JP6775178B2 - Manufacturing method of electrolytic capacitors - Google Patents

Description

The present invention relates to a method for manufacturing an electrolytic capacitor.

Conventionally, an anode foil on which a dielectric film (also referred to as an oxide film or a chemical conversion film) is formed by a chemical conversion treatment and an opposing cathode foil are wound to prepare a winding element, and then the anode foil of the winding element is reconverted. There is known a method for manufacturing an electrolytic capacitor in which the above is applied (see, for example, Patent Document 1).

In the rechemical conversion treatment, the winding element is immersed in the chemical conversion liquid stored in the tank, and the voltage required for forming the dielectric film is applied between the anode foil of the winding element and the tank to form the anode foil. This is a process for rechemical conversion. The anode foil is cut according to the size of the winding element after the chemical conversion treatment, and a dielectric film is not formed on the cut surface. However, by performing the rechemical conversion treatment, the dielectric film is applied to both end surfaces of the anode foil. Can be formed. Further, by the rechemical conversion treatment, cracks formed in the dielectric film on the surface of the anode foil during winding can be repaired.

In the rechemical conversion treatment, the potential of the anode foil rises as the dielectric film grows, so that the applied voltage rises accordingly.

Japanese Unexamined Patent Publication No. 2000-277388

When the above rechemical treatment is performed, the distance between the anode foil and the cathode foil is very small compared to the distance between the cathode foil and the tank, and the resistance between the anode foil and the cathode foil is the same as that of the cathode foil. Since it is smaller than the resistance between the tank and the cathode foil, the potential of the cathode foil tends to increase when the voltage applied to the anode foil is increased. When the potential of the cathode foil becomes high, there is a possibility that a dielectric film is likely to be formed on the cathode foil, which is originally not desired to form a dielectric film. For example, when a dielectric film is formed on the cathode foil, the foil capacity of the cathode foil may be lowered, or the formation of the dielectric film on the anode foil may be hindered.

In view of these problems, it is an object of the present invention to provide a method for manufacturing an electrolytic capacitor in which defects are unlikely to occur in the cathode foil when the anode foil is regenerated.

In the method for manufacturing an electrolytic capacitor according to the first aspect of the present invention, a winding element is produced by winding an anode foil on which a first dielectric film is formed and a cathode foil facing the anode foil. In the above step, while immersing the winding element in the chemical solution stored in the conductive liquid storage tank, a voltage is applied between the anode foil and the liquid storage tank from a DC power source to apply a voltage to the anode foil. The second step of forming the dielectric film of 2 is included. Here, in the second step, the cathode foil is discharged to lower the potential of the cathode foil.

In the method for manufacturing an electrolytic capacitor according to a second aspect of the present invention, a winding element is produced by winding an anode foil on which a first dielectric film is formed and a cathode foil facing the anode foil. A voltage is applied between the anode foil and the conductive member from a DC power source while immersing the winding element and the conductive member in the chemical solution stored in the liquid storage tank to obtain the anode foil. Includes a second step of forming a second dielectric film. Here, in the second step, the cathode foil is discharged to lower the potential of the cathode foil.

In the method for manufacturing an electrolytic capacitor according to a third aspect of the present invention, a first winding element is produced by winding an anode foil on which a first dielectric film is formed and a cathode foil facing the anode foil. In the above step, while immersing the winding element in the chemical solution stored in the conductive liquid storage tank, a voltage is applied between the anode foil and the liquid storage tank from a DC power source to apply a voltage to the anode foil. The second step of forming the dielectric film of 2 is included. Here, in the second step, a constant current is passed through the anode foil by a constant current element provided between the anode foil and the anode side of the DC power supply.

In the method for manufacturing an electrolytic capacitor according to a fourth aspect of the present invention, a first winding element is produced by winding an anode foil on which a first dielectric film is formed and a cathode foil facing the anode foil. A voltage is applied between the anode foil and the conductive member from a DC power source while immersing the winding element and the conductive member in the chemical solution stored in the liquid storage tank to obtain the anode foil. Includes a second step of forming a second dielectric film. Here, in the second step, a constant current is passed through the anode foil by a constant current element provided between the anode foil and the anode side of the DC power supply.

According to the present invention, it is possible to provide a method for manufacturing an electrolytic capacitor in which defects are unlikely to occur in the cathode foil when the anode foil is regenerated.

The effects or significance of the present invention will be further clarified by the description of the embodiments shown below. However, the embodiments shown below are merely examples when the present invention is put into practice, and the present invention is not limited to those described in the following embodiments.

FIG. 1 is a front sectional view of an electrolytic capacitor according to an embodiment. FIG. 2 is a flowchart showing a manufacturing process of the electrolytic capacitor according to the embodiment. FIG. 3A is a front sectional view of the take-up element before the cross-sectional formation step according to the embodiment, and FIG. 3B is a cross-sectional formation step according to the embodiment. It is a front sectional view of the winding element after that. FIG. 4 is a schematic perspective view showing a cross-sectional chemical conversion step according to the first embodiment of the embodiment. FIG. 5 (a) is a schematic view showing a cross-sectional formation process for one winding element according to the first embodiment, and FIG. 5 (b) is shown in FIG. 5 (a) according to the first embodiment. It is a graph which shows the time transition of the anode foil voltage and the cathode foil voltage. FIG. 6 is a schematic view showing a cross-sectional formation process for one take-up element according to the second embodiment of the embodiment. FIG. 7 is a schematic perspective view showing a cross-sectional chemical conversion step according to the third embodiment of the embodiment. FIG. 8 is a schematic view showing a cross-sectional formation process for one winding element according to the fourth embodiment of the embodiment. FIG. 9 is a schematic perspective view showing a cross-sectional formation process for one winding element according to the fifth embodiment of the embodiment. FIG. 10A is a schematic view showing a cross-sectional formation process for one winding element according to the sixth embodiment of the embodiment, and FIG. 10B is a schematic view showing the cross-sectional formation process of one winding element, and FIG. 10B is the sixth embodiment of the embodiment. It is a graph which shows the time transition of the anode foil voltage and the cathode foil voltage shown in FIG. 10A. FIG. 11 is a schematic perspective view showing a cross-sectional chemical conversion process according to a modified example. FIG. 12 is a schematic perspective view showing a cross-sectional chemical conversion process according to a modified example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In the present embodiment, the winding step S2 corresponds to the "first step" described in the claims. Further, the cross-section chemical conversion step S3 corresponds to the “second step” described in the claims. Further, the dielectric film 16 corresponds to the "first dielectric film" described in the claims. Further, the dielectric film 17 corresponds to the "second dielectric film" described in the claims. Further, the chemical conversion solution 120 corresponds to the "chemical solution" described in the claims. Further, the constant current diode 160 corresponds to the "second constant current element" and the "constant current element" described in the claims. Further, the constant current diode 190 corresponds to the "first constant current element" described in the claims.

However, the above description is only for the purpose of associating the configuration of the claims with the configuration of the embodiment, and the invention described in the scope of claims by the above association becomes the configuration of the embodiment. It is not limited in any way.

<Composition of electrolytic capacitor>
First, the electrolytic capacitor 1 manufactured by the method for manufacturing an electrolytic capacitor of the present embodiment will be described. The electrolytic capacitor 1 is a surface mount type electrolytic capacitor, and is a hybrid type electrolytic capacitor in which a conductive polymer and an electrolytic solution are combined as a cathode material.

FIG. 1 is a front sectional view of the electrolytic capacitor 1 according to the present embodiment.

The electrolytic capacitor 1 includes a capacitor element 10, a case 20, a sealing member 30, an electrolytic solution 40, and a seat plate 50.

The capacitor element 10 includes an anode foil 11, a cathode foil 12, a separator 13, an anode lead 14, and a cathode lead 15. The anode foil 11 is formed of an aluminum foil or the like, and a dielectric film 16 (also referred to as a chemical conversion film or an oxide film) is formed on both surfaces thereof by a chemical conversion treatment. Further, on the anode foil 11, a dielectric film 17 is formed on both end surfaces, which are cut surfaces, by a chemical conversion treatment (re-chemical conversion treatment) in a cross-section chemical conversion step described later. The cathode foil 12 is formed of, for example, an aluminum foil. The cathode foil 12 may be configured to cover the surface of the aluminum foil with a carbon film (layer) or a titanium film (layer). The separator 13 is made of an insulating material such as insulating paper and has a thickness of several tens of μm to prevent contact between the anode foil 11 and the cathode foil 12. The anode lead 14 and the cathode lead 15 are configured to include a lead tab terminal connected to the anode foil 11 or the cathode foil 12 and a lead wire connected to the lead tab terminal and functioning as an external terminal.

In the condenser element 10, the anode foil 11 to which the anode lead 14 is connected and the cathode foil 12 to which the cathode lead 15 is connected face each other with the separator 13 interposed therebetween, and the anode foil 11, the cathode foil 12 and the separator 13 are rolled. It is formed into a cylindrical shape by being wound into a shape. Further, in the capacitor element 10, a dielectric film 17 is formed on both end surfaces of the anode foil 11, and a conductive polymer layer which is a cathode material is formed between the anode foil 11 and the cathode foil 12.

The case 20 is formed of a material such as aluminum into a cylindrical shape having an open lower surface, and houses the capacitor element 10. The sealing member 30 is formed of an elastic material such as rubber, contains the capacitor element 10, and closes the opening on the lower surface of the case 20 into which the electrolytic solution 40 is injected. Two through holes 31 are formed in the sealing member 30, and the anode leads 14 and the cathode leads 15 of the capacitor element 10 project from these through holes 31 to the outside of the case 20.

The seat plate 50 is made of an insulating material and is attached to the lower part of the case 20. Two through holes 51 are formed in the seat plate 50. Further, on the bottom surface of the seat plate 50, two accommodating recesses 52 extending outward from the outlets of the through holes 51 are formed. The protruding portions 14a and 15a of the anode lead 14 and the cathode lead 15 projecting out of the case 20 are formed in a flat shape, are passed through the through hole 51 of the seat plate 50, and are bent to both sides to accommodate the seat plate 50. It is housed in 52.

<Manufacturing method of electrolytic capacitors>
Next, a method of manufacturing the electrolytic capacitor 1 will be described.

FIG. 2 is a flowchart showing a manufacturing process of the electrolytic capacitor 1 according to the present embodiment. FIG. 3A is a front sectional view of the take-up element 10A before the cross-sectional formation step S3 is performed according to the present embodiment, and FIG. 3B is a cross-sectional formation according to the present embodiment. It is a front sectional view of the take-up element 10A after step S3 is performed.

The manufacturing process of the electrolytic capacitor 1 according to the present embodiment includes a lead attachment step S1, a winding step S2, a cross-sectional formation step S3, a conductive polymer polymerization step S4, a casing step S5, and an aging step S6. , Including the lead processing step S7. Prior to the manufacturing process, the anode foil 11 on which the dielectric film 16 is formed on both sides and the cathode foil 12 are cut (cut) into strips having a predetermined width according to the size of the capacitor element 10.

In the lead attaching step S1, the anode lead 14 and the cathode lead 15 are connected to the strip-shaped anode foil 11 and the cathode foil 12, respectively, by a method such as caulking or ultrasonic welding. In the winding step S2, the anode foil 11 to which the anode lead 14 is connected and the cathode foil 12 to which the cathode lead 15 is connected are set so as to face each other with the separator 13 interposed therebetween, and these anode foil 11 and the cathode foil By winding the 12 and the separator 13 in a roll shape, the winding element 10A as shown in FIG. 3A is manufactured.

In the cross-section chemical conversion step S3, the anode foil 11 of the take-up element 10A is subjected to a chemical conversion treatment again, and as shown in FIG. A body film 17 is formed. Further, when a crack is generated in the dielectric film 16 on both sides of the anode foil 11 during the winding step S2, the crack is repaired. After that, the winding element 10A is dried. The cross-section chemical formation step S3 will be described in detail later.

In the conductive polymer polymerization step S4, the winding element 10A is impregnated with the dispersion liquid of the conductive polymer, polymerized and dried to form a conductive polymer layer between the anode foil 11 and the cathode foil 12. It is formed. As a result, the capacitor element 10 is completed.

In the casing step S5, the capacitor element 10 is housed in the case 20, and after the electrolytic solution 40 is injected into the case 20, the opening of the case 20 is sealed by the sealing member 30. In the aging step S6, heat and voltage are applied to the capacitor element 10. As a result, the LC characteristics of the capacitor element 10 are stabilized.

In the lead processing step S7, the protruding portions 14a and 15a of the anode lead 14 and the cathode lead 15 projecting out of the case 20 are cut to a predetermined length and then crushed to be flattened. After that, the protruding portions 14a and 15a are passed through the through hole 51 of the seat plate 50, further bent on both sides, and accommodated in the accommodating recess 52 of the seat plate 50.

In this way, the electrolytic capacitor 1 is completed by performing the lead attaching step S1 to the lead processing step S7. The completed electrolytic capacitor 1 is packaged and shipped.

Next, the cross-section chemical formation step S3 will be described in detail.

<Example 1 of cross-section chemical conversion step>
FIG. 4 is a schematic perspective view showing a cross-sectional chemical conversion step S3 according to the first embodiment of the present embodiment. FIG. 5A is a schematic view showing a cross-sectional forming step S3 for one winding element 10A according to the first embodiment, and FIG. 5B is a schematic view showing the cross-sectional formation step S3 according to the first embodiment, FIG. 5A. It is a graph which shows the time transition of the anode foil voltage Va and the cathode foil voltage Vk shown in.

As shown in FIG. 4, in the cross-section chemical conversion step S3, a plurality of winding elements 10A are subjected to chemical conversion treatment at one time.

A chemical conversion apparatus 100 is used for the cross-section chemical conversion step S3. The chemical conversion device 100 includes a liquid storage tank 110 capable of accommodating a plurality of winding elements 10A. The liquid storage tank 110 is formed of a conductive material such as stainless steel (more preferably plated with gold). A chemical conversion solution 120, which is a chemical solution for chemical conversion, is stored in the liquid storage tank 110. A plurality of winding elements 10A are immersed in the chemical conversion liquid 120. The anode lead 14 and the cathode lead 15 of each take-up element 10A are exposed from the chemical conversion liquid 120, and the anode lead 14, that is, the anode foil 11 is electrically connected to the anode side of the DC power supply 130 by the first connection line 140, and the cathode. The lead 15, that is, the cathode foil 12, is electrically connected to the cathode side of the DC power supply 130 by the second connecting line 150.

The first connecting line 140 is composed of a first main line 141 extending from the anode side of the DC power supply 130 and a first branch line 142 branching from the first main line 141 and extending to each anode lead 14. A constant current diode 160 is provided on each first branch line 142. On the other hand, the second connection line 150 is composed of a second main line 151 extending from the cathode side of the DC power supply 130 and a second branch line 152 branching from the second main line 151 and extending to each cathode lead 15. A resistance element 170 is provided on the second main line 151. The resistance value Rc of the resistance element 170 is set to a value very smaller than the resistance value Rb between the cathode foil 12 and the liquid storage tank 110 due to the chemical conversion liquid 120 shown in FIG. 5A.

The liquid storage tank 110 is electrically connected to the cathode side of the DC power supply 130 by the third connection line 180.

When a voltage is applied between the anode foil 11 and the liquid storage tank 110 by the DC power supply 130, a dielectric film 17 (see FIG. 3B) is formed on both end surfaces of the anode foil 11 by electrolysis. As shown in FIG. 5B, when the dielectric film 17 grows with the passage of time, the voltage on both end faces of the anode foil 11 (hereinafter, “anode foil”) according to the growth of the dielectric film 17. The voltage Va ”) rises. Therefore, the applied voltage is increased accordingly. The applied voltage is maintained constant when it finally reaches the preset chemical conversion voltage Vf, and then the anode foil voltage Va also reaches the chemical conversion voltage Vf like the applied voltage and becomes constant. In this way, the dielectric film 17 having the desired thickness corresponding to the chemical conversion voltage Vf is formed on the anode foil 11.

Here, a constant current diode 160 is provided in each first branch line 142 of the first connection line 140, and if the potential difference between the applied voltage and the anode foil voltage Va is a certain value or more, the applied voltage is large. Regardless of this, a constant current flows through the anode foil 11. The larger the potential difference between the applied voltage and the anode foil voltage Va, the larger the current flows through the anode foil 11, but if the current value is too large, the dielectric film 17 grows too fast and a dense dielectric film 17 is not formed. .. That is, the workmanship of the dielectric film 17 deteriorates. On the other hand, if the current value flowing through the anode foil 11 is too small, it takes too much time for the dielectric film 17 to grow, and it takes a long time for the dielectric film 17 having the desired thickness to be formed. It ends up. Therefore, in the present embodiment, an appropriate value of the current flowing through the anode foil 11 is determined in consideration of the workmanship of the dielectric film 17 and the time required for formation, so that a constant current of such an appropriate value flows. The constant current diode 160 is selected.

As described above, in the present embodiment, even if the applied voltage is raised too quickly and the potential difference between the applied voltage and the anode foil voltage Va becomes too large, the current flowing through the anode foil 11 is maintained at an appropriate value. It is possible to form a dense dielectric film 17 on both end faces of the anode foil 11.

Further, the resistance value Ra between the anode foil 11 and the cathode foil 12 by the chemical conversion liquid 120 shown in FIG. 5A is much higher than the resistance value Rb between the cathode foil 12 and the liquid storage tank 110. Since it is small, the voltage on both end faces of the cathode foil 12 (hereinafter referred to as “cathode foil voltage Vk”) shown in FIG. 5A increases as the anode foil voltage Va increases, and the cathode foil 12 is electrolyzed. A dielectric film is easily formed on the surface. However, in the present embodiment, the cathode foil 12 is electrically connected to the cathode side of the DC power supply 130 via the resistance element 170, and the resistance value Rc of the resistance element 170 is the cathode foil 12 and the liquid storage tank 110. Since it is very small compared to the resistance value Rb between and, the cathode foil 12 discharges and the potential of the cathode foil 12 is forcibly lowered. As a result, as shown in the solid line curve of FIG. 5B, the cathode foil voltage Vk is maintained in a low state. As a result, the cathode foil voltage Vk is less likely to exceed the oxide film voltage at which the dielectric film (oxide film) is formed on the cathode foil 12, and the dielectric film is less likely to be formed on the cathode foil 12.

When the cathode foil 12 is not electrically connected to the cathode side of the DC power supply 130 and forced discharge is not performed from the cathode foil 12 as in the conventional case, as shown in the broken line curve of FIG. 5 (b). In addition, the cathode foil voltage Vk may increase as the anode foil voltage Va increases. In this case, a dielectric film is likely to be formed on the cathode foil 12.

<Effect of Example 1>
As described above, according to the first embodiment, the following effects can be obtained.

Since the cathode foil 12 is electrically connected to the cathode side of the DC power supply 130 via the resistance element 170 so as to be discharged from the cathode foil 12, the cathode foil voltage is discharged even if the anode foil voltage Va rises. Vk can be kept low. As a result, the formation of the dielectric film on the cathode foil 12 can be suppressed, which prevents the foil capacity of the cathode foil 12 from being lowered and the formation of the dielectric film 17 of the anode foil 11 from being hindered. it can. Further, when the cathode foil 12 is configured to cover the aluminum foil with a carbon film or the like, it is possible to prevent the carbon film or the like from peeling off due to the formation of the dielectric film.

Further, by electrically connecting the anode foil 11 to the anode side of the DC power supply 130 via the constant current diode 160, the current flowing through the anode foil 11 can be maintained at an appropriate value, so that both ends of the anode foil 11 can be maintained. It is possible to prevent the sudden growth of the dielectric film 17 formed on the surface. As a result, a dense dielectric film 17 can be formed on both end faces of the anode foil 11.

Further, since the sudden growth of the dielectric film 17 is prevented and the sudden rise of the anode foil voltage Va is prevented, the rise of the cathode foil voltage Vk accompanying the rise of the anode foil voltage Va is also suppressed, and the cathode foil. Further suppression of the formation of the dielectric film on 12 is expected.

<Example 2 of cross-section chemical conversion step>
FIG. 6 is a schematic view showing a cross-sectional formation step S3 for one take-up element 10A according to the second embodiment of the present embodiment.

In the cross-section chemical conversion step S3 of this embodiment, in the chemical conversion apparatus 100, a constant current diode 190 is provided on the second main line 151 of the second connection line 150 in place of the resistance element 170. Other configurations of the chemical conversion device 100 are the same as those in the first embodiment.

When the cathode foil 12 is electrically connected to the cathode side of the DC power supply 130 via the constant current diode 190 as in the present embodiment, the cathode foil 12 is discharged as in the first embodiment. The potential of the cathode foil 12 is forcibly lowered, and the cathode foil voltage Vk is maintained in a low state. This makes it difficult for a dielectric film to be formed on the cathode foil 12. Further, in this embodiment, the same effects as those of the other examples 1 can be obtained.

<Example 3 of cross-section chemical conversion step>
FIG. 7 is a schematic perspective view showing the cross-sectional chemical conversion step S3 according to the third embodiment of the present embodiment.

In the cross-section chemical conversion step S3 of this embodiment, in the chemical conversion apparatus 100, a resistance element 170 is provided on each second branch line 152 of the second connection line 150. Other configurations of the chemical conversion device 100 are the same as those in the first embodiment.

In this embodiment, since each cathode foil 12 is electrically connected to the cathode side of the DC power supply 130 via each resistance element 170, discharge is performed from the cathode foil 12 and the cathode is discharged as in the first embodiment. The potential of the foil 12 is forcibly lowered, and the cathode foil voltage Vk is maintained in a low state. This makes it difficult for a dielectric film to be formed on the cathode foil 12. Moreover, when one winding element 10A is short-circuited, in the first embodiment, the current flowing through the resistance element 170 changes, which may affect the potential of the cathode foil 12 of the other winding element 10A. In this embodiment, the potential of the cathode foil 12 of the other winding element 10A is not affected.

Further, in this embodiment, the same effects as those of the other examples 1 can be obtained.

In this modified example, the constant current diode 190 used in the third embodiment may be provided on each second branch line 152 instead of the resistance element 170.

<Example 4 of cross-section chemical conversion step S3>
FIG. 8 is a schematic view showing a cross-sectional formation step S3 for one take-up element 10A according to the fourth embodiment of the present embodiment.

In the cross-section chemical conversion step S3 of this embodiment, in the chemical conversion apparatus 100, the cathode lead 15, that is, the cathode foil 12 is grounded by the fourth connecting wire 200 via the resistance element 170. Further, the liquid storage tank 110 is grounded by the fifth connection line 210 via the resistance element 220. Other configurations of the chemical conversion device 100 are the same as those in the first embodiment.

In this embodiment, since the cathode foil 12 is grounded via the resistance element 170, a discharge is performed from the cathode foil 12 to forcibly lower the potential of the cathode foil 12, and the cathode foil 12 is forcibly lowered, as in the first embodiment. The voltage Vk is kept low. This makes it difficult for a dielectric film to be formed on the cathode foil 12. Further, in this embodiment, the reference potential can be adjusted by grounding the liquid storage tank 110 in the same manner as the cathode foil 12.

Further, in this example, the same effects as those of the other examples 1 can be obtained.

In this modification, the constant current diode 190 used in the third embodiment may be provided on the fourth connection line 200 instead of the resistance element 170.

<Example 5 of cross-section chemical conversion step S3>
FIG. 9 is a schematic view showing a cross-sectional formation step S3 for one take-up element 10A according to the fifth embodiment of the present embodiment.

In the cross-section chemical conversion step S3 of this embodiment, in the chemical conversion apparatus 100, the liquid storage tank 110 is not electrically connected to the cathode side of the DC power supply 130. Instead, a conductive member 230 made of stainless steel (more preferably plated with gold) is immersed in the chemical conversion liquid 120 stored in the liquid storage tank 110, and the conductive member 230 is subjected to a DC power supply by the sixth connection line 240. It is electrically connected to the cathode side of 130. Other configurations of the chemical conversion device 100 are the same as those in the first embodiment. In this embodiment, a voltage is applied from the DC power supply 130 between the anode foil 11 and the conductive member 230 to perform the chemical conversion treatment of the anode foil 11.

Also in this example, the same action and effect as in Example 1 can be obtained.

In this modification, the second connecting wire 150 may be provided with the constant current diode 190 used in the third embodiment instead of the resistance element 170.

<Example 6 of cross-section chemical conversion step S3>
FIG. 10A is a schematic view showing a cross-sectional forming step S3 for one winding element 10A according to the sixth embodiment of the present embodiment, and FIG. 10B is an embodiment of the present embodiment. It is a graph which shows the time transition of the anode foil voltage Va and the cathode foil voltage Vk shown in FIG. 10A according to Example 6.

In the cross-sectional chemical conversion step S3 of this embodiment, a voltmeter 250 for measuring the cathode foil voltage Vk and a voltage applied by the DC power supply 130 according to the cathode foil voltage Vk measured by the voltmeter 250 are applied to the chemical conversion apparatus 100. A voltage control unit 260 for adjustment is provided. Further, in the chemical conversion apparatus 100, each constant current diode 160 is not provided on the first connection line 140. Other configurations of the chemical conversion device 100 are the same as those in the first embodiment.

When the cathode foil voltage Vk measured by the voltmeter 250 reaches the preset upper limit value Vkmax of the cathode foil voltage Vk, the voltage control unit 260 stops the increase of the applied voltage, and then the cathode foil voltage Vk becomes the upper limit. The applied voltage is increased so as not to exceed the value Vkmax. The upper limit value Vkmax can be a value lower than the oxide film voltage of the cathode foil 12.

In this embodiment, as shown in FIG. 10B, the cathode foil voltage Vk is suppressed to a voltage lower than the upper limit value Vkmax to suppress the formation of a dielectric film on the cathode foil 12 and the damage of the cathode foil 12. The time required for the anode foil voltage Va to reach the specified chemical conversion voltage Vf can be shortened, and the time for forming the dielectric film on the anode foil 11 can be shortened.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and application examples of the present invention also have various changes in addition to the above embodiments. It is possible.

For example, in the first embodiment, each anode foil 11 is electrically connected to the anode side of the DC power supply 130 via the constant current diode 160. However, when the constant current diode 160 is considered unnecessary, for example, the applied voltage can be adjusted accurately so that the current flowing through the anode foil 11 can be maintained at a substantially constant value, as shown in FIG. The constant current diode 160 may not be provided in the chemical conversion device 100. Similarly, in Examples 2 to 5, the constant current diode 160 may not be provided in the chemical conversion apparatus 100.

Further, in the first embodiment, the cathode foil 12 is electrically connected to the cathode side of the DC power supply 130 by the second connecting line 150. However, for example, when the oxide film voltage of the cathode foil 12 used for the winding element 10A is relatively high, it is difficult to form a dielectric film on the cathode foil 12 without forcibly discharging the cathode foil 12. , As shown in FIG. 12, the cathode foil 12 does not have to be electrically connected to the cathode side of the DC power supply 130 by the second connecting line 150. Similarly, in Examples 2, 3 and 5, the cathode foil 12 does not have to be electrically connected to the cathode side of the DC power supply 130 by the second connecting line 150. Similarly, in the fourth embodiment, the cathode foil 12 may not be grounded by the fourth connecting wire 200.

Further, in the above-mentioned Examples 1, 3 to 6, a constant current diode 190 may be provided in parallel with the resistance element 170.

Further, in the above embodiment, the electrolytic capacitor 1 is a hybrid type electrolytic capacitor in which a conductive polymer and an electrolytic solution 40 are compounded as a cathode material, and the method for manufacturing such an electrolytic capacitor of the present invention is applied. The method of manufacturing electrolytic capacitors was applied. However, even if the method for manufacturing an electrolytic capacitor of the present invention is applied to a method for manufacturing a so-called solid electrolytic capacitor using a conductive polymer as a cathode material or a method for manufacturing an electrolytic capacitor using an electrolytic solution as a cathode material. Good.

Further, in Examples 1 to 5, the voltage applied between the anode foil 11 and the liquid storage tank 110 is increased over time to the chemical conversion voltage Vf, but the anode foil 11 and the liquid storage tank 110 are used. The chemical conversion voltage Vf may be applied between them from the beginning. By doing so, it is not necessary to adjust the magnitude of the applied voltage. In this case, since the potential difference between the chemical conversion voltage Vf and the anode foil voltage Va becomes considerably large for a while after the voltage application is started, the constant current diode 160 is connected in series from the viewpoint of protection of the constant current diode 160. A resistance element may be provided.

In addition, various modifications of the embodiment of the present invention can be made as appropriate within the scope of the technical idea shown in the claims.

The present invention is useful in a method for manufacturing an electrolytic capacitor used in various electronic devices, electric devices, industrial devices, electrical components of vehicles, and the like.

S2 winding process (first process)
S3 cross-section chemical formation step (second step)
1 Electrolytic capacitor 10 Capacitor element 10A Winding element 11 Anode foil 12 Cathode foil 16 Dielectric film (first dielectric film)
17 Dielectric film (second dielectric film)
100 Chemical conversion equipment 110 Liquid storage tank 120 Chemical conversion liquid (chemical solution)
130 DC power supply 160 Constant current diode (second constant current element, constant current element)
170 Resistance element 190 Constant current diode (first constant current element)

Claims (6)

The first step of winding the anode foil on which the first dielectric film is formed and the cathode foil facing the anode foil to produce a winding element, and
While immersing the winding element in the conductive chemical solution stored in the conductive liquid storage tank, a voltage is applied between the anode foil and the liquid storage tank from a DC power source to apply a second voltage to the anode foil. Including a second step of forming a dielectric film of
In the second step, a resistance element is interposed between the cathode foil and the cathode side of the DC power supply in parallel with an electric circuit including the chemical solution and the liquid storage tank to discharge the cathode foil. To lower the potential of the cathode foil.
A method for manufacturing an electrolytic capacitor, which is characterized in that. The first step of winding the anode foil on which the first dielectric film is formed and the cathode foil facing the anode foil to produce a winding element, and
While immersing the take-up element and the conductive member in the conductive chemical solution stored in the liquid storage tank, a voltage is applied between the anode foil and the conductive member from a DC power source to the anode foil. Including a second step of forming a second dielectric film,
In the second step, a resistance element is interposed between the cathode foil and the cathode side of the DC power supply in parallel with an electric circuit containing the chemical solution and the conductive member to discharge the cathode foil. To lower the potential of the cathode foil.
A method for manufacturing an electrolytic capacitor, which is characterized in that. The first step of winding the anode foil on which the first dielectric film is formed and the cathode foil facing the anode foil to produce a winding element, and
While immersing the winding element in the conductive chemical solution stored in the conductive liquid storage tank, a voltage is applied between the anode foil and the liquid storage tank from a DC power source to apply a second voltage to the anode foil. Including a second step of forming a dielectric film of
In the second step, the cathode is provided by interposing a first constant current element in parallel with the electric circuit including the chemical solution and the liquid storage tank between the cathode foil and the cathode side of the DC power supply. Discharge from the foil to lower the potential of the cathode foil.
A method for manufacturing an electrolytic capacitor, which is characterized in that. The first step of winding the anode foil on which the first dielectric film is formed and the cathode foil facing the anode foil to produce a winding element, and
While immersing the take-up element and the conductive member in the conductive chemical solution stored in the liquid storage tank, a voltage is applied between the anode foil and the conductive member from a DC power source to the anode foil. Including a second step of forming a second dielectric film,
In the second step, the cathode is provided by interposing a first constant current element in parallel with an electric circuit containing the chemical solution and the conductive member between the cathode foil and the cathode side of the DC power supply. Discharge from the foil to lower the potential of the cathode foil.
A method for manufacturing an electrolytic capacitor, which is characterized in that. In the method for manufacturing an electrolytic capacitor according to any one of claims 1 to 4 .
In the second step, a constant current is passed through the anode foil by a second constant current element provided between the anode foil and the anode side of the DC power supply.
A method for manufacturing an electrolytic capacitor, which is characterized in that. In the method for manufacturing an electrolytic capacitor according to any one of claims 1 to 4 .
In the second step, the voltage applied to the anode foil is increased, the potential of the cathode foil is measured, and the rising gradient of the applied voltage is adjusted according to the measured potential.
A method for manufacturing an electrolytic capacitor, which is characterized in that.