JPH0445966B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for manufacturing a solid electrolytic capacitor having good performance using a conductive polymer compound as a solid electrolyte. (Prior Art and Problems to be Solved by the Invention) Conventional solid electrolytic capacitors, for example solid electrolytic capacitors made from aluminum, are made by depositing a dielectric material, oxide oxide, on an etched porous aluminum foil with a large specific surface area. An aluminum layer is provided, and a solid electrolyte is used instead of a liquid electrolyte for the electrolyte layer between this dielectric layer and the cathode. In this way, it is preferable to use a solid electrolyte instead of a liquid electrolyte because problems such as leakage do not occur. These solid electrolytic capacitors are made of aluminum with an anodized film,
It has a structure in which a solid electrolyte is layered on a metal such as tantalum, and the solid electrolyte in this type of solid electrolytic capacitor mainly uses manganese dioxide formed by thermally decomposing manganese nitrate.
However, in this thermal decomposition process, the heat required during thermal decomposition and the oxidizing effect of the NOx gas generated damage the dielectric metal oxide film such as aluminum and tantalum, which ultimately results in There are extremely serious drawbacks such as a decrease in the dielectric properties of solid electrolytic capacitors, such as a decrease in withstand voltage and an increase in leakage current. In order to compensate for these drawbacks, attempts have been made to form a solid electrolyte layer without applying high heat, that is, to use a highly conductive organic semiconductor material as the solid electrolyte. Among such solid electrolytes, conductive polymer compounds have been attracting attention because they are relatively inexpensive to manufacture and have relatively good adhesion to dielectric films. However, such conductive polymer compounds are produced by applying an aqueous solution in which an oxidizing agent is dissolved onto the dielectric layer of a solid electrolytic capacitor, and then removing the solvent.
Next, this oxidizing agent is made by reacting and polymerizing a monomer that provides a conductive polymer compound, but the conductivity of the conductive polymer compound layer formed in this way is not necessarily satisfactory. do not have. In order to solve this problem, when the dielectric layer of the solid electrolytic capacitor is treated with a solution in which an oxidizing agent is dissolved, a substance that acts as a dopant is added to the oxidizing agent solution. However, there was a problem in that it was difficult to obtain the intended dopant effect within the resulting conductive polymer compound layer. These drawbacks have been confirmed as a decrease in the electrical characteristics of the solid electrolytic capacitor due to an increase in the LC value and an increase in the ESR value after long-term use. (Means for Solving the Problems) According to the present invention, in manufacturing a solid electrolytic capacitor using a conductive polymer compound as a solid electrolyte, a porous dielectric layer is replaced with an oxidizing agent containing a dopant action imparting agent. After treatment with a solution, a conductive polymer compound is produced on the dielectric layer by vapor phase polymerization, and then the formed conductive polymer compound layer is electrolyzed in a solution containing a dopant action imparting agent. A method of manufacturing a solid electrolytic capacitor is provided. The type of porous dielectric used in the present invention is not particularly limited, but for example, aluminum,
Oxides of metals such as tantalum, niobium, titanium, and zirconium can be suitably used. These porous dielectrics are made by making the surface of the corresponding metal plate or wire metal, preferably metal foil, which is the base thereof, porous by etching or the like, and then by electrooxidizing the surface layer. It can be processed and made. According to this invention, after these porous dielectric layers are treated with an oxidizing agent solution containing a dopant effect imparting agent, a conductive polymer compound is formed on the dielectric layer by vapor phase polymerization, and then A solid electrolytic capacitor is manufactured by electrolytically treating the formed conductive polymer compound layer in a solution containing a dopant effect imparting agent. Dopant imparting agents that can be used in this invention include compounds containing boron tetrafluoride, sulfonic acids or derivatives thereof, metal halide compounds, hydrohalic acids, metal chelate compounds, sulfuric acid, phosphoric acid, perhalogen acids. Examples include inorganic acids such as or salts thereof, carboxylic acids, phosphates, sulfates, and polymeric compounds such as ion exchange resins. Examples of boron tetrafluoride salt-containing compounds that can be used as the dopant imparting agent include alkali metal or alkaline earth metal salts of boron tetrafluoride, ammonium or alkylammonium salts of boron tetrafluoride,
Examples include nitrogen-containing or oxygen-containing heterocyclic compound salts of boron tetrafluoride. Here, typical examples of alkali metal or alkaline earth metal salts of boron tetrafluoride are as follows:
Examples include LiBF ₄ , NaBF ₄ , KBF ₄ , and the like. In addition, typical examples of ammonium or alkyl ammonium salts of boron tetrafluoride include NH ₄ BF ₄ , tetramethylammonium BF ₄ ,
Tetraethylammonium BF ₄ , Tetra-n-butylammonium BF ₄ , Trimethylammonium
Examples include BF ₄ , dimethylammonium BF ₄ and methylammonium BF ₄ . In addition, examples of nitrogen-containing or oxygen-containing heterocyclic compound salts of boron tetrafluoride include lutidinium BF ₄ , pyridinium BF ₄ , picolinium BF ₄ , 2,4,6-trimethylpyrylium BF ₄ , collidinium BF ₄ , quinolinium BF ₄ , pyrylium BF ₄ , imidazolium BF ₄ and the like. Specific examples of sulfonic acids or derivatives thereof that can be used as dopant imparting agents in this invention include p-toluenesulfonic acid, p-ethylbenzenesulfonic acid, p-hydroxybenzenesulfonic acid, dodecylbenzenesulfonic acid, Arylsulfonic acids such as 2-naphthalenesulfonic acid, alkylsulfonic acids such as methylsulfonic acid, ethylsulfonic acid, trifluoromethylsulfonic acid, dodecylsulfonic acid, 2,6-naphthalenedisulfonate, 2,7-naphthalenedisulfonate, 1 , disulfonates such as 2-ethanedisulfonate, alkyl sulfates such as N-dodecyl sulfate, and salts thereof such as tetramethylammonium hydrogen sulfate and tetraethylammonium p-toluenesulfonic acid. . Metal halides that can be used as dopant imparting agents in this invention include:
Specific examples include FeCl ₃ , FeBr ₃ , cupric chloride, cupric bromide, and aluminum bromide. Examples of metal chelates that can be used as a dopant imparting agent in the present invention include iron acetylacetonate, iron oxine, nickel acetylacetonate, cobalt acetylacetonate, iron ethylenediamine tetraacetate, and the like. Inorganic acids or salts thereof that can be used as dopant-imparting agents in this invention include:
Hydrohalic acid such as HCl, HBr, HI, HF, sulfuric acid, H ₃ PO ₄ , HNO ₃ or their Na, K,
Salts with alkali metals or alkaline earth metals such as Ca, Mg, and ammonium, HClO ₄ , or
Examples include perhalogen acids such as NaClO ₄ or their salts. In this invention, carboxylic acids that can be used as dopant imparting agents include acetic acid,
Examples include mono- or dicarboxylic acids such as oxalic acid, formic acid, butyric acid, and succinic acid; aromatic or heterocyclic carboxylic acids such as benzoic acid, salicylic acid, and nicotinic acid; and halogen-substituted carboxylic acids such as trifluoroacetic acid. Further, in the present invention, as dopant imparting agents, phosphonates such as phenylphosphonate and ethylphosphonate, polystyrene sulfonic acid, polyvinyl sulfonic acid, polyacrylamide-2-methyl-1
Examples include polymeric compounds such as ion exchange resins such as propane sulfonic acid, polystyrene-maleic acid copolymer, and sodium sulfonate of naphthalene formaldehyde polymer. Particularly preferred dopant-imparting agents used in this invention are compounds containing tetrafluoroborate salts and sulfonic acids, such as lutidine.
BF ₄ , Tetraethylammonium BF ₄ , LiBF ₄ ,
Examples include p-toluenesulfonic acid, tetramethylammonium hydrogensulfate, and tetraethylammonium p-toluenesulfonic acid. In this invention, the dopant-imparting agent used in the oxidizing agent solution and the dopant-imparting agent used in the electrolytic solution when electrolytically treating a conductive polymer compound may be the same or different, Further, the dopant-imparting agents added to each solution can be used alone or in combination of two or more. In this case, particularly preferred results can be obtained if the dopant-imparting agent used in the oxidizing agent solution and the dopant-imparting agent used in the electrolytic solution are the same or have the same function. The type of oxidizing agent used in this invention is not particularly limited, but typical examples of the oxidizing agent include ammonium persulfate, sodium persulfate, potassium persulfate, pyridine-N-oxide, alkylpyridine-N-oxide, Quinone, alkylquinone, chloranil, hydrogen peroxide, dimethyl sulfoxide, sodium chlorate, potassium chlorate, ammonium chlorate, sodium bromate, potassium bromate, ammonium bromate, ferric sulfate,
FeCl ₃ , FeBr ₃ , Fe(NO ₃ ) ₃ , Fe ₂ (C ₂ O ₄ ) ₃ , Fe
(ClO ₄ ) ₃ , K ₃ Fe(CN) ₆ , (C ₅ H ₅ ) ₂ Fe ⁺ FeCl ₄ ^- ,
CuCl ₂ , CuBr ₂ , CuSO ₄ , Cu(NO ₃ ) ₂ , HNO ₃ ,
Examples include PbO ₂ , diazonium salts, but especially ammonium persulfate, FeCl ₃ , quinone, FeBr ₃ ,
(C ₅ H ₅ ) ₂ Fe ⁺ FeCl ₄ ^- can be suitably used. Among them,
FeCl ₃ and ammonium persulfate are particularly preferred. As the oxidizing agent of the present invention, ammonium persulfate, which is particularly required to be used in the form of an aqueous solution, is particularly preferred. In the present invention, a solvent having a high viscosity and a high boiling point may be added to the oxidizing agent solution. Especially as an oxidizer solution,
When an aqueous solution is used, it is effective to mix and use a solvent with a high viscosity and a high boiling point. As such a solvent having a high viscosity and a high boiling point, a solvent having compatibility with water and/or a solvent having compatibility with the above-mentioned dopant-imparting agent is preferably mentioned. As the solvent having such high viscosity and high boiling point, polar solvents are even more preferable. Representative examples of solvents with such high viscosity and high boiling point include organic amides, sulfur-containing compounds, esters, alcohols, phosphoric acid, polyphosphoric acid, and their salts, etc. can be given. Examples of such organic amides include organic acid amides and/or their N-substituted products, such as formamide, dimethylformamide, diethylformamide, acetamide, N-methylacetamide, N,N -dimethylacetamide, N-ethylacetamide, N,N
-diethylacetamide, propionamide, N
-Methylpyrropionamide, pyrrolidone, N-methylpyrrolidone, N-ethylpyrrolidone, piperidone, N-methylpiperidone, N-ethylpiperidone, ethylamide phosphate, hexamethyltriamide phosphate, dimethyloxazolidinone, ethyloxazolidinone, and the like. Examples of the sulfur-containing compound used in the method of the present invention include sulfur oxides, such as sulfolane, methylsulfolane, ethylsulfolane, dimethylsulfoxide, diethylsulfoxide, and the like. The esters used in the method of the present invention include monoesters, diesters, and polyesters of monocarboxylic acids, dicarboxylic acids, and polycarboxylic acids, as well as esters of carbonic acid. and esters of phosphoric acid such as triethyl phosphate and trimethyl phosphate. Furthermore, the alcohol residue portion or acid residue portion of such esters may be substituted with a hydrophilic group such as a hydroxyl group or a carboxyl group, and furthermore, these esters form a lactone ring. It may be something. Representative examples of such esters include 3-methoxybutyl acetate, 3-ethoxybutyl acetate, dimethyl maleate, diethyl maleate, ethylene glycol diacetate, propylene glycol diacetate. , propylene carbonate, γ-butyrolactone, γ-caprolactone, γ-caprylolactone, and the like. Examples of alcohols and ethers that can be used in this invention include monohydric or dihydric alcohols, polyhydric alcohols, and tertiary alcohols, as well as those having one or more ether bonds in the molecule. Things can be given. Typical examples of such alcohols and ethers include 1,3-propanediol, tertiary butyl alcohol, ethylene glycol, propylene glycol, 2-methoxyethanol, 2-isopropoxyethanol, benzyl alcohol, and ethylene. Examples include glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, and the like. As the solvent that can be used in the method of this invention, as described above, any solvent can be used as long as it achieves the purpose of this invention, and two types of such solvents can be used. Or more can be used in combination. The oxidizing agent solution containing the dopant-imparting agent of the present invention is prepared by first dissolving one or more of the above-mentioned oxidizing agents in an arbitrary combination in water or a normal solvent, and then dissolving one of the above-mentioned dopant-imparting agents in water or an ordinary solvent. or any combination of the above-mentioned dopant-imparting agents, or into a mixture of water or a normal solvent and one or more of the dopant-imparting agents selected in any combination. It is prepared by dissolving one or more selected oxidizing agents in any combination. The amounts of the oxidizing agent and dopant imparting agent used in this case are not particularly limited, but can be appropriately determined and used so as to provide a solid electrolytic capacitor with good properties. The oxidizing agent solution containing the dopant imparting agent of the present invention is preferably tetraethylammonium BF ₄ , lutidine BF ₄ , tetramethylammonium hydrogen sulfate, LiBF ₄ , p
A dopant imparting agent selected from -toluenesulfonic acid and tetraethylammonium p-toluenesulfonic acid is added as an oxidizing agent to an aqueous solution containing ammonium persulfate. To treat a porous dielectric with an oxidant solution containing the dopant-imparting agent of the present invention, the porous dielectric is immersed in the oxidant solution, or the porous dielectric is soaked in the oxidant solution. This can be done by applying and then removing the solvent. Furthermore, in order to treat a porous dielectric material with an oxidizing agent solution containing the dopant-imparting agent of the present invention, the oxidizing agent solution in the form of a mist can be sprayed onto the surface of the porous dielectric material. can. The conductive polymer compound that can be formed on the porous dielectric layer by vapor phase polymerization in the method of this invention is a polymer having the structure of the following formula (1) or formula (2) as a repeating unit. It is a compound. (In the formula, R ₁ to R ₈ may be the same or different,
Represents a halogen such as hydrogen, chlorine, bromine, iodine, or fluorine, an alkyl group, an alkoxy group, an amino group, an alkyl-substituted amino group, a dialkyl-substituted amino group, an aryl group such as a phenyl group, or a cyano group, or R ₁ - Two substituents selected from R ₅ and R ₆ and R ₇ may be taken together to form an unsubstituted or substituted aliphatic ring or aromatic ring,
X represents N- _R8 , S, O, Se, or Te. ) Typical examples of high molecular compounds include polypyrrole, poly-3-methylpyrrole,
Poly-N-methylpyrrole, polythiophene, poly-3-ethylthiophene, poly-3,4-dimethylthiophene, polyfuran, polyindole,
Examples include polyaniline, poly-2-methylaniline, polyethoxyaniline, and the like. Typical examples of monomers that provide the conductive polymer include 3-methylpyrrole, thiophene, and 3-methylpyrrole.
Methylthiophene, 3-ethylthiophene, furan, 3-methylfuran, 3,4-dimethylthiophene, indole, pyrrole, 3-ethylpyrrole, 3,4-dimethylpyrrole, 3-propylpyrrole, 3-isopropylpyrrole, methylaniline etc. can be given. Further, a known dopant may be used as a dope in these conductive polymer compounds in the gas phase or liquid phase. These treatments can be performed separately from the treatment using the dopant-imparting agent of this invention. As this dopant, for example,
Examples include NO ₂ , BF ₄ , SO ₃ and FeCl ₃ . The gas phase polymerization method in this invention is carried out by, for example, the formula
A monomer solution that provides a conductive polymer compound having the repeating unit of formula (1) or formula (2) is entrained in an inert gas such as nitrogen, argon, helium, etc., and an oxidizing agent solution containing the dopant imparting agent is added. A method in which the monomer solution is introduced into a treated porous dielectric layer and polymerized, or a vapor of a monomer solution is introduced into a porous dielectric layer treated with an oxidizing agent solution containing the dopant-imparting agent and polymerized. etc. There are no particular limitations on the temperature range for gas phase polymerization, but it is generally between -60℃ and +200℃.
It can be carried out at a temperature between, more preferably -
Carry out at temperatures between 15°C and +25°C. Regarding the temperature in this gas phase polymerization, it is particularly preferable to carry out the polymerization at room temperature because it is easy to operate. In addition, the time required to generate a conductive polymer compound by gas phase polymerization is appropriately selected by observing and determining the degree of conductive polymer formation, or by monitoring using an appropriate measuring device. However, it generally takes from several minutes to several hours. A method of electrolytically treating a conductive polymer compound layer according to the present invention in a solution containing a dopant-imparting agent is to electrolytically treat the conductive polymer compound layer in a solution containing a dopant-imparting agent. An example is a method in which a metal plate on which a molecular compound layer has been formed is immersed, and then electrolytically treated using a metal such as aluminum as a counter electrode. In this case, the dopant imparting agent can also be added to the electrolytic solution during the electrolytic treatment. Further, the above electrolyte can be suitably used as long as it is used as a solvent such as water, acetonitrile, dimethylformamide, dimethyl sulfoxide, etc., or two or more thereof. It is also possible to use a mixture of these as appropriate. Furthermore, the solvent that can be used here can be appropriately selected from solvents that have the same high viscosity and high boiling point as those used when added to the oxidizing agent aqueous solution. Particularly preferable solvents for use in this electrolyte include:
Examples include water, a mixture of water and acetonitrile, acetonitrile, propylene carbonate, and γ-butyrolactone. In addition to the dopant imparting agent, various stabilizers, surfactants, charge carriers, and other substances used in ordinary electrolytic treatment can be added to the electrolytic solution. These include acetic acid,
Organic carboxylic acids such as succinic acid, fumaric acid, maleic acid, and salicylic acid; inorganic acids such as hydrochloric acid, phosphoric acid, and sulfuric acid; ammonium salts and pyridinium salts such as ammonium chloride, ammonium bromide, tetraalkylammonium chloride, and trialkylammonium chloride; , pyrrolidinium salts, quinolinium salts, and other nitrogen-containing heterocyclic compound salts, and these can be used depending on the purpose. In the electrolytic treatment of the present invention, the treatment time, voltage used, etc. can be freely selected depending on the purpose, and the type of conductive polymer compound used here, the dopant, etc. It can also be changed depending on the type of imparting agent. The electrolytic treatment time can also be changed depending on the applied voltage and current amount, and the electrolytic treatment time is usually 1 to 30 minutes, more preferably 10 minutes.
~15 minutes. The voltage applied during the electrolytic treatment can be appropriately selected depending on the purpose, but usually 0.5 to 35V, more preferably 1.0 to 20V is sufficient. The applied voltage can also be applied by scanning by switching between positive and negative voltages. Such an electrolytic treatment may be an electrolytic treatment in which the substrate is immersed once or multiple times in an electrolytic solution having a fixed composition or an electrolytic solution having different compositions. According to such a treatment method, it is possible to supply a plurality of types of dopants or to adjust the dopant effects. The manufacturing method of the solid electrolytic capacitor of the present invention described above can be carried out by spreading out the thin metal foil that is the base of the capacitor, or by rolling the metal foil which is the final product form. It can be carried out in a closed state or in a form commonly used by those skilled in the art. When the manufacturing method of the solid electrolytic capacitor of the present invention is carried out with the metal foil that is the base of the capacitor being wrapped, the monomer that provides the conductive polymer compound described above is used between the surfaces of the metal foil. It is necessary that there be sufficient spacing for the conductive polymer to be formed on the surface of the polymer in the vapor phase, but this spacing must be determined by the electrical properties and other properties required for the final product. It can be selected as appropriate. EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but it goes without saying that the scope of the present invention is not limited to these Examples. Example 1 An aluminum foil 1.5 cm x 0.5 cm (purity 99.99%) with a thickness of 90 μm was used as a base material, and the surface of the foil was electrochemically etched by using alternating current and alternating current as an anode. , the surface of the foil is made porous. The porous surface had an average pore diameter of 0.1 μm and a specific surface area approximately 15 times larger. The etched aluminum foil is then electrochemically treated in an ammonium borate solution to form a dielectric oxide film of aluminum oxide (Al ₂ O ₃ , alumina) on the surface of the aluminum foil. Next, the dielectric oxide film of aluminum oxide obtained above was added to an aqueous solution containing 8.3% by weight of tetramethylammonium hydrogen sulfate, 25% by weight of ammonium persulfate (NH ₄ ) ₂ S ₂ O ₈ and 5% by weight of γ-butyrolactone. After immersing the aluminum foil with the aluminum foil under vacuum and pressure, the excess adhering solution is removed. Then, while the surface of the aluminum foil is wet, it is placed in a closed container containing 3-methylpyrrole, and vapor phase polymerization is performed to form a layer made of conductive polymer on the dielectric layer. The process of immersing the aluminum foil in the solution containing ammonium persulfate and then exposing it to the vapor of 3-methylpyrrole to carry out gas phase polymerization was repeated four times. Next, lead wires were attached to the aluminum foil having the conductive polymer compound layer obtained in this way, and LiBF ₄
was immersed in a propylene carbonate (PC) solution containing a concentration of 1 mol/mol, and electrolytically treated by applying current at a voltage of 2.0 V for 10 to 15 minutes using aluminum as a counter electrode. Next, a conductive paste "Dotite XA-167" (trade name) in which silver powder was dispersed in an acrylic solvent was applied onto the poly-3-methylpyrrole film and dried overnight to form a solid electrolytic capacitor. Next, in order to examine the electrical characteristics of the obtained solid electrolytic capacitor, an anode lead wire was connected to the surface of the aluminum foil, and a cathode lead wire was connected to the silver paste on the surface of the 3-methylpyrrole film. , and measured the electrical properties between them. Example 2 A solid electrolytic capacitor was produced in the same manner as in Example 1, except that a γ-butyrolactone solution of p-toluenesulfonic acid was used instead of the propylene carbonate solution of LiBF ₄ in the electrolyte. Manufactured.

[Table] Comparative Example 1 A solid electrolytic capacitor was manufactured in the same manner as in Example 1 except that the treatment in the electrolytic solution was not performed. Example 3 In Example 1, tetramethylammonium hydrogen sulfate in an oxidizing agent aqueous solution
Example 1 except that 15% by weight of a 1 mol/gamma-butyllactone solution of LiBF ₄ was used instead of 8.3% by weight.
A solid electrolytic capacitor was obtained in the same manner as above. Example 4 A solid electrolytic capacitor was manufactured in the same manner as in Example 3, except that a γ-butyrolactone solution of p-toluenesulfonic acid was used instead of the propylene carbonate solution of LiBF ₄ in the electrolytic solution. did. Table 1 shows the characteristic values of the solid electrolytic capacitors in Examples 1 to 4 and Comparative Example 1. From the above results, the solid electrolytic capacitor obtained by the method of the present invention has the advantage of not only exhibiting stable electrical characteristics for long periods of time at high temperatures, but also having a smaller LC value than those without electrolytic treatment. It shows the properties that Furthermore, it can be seen that when p-toluenesulfonic acid is used, the thermal stability is particularly excellent. Example 5 In Example 1, tetramethylammonium hydrogen sulfate in the oxidizing agent aqueous solution
_8.3 % by weight of tetraethylammonium tetrafluoroborate was used instead of 5% by weight of tetraethylammonium tetrafluoroborate _.
Using 1 mol/acetonitrile (AN) solution,
Furthermore, a solid electrolytic capacitor was obtained in the same manner as in Example 1, except that the electrolytic treatment was performed at +2.0 V for 10 minutes. Example 6 Tetramethylammonium hydrogen sulfate 8.3 in the oxidizing agent aqueous solution in Example 1
Example 1 except that 10 weight of lutidine BF ₄ was used instead of the weight percent, and the electrolytic treatment was performed for 15 minutes by scanning the potential from -2.0V to +2.0V. A solid electrolytic capacitor was obtained in the same manner as above. Example 7 In Example 1, tetramethylammonium hydrogen sulfate in an oxidizing agent aqueous solution
Using 5% by weight instead of 8.3% by weight, and replacing 1mol/propylene carbonate solution of LiBF ₄ with 1mol/gamma-butyrolactone (γ-
BL) solution and further electrolytic treatment +
A solid electrolytic capacitor was obtained in the same manner as in Example 1 except that the voltage was 2.0V for 10 minutes. Comparative Example 2 In Example 1, tetramethylammonium hydrogen sulfate was used as the oxidizing agent aqueous solution.
A solid electrolytic capacitor was obtained in the same manner as in Example 1 except that 5% by weight was used instead of 8.3% by weight and the electrolytic treatment was not performed. Table 2 shows the characteristic values of the solid electrolytic capacitors in Examples 5 to 7 and Comparative Example 2.

[Table] From the above results, it can be seen that the solid electrolytic capacitor obtained by the method of the present invention exhibits superior electrical characteristics as compared to the solid electrolytic capacitor that is not subjected to the electrolytic treatment. (Effects of the Invention) As detailed above, the solid electrolytic capacitor manufactured by the method of the present invention has the following advantages compared to conventionally known solid electrolytic capacitors. Even when just adding a dopant to the oxidizing agent, it is an extremely simple method compared to the usual dopant addition method, and it is possible to achieve a large dopant effect, and the LC value of the resulting solid electrolytic capacitor is In addition to being able to significantly reduce the
Stable electrical properties can be obtained. A dopant imparting agent that cannot be used together with an oxidizing agent can be used, and the dopant can be imparted reliably and uniformly, thereby making it possible to obtain a solid electrolytic capacitor having good electrical properties.

Claims (1)

[Claims] 1. In manufacturing a solid electrolytic capacitor using a conductive polymer compound as a solid electrolyte, a porous dielectric layer is treated with an oxidizing agent solution containing a dopant action imparting agent, and then vapor phase polymerization is performed on the dielectric layer. to generate a conductive polymer compound, and then
A method for producing a solid electrolytic capacitor, which comprises electrolytically treating the formed conductive polymer compound layer in a solution containing a dopant action imparting agent.