to which the present invention is applied. FIG. 2 is an explanatory view showing a main part of an apparatus for manufacturing an aluminum electrode plate for electrolytic capacitors to which the present invention is applied. FIG. 1 shows a case where five electrodes are used in the etching apparatus, and FIG. 2 shows an etching apparatus capable of etching a total of six aluminum plates with a total of seven electrodes. The number of electrodes may be three or more, and is not limited to the form described below.

  As shown in FIGS. 1 and 2, an apparatus for manufacturing an aluminum electrode plate for an electrolytic capacitor (hereinafter referred to as an etching apparatus 100) to which the present invention is applied includes an etching tank 30 in which a hydrochloric acid-based etching solution 40 described later is stored, And three or more electrodes 20 disposed so as to face each other in the etching solution 40, and a power supply device 80. The electrode 20 is made of a conductor such as carbon or platinum that does not dissolve in electrolysis in an etching solution. The etching tank 30 is made of an insulator such as resin.

  In the etching apparatus 100 of the present embodiment, the power supply apparatus 80 is connected to the electrodes 20a and 20e disposed at both ends of the three or more electrodes 20, and an alternating current is provided between the two electrodes 20a and 20e. Is applied. The waveform of the alternating current used here is positive / negative symmetrical.

  Moreover, the aluminum plate 10 is arrange | positioned between each electrode 20 which opposes in the three or more electrodes 20, and the electrode 20 and the aluminum plate 10 are arrange | positioned alternately. That is, in the etching apparatus 100, the electrode 20 (electrode 20a), the aluminum plate 10 (aluminum plate 10a), the electrode 20 (electrode 20b), the aluminum plate 10 (aluminum plate 10b), the electrode 20 (electrode 20c), and the aluminum plate 10 ( The aluminum plate 10c), the electrode 20 (electrode 20d), the aluminum plate 10 (aluminum plate 10d), and the electrode 20 (electrode 20e) are arranged in this order while facing each other. Here, the electrode 20 has a width dimension larger than that of the aluminum plate 10.

  In the etching apparatus 100 configured as described above, when an alternating current is applied between the electrodes 20a and 20e disposed at both ends, both surfaces of the aluminum plate 10 are AC etched. At that time, among the three or more electrodes 20, the electrodes 20b, 20c, 20d other than the electrodes 20a, 20e arranged at both ends are not connected to the power supply device 80 and are in an electrically floating state. The aluminum plates 10 are divided from each other, and the aluminum plate 10 is not connected to the power supply device 80 by wiring. For this reason, the aluminum plate 10 is in an electrically floating state.

  In the etching apparatus 100 of this embodiment, a plurality of plate portions 36 are formed in the etching tank 30 on both side walls 32 and 33 facing each other at a predetermined interval. An electrode shielding portion 51 is formed to block between the inner wall and the electrode 20. In this embodiment, the electrode shielding portions 51 are formed on both sides of the electrode 20 in the width direction. Further, the electrode shielding part 51 is formed in a slit shape extending in the vertical direction while being opened inside, and the slit is an electrode holding slit into which both end portions in the width direction of the electrode 20 are inserted. . Further, in the etching apparatus 100 of this embodiment, the etching tank 30 is formed with an aluminum plate shielding part 52 that closes between the inner wall of the etching tank 30 and the aluminum plate 10 by the plate part 36. In this embodiment, the aluminum plate shielding portions 52 are formed on both sides of the aluminum plate 10 in the width direction. Further, the aluminum plate shielding portion 52 is formed in a slit shape extending in the vertical direction while being opened inside, and the slit is used for holding an aluminum plate into which both end portions in the width direction of the aluminum plate 10 are inserted. It is a slit.

  In the etching apparatus 100 configured as described above, when the electrode 20 is inserted into the electrode shielding portion 51 (electrode holding slit) and the aluminum plate 10 is inserted into the aluminum plate shielding portion 52 (aluminum plate holding slit), the etching is performed. A plurality of etching chambers 35 are defined in the tank 30 by the electrode 20 and the aluminum plate 10. Here, with respect to the plurality of etching chambers 35, a plurality of etching solution supply ports 55 for supplying an etching solution for each etching chamber 35 are provided. In the present embodiment, the plurality of etching solution supply ports 55 are opened at the bottom wall 34 among the wall surfaces of the etching tank 30. In the etching tank 30, the etching solution supply ports 55 communicate with the plurality of etchant supply ports 55 on the side opposite to the side on which the electrode 20 is disposed with respect to the bottom wall 34 where the etchant supply ports 55 open. A common etching solution supply path 38 is defined. An etchant supply device (not shown) is connected to the etchant supply path 38, and the etchant supplied from the etchant supply apparatus passes through the etchant supply path 38 and the etchant supply port 55. It is supplied to each etching chamber 35. Further, the etching solution supplied from the etching solution supply port 55 to the etching chamber 35 also exhibits an action of stirring the etching chamber 35. In particular, in this embodiment, the etching solution supply port 55 is opened near both sides sandwiching the lower end portion of the aluminum plate 10. For this reason, the etching solution near the surface of the aluminum plate 10 can be efficiently stirred.

  In the etching tank 30, a plurality of overflow ports 61 are formed near the upper end of the side wall 33, and the etchant overflows from each of the plurality of etching chambers 35. On the outer surface of the side wall 33 of the etching tank 30, a recovery path 39 for recovering the etching solution overflowing to a position below the overflow port 61 is configured.

(Main effects of this form)
As described above, in this embodiment, three or more electrodes 20 are arranged in the etching solution 40 so as to face each other, and the aluminum plate 10 is interposed between the electrodes 20 facing each other in the three or more electrodes 20. An alternating current is applied between the electrodes 20a and 20e disposed at both ends of the three or more electrodes 20. As a result, both surfaces of the aluminum plate 10 are etched. At that time, among the three or more electrodes 20, the electrodes 20b, 20c, 20d other than the electrodes 20a, 20e disposed at both ends, and the aluminum plate 10 disposed between the electrodes 20 need not be fed. Also good. For this reason, it is possible to simplify the apparatus configuration, for example, it is only necessary to wire-connect only some of the electrodes 20. In addition, since it is only necessary to connect the wiring to only some of the electrodes 20, it does not take much time for maintenance such as replacement of the electrodes 20. Furthermore, since it is only necessary to connect the wiring to only some of the electrodes 20, a situation in which the balance of the wiring resistance to each electrode 20 is not lost does not occur. Therefore, the etching current density for the aluminum plate 10 is stable.

  In addition, the etching tank 30 includes an electrode shielding part 51 that blocks between the inner wall of the etching tank 30 and the electrode 20, and an aluminum plate shielding part 52 that blocks between the inner wall of the etching tank 30 and the aluminum plate 10. Since it is provided, it is possible to prevent electrical influences between the plurality of etching chambers 35 via the etching solution. In addition, since the etching tank 30 is provided with a plurality of etching solution supply ports 55 for supplying an etching solution for each of the plurality of etching chambers 35, an electrical connection is made between the plurality of etching chambers 35 via the etching solution. It is possible to prevent influencing each other. Even when such a configuration is adopted, the plurality of etching solution supply ports 55 communicate with the common etching solution supply path 38, and thus the configuration for supplying the etching solution can be simplified. In addition, the etching solution supply path 38 is partitioned and formed on the side opposite to the side where the electrode 20 is disposed with respect to the bottom wall 38 in which the etching solution supply port 55 opens in the etching tank 30, so that a plurality of etching solutions are provided. The etching solution supply path 38 communicating with the supply port 55 can be realized with a simple configuration.

  The electrode shielding portion 51 is configured as an electrode holding slit into which the end portion of the electrode 20 is inserted, and the aluminum plate shielding portion 52 is configured as an aluminum plate holding slit into which the end portion of the aluminum plate 10 is inserted. It is configured. For this reason, the edge part of the electrode 20 can be hold | maintained using the shielding part 51 for electrodes, and the edge part of the aluminum plate 10 can be hold | maintained using the shielding part 52 for aluminum plates.

  Further, since the plurality of etching solution supply ports 55 are opened at the bottom wall 34 of the wall surface of the etching tank 30, the etching solution can be efficiently stirred in the etching chamber 35. Therefore, the composition and temperature of the etching solution in the etching chamber 35 can be made uniform.

(Other embodiments)
FIG. 3 is an explanatory view showing a main part of another manufacturing apparatus (etching apparatus) for an aluminum electrode plate for electrolytic capacitors to which the present invention is applied. FIGS. 3 (a) and 3 (b) show the manufacturing of this embodiment. The device is shown in cross-section and perspective view. FIG. 4 is an explanatory view showing a main part of still another manufacturing apparatus (etching apparatus) for an aluminum electrode plate for electrolytic capacitors to which the present invention is applied. FIGS. 4 (a) and 4 (b) show the present embodiment. The manufacturing apparatus is shown in cross-section and perspective view. Note that the basic configuration of the manufacturing apparatus shown in FIGS. 3 and 4 is the same as that of the etching apparatus 100 described with reference to FIGS. 1 and 2. Therefore, in the following description, common parts are denoted by the same reference numerals and description thereof is omitted.

  In the etching apparatus 100 shown in FIGS. 3A and 3B, as in the etching apparatus 100 described with reference to FIGS. 1 and 2, three or more electrodes 20 are arranged in the etching solution 40 so as to face each other. To do. Further, the aluminum plate 10 is disposed between the electrodes 20 facing each other in the three or more electrodes 20. Then, an alternating current is applied between the electrodes 20a and 20e arranged at both ends of the three or more electrodes 20. As a result, both surfaces of the aluminum plate 10 are etched.

  In the etching apparatus 100 having such a configuration, a plurality of etching chambers 35 are partitioned by the electrode 20 and the aluminum plate 10, and an etching solution supply port 55 is provided for each etching chamber 35. Further, the plurality of etching solution supply ports 55 communicate with a common etching solution supply path 38 formed below the bottom wall 34.

  Here, a plurality of partition plates 53 are provided in the etchant supply path 38, and the etchant supply path 38 is partitioned into individual chambers 381 that correspond one-to-one with the etch chamber 35 by the partition plates 53. Has been. However, the partition plate 53 is formed with an opening 530 that allows communication between the adjacent individual chambers 381. The adjacent individual chambers 381 communicate with each other through the opening 530. Therefore, when an etching solution is supplied to any of the plurality of individual chambers 381, the etching solution is sequentially supplied to each individual chamber 381 and is supplied to each etching chamber 35 through the individual chamber 381.

  In the etching apparatus 100 having such a configuration, the partition plate 53 is provided in the etching solution supply path 38, and the partition plate 53 is a shield that suppresses a current from flowing between the plurality of etching chambers 35 via the etching solution. Functions as a board. Therefore, according to the etching apparatus 100 of this embodiment, compared with the etching apparatus 100 described with reference to FIGS. 1 and 2, an electrical influence is exerted between the etching chambers 35 via the etching solution. It is possible to reliably prevent the fitting.

  Also in the etching apparatus 100 shown in FIGS. 4A and 4B, as in the etching apparatus 100 described with reference to FIGS. 1 and 2, the three or more electrodes 20 are arranged to face each other in the etching solution 40. To do. Further, the aluminum plate 10 is disposed between the electrodes 20 facing each other in the three or more electrodes 20. Then, an alternating current is applied between the electrodes 20a and 20e arranged at both ends of the three or more electrodes 20. As a result, both surfaces of the aluminum plate 10 are etched.

  In the etching apparatus 100 having such a configuration, a plurality of etching chambers 35 are partitioned by the electrode 20 and the aluminum plate 10, and an etching solution supply port 55 is provided for each etching chamber 35. Further, the plurality of etching solution supply ports 55 communicate with an etching solution supply path 38 formed below the bottom wall 34.

  Here, as in the manufacturing apparatus described with reference to FIG. 3, a plurality of partition plates 53 are provided in the etchant supply path 38, and the etchant supply path 38 is formed in the etching chamber by the partition plate 53. 35 is partitioned into a private room 381 corresponding one-to-one. However, in the etching apparatus 100 of this embodiment, unlike the etching apparatus 100 described with reference to FIG. 3, the partition plate 53 is not formed with an opening that allows the adjacent individual chambers 381 to communicate with each other. The private rooms 381 are independent. Therefore, in the etching apparatus 100 of the present embodiment, a common etchant supply path 41 is provided separately from the etchant supply path 38, and the etchant supply path 41 and each chamber 381 of the etchant supply path 38 are connected via the pipe 42. Each communicates. For this reason, when an etching solution is supplied to the etching solution supply path 41, the etching solution is supplied to each etching chamber 35 via the individual chambers 381 of the etching solution supply path 38.

  In the etching apparatus 100 having such a configuration, since the individual chambers 381 of the etching solution supply path 38 are completely separated by the partition plate 53, refer to the etching apparatus 100 described with reference to FIGS. 1 and 2 and FIG. Compared with the etching apparatus 100 described above, it is possible to more reliably prevent electrical influences between the plurality of etching chambers 35.

[Example of etching for aluminum plate 10]
In this embodiment, the aluminum plate 10 is used, for example, to constitute an anode (an aluminum electrode plate for an electrolytic capacitor) of an aluminum electrolytic capacitor in which a functional polymer such as polypyrrole, polythiophene, or polyaniline is used as an electrolyte. That is, after the aluminum plate 10 is etched, an anodic oxide film is formed on the surface thereof, and the aluminum plate 10 is used as an anode of an aluminum solid electrolytic capacitor.

For example, the aluminum plate 10 has an aluminum purity of 99.98% by mass or more, contains less than 30 ppm of copper and 5 to 50 ppm of iron, and the balance is composed of other inevitable impurities. When the number of Fe-containing intermetallic compounds with a particle size of 0.1 to 1.0 μmφ is 1 × 10 ⁷ to 10 ¹⁰ / cm ³ , the proportion of pits with a specific size diameter can be increased. And a capacitor with lower ESR can be produced. This is presumably because the chemical conversion film is formed with a uniform thickness on the pit surface and is easily impregnated with the solid electrolyte because the particle size is small for a large amount of intermetallic compounds.

  Further, the aluminum plate 10 should be Si 60 ppm or less, preferably 40 ppm or less. This is because when Fe and Si exceed the upper limit values, crystallized substances and precipitates of coarse intermetallic compounds containing Fe and Si are generated, and the leakage current increases. In the case of Si, simple Si is also generated, which is not preferable for the same reason. If Cu exceeds the upper limit value, the corrosion potential of the matrix is greatly changed and no good etching may be performed.

On the other hand, the content of 5 to 50 ppm of Fe is a well-known value, and Al _m Fe, Al ₆ Fe, Al ₃ Fe, Al-Fe-Si, Al- (Fe, M) -Si (M is other This is preferable because an intermetallic compound such as (metal) is generated and tends to be a pit starting point for AC etching. Containing less than 30 ppm of Cu is preferable because the corrosion potential of the matrix can be stabilized in the presence of Fe, and pits of a specific size can be easily formed. The preferable content of Cu is 25 ppm or less, and the lower limit is 2 ppm or more, more preferably 3 ppm or more. If it is less than the lower limit, abnormal growth of crystal grains occurs in the heating process of the etching plate, and the mechanical strength decreases. On the other hand, if the Cu content exceeds 30 ppm, dissolution during etching is accelerated abnormally, which is not preferable. As other elements, Ni, Ti and Zr are each 10 ppm or less, preferably 3 ppm or less. Further, other impurities are preferably 3 ppm or less. Since such an element becomes a starting point of pits by the AC etching method, it becomes easy to drill pits having a specific size in a spongy manner.

  Further, the aluminum plate 10 is etched to a deep position so that the thickness is as thick as 150 μm or more, and the thickness of the etching part is 150 μm or more in total on both surfaces. More specifically, the etching is performed up to a deep position so that the etching site is 75 μm or more, 100 μm or more, and further 120 μm or more on one side. Nevertheless, in this embodiment, since the aluminum plate 10 has the above composition, several thousand to several hundreds of thousands of spongy pits can be drilled per square millimeter. Less dissolved. Therefore, the aluminum electrode plate (etched plate) for electrolytic capacitors to which the present invention is applied has a high etching magnification and a high capacitance.

  Moreover, in this embodiment, since the aluminum purity in the aluminum plate 10 is 99.98% by mass or more, it has high toughness and is easy to handle when manufacturing an electrolytic capacitor. If the aluminum purity is less than the lower limit, the hardness increases, the toughness decreases, and damage such as cracking may occur during handling, which is not preferable. The aluminum plate 10 may have various thicknesses depending on the purpose. For example, a thickness of 150 μm to 1 mm, usually 300 to 400 μm is used.

In this embodiment, as an etching method for the aluminum plate 10, there are cases where etching pits are generated and etching pits are grown in one etching process. In some cases, a first etching step for generating etching pits in the aluminum plate 10 and a second etching step for growing etching pits may be performed. Furthermore, an auxiliary etching process may be performed between the first etching process and the second etching process. In either case, as the etching solution, an aqueous solution of hydrochloric acid alone or an aqueous solution obtained by adding sulfuric acid or nitric acid to hydrochloric acid is used. The etching solution temperature is 15 to 55 ° C. As an AC etching condition, an AC waveform having a frequency of 10 to 50 Hz is used. As the AC waveform, a sine waveform, a rectangular waveform, or the like is used. In either case, a positive / negative symmetrical waveform is used. The etching current density is 0.1 to 0.5 A / cm ^{2. Under} such etching conditions, a large number of pits can be drilled on the surface of the aluminum plate 10.

  In any of these etching methods, the etching method and the etching apparatus 100 described with reference to FIGS. 1 and 2 can be used. In addition, when performing the etching process with respect to the aluminum plate 10 several times, the etching apparatus 100 corresponding to each etching process is prepared, and an etching process is performed on each etching apparatus 100 on separate conditions. Further, even when the etching process for the aluminum plate 10 is performed a plurality of times, the common etching apparatus 100 may be used. In this case, for example, after the first etching step is finished, the etching solution for the first etching step is discharged from the etching bath 30, and then the etching solution for the second etching step is stored in the etching bath 30. An etching process may be performed.

(Etching result for aluminum plate 10)
The aluminum plate 10 was etched by the etching method and the etching apparatus 100 described with reference to FIGS. 1 and 2, and then anodized in an aqueous solution of ammonium adipate to form an oxide film having a withstand voltage of about 6V. The capacitance in the aqueous ammonium adipate solution was measured. The results are shown in Table 1. Table 1 shows the capacitance values of the four aluminum plates 10 (aluminum plates 10a, 10b, 10c, and 10d) shown in FIG.

Samples and etching conditions are as follows.
Aluminum plate 10
Thickness: 0.25mm
composition
Aluminum purity: 99.99% by mass or more
Copper: 15ppm
Iron: 30ppm
Silicon: 40ppm
Remainder: Other inevitable impurities Etching conditions First stage etching (first etching process)
Etching solution composition: 3 mol / liter of hydrochloric acid + 0.5 mol / liter of sulfuric acid mixed solution Etching solution temperature: 40 ° C
Electrolytic waveform: sine wave AC, frequency 50Hz
Current density: 0.5A / cm ²
Electricity: 30C / cm ²
Second stage etching (second etching process)
Etching solution composition: 7 mol / liter of hydrochloric acid + 0.5 mol / liter of sulfuric acid mixed solution Etching solution temperature: 25 ° C
Electrolytic waveform: sinusoidal alternating current, frequency 20Hz
Current density: 0.3A / cm ²
Electricity: 450C / cm ²

  As shown in Table 1, the aluminum plate 10 (aluminum plates 10a, 10b, 10c, and 10d) disposed at any position can obtain substantially the same capacitance value and the level of the capacitance value is high. .

  In Table 1, as a reference example, as shown in FIG. 7B, only the electrodes 20a and 20e at both ends are provided, and the electrodes 20b, 20c and 20d shown in FIG. The results of etching the aluminum plate 10 (aluminum plates 10a, 10b, 10c, 10d) are also shown. As shown in Table 1, in the method according to the reference example shown in FIG. 7B, the capacitance value is lower than that of the present embodiment, and four aluminum plates 10a, 10b, 10c, and 10d) are used. Large variations occurred in the capacitance values of the obtained electrodes. For example, in the method according to the reference example shown in FIG. 7B, the capacitance values of the aluminum plates 10b and 10c arranged in the middle are significantly lower than those of the aluminum plates 10a and 10d on both sides. It was. Further, in the method according to the reference example shown in FIG. 7B, the appearance after etching was greatly different between the two surfaces, so that both surfaces were not properly etched.

(Example of electrolytic capacitor)
FIG. 5 is a view showing a cross-sectional photograph of an aluminum etched plate for electrolytic capacitors obtained by applying the present invention. FIG. 6 is an explanatory diagram when an electrolytic capacitor is manufactured using an anode obtained by anodizing an aluminum etched plate for an electrolytic capacitor to which the present invention is applied.

  As shown in FIG. 5, an aluminum etched plate 1 for an electrolytic capacitor to which the present invention is applied has etching sites 3 on both sides of a core portion 2.

  Next, the aluminum etched plate 1 for electrolytic capacitors is subjected to, for example, 5V conversion treatment in an aqueous solution of ammonium adipate, and as shown in FIG. 6, the side end surface of the aluminum etched plate 1 for electrolytic capacitors is exposed, and its core An anode lead 6 such as a lead wire is joined to the side end face 4 of the portion 2. As a joining method, laser welding 5 with a spot diameter reduced to less than the thickness of the core is used. The spot diameter is 20-100 μmφ.

  Next, after the surface of the anodized aluminum etched plate for electrolytic capacitors 1 is impregnated with polypyrrole according to a conventional method to form a functional polymer layer, the surface of the etched plate on which the functional polymer layer is formed Then, a cathode is formed using carbon paste, silver paste, or the like, and, for example, an electrolytic capacitor of 2.5 V / 330 μF is manufactured. When impregnating with polypyrrole, an ethanol solution of a pyrrole monomer is dropped into the pit, and ammonium persulfate and an aqueous solution of sodium 2-naphthalenesulfonate are dropped and chemically polymerized to form a precoat layer made of polypyrrole. Next, this electrode plate was immersed in an acetonitrile electrolyte containing a pyrrole monomer and sodium 2-naphthalenesulfonate, and a stainless steel wire was brought into contact with a part of the previously formed chemically polymerized polypyrrole layer to serve as an anode, Electrolytic polymerization is performed using a stainless steel plate as a cathode to form an electropolymerized polypyrrole that becomes a functional polymer layer. In addition, it can replace with polypyrrole and can obtain an equivalent characteristic even if it uses polythiophene.

  According to the present invention, since it is not necessary to wire-connect to all three or more electrodes, the device configuration can be simplified. In addition, since it is not necessary to connect wiring to all of the three or more electrodes, it does not take much time for maintenance such as electrode replacement. Furthermore, since it is not necessary to connect wiring to all three or more electrodes, a situation in which the balance of wiring resistance to each electrode is not lost does not occur, and the etching current density for the aluminum plate is stable. Therefore, an aluminum electrode plate for an electrolytic capacitor having a stable capacitance and the like can be efficiently produced.

DESCRIPTION OF SYMBOLS 1 Aluminum etched plate for electrolytic capacitors 2 Core part 3 Etching site 10 Aluminum plate 20 Electrode 30 Etching tank 35 Etching chamber 38 Etching solution supply path 40 Etching solution 41 Etching solution supply path
51 Electrode shield 52 Aluminum plate shield 55 Etching solution supply port 80 Power supply device 100 Etching device (manufacturing device)

Claims (8)

In the method for producing an aluminum electrode plate for an electrolytic capacitor in which an aluminum plate is AC-etched in an etching solution stored in an etching tank,
In the etching solution, three or more electrodes that do not dissolve by electrolysis in the etching solution are arranged to face each other.
A plurality of the aluminum plates are arranged in a state of being divided from each other between the electrodes facing each other in the three or more electrodes,
Of the three or more electrodes, an AC current is applied only between the electrodes disposed at both ends, and AC etching is performed on both surfaces of the aluminum plate without energizing the electrodes other than the electrodes disposed at both ends. A method for producing an aluminum electrode plate for an electrolytic capacitor. In an apparatus for producing an aluminum electrode plate for an electrolytic capacitor that AC-etches an aluminum plate in an etching solution stored in an etching tank,
Three or more electrodes which are arranged so as to face each other in the etching solution and are not dissolved by electrolysis in the etching solution;
Among the three or more electrodes, a power supply device that applies an alternating current only between the electrodes disposed at both ends and does not energize electrodes other than the electrodes disposed at both ends ;
Have
An apparatus for producing an aluminum electrode plate for electrolytic capacitors , wherein a plurality of the aluminum plates are arranged in a state of being divided from each other between the electrodes facing each other in the three or more electrodes.   The etching tank is provided with an electrode shielding part for closing the space between the inner wall of the etching tank and the electrode, and an aluminum plate shielding part for closing the space between the inner wall of the etching tank and the aluminum plate. The apparatus for producing an aluminum electrode plate for electrolytic capacitors according to claim 2. The electrode shielding part is composed of an electrode holding slit into which an end of the electrode is inserted,
The said aluminum plate shielding part consists of a slit for aluminum plate holding in which the edge part of the said aluminum plate is inserted, The manufacturing apparatus of the aluminum electrode plate for electrolytic capacitors of Claim 3 characterized by the above-mentioned.   5. The etching tank is provided with a plurality of etching solution supply ports for supplying the etching solution for each of a plurality of etching chambers partitioned by the electrode and the aluminum plate. The manufacturing apparatus of the aluminum electrode plate for electrolytic capacitors as described in any one of these.   6. The apparatus for producing an aluminum electrode plate for an electrolytic capacitor according to claim 5, wherein the plurality of etching solution supply ports communicate with a common etching solution supply path. The plurality of etching solution supply ports open at the wall surface of the etching tank,
7. The etching solution supply path is defined in a section opposite to a side on which the electrode is disposed with respect to the inner wall where the etching solution supply port opens in the etching tank. For manufacturing aluminum electrode plates for electrolytic capacitors.   8. The apparatus for producing an aluminum electrode plate for an electrolytic capacitor according to claim 7, wherein the plurality of etching solution supply ports are opened at a bottom wall of a wall surface of the etching tank.

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