WO1997036303A1

WO1997036303A1 - Paste composition for preparing solid electrolyte and method for manufacturing solid electrolytic capacitor using the same

Info

Publication number: WO1997036303A1
Application number: PCT/JP1997/000974
Authority: WO
Inventors: Takafumi Dohdoh; Takehiro Shimizu
Original assignee: Hitachi Chemical Co., Ltd.
Priority date: 1996-03-26
Filing date: 1997-03-24
Publication date: 1997-10-02

Abstract

A paste composition for preparing solid electrolyte, containing (A) a manganese oxide powder, (B) a dispersion resin, and (C) a dispersion medium as essential components and a method for manufacturing a solid electrolytic capacitor using the composition. The paste composition has an excellent conductivity. A film of a prescribed thickness can be formed only by one application of this paste composition. When the method for manufacturing solid electrolytic capacitor using the paste composition is used, the manufacturing time of a solid electrolytic capacitor can be shortened. The leak current characteristic, heat resistance, and moisture resistance of the capacitor and the external size accuracy of the capacitor can be improved.

Description

TECHNICAL FIELD The present invention relates to a paste composition for forming a solid electrolyte and a method for producing a solid electrolytic capacitor using the same.

The present invention relates to a paste composition for forming a solid electrolyte used for forming an electrode layer on an electronic component such as a capacitor, and a method for producing a solid electrolytic capacitor using the same. Background art

Conventionally, for forming solid electrolytes for electronic components such as tantalum capacitors, a method of thermally decomposing a manganese nitrate solution has been used. A sintered body made ie evening valve metal such as emissions Yuru powder using as the anode body, to form formed a T a '0 ₅ oxide coating by chemical conversion treatment on the sintered body . Next, the sintered body after chemical formation is immersed in an aqueous solution of manganese nitrate or the like at an arbitrary concentration, and baked at an arbitrary temperature to thermally decompose manganese nitrate to form manganese dioxide or the like. After firing, re-chemical conversion treatment is performed to repair the oxide film damaged by heating. Then, the steps of immersion, sintering and re-chemical conversion are repeated several to several ten times to form a manganese dioxide layer or the like having an arbitrary thickness. After forming a manganese dioxide layer, a cathode layer is formed by successively applying carbon, silver paste, and the like. Then, a manufacturing method is used in which an external lead is soldered after the application and the resin is packaged by a resin dipping method, a resin molding method, or the like.

In this method, after the sintered body is immersed in an aqueous solution of manganese nitrate, the thickness of the coating layer that can be formed at one time during the thermal decomposition step of the chemical conversion treatment is extremely small. It was necessary to repeat the pyrolysis process several times to several times to form the slag, and there was a problem that the time required and the energy cost were extremely large. Also, nitric acid manga In the pyrolysis process, NO was generated due to the thermal decomposition of gas, and there were also environmental problems such as the treatment of these decomposition gases. Also, due to the performance of the solid electrolytic capacitor, this method makes it difficult for the thickness of the manganese dioxide layer and the like to be uniform, and if this thickness is small, the carbon layer directly contacts the oxide film and leaks. There was a problem that the current easily increased. In addition, when the sintered body is square, the manganese dioxide layer and the like are thicker at the corners than at the other parts. There was a problem that the water resistance and moisture resistance were reduced. In addition, there is a problem that when the resin sheathing is performed by the resin dipping method, the dimensions are likely to vary, and when the resin sheath shrinks, the corners are stressed and the characteristics are likely to deteriorate.

Regarding the above problems, Japanese Patent Application Laid-Open No. 51-76559 describes that manganese dioxide powder is mixed into volatile solvents such as water, alcohol, thinner, carbon tetrachloride, and ammonium carbonate. A method is disclosed. However, in this method, the manganese dioxide powder in the solution is difficult to disperse, and the particles agglomerate during storage. Sedimentation occurs, making it difficult to obtain a uniform coating film.

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Also, Japanese Patent Application Laid-Open No. 7-233298 discloses a method of replacing a part of the metal powder used for the conductive base with manganese dioxide powder. In this method, however, a solid electrolyte is used. All the properties could not be fully realized.

The present invention has been made to solve the above-mentioned problems, and a paste composition for forming a solid electrolyte capable of forming a uniform coating film in which manganese dioxide powder is unlikely to settle, and an electrolytic solution. Provided is a method for manufacturing a solid electrolytic capacitor using the base composition, which can shorten the manufacturing time of a capacitor, improve leakage current characteristics, heat resistance, moisture resistance, etc., and improve the accuracy of external dimensions. The purpose is to do. Disclosure of the invention The present invention has the following gist to achieve the above object.

[1] A paste composition for forming a solid electrolyte, comprising (A) manganese dioxide powder, (B) a dispersing resin and (C) a dispersing medium as essential components. Since this composition has excellent conductivity and can obtain a predetermined film thickness by one application, it is suitable for forming a solid electrolyte layer of a tantalum capacitor element.

[2] In addition to the essential components (A) to (C), further contains (D) a cutting agent of silane, titanate, aluminum or zirconium as a component. The paste composition for forming a solid electrolyte according to [1]. This composition has the effects of the composition described in [1], can further improve the uniformity of the coating film, and can have excellent stability during use.

[3] (A) The paste composition for forming a solid electrolyte according to [1] or [2], wherein the manganese dioxide powder has an average particle size of 0.01 to 50 m. This composition can improve the uniformity of the coating by limiting the particle size of the manganese dioxide powder in addition to the invention of [2], and can produce a coating with uniform film quality.

The paste composition for forming a solid electrolyte according to any one of [1] to [3], comprising a manganese dioxide powder having a [4] type crystal structure. By using manganese dioxide powder having a ^ -type crystal structure, this composition can improve the conductivity of the manganese dioxide powder itself and reduce the resistance of the coating film.

~ [5] (B) The dispersing resin is cellulose and its derivatives, polyglycols, polyacrylic acid, polyacrylic acid soda, polyacrylinoleamide, polyvinyl vinylidone, polydisperse resin. Vinyl ether, water-soluble alk Is a water-soluble polymer resin selected from the group consisting of polymethacrylate, polymaleic acid copolymer, polyethylenimine and polyvinyl alcohol [1] to [

4] The paste composition for forming a solid electrolyte according to any one of the above. By using a water-soluble polymer resin as the dispersing resin, the composition can be easily dispersed in a dispersing medium and can provide a stable paste composition for forming a solid electrolyte. .

[6] (C) the dispersion medium is at least one organic solvent or pure water selected from the group consisting of alcohols, ethylene glycols and propylene glycols, or a mixture thereof [1] to The paste composition for forming a solid electrolyte according to any one of [5]. In this composition, manganese dioxide powder is easily prepared by using an organic solvent selected from alcohol, ethylene glycol, and propylene glycol, or pure water, or a mixture thereof as a dispersion medium. And a stable solid electrolyte layer can be formed.

[7] A method for producing a solid electrolytic capacitor using the paste composition for forming a solid electrolyte according to any one of [1] to [6]. This method can provide a method for manufacturing a solid electrolytic capacitor capable of shortening the manufacturing time, improving leakage current characteristics, heat resistance, moisture resistance, and improving the accuracy of external dimensions.

[8] After forming an anodized film on the sintered body obtained from the valve metal powder, or after immersing the sintered body with the formed anodized film in a semiconductor mother liquor and thermally decomposing, [6] A method for producing a solid electrolytic capacitor, which is immersed in the paste composition for forming a solid electrolyte according to any one of [6] and dried to form a semiconductor layer. This method can exert the same effect as the above [7]. BRIEF DESCRIPTION OF THE DRAWINGS -. ⁵

FIG. 1 shows a characteristic graph of equivalent series resistance ESR of Examples 7 and 8 of the present invention and Comparative Example 3.

FIG. 2 shows characteristic graphs of leakage currents of Examples 7 and 8 and Comparative Example 3 of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the base composition for forming a solid electrolyte of the present invention and a method for producing a solid electrolytic condenser using the same will be described in detail.

I. Paste composition for forming solid electrolyte

The paste composition for forming a solid electrolyte of the present invention contains (A) manganese dioxide powder, (B) a dispersion resin and (C) a dispersion medium as essential components.

1. Manganese dioxide powder (A)

Examples of the (A) manganese dioxide powder used in the present invention include powders having an α-type, a type, a 7-type or a type crystal structure, and include a type crystal structure in consideration of conductivity. Manganese dioxide powder is preferred. Manganese dioxide containing Form 3 can be easily obtained by heating manganese dioxide at 250 ° C to 400 ° C for 1 to 5 hours. The average particle size of the manganese dioxide powder is 0.01 !, considering the conductivity and the applicability of the paste. Those with a size of ~ 50 are preferred, and those with a value of 0.01-10 ^ m are more preferred. The shape of the manganese dioxide powder is not limited to such a force as exemplified by a sphere, an irregular shape, and a crushed shape.

The blending amount of the manganese dioxide powder in the present invention is preferably 1 to 90% by weight of the total amount of (A) manganese dioxide powder (B) dispersed resin and (C) dispersion medium, and is preferably 5 to 80%. %, More preferably 20% to 70% by weight. If the content is less than 1% by weight, it is difficult to form a coating film and the solid electrolyte functions as a solid electrolyte. When the content exceeds 9-0 unit amount%, the coatability as a paste and the adhesiveness to a substrate tend to decrease.

2. Dispersion resin (B)

The (B) dispersed resin used in the present invention is (A) one that improves the dispersibility of the manganese dioxide powder, water-soluble, and (A) one that easily binds to the manganese dioxide powder. Although there is no particular limitation, derivatives such as cenorellose, methinoresenolylose, ethylcellulose, carboxymethylcellulose, and hydroxyshethylcellulose, polyethylene glycol, and polypropylene glycol Polyacrylic acid, polyacrylic acid, polyacrylic acid soda, polyacrylamide, polyvinyl borolidone, water-soluble alkyd, polyvinyl ether, polymalein Acid copolymers, polyethyleneimine and polyvinyl alcohol are exemplified as being preferred. These (B) dispersed resins may be used alone or in combination. In the present invention, the compounding amount of (B) the dispersing resin is 0.5 to 40% by weight of the total amount of (A) manganese dioxide powder, (B) the dispersing resin and (C) the dispersing medium. The content is preferably 1 to 20% by weight, more preferably 2 to 10% by weight. If the amount is less than 0.5% by weight, the dispersion of manganese dioxide tends to be insufficient. If the amount exceeds 40% by weight, the conductivity tends to decrease and the performance as a solid electrolyte tends to deteriorate. is there.

3. Dispersion medium (C)

The (C) dispersion medium used in the present invention is not particularly limited as long as it can dissolve the (B) dispersion resin and maintain the dispersion stability of (A) manganese dioxide powder, but are not limited to alcohol-based dispersion media. Examples of the preferred solvent include an ethylene glycol-based or propylene glycol-based organic solvent, or pure water or pure water in which a manganese salt such as manganese nitrate is dissolved. Is done. -.

These organic solvents or pure water may be used alone or in a combination of two or more at any ratio.

In the present invention, the blending amount of (C) the dispersion medium is preferably 10 to 95% by weight of the total amount of (A) manganese dioxide powder, (B) the dispersion resin, and (C) the dispersion medium. The content is more preferably from 20 to 90% by weight, and particularly preferably from 25 to 80% by weight. If the compounding power is less than 10% by weight, the dispersion of the manganese dioxide powder becomes insufficient, and if it exceeds 95% by weight, the film thickness of the coating film becomes too thin to obtain a sufficient film thickness at one time. Tend.

4. Coupling agent (D)

In the present invention, it is preferable to use (D) a coupling agent as necessary in order to stably disperse (A) manganese dioxide. (D) The method of using the coupling agent is as follows: (A) manganese dioxide, (B) dispersing resin, and (C) dispersing medium by directly adding to (A) There is a method in which manganese dioxide powder is used after treatment with (D) a capping agent. (A) The method of treating manganese dioxide powder includes, for example, (A) a method of adding (D) a coupling agent directly to manganese dioxide powder and mixing with stirring (dry treatment method) and a method of hexane. (D) A coupling agent is preliminarily dissolved in a solvent such as toluene or the like, and (A) manganese dioxide powder is added thereto, mixed and stirred, and then the solvent is removed and dried (wet processing method). Can be

(D) As a coupling agent, when (A) manganese dioxide powder is dispersed in (B) a dispersing medium with (B) a dispersing resin, (A) the manganese dioxide powder is compatible with the resin. It is not particularly limited as long as it is easy to improve the dispersion stability, and silane-based, aluminum-based, titanate-based, and zirconium-based cutting agents are preferred. It is illustrated as an example. Addition of (D) coupling agent in the present invention The amount is, (A) 0. 1 ~ 1 0 parts by weight lay favored relative to manganese dioxide powder ⁸ 1 0 0 parts by weight, 0. 3 Chi parts by weight rather more preferable, 0.5 to 2 weight Department is particularly preferred. If (D) the amount of the coupling agent added is less than 0.1 part by weight, the dispersibility of the (A) manganese dioxide powder tends to decrease. The conductivity tends to decrease.

5. Additives, modifiers

The paste composition for forming a solid electrolyte of the present invention may be, for example, an antioxidant, a chelating agent, or an additive having various functions, as long as it does not adversely affect the properties of the cured product when the paste and the coating film are formed. , A modifier and the like can be added. In addition, carbon black, graphite carbon, or the like can be used in combination to impart conductivity. The amount of these is preferably 0.5 to 10 parts by weight based on 100 parts by weight of the manganese dioxide powder.

The base composition for forming a solid electrolyte of the present invention may be prepared by mixing a predetermined amount of (A) manganese dioxide powder, (B) a dispersion resin and (C) a dispersion medium with an ordinary stirrer, triturator, three-roll or roll mill. It can be easily obtained by uniformly kneading or dispersing using a solvent or the like, and a uniform and thick coating film can be obtained by one application without changing the characteristics as a solid electrolyte. It can be suitably used as a solid electrolyte layer such as a tantalum capacitor.

I I. Manufacturing method of solid electrolytic capacitor

The present invention relates to a method for producing a solid electrolytic capacitor using the paste composition for forming a solid electrolyte. For example, a solid electrolytic capacitor can be obtained by forming an anodized film on a sintered body obtained from a valve metal powder or by immersing the sintered body with the anodized film in a semiconductor mother liquor and thermally decomposing it. Immersed in the paste composition for solid electrolyte formation described above and dried Thus, a solid electrolytic capacitor is manufactured by forming a semiconductor layer.

More specifically, a preferred manufacturing method is described below. A valve metal such as tantalum is embedded in one end of a tantalum lead wire or the like, the other end is drawn out, compression-molded with a press, and then pressed in a vacuum. Heat at a temperature of about 100 ° C for several 10 minutes to form a sintered body. Next, the sintered body is welded to a metal bar such as stainless steel at a place such as a tan wire, and the sintered body is formed by applying a voltage in a chemical solution such as nitric acid and phosphoric acid. , An anodic oxide film of Ta ₂ O, is formed. Alternatively, the sintered body having the anodic oxide film formed thereon is immersed in a semiconductor mother liquor such as a manganese nitrate solution to be impregnated with the solution, and then baked at a temperature of 200 ° C. to 350 ° C. to undergo thermal decomposition. Then, a semiconductor layer mainly including a manganese dioxide layer is formed inside the sintered body, and then re-formed to repair the anodized film damaged by sintering. The above immersion, firing and re-chemical processes are repeated two or three times as necessary.

Next, after immersing the sintered body in the paste composition for forming a solid electrolyte of the present invention for several seconds, it is first dried at room temperature, and then dried at 160 ° C. to 220 ° C., preferably 18 ° C. Dry at a temperature of 0 ° C. to 200 ° C. to form a semiconductor layer such as a manganese dioxide layer. This immersion and drying step may be repeated two or more times as necessary to obtain a semiconductor layer having a sufficient thickness. After the formation of the semiconductor layer, carbon and silver paste are sequentially applied to form a cathode layer, and the sintered body is connected to a lead frame or the terminal is pulled out of the sintered body. Connect to the lead wire and cathode layer. Finally, a resin exterior is formed by a resin dipping method or a resin molding method. Example

Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the scope of the present invention is not limited thereto.

'[Example 1]

Manganese dioxide powder (RB-A manufactured by Mitsui Kinzoku Co., Ltd.) was heated at 350 ° C for 3 hours. (Average particle size: 2 m) 10 Q Add 60 parts by weight of n-hexane and 1 part by weight of AL-M (Ajinomoto Co., Alumino-based coupling agent) Then, the mixture was stirred and mixed with a roll mill. Thereafter, n-hexane was removed to obtain a manganese dioxide powder having a surface-treated type crystal structure.

To 100 parts by weight of the above-mentioned surface-treated manganese dioxide powder having a ^ -type crystal structure, 5 parts by weight of sodium polyacrylate AC—103 (manufactured by Nippon Pure Chemical Co., Ltd.) and 400 parts of pure water were added. The parts by weight were preliminarily mixed in a mortar and kneaded with three rolls to obtain a paste composition for forming a solid electrolyte. Table 1 shows the measurement results of the conductivity, the dispersibility, and the coating thickness of the paste composition for forming a solid electrolyte.

The conductivity was measured by forming a coating film of about 50 m on a ceramic plate by screen printing, and after curing, using a digital multimeter by a four-terminal method. The dispersibility was measured using a grain gauge according to the method of JIS-K540. The thickness of the coating was measured by dipping a ceramic plate of 1 × 2 cm in a paste for about 3 seconds, pulling it up, drying it, and measuring the coating thickness using a micrometer.

[Example 2]

100 parts by weight of the surface-treated manganese dioxide powder having a / 5-type crystal structure used in Example 1 was added to 5 parts by weight of sodium polyacrylate (AC_103) and the product AL— After preliminarily mixing 2 parts by weight of M and 40 parts by weight of pure water in a mortar, the mixture was kneaded with three rolls to obtain a paste composition for forming a solid electrolyte. Table 1 shows the conductivity, dispersibility, and coating film thickness of this base composition.

'[Example 3]

The same procedure as in Example 1 was carried out except that a 50% by weight aqueous solution of manganese nitrate was used as the dispersion medium. Table 1 shows the dispersibility and coating film thickness. [Example 4]

The same procedure as in Example 1 was carried out except that the dispersing resin and polyvinylpyrrolidone (manufactured by ISBI JAPAN Co., Ltd.) were used, and the conductivity, dispersibility, Table 1 shows the coating thickness.

[Example 5]

The procedure was performed in the same manner as in Example 2 except that Plankt KRTTS (manufactured by Ajinomoto Co., Ltd., titanate-based coupling agent) was used as the coupling agent, and the conductivity of the obtained conductive paste composition was measured. Table 1 shows the dispersibility and coating film thickness.

[Comparative Example 1]

A manganese dioxide layer is formed on a ceramic substrate by a conventional method of thermally decomposing a 50% by weight aqueous solution of manganese nitrate without using a paste composition in which manganese dioxide powder is dispersed to form a conductive and coated film. Table 1 shows the results of the examination.

From the results in Table 1, it was found that the conductive paste composition of the present invention had good dispersibility and excellent conductivity, and was able to obtain a predetermined film thickness by one application. .

[table 1 ]

* P V P (polyvinyl bi- o-ridone)

* * LM LM (Finding HM, aluminum-based fusing agent)

* * * TTS («« $ Company M, titanate strength 7 printing agent)

* * * * P GM (Bu σ bilen glycol monomethyl ether)

[Example 6]

First, fill one end of a 0.24 mm tantalum lead wire, pull out the other end, and breathe the fine powder of tantalum to form a 1.97 mm x 2.1 mm X 2.8 nun square compact. After sintering the formed body, it was formed by nitric acid to form an anodic oxide film of Ta0-. After chemical formation, the sintered body was converted to manganese nitrate. Immersed, fired, and re-chemically formed in the solution. This series of processing was repeated four times. Next, the paste composition for forming a solid electrolyte prepared in Example 1 was used as a stock solution, and the sintered body was immersed for a few seconds in a solution diluted with pure water to a stock solution: pure water = 1: 7 (volume ratio). Crushed and dried. The immersion and drying treatments were repeated twice to form a manganese dioxide layer, and then carbon and silver paste were sequentially applied to form a cathode layer. After formation of the cathode layer, the sintered body was connected to a lead frame, and a resin exterior was formed by a resin molding method to produce a solid electrolytic capacitor.

[Comparative Example 2]

To form a manganese dioxide layer, the sintered body was immersed in a manganese nitrate solution, and the process of thermal decomposition and re-chemical formation by chemical formation was repeated eight times, and the paste composition for forming a solid electrolyte formed in Example 1 was obtained. A solid electrolytic capacitor according to a conventional method was manufactured under the same conditions as in Example 6, except that no material was used.

The results of evaluating the characteristics of the 16 V 35 F tantalum chip type solid electrolytic capacitors manufactured in Example 6 and Comparative Example 2 are shown in Table 2, where _c represents 500 samples. did. As is clear from Table 2, Example 6 shows the same characteristics as Comparative Example 2. That is, it was clarified that Example 6 exhibited good characteristics even when a series of steps such as immersion in a manganese nitrate solution and thermal decomposition were performed 1 to 2 times in the comparative example which is a conventional method.

[Table 2]

[Example Ί]

After repeating the series of processes of immersing the sintered body in a manganese nitrate solution, sintering, and re-forming as shown in Example 6 three times, the solid electrolyte-forming paste composition prepared in Example 1 was used as a stock solution. The sintered body was immersed in a solution diluted with pure water to a stock solution: pure water = 1: 5 (volume ratio) for several seconds and dried at 100 ° C. to 280 ° C. A solid electrolytic capacitor was produced under the same conditions as in Example 6, except that the immersion and drying treatments were repeated twice to form a manganese dioxide layer.

[Example 8]

The paste composition for forming a solid electrolyte prepared in Example 1 was used as a stock solution, and solid solution was prepared under the same conditions as in Example 6 except that the stock solution was diluted with pure water to a stock solution: pure water == 1:10 (volume ratio). An electrolytic capacitor was manufactured.

[Comparative Example 3]

A solid electrolytic capacitor was produced by the conventional method under the same conditions as in Comparative Example 2, except that the sintered body was immersed in a manganese nitrate solution, and the steps of thermal decomposition and re-chemical formation by chemical conversion were repeated six times.

Equivalent series resistance ESR and leakage current L of the 7 V 22 F rated tantalum solid electrolytic capacitors produced in Examples I and 8 and Comparative Example 3. The results of measuring C are shown in FIGS. 1 and 2. Here, the number of samples in each of Examples 7 and 8 and Comparative Example 3 was set to 20 for each drying temperature. As is clear from FIG. 1, the equivalent series resistance ESR of Examples 7 and 8 is almost the same as or less than that of Comparative Example 3 when the drying temperature is 160 ° C. or higher. Also, as is clear from FIG. 2, the leakage current LC of Examples 7 and 8 is almost the same as or less than that of Comparative Example 3 if the drying temperature is lower than 200 ° C. to 220 ° C. It has become. Therefore, if the drying temperature is above 160 ° C. and below 200 ° C. (up to 220 ° C.), both ESR and LC have the same or better characteristics as those of Comparative Example 3. It is also clear that a range of 180 to 200 for both properties is a particularly preferred drying temperature.

As described above, the paste composition for forming a solid electrolyte of the present invention is suitable for uniformly forming a solid electrolyte of an electronic component such as a solid electrolytic capacitor such as an indium capacitor. The method for producing a solid electrolytic capacitor using the paste composition for forming is effective for producing a solid electrolytic capacitor such as a tantalum capacitor in a short time and with high accuracy.

Claims

The scope of the claims

1. A paste composition for forming a solid electrolyte, comprising (A) manganese dioxide powder, (B) a dispersing resin and (C) a dispersing medium as essential components.

2. In addition to the essential components (A) to (C), a silane-based, titanium-based, aluminum-based or zirconium-based (D) coupling agent is also included as a component. 2. The paste composition for forming a solid electrolyte according to claim 1, wherein the paste composition comprises:

3. The paste composition for forming a solid electrolyte according to claim 1, wherein (A) the manganese dioxide powder has an average particle size of 0.01 to 50 m.

4. The base composition for forming a solid electrolyte according to any one of claims 1 to 3, comprising manganese dioxide powder having a type crystal structure.

5. (B) The dispersing resin is cellulose and its derivatives, polyglycols, polyacrylic acid, polyacrylic acid soda, polyacrylamide, and polyvinylpyrrolidone. A water-soluble polymer resin selected from the group consisting of poly (vinyl ether), polyvinyl ether, water-soluble alkyd, polymaleic acid copolymer, polyethylene imide and polyvinyl alcohol. 5. The paste composition for forming a solid electrolyte according to any one of 4.

6. (C) The dispersion medium is at least one kind of an organic solvent or pure water selected from the group consisting of alcohol, ethylene glycol and propylene glycol, or a mixture thereof. Item 6. The paste composition for forming a solid electrolyte according to any one of Items 1 to 5.

7. The paste for forming a solid electrolyte according to any one of claims 1 to 6. Method for producing solid electrolytic capacitor using composition

8. After forming an anodic oxide film on the sintered body obtained from the powder of valve action metal, or after immersing the sintered body with the formed anodic oxide film in a semiconductor mother liquor and thermally decomposing it, claim 1. 7. A method for producing a solid electrolytic capacitor, comprising immersing in the base composition for forming a solid electrolyte according to any one of 6 and drying to form a semiconductor layer.