JP4442361B2 - Manufacturing method of solid electrolytic capacitor - Google Patents

Description

  The present invention relates to a method of manufacturing a solid electrolytic capacitor, and more particularly to a method of manufacturing a solid electrolytic capacitor that has been improved to improve the capacitance and breakdown voltage of the solid electrolytic capacitor and to increase the size and capacity.

  An electrolytic capacitor using a metal having a valve action such as tantalum or aluminum is obtained by expanding the dielectric by making the valve action metal as the anode-side counter electrode into the shape of a sintered body or an etching foil. Since it is small and a large capacity can be obtained, it is widely used. In particular, a solid electrolytic capacitor using a solid electrolyte as an electrolyte has features such as small size, large capacity, low equivalent series resistance, easy to chip, and suitable for surface mounting. It is indispensable for miniaturization, high functionality and low cost of electronic equipment.

  In this type of solid electrolytic capacitor, as a small-sized and large-capacity application, an anode foil and a cathode foil made of a valve metal such as aluminum are generally wound with a separator interposed therebetween to form a capacitor element. It is impregnated with a driving electrolyte, and has a sealed structure in which a capacitor element is housed in a metal case such as aluminum or a case made of synthetic resin. As the anode material, aluminum, tantalum, niobium, titanium and the like are used, and as the cathode material, the same kind of metal as the anode material is used.

  As solid electrolytes used for solid electrolytic capacitors, manganese dioxide and 7,7,8,8-tetracyanoquinodimethane (TCNQ) complexes are known. There is a technique (see Patent Document 1) that focuses on a conductive polymer such as polyethylenedioxythiophene (hereinafter referred to as PEDT) having excellent adhesion to an oxide film layer of an electrode.

  A solid electrolytic capacitor of a type in which a solid electrolyte layer made of a conductive polymer such as PEDT is formed on such a wound capacitor element is produced as follows. First, the surface of the anode foil made of valve action metal such as aluminum is roughened by electrochemical etching treatment in an aqueous chloride solution to form many etching pits, and then in an aqueous solution such as ammonium borate. A voltage is applied to form an oxide film layer serving as a dielectric (chemical conversion). Similar to the anode foil, the cathode foil is made of a valve metal such as aluminum, but the surface is only subjected to etching treatment.

Thus, the anode foil having the oxide film layer formed on the surface and the cathode foil having only the etching pits are wound through a separator to form a capacitor element. Subsequently, a polymerizable monomer such as 3,4-ethylenedioxythiophene (hereinafter referred to as EDT) and an oxidizer solution are respectively discharged into the capacitor element subjected to restoration conversion, or immersed in a mixed solution of the two. The polymerization reaction is promoted in the capacitor element, and a solid electrolyte layer made of a conductive polymer such as PEDT is generated. Thereafter, the capacitor element is housed in a bottomed cylindrical outer case, and the opening of the case is sealed with a sealing rubber to produce a solid electrolytic capacitor.
JP-A-2-15611

By the way, in recent years, with the digitization of electronic equipment, a capacitor having a small size and a large capacity has been demanded. As a method for this, it is conceivable to increase the etching magnification of the aluminum foil. It has been difficult to increase the capacitance from the electrode material, for example, the dissolution progresses at the same time and prevents the increase in the area expansion rate.
Such a problem occurs not only when EDT is used as the polymerizable monomer but also when other thiophene derivatives, pyrrole, aniline, and the like are used.

  The present invention has been proposed in order to solve the above-described problems of the prior art, and the object thereof is to improve the capacitance and withstand voltage of the solid electrolytic capacitor and to increase the size and capacity. It is providing the manufacturing method of a solid electrolytic capacitor.

In order to solve the above-mentioned problems, the present inventor has intensively studied on a method for manufacturing a solid electrolytic capacitor capable of improving capacitance and withstand voltage and reducing the size and capacity, and has completed the present invention. It is a thing.
That is, the present inventor has found that a metal corrosive substance exists between the oxide film layer of the anode foil and the conductive polymer layer, and the presence of the metal corrosive substance has a capacity appearance rate of the solid electrolytic capacitor. It was found that this was a factor that caused the decline. In particular, it was found that the lower the formation voltage of the anode foil, the lower the capacity appearance rate.

  Therefore, as a result of various studies based on this knowledge, a capacitor element was formed by winding a cathode foil and an anode foil formed with a dielectric oxide film through a separator, and this capacitor element was impregnated with a conductive polyaniline solution. After applying a voltage to the anode foil, or removing the solvent while applying the voltage, while forming a conductive polyaniline film, this conductive polyaniline film is deposited on the dielectric oxide film, An anode in which the conductive polyaniline film is formed by impregnating the polymerizable monomer and the oxidizing agent in the range of 0.4 to 15 when the molar ratio of the polymerizable monomer and the oxidizing agent is 1, and the polymerizable monomer is 0.4 to 15. It has been found that good results can be obtained by forming a conductive polymer layer on the electrode body.

  That is, when the solid electrolytic capacitor obtained as described above was analyzed, no corrosive metal was generated between the oxide film of the anode foil and the conductive polymer layer, and the characteristics of this solid electrolytic capacitor were examined. It has been found that the capacitance increases and the withstand voltage characteristics also improve.

  Furthermore, according to the present invention, unlike chemical polymerization in which a capacitor element is impregnated with a polymerizable monomer solution and an oxidant solution, and electrolytic polymerization in which a voltage is applied by impregnating a capacitor element with a polymerizable monomer solution, it is made conductive. There is also an advantage that a polyaniline film that becomes a conductive layer can be easily formed by adding a simple manufacturing process of impregnating a capacitor element with a solution containing polyaniline and then removing the solvent.

In particular, it was found that the withstand voltage of the anode foil can be improved by setting the polymerizable monomer to 3 or more when the molar ratio of the polymerizable monomer to the oxidant is 1 when the oxidant is 1.
It was also found that the ESR characteristics of the solid electrolytic capacitor can be improved by setting the polymerizable monomer to the oxidizing agent to less than 4 when the molar ratio of the polymerizable monomer to the oxidizing agent is 1. is there.

(1) Manufacturing method of solid electrolytic capacitor The manufacturing method of the solid electrolytic capacitor based on this invention is as follows. That is, an anode foil and a cathode foil having an oxide film layer formed on the surface thereof are wound through a separator to form a capacitor element, and this capacitor element is subjected to restoration conversion. Subsequently, this capacitor element was impregnated with a conductive polyaniline solution adjusted to a concentration of 5 wt% or less, and after applying voltage to the anode foil (or while applying voltage), the solvent was removed, A conductive polyaniline film is formed.
Thereafter, when the molar ratio of the polymerizable monomer and the oxidizing agent is set to 1 when the oxidizing agent is 1, the polymerizable monomer is set to 0.4 to 15, both are impregnated in the capacitor element, A polymerization reaction is generated to form a solid electrolyte layer. Thereafter, the capacitor element is inserted into an outer case, a sealing rubber is attached to the opening end, and sealing is performed by caulking, and then aging is performed to form a solid electrolytic capacitor.

  A series of impregnation, voltage application, and solvent removal steps may be performed a plurality of times. When a series of impregnation, voltage application, and solvent removal steps are performed a plurality of times, the conductive polyaniline film layer is formed into the etching pits, and the adhesion is improved, so that the capacitance is further improved.

In addition, as a method of attaching the polymerizable monomer and the oxidizing agent on the anode electrode body in the capacitor element, the capacitor element is immersed in the polymerizable monomer solution and then immersed in the oxidizing agent solution, or the oxidizing agent solution A method of immersing the capacitor element in a polymerizable monomer solution, a method of injecting a polymerizable monomer into the capacitor element, a method of injecting an oxidant solution, or a method of injecting an oxidant solution into the capacitor element and then polymerizing A method of injecting the polymerizable monomer, a method of immersing the capacitor element in a mixed solution in which the polymerizable monomer and the oxidizing agent are mixed, or a method of injecting the mixed solution into the capacitor element can be used.
In addition to the above-described method of impregnating the capacitor element with the polymerizable monomer and the oxidant solution and attaching both solutions onto the anode electrode body, a method of directly applying both solutions onto the anode electrode body is used. You can also.

(2) Application Mode Examples of the anode electrode body of the present invention include electrode foils made of valve action metals such as aluminum, tantalum, niobium, and titanium, and sintered bodies such as tantalum and niobium. The electrode foil is wound or laminated via a separator to form a capacitor element, and the sintered body is applied as a capacitor element as it is.

(3) Conductive polyaniline solution The solvent of the conductive polyaniline solution is preferably paraxylene or water. The concentration is preferably 5 wt% or less. This is because when the concentration exceeds 10%, a uniform polyaniline film cannot be formed.

(4) Method of impregnating conductive polyaniline solution As a method of impregnating the capacitor element formed as described above with a conductive polyaniline solution, there are the following two methods.
In the first method, a conductive polyaniline solution prepared at a predetermined concentration is placed in a predetermined container, a capacitor element is immersed in this solution, and a voltage is applied to the anode foil through the anode lead in the immersed state. Is the method. In this case, the cathode is connected to a cathode lead or a cathode terminal plate newly provided in the container. When there is no cathode lead in the state of an element such as an element made of a single electrode foil or an element made of a sintered body, the cathode terminal plate is used.
The second method is a method in which a conductive polyaniline solution prepared at a predetermined concentration is directly injected and impregnated into a capacitor element using a nozzle or the like, and then a voltage is applied to the anode foil through the anode lead. It is. In this case, the cathode is connected to the cathode lead.

Note that a pulse voltage may be applied as the voltage application to the anode foil. The voltage applied to the anode foil is preferably equal to or lower than the formation voltage of the anode foil. This is because if the anode foil is formed at a voltage equal to or higher than that, the anode foil is formed in the conductive polyaniline solution, the oxide film is formed thick, and a desired capacitance cannot be obtained. However, when a solution in which the anode foil is not formed is used as the conductive polyaniline solution, a voltage higher than the formation voltage of the anode foil may be applied.
Also, using an anode foil that has been preliminarily formed at a lower voltage, a voltage higher than the formation voltage of the anode foil is applied in the conductive polyaniline solution to form the anode foil so as to have a desired oxide film thickness. It can also be implemented.

(5) Solvent removal method After impregnating the capacitor element with the conductive polyaniline solution, the method for removing the solvent of the conductive polyaniline solution is to apply the voltage to the anode foil or while applying the voltage. A method of removing the solvent by heat treatment in a thermostatic bath or the like in a state of being immersed in a container can be used.

Or after applying a voltage as mentioned above, the method of removing a solvent by pulling up a capacitor | condenser element from a container, and also heat-processing while applying a voltage, or heat-processing without applying a voltage can be used. .
Note that the second method shown in the above section “(4) Method of impregnating conductive polyaniline solution” is more preferable because it facilitates heat treatment.

  In this case, the voltage applied to the anode foil is preferably equal to or lower than the formation voltage of the anode foil. This is because if the anode foil is formed at a voltage equal to or higher than that, the anode foil is formed in the conductive polyaniline solution, the oxide film is formed thick, and a desired capacitance cannot be obtained. However, when a solution in which the anode foil is not formed is used as the conductive polyaniline solution, a voltage higher than the formation voltage of the anode foil may be applied.

(6) Molar ratio of polymerizable monomer and oxidizer (6-1) When the molar ratio of polymerizable monomer and oxidizer is 3: 1 or more Various changes were made in the molar ratio of polymerizable monomer and oxidizer during the polymerization reaction. Then, when it was investigated whether or not the withstand voltage of the solid electrolytic capacitor could be improved, when the molar ratio of the polymerizable monomer to the oxidizing agent was 1, the polymerizable monomer was 3 or more, preferably It has been found that the withstand voltage increases when it is 4 or more, more preferably 6 or more. In addition, when the oxidizer is 1, when the polymerizable monomer exceeds 15, the withstand voltage effect is reduced, and the ESR is increased and the capacitance is greatly reduced. Therefore, the polymerizable monomer does not exceed 15. It is desirable.

  In this way, if the polymerization reaction proceeds with a large amount of polymerizable monomers, the remaining oxidant decreases, resulting in a decrease in monomers, oxidants and other reaction residues that were not involved in the polymerization reaction. Therefore, it is considered that the withstand voltage characteristic is improved.

(Examination of withstand voltage of anode foil)
Next, the present inventors examined the behavior of the current when a voltage was applied to the solid electrolytic capacitor and the applied voltage was raised, and the result shown in FIG. 1 was obtained. In addition, the A curve of FIG. 1 is a case where the formation voltage of anode foil is comparatively high, and B curve is a case where the formation voltage of anode foil is low.

  First, the B curve will be described. That is, when the formation voltage of the anode foil is as low as 20 Vfs or less, current starts to flow once at time b, and after reaching a peak, the current drops. Next, at time point c, a large current flows, resulting in a short circuit.

  This behavior can be considered as follows. That is, when the applied voltage of the solid electrolytic capacitor is increased, the conductive polymer retains conductivity, so that the voltage is applied to the anode foil. When the applied voltage reaches b, the anode foil causes dielectric breakdown and shorts. When the anode foil is short-circuited, the applied voltage is applied to the conductive polymer, a large current flows through the conductive polymer, the conductive polymer is insulated, and no current flows. When the applied voltage is further increased, the insulated conductive polymer is short-circuited due to dielectric breakdown. From this, it can be seen that the voltage b is the withstand voltage of the anode foil and the voltage c is the withstand voltage of the conductive polymer.

  On the other hand, when the formation voltage of the anode foil is relatively high, such as 25 to 30 Vfs, when a voltage is applied to the solid electrolytic capacitor and the applied voltage is increased, the peak starting from b like the B curve is It does not appear and a short circuit occurs at the time of the voltage a higher than the voltage c.

  This behavior can be considered as follows. That is, since the formation voltage of the anode foil is high up to the voltage of a, the conductive polymer keeps the conductivity and the voltage is applied to the anode foil, but the anode foil causes dielectric breakdown at the voltage of a. It leads to a short. After that, a large current flows and the conductive polymer is insulated by the current. As described above, the withstand voltage of the insulated polymer is c, and the voltage of a is higher than this. The insulation breakdown of the insulated polymer occurs, and the solid electrolytic capacitor is short-circuited. From the above, it was found that the voltage a is the withstand voltage of the anode foil.

  Subsequently, solid electrolytic capacitors were formed by variously changing the molar ratio of the polymerizable monomer and the oxidizing agent, voltage was applied to each solid electrolytic capacitor, and the behavior of current when the applied voltage was increased was examined. The result as shown in the C curve of FIG. 1 was obtained. That is, it was found that the withstand voltage of the anode foil increased from a to a ′ as the monomer: oxidant molar ratio was increased. In other words, it was found that the withstand voltage of the anode foil increases as the molar ratio of monomer: oxidant increases even if the formation voltage of the anode foil is the same. The reason is considered to be that the smaller the ratio of the oxidizing agent to the monomer, the less the influence of the oxidizing agent on the anodized film.

Furthermore, the present inventors can obtain a solid electrolytic capacitor having a desired withstand voltage by using an anode foil in which an oxide film is formed at a lower formation voltage than in the past when the monomer: oxidant molar ratio is increased. As a result, a good result was obtained. Thus, it was found that the capacitance and ESR can be greatly improved as a result of the low formation voltage of the anode foil.
It has been found that the formation voltage of the anode foil can be reduced to 1.5 to 3.0 times, more preferably 1.5 to 2.5 times the rated voltage.

  Here, after impregnating the anode electrode body with a conductive polyaniline solution and applying a voltage (or while applying a voltage), the solvent is removed to form a conductive polyaniline film on the oxide film of the anode electrode body. In this case, with this conductive polyaniline film, the withstand voltage is further increased, and a result like the curve D in FIG. 1 is obtained. The withstand voltage of the anode foil is increased from a ′ → a ″, and the solid electrolytic capacitor It was found that the withstand voltage was further improved.

(Action / Effect)
As described above, on the oxide film of the anode electrode body constituting the capacitor element, a good conductive polyaniline film formed by voltage application is deposited, and the polymerizable monomer and oxidant impregnated in the capacitor element are By mixing the polymerizable monomer and the oxidizing agent so that the polymerizable monomer has a molar ratio of 3 or more when the oxidizing agent is 1, the withstand voltage of the solid electrolytic capacitor can be greatly improved, and A solid electrolytic capacitor having a desired withstand voltage can be obtained even when using an anode foil having an oxide film formed at a formation voltage lower than that of the conventional formation voltage, so that the capacitance and ESR can be greatly improved. it can.

(6-2) When the molar ratio of the polymerizable monomer to the oxidizing agent is less than 4: 1 Further, when the molar ratio of the polymerizable monomer to the oxidizing agent is 1, the polymerizable monomer is less than 4, preferably Has been found to reduce ESR when less than 3, more preferably 2.5 to 1. Thus, it is considered that when the polymerization reaction is allowed to proceed in a state where the ratio of the oxidizing agent to the polymerizable monomer is large, the amount of the conductive polymer formed increases, and thus the ESR characteristics are improved. If the molar ratio of the polymerizable monomer to the oxidizing agent is set to 1 and the oxidizing monomer is less than 0.4, if the polymerizable monomer is less than 0.4, the effect of reducing ESR is reduced and the capacitance is greatly reduced. Therefore, the polymerizable monomer is preferably set to 0.4 or more.

  In addition, as the method of impregnating the capacitor element with the polymerizable monomer and the oxidizing agent, the above-described various methods can be used. When the molar ratio of the polymerizable monomer and the oxidizing agent is set to 1, the polymerization is performed. In the case where the monomer content is less than 4, a method of immersing the capacitor element in the monomer solution and then immersing in the oxidant solution is preferable. The reason is that if the ratio of the oxidizing agent to the monomer is increased, the progress of the polymerization reaction becomes faster, and therefore, when a mixed solution of the monomer and the oxidizing agent is used, a polymer is formed before impregnation.

(Action / Effect)
As described above, on the oxide film of the anode electrode body constituting the capacitor element, a good conductive polyaniline film formed by voltage application is deposited, and the polymerizable monomer and oxidant impregnated in the capacitor element are By mixing the polymerizable monomer and the oxidizing agent so that the polymerizable monomer has a molar ratio of less than 4 when the oxidizing agent is 1, the ESR characteristic of the solid electrolytic capacitor can be greatly improved. Capacitance can be improved.

(7) EDT
When EDT is used as the polymerizable monomer, it is preferable to use an EDT solution impregnated in the capacitor element in which EDT is dissolved in a volatile solvent so that its concentration is 25 to 32 wt%.
Examples of the volatile solvent include hydrocarbons such as pentane, ethers such as tetrahydrofuran, esters such as ethyl formate, ketones such as acetone, alcohols such as methanol, nitrogen compounds such as acetonitrile, and the like. Of these, methanol, ethanol, acetone and the like are preferable.

(8) Oxidizing agent As the oxidizing agent, an aqueous solution of ferric paratoluenesulfonate, periodic acid or iodic acid dissolved in ethanol can be used, and the concentration of the oxidizing agent with respect to the solvent is preferably 45 to 55 wt%, 50-55 wt% is more preferable. The higher the oxidant concentration in the solvent, the lower the ESR. As the oxidant solvent, the volatile solvent used in the monomer solution can be used, and ethanol is particularly preferable. Ethanol is suitable as the oxidant solvent because it is easy to evaporate due to its low vapor pressure and the remaining amount is small.

(9) Chemical conversion liquid for restoration chemical conversion Chemical liquids for restoration chemical conversion include phosphoric acid type chemical conversion liquids such as ammonium dihydrogen phosphate and diammonium hydrogen phosphate, boric acid type chemical conversion liquids such as ammonium borate, and adipic acid. An adipic acid-based chemical conversion liquid such as ammonium can be used, and among these, it is desirable to use ammonium dihydrogen phosphate. The immersion time is preferably 5 to 120 minutes.

(10) Other polymerizable monomer The polymerizable monomer used in the present invention includes, in addition to the above EDT, a thiophene derivative other than EDT, aniline, pyrrole, furan, acetylene, or a derivative thereof, and a predetermined oxidizing agent. As long as it is oxidatively polymerized to form a conductive polymer, it can be applied. As the thiophene derivative, one having the following structural formula can be used.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the solid electrolytic capacitor which enabled the improvement of the electrostatic capacitance and withstand pressure | voltage of a solid electrolytic capacitor, and size reduction and large capacity | capacitance can be provided.

  Subsequently, the present invention will be described in more detail based on Examples, Comparative Examples, and Conventional Examples manufactured as follows.

Example 1
An anode foil having an etching layer and an oxide film layer (formation voltage 42 V) formed on the surface of the aluminum foil and a cathode foil having an etching layer formed on the surface of the aluminum foil are wound through a separator to form a capacitor element. Formed. As the separator, a nonwoven fabric made of 40 μm 6-nylon nanofibers was used.
The capacitor element was immersed in a container containing a conductive conductive polyaniline-containing solution, and a voltage was applied to the anode foil (35 V). Thereafter, the capacitor element was pulled out of the solution and heat-treated at 50 ° C. for 90 minutes to remove the solvent. The formation process of this electroconductive polyaniline film was performed 3 times. As the conductive polyaniline solution, a 2 wt% conductive polyaniline solution using paraxylene as a solvent was used.
Subsequently, an ethanol solution of EDT and 45% ferric paratoluenesulfonate was immersed in a solution in which the molar ratio of the monomer and the oxidizing agent was 2.5: 1, and the mixture was heated at 60 ° C. for 30 minutes. Heat polymerization was performed at 150 ° C. for 60 minutes to form a conductive polymer layer. And this capacitor | condenser element was inserted in the bottomed cylindrical outer case (aluminum case), sealing rubber | gum (butyl rubber) was attached to the opening edge part, and it sealed by the crimping process. Thereafter, aging was performed by applying a voltage of 37 V at 150 ° C. for 120 minutes to form a solid electrolytic capacitor.

(Example 2)
The molar ratio of the monomer and the oxidizing agent in Example 1 was changed to 6.0: 1, and the other conditions and steps were the same as in Example 1.

(Example 3)
The method for forming the conductive polyaniline film in Example 1 was changed, and after impregnating the capacitor element with a solution containing conductive polyaniline using a nozzle, the capacitor element was placed in a thermostatic bath, The solvent was removed by heat treatment while applying a voltage (35 V). Other conditions and steps were the same as in Example 1.

Example 4
The molar ratio of the monomer and the oxidizing agent in Example 3 was changed to 6.0: 1, and other conditions and steps were the same as in Example 3.

(Conventional example 1)
Without forming a conductive polyaniline film, a polymerization process was performed after the capacitor element was formed. Other conditions and steps were the same as in Example 1.

(Conventional example 2)
Without forming a conductive polyaniline film, a polymerization process was performed after the capacitor element was formed. Other conditions and steps were the same as in Example 2.

[Comparison result]
The electrical characteristics of the examples and conventional examples obtained by the above method were examined, and the results shown in Table 1 were obtained.

As is clear from Table 1, Example 1 and Example 3 using the mixed solution in which the conductive polyaniline film was formed and the molar ratio of the monomer and the oxidizing agent was 2.5: 1 are the same as those in Conventional Example 1. In comparison, the capacitance increased about 1.15 times and about 1.23 times, respectively. In addition, the breakdown voltage increased by about 1.07 times and about 1.08 times, respectively, compared to the conventional example, and the ESR decreased by about 0.88 times and about 0.83 times, respectively, compared with the conventional example.
In addition, comparing Example 1 and Example 3 in which the molar ratio of the monomer and the oxidizing agent is the same and the formation method of the conductive polyaniline film is different, Example 2 in which the solvent was removed while applying a voltage was more Good results were obtained.

Next, Example 2 and Example 4 using the mixed solution in which the conductive polyaniline film was formed and the molar ratio of the monomer and the oxidizing agent was 6.0: 1 were compared with the conventional example 2 in the capacitance. Increased by about 1.16 times and about 1.24 times, respectively. In addition, the breakdown voltage increased by about 1.09 times and about 1.13 times, respectively, as compared with the conventional example, and the ESR decreased by about 0.88 times and about 0.87 times, respectively, compared with the conventional example.
Further, when Example 2 and Example 4 in which the molar ratio of the monomer and the oxidizing agent are the same and the formation method of the conductive polyaniline film is different are compared, Example 4 in which the solvent was removed while applying a voltage was more Good results were obtained.

The figure which shows the relationship between the voltage applied to the solid electrolytic capacitor and the current (V-I curve)

Claims (6)

In the method for producing a solid electrolytic capacitor in which an electrolyte layer made of a conductive polymer is formed on an anode electrode body on which a dielectric oxide film is formed,
A conductive polyaniline solution is attached to the anode electrode body on which the dielectric oxide film is formed, a voltage is applied to the anode electrode body, and then the solvent is removed to form the conductive polyaniline film. Depositing on the dielectric oxide film;
When the molar ratio of the polymerizable monomer and the oxidizing agent is set to 1 when the oxidizing agent is 1, the polymerizable monomer is set to 0.4 to 15, and both are attached to the anode electrode body on which the conductive polyaniline film is formed. Forming a conductive polymer layer;
A method for producing a solid electrolytic capacitor, comprising: In the method for producing a solid electrolytic capacitor in which an electrolyte layer made of a conductive polymer is formed on an anode electrode body on which a dielectric oxide film is formed,
A conductive polyaniline solution is adhered to the anode electrode body on which the dielectric oxide film is formed, and the solvent is removed while applying a voltage to the anode electrode body to form a conductive polyaniline film. Depositing on the dielectric oxide film;
When the molar ratio of the polymerizable monomer and the oxidizing agent is set to 1 when the oxidizing agent is 1, the polymerizable monomer is set to 0.4 to 15, and both are attached to the anode electrode body on which the conductive polyaniline film is formed. Forming a conductive polymer layer;
A method for producing a solid electrolytic capacitor, comprising:   3. The solid electrolytic capacitor according to claim 1, wherein when the molar ratio of the polymerizable monomer to be impregnated and the oxidizing agent is set to 1, the polymerizable monomer is 3 or more. Production method.   3. The solid electrolytic capacitor according to claim 1, wherein the molar ratio of the polymerizable monomer to be impregnated and the oxidizing agent is less than 4 when the oxidizing agent is 1, and the polymerizable monomer is less than 4. 4. Production method.   The method for producing a solid electrolytic capacitor according to any one of claims 1 to 4, wherein the conductive polymer is a polymer of a thiophene derivative.   The method for producing a solid electrolytic capacitor according to claim 5, wherein the thiophene derivative is 3,4-ethylenedioxythiophene.

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