JP2010177421A - Method of manufacturing solid electrolytic capacitor, and solid electrolytic capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method which can manufacture a solid electrolytic capacitor in which equivalent series resistance (ESR) is reduced without increasing the number of processes. <P>SOLUTION: A manufacturing method includes a step of forming a dielectric layer 3 on a positive electrode 1, a step of polymerizing a conductive polymeric monomer under the coexistence of oxidant and a silane coupling agent having a basic group and forming a conductive polymer layer 4a on the dielectric layer 3, and a step of forming a negative electrode layer 7 on a conductive polymer layer 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a solid electrolytic capacitor having a conductive polymer layer and a solid electrolytic capacitor.

  Conductive polymers are widely applied to solid electrolytic capacitors and antistatic coatings, and are expected to be used in a wide range of applications such as organic electroluminescent devices (organic EL devices), organic solar cells, organic transistors, touch panels, and battery electrodes. Has been. In a solid electrolytic capacitor, by using a conductive polymer membrane as an electrolyte membrane, leakage of the electrolytic solution and changes in characteristics due to drying of the electrolytic solution can be suppressed.

  As the electrolyte membrane of the solid electrolytic capacitor, manganese dioxide, a charge transfer complex, a conductive polymer, or the like can be used. From the viewpoint of conductivity, the conductive polymer is excellent. A conductive polymer having high conductivity is often used as a material on the capacitor element side, and a solid electrolytic capacitor with a low equivalent series resistance (ESR) of the element can be obtained.

  In recent years, electronic devices have been digitized and, for example, there is a tendency to increase the operation speed such as the number of clocks and the operation frequency. Therefore, an element having a small equivalent series resistance (ESR) is preferred as a capacitor for noise removal. . That is, since the smaller the ESR value, the better the ripple (alternating current component) removal capability, there is a need for a solid electrolytic capacitor having a particularly low ESR using a conductive polymer as the cathode side material.

  Patent Document 1 discloses a first conductive polymer layer formed of a polypyrrole film formed by chemical polymerization after anodizing a valve metal anode to form a dielectric coating, and polypyrrole formed by electrolytic polymerization. A method of sequentially forming a second conductive polymer layer made of a film is disclosed.

  In addition to polypyrrole, conductive polymer materials include polythiophene, polyaniline, or derivatives thereof. Among them, polythiophene has higher conductivity and excellent thermal stability than polypyrrole and polyaniline. It is expected and may be selected.

  As a method for forming a polythiophene film, a method of forming a polymer film by immersing a substrate in a mixture of a monomer and an oxidant and then performing post-treatment, etc. Are described in Patent Document 2.

  In such a method of polymerizing a polymer film using an oxidant solution and a monomer solution, it is easy to form a solid electrolyte and mass production is possible in a short time. However, it is possible to control the reaction or control the form of the polymer film. difficult. In addition, it is necessary to pay attention to the fact that the life of the solution is relatively short in the method of immersing in the mixed solution of the oxidant solution and the monomer solution. In addition, in the method in which the immersion in the oxidant solution and the monomer solution is repeated, it is necessary to pay attention to the fact that the life of the solution is relatively short and that the mixing conditions of the solution change due to the immersion.

  On the other hand, as a polymerization method by chemical polymerization, there is a method of forming a conductive polymer layer by immersing an anode body in a solution containing an oxidant, placing the anode body in a monomer vapor, and subjecting the monomer to gas phase polymerization. For example, it is disclosed in Patent Document 3.

  According to such a gas phase polymerization method, since the polymerization proceeds in an atmosphere of monomer vapor, the conductive polymer monomer solution is not contaminated. Further, there is an advantage that the monomer can be easily introduced into the holes inside the anode body of the capacitor by directly blowing the gas containing the vapor.

  However, compared with chemical polymerization in solution, it is difficult to control the blending ratio of oxidant and monomer, and it is difficult to control film properties such as conductivity, adhesion, and filling degree of the anode body. There is a problem.

  As a method for improving the adhesion of the conductive polymer film, for example, Patent Document 4 discloses a method of applying a silane coupling agent before forming the conductive polymer film. However, according to these methods, there is a problem that the number of surface treatment steps using a silane coupling agent increases.

  In Patent Document 5, an equivalent is obtained by forming a conductive polymer film using a chemical polymerization solution containing a monomer, an oxidizing agent, and a silane coupling agent such as γ-glycidoxypropyltrimethoxysilane. A method of manufacturing a solid electrolytic capacitor with reduced series resistance (ESR) has been proposed.

  However, as described above, there is a need for a solid electrolytic capacitor with a further reduced equivalent series resistance (ESR).

JP-A-4-48710 JP 2007-48936 A Japanese Patent Laid-Open No. 3-6217 JP-A-4-73924 JP 11-329900 A

  An object of the present invention is to provide a solid electrolytic capacitor manufacturing method and a solid electrolytic capacitor capable of manufacturing a solid electrolytic capacitor having a reduced equivalent series resistance (ESR).

  The production method of the present invention comprises a step of forming a dielectric layer on an anode, and polymerizing a conductive polymer monomer in the presence of a silane coupling agent having a basic group and an oxidizing agent, The method includes a step of forming a conductive polymer layer thereon and a step of forming a cathode layer on the conductive polymer layer.

  In the present invention, a conductive polymer monomer is polymerized in the presence of a silane coupling agent having a basic group and an oxidizing agent to form a conductive polymer layer on the dielectric layer. Thereby, a solid electrolytic capacitor with reduced ESR can be manufactured.

  By polymerizing the conductive polymer monomer in the presence of a silane coupling agent having a basic group and an oxidizing agent, the polymerization rate of the conductive polymer monomer can be controlled, and the conductivity formed thereby. The conductivity of the conductive polymer layer can be improved. Moreover, since the silane coupling agent is contained, the adhesiveness and adhesive force of the dielectric material layer which is a base material and a conductive polymer layer can be improved. In the present invention, it is possible to improve conductivity by controlling the polymerization rate and the like, and to improve adhesion and adhesion to the dielectric layer, thereby reducing ESR.

Examples of the basic group in the silane coupling agent of the present invention include a substituent having an amino group such as a primary amine, a secondary amine, and a tertiary amine. Primary amines include NH ₂ groups. Examples of substituents having secondary and tertiary amines include 2-hydroxyethylamino group, bishydroxyethylamino group, ethylamino group, diethylamino group, 2-aminoethylamino group, cyclohexylamino group, and tris (hydroxymethyl) methyl. Examples thereof include an amino group, a butylamino group, a dibutylamino group, a 6-aminohexylamino group, a hexylamino group, a dihexylamino group, a methylamino group, a dimethylamino group, a diisopropanolamino group, and a diphenylamino group.

  Examples of other basic groups include basic groups composed of pyridine, triazine, aminopyridine, pyrrolidine, piperidine, pyrimidine, guanine, and derivatives thereof.

  Examples of the oxidizing agent used in the present invention include transition metal salts of organic sulfonic acids such as iron paratoluenesulfonate. In the present invention, iron paratoluenesulfonate is particularly preferably used.

  Other oxidizing agents include peroxodisulfate such as ammonium peroxodisulfate (ammonium persulfate), sodium peroxodisulfate (sodium persulfate), potassium peroxodisulfate (potassium persulfate), ferric chloride, ferric sulfate , Transition metal compounds such as ferric nitrate and cupric chloride, metal halogen compounds such as boron trifluoride, metal oxides such as silver oxide and cesium oxide, peroxides such as hydrogen peroxide and ozone, and peroxides Examples thereof include organic peroxides such as benzoyl.

  In the present invention, the method for polymerizing the conductive polymer monomer is particularly limited as long as the method can polymerize the conductive polymer monomer in the coexistence of the silane coupling agent having a basic group and the oxidizing agent. However, a gas phase polymerization method in which a conductive polymer monomer is supplied in a vapor state and polymerized is preferably used. Specifically, a solution containing a silane coupling agent and an oxidizing agent is brought into contact with the dielectric layer, the silane coupling agent and the oxidizing agent are attached to the surface of the dielectric layer, and the silane coupling agent and the oxidizing agent are Examples include a method in which a vapor of a conductive polymer monomer is brought into contact with the surface of an attached dielectric layer, and the monomer is vapor-phase polymerized.

  Further, the conductive polymer layer may be formed by a solution polymerization method instead of the gas phase polymerization method. Specifically, the conductive polymer layer is obtained by bringing a dielectric layer into contact with a solution containing a silane coupling agent, an oxidizing agent, and a conductive polymer monomer, and polymerizing the conductive polymer monomer on the dielectric layer. The method of forming is mentioned. In such a solution polymerization method, the conductive polymer layer can be formed by a process in which the anode on which the dielectric layer is formed is immersed in the solution and then pulled up and dried. By repeating such dipping and drying steps, a conductive polymer layer having a predetermined thickness can be formed.

  In this invention, it is preferable that the addition amount of a coupling agent is 0.01-3 molar equivalent with respect to 1 mol of oxidizing agents, More preferably, it is 0.05-1.5 molar equivalent. If the amount of coupling agent added is too small, the effect of the present invention that ESR can be reduced may not be sufficiently obtained. Moreover, when there is too much addition amount of a coupling agent, it becomes difficult to acquire the effect proportional to the addition amount of a coupling agent, and there exists a possibility that the electrical conductivity of a conductive polymer layer may fall.

  Examples of the conductive polymer monomer used in the present invention include pyrrole, thiophene, aniline, and derivatives thereof. By polymerization of the monomer, a π-conjugated conductive polymer having a monomer repeating unit can be obtained. Therefore, by using the monomer, a conductive polymer composed of, for example, polypyrroles, polythiophenes, polyanilines, and copolymers thereof can be obtained.

  The solid electrolytic capacitor of the present invention is a solid electrolytic capacitor that can be produced by the production method of the present invention, and is characterized in that the silane coupling agent is contained in a conductive polymer layer.

  Since the solid electrolytic capacitor of the present invention is manufactured by the manufacturing method of the present invention, it can be manufactured without increasing the number of steps, and ESR can be reduced.

  In the solid electrolytic capacitor of the present invention, the basic group of the silane coupling agent contained in the conductive polymer layer is preferably a group having a nitrogen atom, and more preferably an amino group among the groups having a nitrogen atom. Preferably there is.

  According to the present invention, a solid electrolytic capacitor with reduced ESR can be manufactured without increasing the number of steps.

  Therefore, the solid electrolytic capacitor of the present invention is a solid electrolytic capacitor capable of reducing ESR.

The typical sectional view showing the solid electrolytic capacitor of one embodiment according to the present invention. The schematic diagram for showing the manufacturing process in the Example according to this invention. The schematic diagram which shows the manufacturing process in a comparative example. The figure which shows the change of the electrical conductivity of the conductive polymer layer by the addition ratio of a coupling agent.

  Hereinafter, the present invention will be described with reference to specific embodiments, but the present invention is not limited to the following embodiments.

  FIG. 1 is a schematic cross-sectional view showing a solid electrolytic capacitor according to an embodiment of the present invention.

  As shown in FIG. 1, a part of the anode lead 2 is embedded in the anode 1. The anode 1 is produced by molding a powder made of a valve metal or an alloy containing the valve metal as a main component and sintering the molded body. Therefore, the anode 1 is formed from a porous body. Although not shown in FIG. 1, this porous body has a large number of fine holes communicating from the inside to the outside. In the present embodiment, the anode 1 is formed so that its outer shape is a substantially rectangular parallelepiped. Examples of the valve metal include tantalum, niobium, titanium, aluminum, haufnium, and zirconium. Among these, tantalum, niobium, aluminum, and titanium, in which the oxide that is a dielectric is relatively stable even at high temperatures, are particularly preferably used. As an alloy having a valve metal as a main component, an alloy of two or more kinds of valve metals such as tantalum and niobium can be cited.

  A dielectric layer 3 is formed on the surface of the anode 1. The dielectric layer 3 is also formed on the surface of the hole of the anode 1. In FIG. 1, the dielectric layer 3 formed on the outer peripheral side of the anode 1 is schematically shown, and the dielectric layer formed on the surface of the hole of the porous body is not shown. The dielectric layer 3 can be formed by anodizing the surface of the anode 1.

  A first conductive polymer layer 4a is formed on the surface of the dielectric layer 3, and a second conductive polymer layer 4b is formed on the first conductive polymer layer 4a. ing. In the present embodiment, the first conductive polymer layer 4a is formed according to the manufacturing method of the present invention. Accordingly, the first conductive polymer layer 4a is formed by chemical polymerization such as gas phase polymerization or solution polymerization. The second conductive polymer layer 4b is formed by electrolytic polymerization. The conductive polymer layer 4 is composed of the first conductive polymer layer 4a and the second conductive polymer layer 4b. The conductive polymer layer 4 is also formed on the dielectric layer 3 on the surface of the hole of the anode 1. The conductive polymer layer 4 formed on the dielectric layer 3 on the surface of the hole of the anode 1 may be formed only from the first conductive polymer layer 4a, or the first The conductive polymer layer 4a and the second conductive polymer layer 4b may be used.

  A carbon layer 5 is formed on the conductive polymer layer 4 formed on the outer peripheral side of the anode 1, and a silver paste layer 6 is formed on the carbon layer 5. A cathode layer 7 is composed of the carbon layer 5 and the silver paste layer 6. The carbon layer 5 can be formed by applying a carbon paste and then drying it. The silver paste layer 6 can be formed by applying a silver paste and then drying it.

  An anode terminal 10 is connected to the anode lead 2 by welding or the like. A cathode terminal 9 is connected to the cathode layer 7 via a conductive adhesive layer 8.

  The periphery of the capacitor element is covered with a mold exterior resin 11 such as an epoxy resin. The anode terminal 10 and the cathode terminal 9 are provided so as to be drawn out of the mold exterior resin 11.

  As described above, the solid electrolytic capacitor 12 of the present embodiment is configured.

Example 1
The solid electrolytic capacitor of one embodiment according to the present invention shown in FIG. 1 was manufactured as follows.

  Using the tantalum particles, a rectangular parallelepiped shaped body is formed, and one end of the anode lead 2 made of tantalum is embedded in the shaped body. By sintering this molded body in vacuum, the anode 1 in which a part of the anode lead 2 is embedded is produced.

  Next, anodic oxidation is performed by immersing the anode 1 in an aqueous phosphoric acid solution and applying a voltage to the anode 1. Thereby, the dielectric layer 3 made of tantalum oxide or the like is formed on the surface of the anode 1. As described above, the anode 1 is a porous body, and the dielectric layer 3 is also formed on the surfaces of the pores of the porous body.

  Next, the first conductive polymer layer 4a is formed on the surface of the dielectric layer 3 as follows.

  FIG. 2 is a schematic diagram for explaining a process of forming the first conductive polymer layer 4 a on the dielectric layer 3.

First, aminopropyltrimethoxysilane (ATS), which is a silane coupling agent having an NH ₂ group as a basic group, is added to a solution in which iron paratoluenesulfonate is dissolved in isopropyl alcohol to a concentration of 10% by weight. Are added so as to have an equivalent number of moles to prepare an oxidizing agent solution. At this time, the concentration of the oxidizing agent solution is not particularly limited, and is generally set in the range of 5 to 50% by weight. As shown in step (a) of FIG. 2, the anode 20 on which the dielectric layer is formed is immersed in the oxidant solution 21 and held in the oxidant solution 21 for 10 minutes, and then lifted for about 5 to 15 minutes. dry. Thereby, iron paratoluenesulfonate and a silane coupling agent are adhered to the surface of the dielectric layer.

  Next, as shown in step (b) of FIG. 2, an anode 22 having a dielectric layer to which iron paratoluenesulfonate and a silane coupling agent are attached is placed in a container 25. In the container 25, a solution of ethylenedioxythiophene (EDOT) is disposed, and from this solution, a vapor 24 of ethylenedioxythiophene (EDOT) is discharged, and in the container 25, a vapor 24 of EDOT is discharged. Is full. The atmospheric temperature in the container 25 is generally in the range of 30 ° C to 100 ° C. The EDOT vapor contacts the dielectric layer with iron paratoluenesulfonate and silane coupling agent attached to the surface, which causes EDOT to polymerize on the surface of the dielectric layer, and consists of polyethylene dioxythiophene (PEDOT). A first conductive polymer layer 4 a is formed on the dielectric layer 3. After leaving in the container 25 for about 30 to 60 minutes to form the first conductive polymer layer 4a on the surface of the dielectric layer, the anode 22 is taken out from the container 25, washed in ethanol, and heated to 60 ° C. For about 10 minutes.

  Thus, in this embodiment, since the silane coupling agent can be attached to the surface of the dielectric layer at the same time as the formation of the first conductive polymer layer 4a, the silane coupling agent as in the prior art. Need not be formed on the dielectric layer first. Therefore, in the case of gas phase polymerization, by containing aminopropylmethoxysilane (ATS) in the oxidizing agent as described above, the silane coupling agent is made to be a dielectric layer while forming the first conductive polymer layer 4a. Since it can be formed above, the number of steps is not increased.

  Next, the anode on which the first conductive polymer layer 4a is formed is immersed in an aqueous solution containing a monomer such as ethylenedioxythiophene (EDOT) or pyrrole (Py) and an additive such as naphthalenesulfonic acid. Then, by applying a voltage to the anode, electrolytic polymerization is performed, and a second conductive high layer made of polyethylenedioxythiophene (PEDOT) or polypyrrole (PPy) is formed on the first conductive polymer layer 4a. The molecular layer 4b is formed. In this embodiment, PPy is formed as the first conductive polymer layer 4b.

  Next, after applying a carbon paste containing carbon particles on the second conductive polymer layer 4b, the carbon layer 5 is formed by drying. A silver paste containing silver particles is applied onto the carbon layer 5 and dried to form a silver paste layer 6. As described above, the cathode layer 7 is formed on the conductive polymer layer 4.

  Next, the anode terminal 10 is connected to the anode lead 2 exposed from the anode 1 by welding. A cathode terminal 9 is connected to the cathode layer 7 through a conductive adhesive layer 8 made of a silver paste containing silver particles.

  Next, a mold exterior resin 11 made of an epoxy resin composition was formed so that parts of the anode terminal 10 and the cathode terminal 9 were exposed, and the solid electrolytic capacitor of this embodiment was produced.

  About the produced solid electrolytic capacitor, the electrostatic capacitance and ESR were measured using the LCR meter. The capacitance was measured using a frequency of 120 Hz, and the ESR was measured at a frequency of 100 kHz. The capacitance was about 250 μF and the ESR was 9.5 mΩ.

(Comparative Example 1)
A solid electrolytic capacitor was obtained in the same manner as in Example 1 except that an oxidant solution containing no silane coupling agent and imidazole added as a control agent for controlling the monomer reaction was used as the oxidant solution. Was made.

  FIG. 3 is a schematic diagram for explaining a process of forming the first conductive adhesive layer 4a.

  In the step (a) shown in FIG. 3, as described above, the anode 20 in which the dielectric layer is formed in the oxidant solution 26 containing no silane coupling agent and containing imidazole is the same as in Example 1 above. Then, the anode 27 was pulled up and dipped, and an anode 27 having a dielectric layer with iron paratoluenesulfonate iron and imidazole adhering to the surface was produced. In addition, imidazole was added so that it might become an equivalent mole number 1.2 times the mole number of an oxidizing agent, and the oxidizing agent solution 26 was prepared.

  As shown in step (b) of FIG. 3, EDOT vapor is brought into contact with the surface of the anode 27 having a dielectric layer with iron paratoluenesulfonate and imidazole attached to the surface in the same manner as in Example 1 above. The first conductive polymer layer 4a made of PEDOT was formed on the surface.

  Except for the above, a solid electrolytic capacitor was produced in the same manner as in Example 1, and the capacitance and ESR were measured in the same manner as described above. The capacitance was about 250 μF and the ESR was 10.1 mΩ.

  As is clear from the comparison of the results of Example 1 and Comparative Example 1, according to the present invention, a silane coupling agent having a basic group is contained in the oxidant solution, and the first conductive polymer is used by using the silane coupling agent. By forming the layer 4a, the adhesion between the dielectric layer and the first conductive polymer layer 4a can be enhanced by the silane coupling agent containing a basic group, so the dielectric layer and the first conductivity Contact resistance with the polymer layer 4a can be reduced. Furthermore, since the polymerization rate of the conductive polymer monomer can be controlled by including a silane coupling agent containing a basic group in the oxidizing agent, the conductivity of the first conductive polymer layer 4a is improved. be able to. Therefore, since the solid electrolytic capacitor of Example 1 can reduce contact resistance and improve conductivity as described above, ESR can be reduced by the comparative example.

<Examination of addition amount of silane coupling agent>
In the oxidizing agent solution prepared in Example 1 above, the amount of the silane coupling agent added was 0.8 mol, 0.9 mol, 1 mol, 1.1 mol, 1.2 mol with respect to 1 mol of the oxidizing agent. The change in conductivity of the conductive adhesive layer due to the amount of silane coupling agent added was examined.

  After attaching an oxidizing agent and a silane coupling agent on a glass substrate, EDOT vapor is introduced onto the glass substrate in the same manner as in Example 1 to form a conductive polymer layer on the glass substrate. did.

  The conductivity of the formed conductive polymer layer was measured, and the relationship with the added molar amount of the silane coupling agent is shown in FIG.

  As shown in FIG. 4, it can be seen that particularly good conductivity can be obtained in the range of 0.9 to 1.1 mol with respect to 1 mol of the oxidant.

<Examination of functional group of silane coupling agent>
As the silane coupling agent, the following three types of silane coupling agents were used, and the influence of the type of functional group of the silane coupling agent was examined.

ATS: aminopropyltrimethoxysilane GOPMSi: 3-glycidyloxypropyltrimethoxysilane TTFOSi: triethoxy-1H, 1H, 2H, 2H-tridecafluoro-n-octylsilane

ATS has an NH ₂ group as a functional group, GOPMSi has a glycidyl group as a functional group, and TTFOSi is a silane coupling agent having three ethoxy groups and a fluorine-substituted alkyl group. is there.

  Ethylenedioxythiophene (EDOT) as a monomer, a solution having a concentration of 40% by weight obtained by dissolving iron paratoluenesulfonate as an oxidizing agent in butanol, and the above silane coupling agent in a molar ratio (EDOT: paratoluenesulfonic acid) (Iron: silane coupling agent) was prepared in a 1: 8: 3 ratio.

  This solution was spin-coated on a glass substrate at 1000 rpm for 30 seconds, then heat-treated (heated at 50 ° C. for 5 minutes and left in the atmosphere for 1 hour), and then washed with water to determine the conductivity of the formed conductive polymer layer. It was measured. The measurement results are shown in Table 1.

As shown in Table 1, when ATS having an NH ₂ group which is a basic group as a functional group was used, very high electrical conductivity was obtained. On the other hand, when the silane coupling agent of GOPMSi and TTFOSi was used, high conductivity was not obtained.

  In the present invention, it is considered that the reason why a conductive polymer layer having high conductivity can be obtained by using a silane coupling agent having a basic group is as follows.

  By allowing a silane coupling agent having a basic group to coexist with an oxidizing agent, the basic group of the silane coupling agent acts, for example, by coordination with the metal ion of the oxidizing agent, and the rate of the oxidation polymerization reaction. It is thought that the electrical conductivity of the conductive polymer layer is improved by controlling in a direction to suppress the above. In particular, a basic group containing a nitrogen atom is a weak base and thus has good controllability. In addition, the lone pair of nitrogen atom is attracted to the metal ion of the oxidant in a coordinated manner, thereby acting as an oxidant. It is considered that the oxidative polymerization rate is efficiently controlled in the direction of suppression. The reason why the conductivity of the conductive polymer can be improved by suppressing the oxidative polymerization rate in this way is not clear, but the molecular arrangement of the conductive polymer layer by suppressing the oxidative polymerization rate is not clear. It is considered that the conductivity of the conductive polymer could be improved because the orientation of the film could be improved. In particular, the conductive polymer formed by the gas phase polymerization method was difficult to control the conductivity of the conductive polymer as compared with the solution polymerization method. The conductivity of the polymer can be improved. Therefore, when a silane coupling agent whose functional group is not a basic group is used, it is considered that the effect specific to the present invention of improving conductivity cannot be obtained.

<Comparison with primer treatment (pre-coating) with silane coupling agent>
A primer treatment for applying ATS first was performed on a glass substrate, and then a solution containing an oxidant and EDOT was spin-coated to form a conductive polymer layer. The conductivity of the produced conductive polymer layer was about 100 S / cm, and a high conductivity such as ATS shown in Table 1 was not obtained.

  Therefore, it is considered that the effects of the present invention are exhibited when the silane coupling agent having a basic group contacts the monomer in the presence of an oxidizing agent.

(Example 2)
In Example 1, the first conductive polymer layer 4a is formed by a gas phase polymerization method. In the present invention, the first conductive polymer layer 4a can be formed by solution polymerization instead of such a gas phase polymerization method. In this case, ethylenedioxythiophene (EDOT) as a monomer, a solution having a concentration of 40% by weight in which iron paratoluenesulfonate as an oxidizing agent is dissolved in butanol, and a silane coupling agent having a basic group are mixed with each other. A solution in which the ratio (EDOT: iron paratoluenesulfonate: silane coupling agent) was mixed in the range of 1: 2: 1 to 1: 8: 1 was prepared, and the anode 1 having the dielectric layer 3 formed thereon was prepared. After soaking, pull up and dry. The conductive polymer layer can be formed by immersing in the solution for 30 seconds and heat-treating in an atmosphere at 60 ° C. for 10 minutes after the pulling. The conductive polymer layer 4 can be formed on the dielectric layer 3 by repeating such immersion and drying, for example, 2 to 5 times.

  In the above embodiment, a conductive polymer layer is formed by immersing an anode on which a dielectric layer is formed, using a solution containing a monomer, an oxidizing agent, and a silane coupling agent having a basic group. However, the following method may be adopted as another method for forming the conductive polymer layer.

  That is, the steps of preparing an oxidant solution containing a silane coupling agent and an oxidant and a monomer solution containing a monomer, immersing in the oxidant solution, immersing in the monomer solution, and then drying are performed a plurality of times. The conductive polymer layer can also be formed by a repeated method. In this case, each immersion time is generally about 1 minute to 5 minutes, for example.

  As described above, various methods for forming the conductive polymer layer have been described. However, the present invention is not limited to the methods of the above-described examples, and the coexistence of a silane coupling agent having a basic group and an oxidizing agent is present. In addition, there is no particular limitation as long as it is a method capable of polymerizing the conductive polymer monomer.

DESCRIPTION OF SYMBOLS 1 ... Anode 2 ... Anode lead 3 ... Dielectric layer 4a ... 1st conductive polymer layer 4b ... 2nd conductive polymer layer 4 ... Conductive polymer layer 5 ... Carbon layer 6 ... Silver paste layer 7 ... Cathode layer 8: Conductive adhesive layer 9 ... Cathode terminal 10 ... Anode terminal 11 ... Mold exterior resin 20 ... Anode with dielectric layer formed 21 ... Oxidant solution 22 ... Dielectric with oxidant and silane coupling agent attached Anode having body layer 23 ... monomer solution 24 ... monomer vapor 25 ... vessel 26 ... oxidant solution 27 ... anode having dielectric layer with oxidant attached

Claims (6)

Forming a dielectric layer on the anode;
A step of polymerizing a conductive polymer monomer in the presence of a silane coupling agent having a basic group and an oxidizing agent to form a conductive polymer layer on the dielectric layer;
And a step of forming a cathode layer on the conductive polymer layer.   The method for producing a solid electrolytic capacitor according to claim 1, wherein the basic group is an amino group.   The method for producing a solid electrolytic capacitor according to claim 1, wherein the oxidizing agent is iron paratoluenesulfonate.   The solution containing the silane coupling agent and the oxidizing agent is brought into contact with the dielectric layer and then dried to attach the silane coupling agent and the oxidizing agent to the surface of the dielectric layer, The conductive polymer layer is formed by bringing the vapor of the conductive polymer monomer into contact with the surface of the dielectric layer to which the silane coupling agent and the oxidizing agent are attached, and vapor-phase polymerizing the monomer. The manufacturing method of the solid electrolytic capacitor of any one of Claims 1-3 characterized by the above-mentioned. A solid electrolytic capacitor manufactured by the method according to any one of claims 1 to 4,
A solid electrolytic capacitor, wherein the conductive polymer layer contains the silane coupling agent. The solid electrolytic capacitor according to claim 5, wherein the basic group of the silane coupling agent is an amino group.

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