JP2001210559A - Method for manufacturing solid electrolytic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a solid electrolytic capacitor which can improve leakage current characteristic and an equivalent series resistance characteristic, is superior in heat resistance, and can improve yield. SOLUTION: The method for manufacturing a solid electrolytic capacitor with sequential lamination of solid electrolyte layers, consisting of an conductive polymer and cathode layers on a surface of an oxide film after forming the oxide film on elements consisting of a metal having a valve action, includes forming a solid electrolyte layer by carrying out the treatment more than twice, of putting a solution for forming electroconductive polymer on the elements with an formed oxide film thereon and eliminating the solution hanging from and attached to the above elements, and afterwards, subjecting the solution to chemical oxidative polymerization oxidation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a solid electrolytic capacitor, and more particularly to a method for manufacturing a solid electrolytic capacitor having a solid electrolyte made of a conductive polymer.

[0002]

2. Description of the Related Art Small solid electrolytic capacitors are incorporated in small electronic devices such as video cameras, mobile phones, and notebook computers. This type of solid electrolytic capacitor is manufactured, for example, as follows. That is, one end of an anode lead wire made of a valve metal such as tantalum is buried in advance, and a powder obtained by mixing a binder with a fine powder of a valve metal such as tantalum or aluminum is press-molded, and then vacuum pressed. To form a sintered body.
Then, the sintered body is immersed in a chemical conversion solution and subjected to chemical conversion treatment to form an oxide film. After forming the oxide film, a manganese dioxide layer or a solid electrolyte layer made of a conductive polymer such as polyaniline or polypyrrole is formed. Thereafter, a carbon layer and a silver layer are sequentially formed to form a cathode layer. Then, the anode terminal is connected to the anode lead wire, and the cathode terminal is connected to the silver layer. Further, an exterior made of a synthetic resin such as an epoxy resin is formed.

Conventionally, a solid electrolyte layer made of a conductive polymer is formed by a chemical oxidation polymerization method, an electrolytic oxidation polymerization method, or the like. The solid electrolytic capacitor, in which the solid electrolyte layer is formed by the chemical oxidation polymerization method, can be manufactured from a small one to a large one, and has a wide application range. In order to form the solid electrolyte layer by the chemical oxidation polymerization method, a) a monomer such as pyrrole, aniline, thiophene, ethylenedioxythiophene, or phenylenevinylene and a conductivity-imparting agent such as sulfonic acid or sulfuric acid (hereinafter referred to as a dopant) ) And solution B in which an oxidizing agent is dissolved, and the element after forming an oxide film is alternately immersed in these solutions A and B to perform chemical oxidative polymerization. Or b) dipping the device in a solution in which a monomer, a dopant, and an oxidizing agent are dissolved to cause a chemical oxidative polymerization reaction. And a solid electrolyte layer must be formed not only on the surface of the device but also inside it,
The immersion treatment is repeated twice or more so that the solution sufficiently penetrates into the inside of the device.

[0004]

However, when the solid electrolyte layer is formed by the chemical oxidation polymerization method, the device is immersed in a solution, then pulled out of the solution, and the temperature is raised to cause a chemical oxidation polymerization reaction. Is repeated in the same direction, the liquid easily accumulates on the lower surface of the element by the action of gravity, and an R-shaped thick solid electrolyte layer is formed on the lower surface of the element. When high-temperature heat is applied to the solid electrolytic capacitor as in a solder heat resistance test or the like, the solid electrolyte layer expands greatly in a direction in which the solid electrolyte layer is separated from the element. For this reason, the solid electrolyte layers are easily peeled off from the oxide film layer, and the solid electrolyte layers are in insufficient contact with each other. As a result, the leakage current and the equivalent series resistance (hereinafter referred to as ESR) of the solid electrolytic capacitor increase, and there is a variation defect. In addition, when the liquid accumulates on the lower surface of the element, it is difficult for the liquid to penetrate into the element at a location below the element, and it is difficult to form a solid electrolyte layer inside the element. For this reason, the initial leakage current and ESR of the solid electrolytic capacitor are relatively large, and the variation is large.
There is a disadvantage that it is difficult to improve the yield.

An object of the present invention is to provide a method for manufacturing a solid electrolytic capacitor which can improve the above drawbacks, improve the leakage current characteristics and the ESR characteristics, have excellent heat resistance, and improve the yield. .

[0006]

According to the present invention, in order to solve the above-mentioned problems, an oxide film is formed on an element made of a metal having a valve action, and then a surface of the oxide film is formed from a conductive polymer. In a method for manufacturing a solid electrolytic capacitor in which a solid electrolyte layer and a cathode layer are sequentially laminated, a solution for forming a conductive polymer is attached to an element on which an oxide film is formed, and then a solution attached to the element and sagging. Is repeated two or more times, and then a chemical oxidation polymerization treatment is performed to form the solid electrolyte layer.

According to the present invention, since a solution for forming a conductive polymer is attached to the device and then the solution that hangs down from the device is removed, a chemical oxidation polymerization treatment is performed thereafter to form a solid electrolyte layer. In this case, it is possible to prevent the thickness of the solid electrolyte layer formed at a specific portion of the device from becoming too large as compared with other portions. Therefore, even when high-temperature heat is applied in a solder heat resistance test or the like, an increase in leakage current or ESR due to thermal expansion in the thickness direction of the solid electrolyte layer can be prevented. In addition, since the solution dripping from the element is removed, the solution easily permeates into the element, and a solid electrolyte layer is easily formed inside the element. Therefore, leakage current and ES
The initial characteristics of R and the like are improved, and the yield is improved.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. First, tantalum and aluminum,
A binder in which camphor, an acrylic resin, or the like is dissolved in an organic solvent is added to fine powder of a valve action metal such as niobium and mixed. After mixing, the mixture is heated to volatilize and remove the organic solvent. Next, the fine powder of the valve action metal is compression-molded by a press or the like into a square or cylindrical shape with the anode lead wire 1 made of a valve action metal such as tantalum pulled out. After compression molding, 1600 in an atmosphere such as vacuum
Sintering is performed by heating at a high temperature of about 2200 ° C. for about 15 to 60 minutes to form a sintered body 2 as shown in FIG.
During this sintering, impurities in the powder are also evaporated.

After sintering, a disk-shaped insulating plate 3 made of Teflon, silicone rubber, silicone resin or the like is arranged at the root of the anode lead wire 1. The insulating plate 3 has a thickness of, for example, less than 0.2 mm, preferably about 0.1 mm. That is, the smaller the thickness of the insulating plate 3, the larger the size of the sintered body without changing the size of the whole capacitor, the larger the capacity, and the smaller the capacity when the capacity is fixed. .

[0010] Then, as shown in FIG.
Of the anode lead wire 1 drawn out from the metal plate is welded to an elongated metal plate 4 made of aluminum, stainless steel or the like. A plurality of sintered bodies 2 are attached to the metal plate 4 to improve work efficiency. Then, in this state, the sintered body 2 is immersed in a chemical conversion solution such as nitric acid or phosphoric acid to a predetermined level by visual observation or the like, and a DC voltage corresponding to a rated voltage is applied thereto to perform a chemical conversion treatment. By this chemical conversion treatment, an oxide film is formed at a rate of about 16 ° / V, and finally an oxide film 5 having a thickness of about 200 to 6000 ° is formed as shown in FIG.

After forming the oxide film 5, a solid electrolyte layer 6 made of a conductive polymer is formed on the surface thereof as shown in FIG. This solid electrolyte layer 6 is formed by an electrolytic polymerization method or a chemical oxidation polymerization method. For example, in the case of the latter method, it is formed as follows.

That is, in the first method, first, FIG.
As shown in FIG. 7, a container 7 is filled with a solution 7 in which a monomer, a dopant, and an oxidizing agent 5 are dissolved in the same solvent.
The sintered body 2 after forming is immersed in the solution 7. After immersing the sintered body 2 for a predetermined time, the sintered body 2 is drawn out of the solution 7. In this state, as shown in FIG. 2B, the solution 9 is attached to the lower part of the sintered body 2 so as to hang down. Next, as shown in FIG. 2 (c), the lower part of the sintered body 2 is brought into contact with a sheet-shaped tool 10 made of a permeable material such as permeable paper or permeable fibrous sheet, The falling solution 9 is applied to the sheet
Absorb and remove. Thereafter, the sintered body 2 is left at a predetermined temperature to undergo a chemical oxidation polymerization reaction, and further dried to produce a conductive polymer. The above processes from immersion to drying are repeated at least twice to form the solid electrolyte layer 6 having a predetermined thickness. This first method is characterized in that the solid electrolyte layer 6 is easily formed inside the sintered body 2 and hardly formed outside.

In the second method, the monomer, the dopant and the oxidizing agent are divided into the following two kinds of solutions, and the sintered body 2 is alternately immersed. That is, the two types are divided into a) a solution in which a monomer and a dopant are dissolved and a solution in which an oxidant is dissolved, b) a solution in which a monomer is dissolved and a solution in which an oxidant and a dopant are dissolved, c) a monomer and a dopant And a solution in which an oxidizing agent and a dopant are dissolved. Then, first, the sintered body 2 after forming the oxide film 5 is immersed in one solution for a predetermined time. Next, the sintered body 2 is pulled out of the solution, and the sheet-like member 10 made of a permeable material is used in the same manner as in the first method.
And the lower part of the sintered body 2 is brought into contact with the sintering body 2 to remove the solution that has been dripped down and adhered thereto. After removing the solution, the sintered body 2 is left under a predetermined temperature and humidity. After leaving for a predetermined time, the sintered body 2 is immersed in the other solution for a predetermined time. After the immersion, the lower part of the sintered body 2 is brought into contact with the sheet-like member 10 made of a permeable material in the same manner as described above, and the solution that is hanging down and attached is removed.
After the removal, the sintered body 2 is left at a predetermined temperature to undergo a chemical oxidative polymerization reaction to generate a conductive polymer, and further dried. The process from the first immersion process to the drying process is repeated a predetermined number of times to form a solid electrolyte layer 6 having a predetermined thickness. This second method is characterized in that the solid electrolyte layer 6 is hard to be formed inside the sintered body 2 and is easily formed outside.

In a third method, a solid electrolyte layer made of a conductive polymer is formed by the first method, and then treated by the second method to form a conductive polymer layer on the surface of the solid electrolyte layer. Another solid electrolyte layer composed of: The third method can make up for the disadvantages of the first method and the second method, and can easily form the solid electrolyte layer 6 having a predetermined thickness both inside and outside the sintered body.

Examples of the monomer include acetylene, paraphenylene, pyrrole, vinylene, phenylene, phenylenevinylene, aniline, thiophene, ethylenedioxythiophene, imidazole, thiazole, and the like.
The concentration is adjusted to about 0.1 to 1.0 mol / l using furan or the like.

As the substance to which the dopant is applied, a sulfonic acid compound, a carboxylic acid compound, a phosphoric acid compound, sulfuric acid, or the like is used. Particularly as a sulfonic acid compound,
For example, P-toluenesulfonic acid, sulfoneisophthalic acid, sulfosuccinic acid, methanesulfonic acid, phenolsulfonic acid, sulfosalicylic acid, benzenesulfonic acid, benzenedisulfonic acid, alkylbenzenesulfonic acid and derivatives thereof, camphorsulfonic acid, sulfoneacetic acid, diphenol Acids such as sulfonic acid, naphthalenesulfonic acid and its derivatives, and anthraquinonesulfonic acid and its derivatives are used. The concentration of this acid compound is 0.05-1.0mo
about l / l. In addition, as the salt compound used as the substance imparting the dopant, an ammonium salt, a sodium salt, or a potassium salt of the above-mentioned acid compound is used. That is, in the case of a sulfonic acid compound, ammonium salts such as ammonium sulfoisophthalate, ammonium sulfosuccinate, ammonium methanesulfonate, ammonium phenolsulfonate, ammonium sulfosalicylate,
Salts such as ammonium benzenesulfonate, ammonium benzenedisulfonate, ammonium alkylbenzenesulfonate and derivatives thereof, ammonium camphorsulfonate, ammonium sulfonate, and ammonium diphenolsulfonate are used. Examples of the sodium salt include sodium sulfoisophthalate, sodium sulfosuccinate, sodium methanesulfonate, sodium phenolsulfonate, sodium sulfosalicylate, sodium benzenesulfonate, sodium benzenedisulfonate, sodium alkylbenzenesulfonate and derivatives thereof, and camphorsulfonic acid. sodium,
Use salts such as sodium sulfonate acetate and sodium diphenol sulfonate. Further, as the potassium salt,
Potassium sulfoisophthalate, potassium sulfosuccinate, potassium methanesulfonate, potassium phenolsulfonate, potassium sulfosalicylate, potassium benzenesulfonate, potassium benzenedisulfonate, potassium alkylbenzenesulfonate and derivatives thereof, potassium camphorsulfonate, potassium sulfonate, Salts such as sulfoaniline and potassium diphenolsulfonate are used. The concentration of these ammonium salt, sodium salt, and potassium salt compounds is also 0.05 to 1.0 mol.
/ L. Further, hydrochloric acid, sulfuric acid, or the like may be added to increase the solubility of the salt compound and lower the concentration in the solution.

The oxidizing agent includes, for example, potassium dichromate, sodium dichromate, ammonium peroxodisulfate, hydrogen peroxide, ferric chloride, potassium permanganate,
0.1 to 1.0 mol using manganese dioxide, lead dioxide, etc.
/ L concentration.

To penetrate the sintered body 2 into the solution,
For example, this is performed using an immersion device 11 as shown in FIG. That is, a cassette 12 capable of holding a plurality of metal plates 4 connected to a plurality of sintered bodies 2 so that a plurality of sintered bodies 2 can be simultaneously immersed is used. This cassette 12
Is formed by a flat metal frame 14 having a hollow rectangular shape, having an outwardly facing brim 13 at the lower end, and having different widths between adjacent sides. Also, two opposite side frames 14a
And 14b have kerfs 15a and 15
b is provided. The plurality of metal plates 4 are arranged in the cassette 12 by inserting both ends of the metal plate 4 on which the sintered body 2 is attached into the cut grooves 15a and 15b. Further, the cassette 12 is provided with four bar-shaped supports 16 which can move up and down at two opposite sides of the flanges 13a and 13b.
And placed on top of it. Further, a tank 17 filled with a solution used to form a conductive polymer is disposed below the cassette 12. Therefore, by lowering the support 16 and bringing the cassette 12 closer to the tank 17, the plurality of sintered bodies 2 held in the cassette 12 can be simultaneously immersed in the solution in the tank 17, and the efficiency of the immersion treatment can be improved. Is improved.

As shown in FIG. 4, for example, the sheet-like member 10 may be used after being adhered to the surface of an elastic body 17 such as a sponge. In this case, when the sintered body 2 comes into contact with the sheet-shaped tool 10, the sintered body 2 receives a stress, but since the elastic body 18 is arranged under the sheet-shaped tool 10, the sintered body 2
Is pressed by the elastic body 18, so that the stress applied to the sintered body 2 can be reduced. Accordingly, when the sintered body 2 is subjected to stress, the contact between the anode lead wire 1 and the valve metal is displaced, so that characteristics such as leakage current are deteriorated. However, the stress is reduced by using the elastic body 18. Therefore, deterioration of characteristics can be reduced.

The solution dripping from the lower part of the sintered body 2 is removed using, for example, a liquid removing device 19 as shown in FIG. Also in this liquid removing device 19, the same cassette 12 as in FIG. 3 is used in order to simultaneously process a plurality of sintered bodies 2. Then, similarly to FIG. 3, the cassette 12 is arranged on a bar-shaped support 20 that can move up and down. A sheet-like member 21 such as a permeable fibrous sheet is arranged below the cassette 12. This sheet-like tool 21
The feed roller 2 is wound around the feed roller 22.
2, travels below the cassette 12, and is wound by the winding roller 23. Sheet tool 21
Is delivered by the delivery roller 24 and the pressing roller 25.
This is performed by sandwiching the sheet-like member 21 between them and rotating the delivery roller 24 by the delivery motor 26. Then, the take-up roller 23 is rotated by the take-up motor 27 to take up the sheet-like member 21 around the take-up roller 22.
Appropriate tension is applied to the sheet-like member 21. An elastic body 28 such as a sponge is disposed below the sheet-like member 21 below the cassette 12. That is, in order to remove the solution from the sintered body 2 by the liquid removing device 19, the support 20 is lowered to bring the sintered body 2 held in the cassette 12 into contact with the sheet-like tool 21. As a result, the solution hanging from the lower portion of the sintered body 2 is removed. Sintered body 2
Is brought into contact with the sheet-like member 21 for a predetermined time to remove the solution. Then, the support member 20 is raised to raise the cassette 12, and the sintered body 2 is separated from the sheet-like member 21. And cassette 1
Almost simultaneously with the raising of 2, or after the raising process, the delivery motor 26 and the winding motor 27 are simultaneously driven, and the sheet-like member 21 is caused to travel by the used amount. After traveling, the delivery motor 26 and the winding motor 27 are stopped. By repeating this operation, the solution drooping from the sintered body 2 can be removed every time of immersion in the solution.

After forming the solid electrolyte layer 6 made of a conductive polymer by the above method or the like, a graphite solution is applied to the surface of the solid electrolyte layer 6 to form a graphite layer 28 as shown in FIG. . After forming the graphite layer 28, as shown in FIG. 1F, a silver paste is applied to the surface to form a silver layer 29, which is combined with the graphite layer 28 to form a cathode layer 30, thereby forming a capacitor element. Silver layer 29
After forming the lead frame-shaped cathode terminal 3 with a conductive adhesive 31 such as a silver conductive paste as shown in FIG.
2 is connected to the silver layer 29, and the anode lead wire 1 is connected to the anode terminal 33 having a lead frame shape. Then, as shown in FIG. 1H, an outer package 34 made of resin is formed by a resin molding method, a resin dipping method, or the like. After the exterior 34 is formed, aging treatment is performed at a voltage of about 1.5 to 2.0 times the rated voltage in a high temperature (for example, 85 ° C. or higher) atmosphere. In addition, the temperature at the time of an aging process is 85-125 degreeC.
Is preferable, and the range of 85 to 105 ° C. is particularly effective.

After the aging treatment, the lead frame is cut, and the cathode terminal 32 and the anode terminal 33 are bent along the surface of the exterior 34 as shown in FIG.

[0023]

EXAMPLE Next, a solid electrolytic capacitor was manufactured by the method of the embodiment of the present invention, and the initial characteristics of the leakage current and ESR and both characteristics after the solder heat resistance test were measured together with those manufactured by the conventional method. did. The manufacturing conditions of the example and the conventional example are as follows.

Example: First, a powder obtained by mixing a binder with fine tantalum powder is press-molded into a square shape. At this time, one end of a tantalum anode lead wire is inserted into the powder, and the other end is drawn out. After compression molding, sinter in vacuum to 1.62 mm x 3.25 mm x 3.80 mm
A corner sintered body is formed. Next, 0.1 wt
And a chemical conversion treatment at a chemical conversion voltage of 25 V to form an oxide film thereon. After forming the oxide film,
A solid electrolyte layer made of a conductive polymer of polyaniline is formed. The formation of the solid electrolyte layer made of polyaniline is performed using the third method described above. That is, first, a solution A in which a monomer consisting of aniline and a dopant consisting of P-toluenesulfonic acid are dissolved in a mixed solvent of water and ethyl alcohol, and a solution B in which an oxidizing agent consisting of ammonium peroxodisulfate is dissolved in water. At a temperature of 3 ° C. in advance, the solution A and the solution B are mixed to form a solution C in this state. Then, the solution C is filled in the tank 17 of the immersion device 11 shown in FIG. And this immersion device 1
1 is immersed in a solution C at a temperature of 4 ° C. for 15 minutes. After the immersion, the sintered body is pulled out of the solution C, and the solution hanging from the lower part of the sintered body is removed using the liquid removing device 19 shown in FIG. In addition, a fibrous sheet is used as the sheet-like member 21 and a sponge is used as the elastic body 28. After removing the solution, the sintered body was heated to a temperature of 4 ° C.
It is left in each atmosphere of 0 ° C. and 120 ° C. in order to cause a chemical oxidative polymerization reaction, and is dried to produce a conductive polymer.
The process from dipping in the solution C to forming the conductive polymer is repeated 20 times. Thereafter, a solid electrolyte layer is further formed using the solution A and the solution B alone. That is, first, the solution A was placed in the tank 17 of the immersion device 11 shown in FIG.
Fill. Next, the sintered body treated with the solution C is immersed in the solution A at a temperature of 15 ° C. for 15 minutes. After immersion, the sintered body is pulled out of the solution A, and the solution attached to the lower portion is removed using the apparatus 19 shown in FIG. After removing the solution, the tank 17 is filled with the solution B again using the immersion device 11 shown in FIG. 3, and the sintered body is immersed for 15 minutes while maintaining the solution B at a temperature of 15 ° C. After immersion, the sintered body is drawn out of the solution B, left in an atmosphere at a temperature of 50 ° C., subjected to a chemical oxidation polymerization reaction, and dried to produce a conductive polymer.
The process from dipping in the solution A to forming the conductive polymer is repeated 20 times to form a solid electrolyte layer made of polyaniline having a predetermined thickness. After the formation of the solid electrolyte layer, a carbon paste is applied and cured by leaving it in an atmosphere at a temperature of 180 ° C. for 30 minutes to form a carbon layer. After the formation of the carbon layer, a silver paste is applied, and left to stand in an atmosphere at a temperature of 180 ° C. for 30 minutes to cure, thereby forming a silver layer. After the silver layer is formed, the silver layer is connected to the cathode terminal of the lead frame with silver paste, and the anode lead wire is connected to the anode terminal of the lead frame by resistance welding. Thereafter, an exterior made of epoxy resin is formed by a transfer molding method. After forming the exterior, aging treatment is performed, and further, the cathode terminal and the anode terminal are formed to produce a tantalum chip type solid electrolytic capacitor rated at 6.3 V and 150 μF.

Conventional Example: The same processing as in the example was performed, except that the process of removing the solution drooping from the sintered body using the liquid removing device 19 shown in FIG. 5 was omitted.

In the soldering heat resistance test, a solder paste is applied to a printed circuit board to which a capacitor can be connected, and a sample capacitor connected to the printed circuit board is placed in a reflow furnace having a maximum temperature of 240 ° C. This is performed by passing through an atmosphere at a temperature of 200 ° C. or higher for 10 to 20 seconds. The leakage current is applied to the sample at a rated voltage of 6.3.
The measured value is one minute after V is applied. ESR is a measured value at 100 KHz. The number of samples is 40 each. Table 1 shows the measurement results.

[0027]

[Table 1]

As is clear from Table 1, the embodiment of the present invention has a leakage current of 2.
4-37.5% size and ESR about 81.8%
And after the soldering heat resistance test, the leakage current is reduced to 1 to about 14.2%, and
The SR has each dropped to a magnitude of about 65.7%. Also, the variation in the leakage current and the ESR is smaller in the example than in the conventional example both in the initial value and after the soldering heat resistance test.

[0029]

As described above, according to the production method of the present invention, an oxide film is formed on an element made of a metal having a valve action, and then a solid electrolyte layer made of a conductive polymer is formed on the surface of the oxide film. And a method for manufacturing a solid electrolytic capacitor in which a cathode layer is sequentially laminated, wherein a solution for forming a conductive polymer is adhered to the element on which the oxide film is formed, and then the solution that has adhered to the element and drooped is removed. Is repeated two or more times, and then the solid electrolyte layer is formed by chemical oxidation polymerization treatment, so that the leakage current characteristics and ESR characteristics can be improved, the heat resistance is excellent, the life can be improved, and the yield can be improved. A solid electrolytic capacitor that can be improved is obtained.

[Brief description of the drawings]

FIG. 1 shows a process chart of an embodiment of the present invention.

FIG. 2 is a schematic view of a step of forming a solid electrolyte layer according to an embodiment of the present invention.

FIG. 3 is a perspective view of an immersion apparatus for immersing the sintered body according to the embodiment of the present invention in a solution for forming a conductive polymer.

FIG. 4 is a schematic view showing a step of removing a conductive polymer forming solution attached to a lower portion of the sintered body according to the embodiment of the present invention.

FIG. 5 is a perspective view of a liquid removing apparatus used in a process for removing a solution for forming a conductive polymer attached to a lower portion of a sintered body according to the embodiment of the present invention.

[Explanation of symbols]

2 ... Sintered body, 5 ... Oxide film, 6 ... Solid electrolyte layer, 1
9: Liquid removing device, 30: Cathode layer, 35: Solid electrolytic capacitor. Reference number P2530

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinichi Endo 16th Ohira Okuma, Miharu-cho, Tamura-gun, Fukushima Prefecture Inside the Miharu Plant of Hitachi AIC Inc.

Claims (1)

[Claims] 1. A method for manufacturing a solid electrolytic capacitor, comprising: forming an oxide film on an element made of a metal having a valve action; and sequentially laminating a solid electrolyte layer and a cathode layer made of a conductive polymer on the surface of the oxide film. In step (2), a process for attaching a solution for forming a conductive polymer to the element on which the oxide film is formed, and then removing the solution attached to the element and dripping therefrom is performed in two steps.
A method for producing a solid electrolytic capacitor, wherein the solid electrolytic layer is formed by performing chemical oxidative polymerization treatment at least twice.