JP2009004409A - Apparatus and method for manufacturing etching foil for electrolytic capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and method for manufacturing an etching foil for an electrolytic capacitor which prevent a drop in an etching rate due to unnecessary chemical dissolution of an aluminum foil. <P>SOLUTION: According to the apparatus 1 for manufacturing the etching foil for the electrolytic capacitor, unnecessary chemical dissolution of the aluminum foil 10 tends to occur around an in-liquid roller 25 in an etching bath 20 holding an etching liquid and such an electroless location is separated from a spot opposite to electrodes 21 and 22. For this reason, such a nonelectrolyte spot is isolated from the surroundings via an enclosure 30, which is filled with water. A place encircled with the enclosure 30 is thus filled with water or an etching liquid having extremely low acid concentration. Inside the enclosure 30, therefore, unnecessary chemical dissolution does not occur on the surface of the aluminum foil 10 even if the aluminum foil 10 is disposed at the nonelectrolyte spot not opposite to the electrodes 21 and 22. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a manufacturing apparatus and a manufacturing method of an electrolytic capacitor etching foil used for an aluminum electrolytic capacitor.

In recent years, with the miniaturization of electronic devices, it is desired to increase the capacity of capacitors. As a method of increasing the electrostatic capacitance of the electrolytic capacitor, there is a method of increasing the surface area of the aluminum foil used as the electrode foil. As a means for achieving this, the aluminum foil is energized in an etching solution containing hydrochloric acid. In general, the surface of the aluminum foil is electrochemically roughened.
An apparatus for manufacturing an electrolytic capacitor etching foil for carrying out such a method has an etching tank 120 in which an etching solution is stored, for example, as shown in FIG. A submerged roller 125 that defines the travel path of the aluminum foil 10 and electrodes 121 and 122 that face the aluminum foil in the etching tank 120 are disposed. (For example, refer to Patent Document 1 and Non-Patent Document 1).

JP-A-2005-243671 Isaya Nagata, “Electrolytic Cathode Aluminum Electrolytic Capacitor”, Nihon Bunkyo Kogyo Co., Ltd., February 24, 1997, Second Edition, 1st Printing, P250-252

However, in the manufacturing apparatus 100 shown in FIG. 3, since the electrodes 121 and 122 are not disposed around the submerged roller 125, while the aluminum foil 10 travels around the submerged roller 125, the aluminum foil 10 includes Power is not supplied.
For this reason, while traveling around the submerged roller 125, there is a problem that wasteful chemical dissolution occurs on the surface of the aluminum foil 10 and the etching magnification of the aluminum foil 10 is lowered.
In particular, in order to increase the pit length and the number of pits in the aluminum foil 10 and increase the surface area, it is necessary to increase the amount of electricity to be etched, so the traveling speed of the aluminum foil 10 is set to be slow. As a result, it takes a long time for the aluminum foil 10 to pass around the submerged roller 125, and there is a problem that wasteful chemical dissolution on the surface of the aluminum foil 10 becomes intense.

  In view of the above problems, an object of the present invention is to provide an electrolytic capacitor etching foil manufacturing apparatus and manufacturing method capable of preventing a reduction in etching magnification due to wasteful chemical dissolution of an aluminum foil.

  The present invention solves the above-described problem, and an etching tank in which an etching solution is stored, a submerged roller that defines a travel path of the aluminum foil in the etching tank, and the aluminum foil that travels in the etching tank. In the manufacturing apparatus for an electrolytic capacitor etching foil provided with an electrode facing the electroless capacitor, an electroless portion in the etching tank that is out of a position facing the electrode in a traveling path of the aluminum foil in the etching tank. A partition wall for separating the substrate from the etching solution is disposed.

  The electrode facing the aluminum foil in the etching tank is energized while running the aluminum foil along the traveling path defined by the etching tank storing the etching liquid and the submerged roller in the etching tank. In the method for producing an electrolytic capacitor etching foil for performing electrolytic etching on an aluminum foil, in the etching tank, the electroless portion of the traveling path of the aluminum foil in the etching tank is deviated from the position facing the electrode. A partition wall is separated from the etching solution.

In the present invention, in the etching tank, an electroless portion that is out of a position facing the electrode, that is, around the portion where the submerged roller is disposed, becomes an electroless state and wasteful chemical dissolution occurs. Therefore, the said part is isolate | separated from the circumference | surroundings by a partition.
As a result, even if chemical dissolution occurs at the location, the chemical concentration can be minimized because the aluminum concentration in the etching solution is higher than that outside the partition wall.
Further, as will be described later, by supplying water or an etchant having a lower concentration than the etchant into the space separated by the partition, the acid concentration of the etchant in the space separated by the partition is lowered. As a result, chemical dissolution is less likely to occur. Therefore, when manufacturing an aluminum etching foil, it is possible to prevent a reduction in etching magnification due to useless chemical dissolution, and thus it is possible to manufacture an electrolytic capacitor etching foil having a high capacitance.

In this invention, the said partition is arrange | positioned in the location which can isolate | separate the said liquid roller as the said electroless location, and its periphery from the said etching liquid.
In particular, when the partition wall is provided at the lower end of the electrode, electrochemical dissolution due to leakage current can also be suppressed.

In the present invention, it is preferable that a water supply port for supplying water or an etching solution having a lower concentration than the etching solution is provided in the space separated by the partition walls.
By configuring in this way, water or low-concentration etching solution is supplied one after another from the water supply port, and the acid concentration of the etching solution in the space separated by the partition wall can be lowered, so that wasteful chemical dissolution is prevented. Hard to occur.
Therefore, when manufacturing an aluminum etching foil, it is possible to prevent a reduction in etching magnification due to useless chemical dissolution.

  In this case, it is preferable that the water supply port is provided at a lower portion in a space separated by the partition wall. When water or a low-concentration etching solution is supplied from the lower part in the space separated by the partition walls, the entire space surrounded by the partition walls can be spread.

  In this invention, it is preferable that the opening part which lets the said aluminum foil pass in the said partition is obstruct | occluded by the several round bar (a circular tube is included) arrange | positioned so that the said aluminum foil may be pinched | interposed from both sides. By comprising in this way, inflow of the etching liquid to the inner side of a partition can be prevented, and chemical dissolution of aluminum foil can be prevented.

In the present invention, in the etching tank, the location away from the location facing the electrode, i.e., the location where the submerged roller is disposed, becomes an electroless state and the chemical dissolution of the aluminum foil occurs. The said part is isolate | separated from the circumference | surroundings by a partition.
For this reason, in the space separated from the periphery by the partition wall, the aluminum concentration in the etching solution is higher than the outside of the partition wall, so that chemical dissolution of the aluminum foil hardly occurs.
Therefore, when manufacturing the aluminum etching foil, it is possible to prevent a reduction in etching magnification due to chemical dissolution of the aluminum foil, and thus it is possible to manufacture an electrolytic capacitor etching foil having a high capacitance.

  In addition, by supplying water or a low-concentration etchant into the space separated by the partition walls, the acid concentration of the etchant can be lowered, and the chemical dissolution of the aluminum foil in the space separated by the partition walls can be further improved. It can be surely suppressed.

  Hereinafter, the best mode for carrying out the present invention will be described.

[Configuration of Electrolytic Capacitor Etching Foil Manufacturing Equipment]
FIG. 1 is a configuration diagram of a main part of an apparatus for manufacturing an etching foil for electrolytic capacitors to which the present invention is applied.
2A and 2B are a plan view of an etching tank used in an apparatus for manufacturing an electrolytic capacitor etching foil to which the present invention is applied, and an enlarged sectional view of a bottom portion thereof.

As shown in FIG. 1 and FIGS. 2 (a) and 2 (b), the electrolytic capacitor etching foil manufacturing apparatus 1 of the present invention has an etching tank 20 in which an etching solution is stored. Inside, the submerged roller 25 which prescribes | regulates the travel path of the aluminum foil 10 in the etching tank 20, and the electrodes 21 and 22 which oppose the aluminum foil 10 in the etching tank 20 are arrange | positioned.
The submerged roller 25 is disposed on the bottom side in the etching tank 20, and a power feeding roller 26 is disposed above the etching tank 20. The electrodes 21 and 22 face the portion of the aluminum foil 10 that travels between the power supply roller 26 and the submerged roller 25 from both sides. An etching solution is supplied to the etching bath 20, and the etching solution in the etching bath 20 always overflows, and the eluted aluminum ions are kept at a constant concentration in the etching bath 20.

In the manufacturing apparatus 1 configured as described above, since the electrodes 21 and 22 are not disposed around the submerged roller 25 (electroless portion), while the aluminum foil 10 travels around the submerged roller 25, aluminum is used. The foil 10 is not energized.
Therefore, in the present embodiment, the casing 30 is disposed on the bottom side of the etching tank 20 so as to surround the submerged roller 25. The material of the housing 30 may be any material that satisfies the resistance to etching solution, heat resistance, and strength. For example, heat-resistant vinyl chloride, PP (polypropylene), FRP (fiber reinforced plastic), and the like are suitable. .

Here, openings 30a and 30b for allowing the aluminum foil 10 to pass through are formed on the upper surface of the housing 30, and the openings 30a and 30b are made of glass so as to close the openings 30a and 30b. A tube 31 (round bar) is arranged. For this reason, even if the openings 30a and 30b are formed on the upper surface of the housing 30, the inside and the outside of the housing 30 are sufficiently separated by merely communicating with each other through a slight gap. .
Moreover, the glass tube 31 is arrange | positioned so that two may be paired and the aluminum foil 10 may be pinched | interposed from both sides. For this reason, the position of the aluminum foil 10 is regulated, and the aluminum foil 10 does not rub the edges of the openings 30a and 30b.
In addition, about the glass tube 31, you may employ | adopt any structure of the structure arrange | positioned in the state which can be rotated around the axis line, and the structure arrange | positioned in the state which cannot be rotated around the axis line, but the former case Therefore, it is possible to more reliably prevent the aluminum foil 10 from being rubbed and damaged by the glass tube 31.

  In addition, through holes 30c and 20a are formed in the bottom of the case 30 and the bottom of the etching tank 20, respectively, and water is supplied to the through holes 30c and 20a for introducing water into the inside of the case 30. A tube 32 is connected.

[Operation]
In the manufacturing apparatus and the manufacturing method of the electrolytic capacitor etching foil having such a configuration, the aluminum foil 10 travels in a direction indicated by an arrow H by a driving roller (not shown). And while passing through the inside of the etching tank 20, the aluminum foil 10 is energized between the electrodes 21 and 22, is subjected to electrolytic etching, and becomes an aluminum etching foil for electrolytic capacitors.

At that time, water is supplied to the inside of the housing 30 through the liquid water supply pipe 32. For this reason, the inner side of the housing 30 is adjusted so that the internal pressure is set higher than that of the outer side so that the etching solution does not flow into the housing 30 and water does not flow out of the housing 30. . For this reason, the inside of the housing | casing 30 will be in the state filled with water, and the density | concentration of an outer etching solution will not become thin.
Even when the etching solution flows into the inside of the housing 30 through the openings 30a and 30b, the inside of the housing 30 is diluted with water, so that the etching solution having a very low acid concentration is filled. It will be.

  In addition, even if water flows out from the inside of the housing 30 through the openings 30a and 30b, a high-concentration etching solution is supplied to the outside of the housing 30 in the etching tank 20, so that etching is performed. In the tank 20, the etching solution outside the housing 30 is always adjusted to a predetermined acid concentration.

[Main effects of this embodiment]
As described above, in the vicinity of the submerged roller 25 inside the etching tank 20 where the aluminum foil 10 is removed from the position facing the electrodes 21 and 22, the conventional example (FIG. 3) is a waste aluminum foil chemistry. Although dissolution is likely to occur, in the embodiment of the present embodiment (FIGS. 1 and 2), such an electroless portion is separated from the surroundings by the casing 30, and thus chemical dissolution can be suppressed.
In addition, in this embodiment, since water is supplied to the inside of the housing 30, the portion surrounded by the housing 30 is only filled with an etching solution having a very low water or acid concentration. Even if the aluminum foil 10 is an electroless portion that does not face the electrodes 21 and 22 inside the housing 30, chemical dissolution does not occur on the surface of the aluminum foil 10.
Therefore, when manufacturing aluminum etching foil, since the fall of the etching magnification resulting from chemical dissolution can be prevented, the etching foil for electrolytic capacitors with a high electrostatic capacitance can be manufactured.

Further, in this embodiment, when water is supplied to the inside of the housing 30, water is continuously supplied from the bottom of the etching tank 20 and the bottom of the housing 30 so as to maintain the internal pressure of the housing 30. The pressure inside the housing 30 is greater than that outside. Therefore, it is possible to reliably prevent the etching solution from flowing in from the openings 30 a and 30 b formed on the upper surface of the housing 30.
Further, in this embodiment, the openings 30a and 30b are closed with a slight gap left by the glass tube 31, so that it is ensured that the etching solution will flow from the openings 30a and 30b of the housing 30. Can be prevented.
Therefore, according to this embodiment, water can be efficiently distributed in the entire space isolated by the housing 30.

[Evaluation results]
In order to verify the effectiveness of the manufacturing apparatus 1 of the present invention, six aluminum etching foils for electrolytic capacitors were manufactured using the manufacturing apparatus 1 described with reference to FIGS. It was set to 6.
As the raw material of Examples 1 to 6, a soft material of aluminum foil having a purity of 99.9% and a thickness of 10 μm was used. Moreover, when performing an etching process on this aluminum foil, in this embodiment, two etching tanks 20 described with reference to FIGS. 1 and 2 are prepared, and the following first and second stages are prepared. Etching was performed.
[First stage etching]
Etching solution: sulfuric acid 4 mol / L + hydrochloric acid 1 mol / L aqueous solution temperature: 80 ° C., current density: 0.1 A / cm ² , direct current, quantity of electricity: 25 C / cm ²
[Second stage etching]
Etching solution: 0.5 mol / L hydrochloric acid aqueous solution temperature: 80 ° C., current density: 0.03 A / cm ² , direct current, amount of electricity: 26 C / cm ²
These etching processes were performed while supplying pure water into the housing 30 as described with reference to FIGS.
Next, the aluminum etching foil was washed with pure water and dried, and then formed in an aqueous boric acid solution at a voltage of 250 V to obtain aluminum anode foils for electrolytic capacitors (Examples 1 to 6). In Examples 1 to 6, the amount of pure water supplied into the housing 30 is different, and the conditions for the amount of addition are 0, 0.01, 0.05, 0.1,. 5, 1 (L / min). And the electrostatic capacitance of Examples 1-6 was measured (sample number n = 10).

In addition, an etching foil is manufactured under the same manufacturing conditions as in the embodiment using a conventional manufacturing apparatus for an electrolytic capacitor etching foil (a configuration in which the housing 30 is not provided in the etching tank 20 / see FIG. 3). Using the foil, an aluminum anode foil for electrolytic capacitors according to a conventional example was obtained, and the capacitance of the anode foil was also measured (number of samples n = 10).

  These measurement results are shown in Table 1. In Table 1, it showed as an up rate with respect to the prior art example of the electrostatic capacitance of Examples 1-6.

  As shown in Table 1, the capacitance increased by about 5% compared to the conventional example when the supply amount of pure water was 0.1 L / min or more. Moreover, the electrostatic capacitance rose also in Examples 1-6. Thereby, the effectiveness in the manufacturing apparatus of the etching foil for electrolytic capacitors of this invention was demonstrated.

Note that the capacitance increased by 1.0% even when the supply amount of pure water was 0 L / min. That is, when the periphery of the submerged roller 25 is surrounded by the housing 30, etching is performed in the region separated by the housing 30 compared to the outside of the housing 30 without supplying water to the inside of the housing 30. Since the aluminum concentration in the liquid increases, chemical dissolution of the aluminum foil is unlikely to occur.
Therefore, if the periphery of the submerged roller 25 is surrounded by the housing 30, it is possible to prevent a decrease in the etching magnification due to chemical dissolution to some extent without supplying water to the inside of the housing 30. An etching foil for electrolytic capacitors having a high capacitance can be produced.

[Other embodiments]
In the above embodiment, water is supplied to the inside of the housing 30, but an etching solution having a low acid concentration may be supplied instead of water. Even when such a low concentration etching solution is supplied, the spontaneous dissolution of the aluminum foil can be suppressed inside the housing 30.

  Further, in the above embodiment, the box-shaped housing 30 is used to configure the partition wall for separating the electroless portion separated from the portion facing the electrodes 21 and 22 from the surroundings. May be used.

  Furthermore, in the said form, although the periphery of the submerged roller 25 was isolate | separated by the partition as an electroless location remove | deviated from the location facing the electrodes 21 and 22, in an electroless location removed from the location facing the electrodes 21 and 22 If there is, a portion other than the periphery of the submerged roller 25 may be separated by a partition wall.

  Furthermore, in the above embodiment, the DC etching apparatus has been described as an example. However, the present invention may be applied to an AC etching apparatus.

It is a principal part block diagram of the manufacturing apparatus of the etching foil for electrolytic capacitors to which this invention is applied. (A), (b) is the top view of the etching tank used for the manufacturing apparatus of the etching foil for electrolytic capacitors to which this invention is applied, respectively, and sectional drawing which expands and shows the bottom part. It is explanatory drawing of the manufacturing apparatus of the conventional etching foil for electrolytic capacitors.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Etching foil manufacturing apparatus 10 Aluminum foil 20 Etching tank 20a Through hole 21, 22 Counter electrode 26 Feed roller 25 Submerged roller 30 Housing 30a, 30b Opening 30c Housing through hole 31 Glass tube (round bar)
DESCRIPTION OF SYMBOLS 100 Etching foil manufacturing apparatus 120 Etching tank 121, 122 Counter electrode 125 Submerged roller 126 Feed roller

Claims (7)

An etching tank in which an etching solution is stored;
In an apparatus for producing an etching foil for electrolytic capacitors, comprising: a submerged roller that defines a travel path of an aluminum foil in the etching tank; and an electrode facing the aluminum foil that travels in the etching tank.
In the etching tank, an electrolytic cell is provided that separates an electroless portion, which is separated from a position facing the electrode, of the traveling path of the aluminum foil in the etching tank from an etching solution. Manufacturing equipment for capacitor etching foil.   The said partition is arrange | positioned in the location which can isolate | separate the said submerged roller as the said electroless location, and its periphery from the said etching liquid, The manufacturing of the etching foil for electrolytic capacitors of Claim 1 characterized by the above-mentioned. apparatus.   The electrolytic capacitor etching according to claim 1, wherein a water supply port for supplying water or an etching solution having an acid concentration lower than that of the etching solution is provided in the space separated by the partition wall. Foil manufacturing equipment.   The said water supply opening is provided in the lower part in the space isolate | separated by the said partition, The manufacturing apparatus of the etching foil for electrolytic capacitors of Claim 3 characterized by the above-mentioned.   The opening part through which the said aluminum foil of the said partition is blocked | closed by the some round bar arrange | positioned so that the said aluminum foil may be pinched | interposed from both sides The manufacturing apparatus of the etching foil for electrolytic capacitors as described in a term. While running the aluminum foil along the etching path in which the etching liquid is stored and the running path defined by the submerged roller in the etching tank, the electrode facing the aluminum foil in the etching tank is energized, and aluminum In the manufacturing method of the etching foil for electrolytic capacitors that performs electrolytic etching on the foil,
In the etching tank, a partition wall that separates an electroless portion, which is out of a position facing the electrode, of the traveling path of the aluminum foil in the etching tank from the etching solution is disposed. Manufacturing method of etching foil for capacitor.   The method for producing an etching foil for an electrolytic capacitor according to claim 6, wherein the space separated by the partition wall is supplied with water or an etching solution having a lower concentration than the etching solution.

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