JPH1092699A - Capacitor and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain easily both a solid electrolytic capacitor and a film capacitor each of which has a high capacitance achieving factor, a high capacitor characteristic, and high heat and moisture resistance. SOLUTION: In a capacitor and its manufacturing method, there are provided a pair of opposite electrodes to each other, a dielectric layer interposed between the electrodes, and a laminated conductive macromolecular layer comprising a first conductive macromolecular layer interposed between the electrodes which contains as its repeated unit a thiophene derivative shown by the chemical formula and a second conductive macromolecular layer which contains as its repeated unit pyrrole or the derivative thereof. As a result, there are obtained easily both a solid electrolytic capacitor and a small-sized film capacitor with a large capacitance each of which has a high capacitance achieving factor, a high capacitor characteristic, and high heat and moisture resistances.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor and a method of manufacturing the same, and more particularly, to a small and large-capacity capacitor excellent in capacitor characteristics such as frequency characteristics and withstand voltage characteristics and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, with the digitization of electric equipment,
As for the capacitor, a capacitor having a small size, a large capacity, and a low impedance in a high frequency region is required.

Conventionally, capacitors used in the high-frequency range include plastic capacitors, mica capacitors, and multilayer ceramic capacitors. However, these capacitors have a large shape and are difficult to increase in capacitance.

On the other hand, as capacitors having a large capacity, there are electrolytic capacitors such as an aluminum dry electrolytic capacitor and an aluminum or tantalum solid electrolytic capacitor.

In these capacitors, a large capacity can be realized because the oxide film serving as a dielectric is extremely thin. On the other hand, since the oxide film is easily damaged, a true cathode for repairing the oxide film is used. It is necessary to provide an electrolyte that also serves as

For example, in an aluminum dry capacitor, an etched anode and cathode aluminum foil are wound through a separator, and the separator is impregnated with a liquid electrolyte for use.

[0007] This liquid electrolyte has a problem that loss is large and impedance frequency characteristics and temperature characteristics are remarkably inferior due to ionic conductivity and large specific resistance.

In addition, there is a problem that liquid leakage, evaporation, and the like are inevitable, and the capacity is reduced and the loss is increased with time.

In a tantalum solid electrolytic capacitor,
Since manganese oxide is used as the electrolyte, the problems of temperature characteristics and changes with time such as capacity and loss are improved, but the frequency characteristics of loss and impedance are reduced due to the relatively high specific resistance of manganese oxide. It was inferior to a ceramic capacitor or a film capacitor.

Further, in the case of a tantalum solid electrolytic capacitor, a process of immersing in a manganese nitrate solution and thermally decomposing at a temperature of about 300 ° C. is repeated several to ten and several times to form an electrolyte composed of manganese oxide. It is necessary and the forming process is complicated in the first place.

In a tantalum solid electrolytic capacitor, an electrolyte composed of manganese oxide is formed by repeating thermal decomposition. Therefore, in order to repair the film damage that has occurred, it is necessary to carry out chemical formation each time. Therefore, the process became complicated.

Therefore, in recent years, after a conductive polymer such as a metal, a conductive metal oxide, or polypyrrole is formed on a dielectric film, the conductive polymer such as polypyrrole is formed by electrolytic polymerization through these conductive layers. A solid electrolytic capacitor formed by forming a conductive polymer has been proposed (JP-A-63-1).
58829, JP-A-63-173313, JP-A-1-253226 and the like.

Further, there has been proposed a solid electrolytic capacitor obtained by forming a conductive polymer having a substituent at the 3- and 4-positions, polythiophene, by chemical polymerization (Japanese Patent Publication No. 2-15 / 1990).
611).

Further, after forming a dielectric comprising an electrodeposited polyimide thin film on an etched aluminum foil, a conductive polymer layer is sequentially formed by chemical polymerization and electrolytic polymerization to form a large-capacity film capacitor as an electrode. (Proceedings of the 58th Annual Meeting of the Institute of Electrical Chemistry, pp. 251-252 (1991)).

[0015]

However, in the case of forming an electropolymerized polymer via a conductive pyrolytic metal oxide such as manganese oxide in a solid electrolytic capacitor, the dielectric film is not heated by heat. Due to damage, in order to obtain a capacitor with a high withstand voltage, it is necessary to carry out chemical formation again before electrolytic polymerization and to repair the same, which further complicates the process.

In addition, when the conductive polymer layer is formed by chemical polymerization using polypyrrole, the polymerization rate is high near room temperature, so that the conductive polymer layer penetrates deep into the pores of the etched aluminum foil or the tantalum sintered body on one side. As a result of polymerization in the middle of the process, blockage of etch pits and pores of the sintered body occurred partially, and it was difficult to form a conductive polymer layer with a high filling factor.

Although this problem can be solved by lowering the polymerization temperature, when water is used as a medium, there is a limit because water freezes at around 0 degrees Celsius.

This problem can be solved by lowering the concentration of the pyrrole monomer, but on the other hand, a new problem arises in that the number of times of polymerization required for coating increases.

Further, when the polypyrrole layer is formed by chemical polymerization, a powdery polymer is obtained, the coating property of the edge portion is inferior on the surface and inside of the capacitor electrode, and the polymerization time for complete coating is extended. What was needed was also an issue.

On the other hand, in the case of electrolytically polymerized polypyrrole,
Since a film-like polymer is obtained, such a problem does not occur, but on the other hand, a film having a high coverage cannot be formed unless conductivity is imparted to the dielectric surface.

Further, when a polythiophene having a substituent at the 3- or 4-position is formed by chemical polymerization, polymerization takes a long time due to a low polymerization rate, or in order to shorten the polymerization time, It was necessary to raise the temperature.

When the polymerization temperature is increased, the oxidizing agent becomes more active, and the dielectric film is damaged.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in the prior art, and provides a simple method of obtaining a solid electrolytic capacitor having a high capacity achievement ratio, high capacitor characteristics, and high heat and humidity resistance. It is an object of the present invention to easily obtain a film capacitor having an achievement ratio, high capacitor characteristics, and high heat and moisture resistance.

[0024]

According to the present invention, there is provided a capacitor comprising:
A pair of electrodes provided to face each other, a dielectric layer provided between the electrodes, and a first conductive polymer provided between the electrodes and containing a thiophene derivative represented by the following chemical formula 2 as a repeating unit And a laminated conductive polymer layer having a second conductive polymer layer containing pyrrole or a derivative thereof as a repeating unit.

[0025]

Embedded image

The thiophene derivative is, for example, 3,4
-Dihydroxythiophene-2,5-dicarboxylic acid ester is reacted with an appropriate alkylene-vic-dihalide and then hydrolyzed to give 3,4 (alkylene-vic-dioxy) thiophene-2,5-carboxylic acid. And it can be obtained by decarboxylation (Polymer, Vol. 35, No. 7, 1994)
1347 pages, Tetrahedron, 23 volumes (1
967) 2437 and J. Am. Am. Chem. So
c. 67 (1945), page 2217).

Further, the method of manufacturing a capacitor according to the present invention comprises:
Such a capacitor can be suitably manufactured. In particular, the first conductive polymer layer and the second conductive polymer layer are stacked by a first conductive polymer layer forming step. Having a first conductive polymer layer forming step of forming a second conductive polymer layer by chemical polymerization and a second conductive polymer layer forming step of forming a second conductive polymer layer by chemical polymerization A conductive polymer layer forming step is performed, or a first conductive polymer layer forming step of forming the first conductive polymer layer by chemical polymerization and a second conductive polymer layer are formed by electrolytic polymerization Performing a laminated conductive polymer layer forming step having a second conductive polymer layer forming step, or impregnating the first conductive polymer layer with a conductive polymer solution to form a first conductive polymer layer.
Performing a laminated conductive polymer layer forming step having a conductive polymer layer forming step of forming and a second conductive polymer layer forming step of forming a second conductive polymer layer by chemical polymerization, or Forming a first conductive polymer layer by impregnating the first conductive polymer layer with a conductive polymer solution; and forming a second conductive polymer layer by electrolytic polymerization on the second conductive polymer layer. It has a configuration for executing a laminated conductive polymer layer forming step having a molecular layer forming step.

With the above configuration, it is easy to obtain a solid electrolytic capacitor having a high capacity achievement ratio, high capacitor characteristics and high heat resistance and moisture resistance, and a small, large capacity, high capacity achievement ratio, high capacitor characteristics, and high heat resistance moisture resistance. Can easily be obtained.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention according to claim 1 is provided with a pair of electrodes provided facing each other, a dielectric layer provided between the electrodes, and provided between the electrodes. Chemical formula 2)
1 containing a thiophene derivative shown as a repeating unit
And a laminated conductive polymer layer having a second conductive polymer layer containing pyrrole or a derivative thereof as a repeating unit.

As described above, the laminated conductive polymer layer functions as an electrolyte also serving as a true cathode in a capacitor in which the dielectric is formed of an oxide film of a valve metal, while it is formed of a polymer thin film. In a capacitor, it functions as a simple electrode.

Further, the substitutable alkylene group is preferably a 1,2-alkylene group such as ethene, 1-propene, 1-hexene, etc., which can be obtained from alpha olefin. It may be a 2-cyclohexene, 2,3-butylene, 2,3-dimethylene 2,3-butylene, 2,3-pentylene group or the like. Most preferred examples are methylene, 1,
2-ethylene and 1,2-propylene groups are exemplified.

With such a configuration, the characteristics and heat resistance of the capacitor are improved. Further, as described in claim 2, the first conductive polymer layer may have a configuration containing a monovalent anion as a dopant, and the yield and electric conductivity of the first conductive polymer layer may be reduced. With the increase, the capacitor characteristics and heat resistance are improved.

Further, as described in claim 3, the first conductive polymer layer may further contain a polyvalent anion as a dopant. It is preferably a sulfonic acid group.

This is because a monovalent anion such as a sulfonic acid group is incorporated into the first conductive polymer in competition with, for example, the polyvalent anion of the transition metal polyvalent salt used as an oxidizing agent. This is because

Here, as described in claim 12, it is preferable that the sulfonic acid group contains one dissociated from an anionic surfactant, and the capacitor properties and heat resistance are further improved by the surfactant action. .

Further, as described in claim 13, the polyvalent anion may be a sulfate group. Here, the polyvalent anion is preferably supplied from a polyvalent acid salt of a transition metal that acts as an oxidizing agent. Examples of the transition metal include iron (III), copper (II), chromium (VI), and cerium. (IV),
Ruthenium (III) and manganese (VII) can be used.

As the polyvalent acid, sulfuric acid, phosphoric acid, permanganic acid, chromic acid, dichromic acid and the like can be used.

On the other hand, the first conductive polymer layer may contain a sulfonic acid-based anion as a dopant, as described in claim 14. And polystyrenesulfonate ions.

With such a configuration, the capacitor characteristics and the heat resistance are improved. Further, as described in claim 4, the second conductive polymer layer also preferably contains a monovalent anion as a dopant, and improves the capacitor characteristics and heat resistance.

Further, the second conductive polymer layer may further contain a polyvalent anion as a dopant. And a sulfonic acid group.

This is because, like the first conductive polymer, a monovalent anion such as a sulfonic acid group competes with a polyvalent anion of the transition metal polyvalent acid salt used as an oxidizing agent, for example. This is because they are taken into the second conductive polymer.

Here, as described in claim 12, it is preferable that the sulfonic acid groups include those dissociated from the anionic surfactant, and the capacitor properties and heat resistance are further improved by the surfactant action. .

Further, the polyvalent anion may be a sulfate group. Further, as described in claim 7, the laminated conductive polymer layer is provided on the opposite side of the first conductive polymer layer so as to be adjacent to the second conductive polymer layer. A structure including a third conductive polymer layer containing a thiophene derivative shown in Chemical formula 2 as a repeating unit may be used.

The third conductive polymer layer contains a monovalent anion as a dopant, as in the eighth embodiment, like the first conductive polymer. The third conductive polymer layer may further contain a polyvalent anion as a dopant, wherein the monovalent anion is a sulfonic group, as described in claim 11.
As described in above, it is preferable that the sulfonic acid groups include those dissociated from an anionic surfactant.

Further, as described in claim 13, the polyvalent anion may be a sulfate group. On the other hand, as described in claim 10, the third conductive polymer layer may contain a sulfonic acid-based anion as a dopant, and as described in claim 14, the sulfonic acid-based anion is a polystyrene sulfonic acid. It may be an ion.

In the above construction, the present invention is characterized in that:
The dielectric layer may be an oxide film of a valve metal forming one of the electrodes, and the valve metal may be aluminum or tantalum.

On the other hand, as described in claim 17, the dielectric layer may be a polymer dielectric, and as described in claim 18, the polymer may be polyimide.

However, as described in claim 19, the first conductive polymer layer is adjacent to such a dielectric layer.

According to a second aspect of the present invention regarding a method for manufacturing a capacitor, a step of arranging a pair of electrodes facing each other and a step of forming a dielectric layer between the electrodes are provided. A first conductive polymer layer forming step of forming a first conductive polymer layer containing a thiophene derivative represented by the above formula (Chemical Formula 2) as a repeating unit by chemical polymerization between the electrodes and pyrrole or a derivative thereof; A second conductive polymer layer forming step of forming a second conductive polymer layer containing as a repeating unit by chemical polymerization, and a laminated conductive polymer layer forming step.

Alternatively, as described in claim 21, a step of arranging a pair of electrodes facing each other, a step of forming a dielectric layer between the electrodes, and a step of forming a dielectric layer between the electrodes; A first conductive polymer layer forming step of forming a first conductive polymer layer containing a thiophene derivative as a repeating unit shown in Chemical formula 2) by chemical polymerization, and a second conductive layer containing pyrrole or a derivative thereof as a repeating unit A laminated conductive polymer layer forming step having a second conductive polymer layer forming step of forming a conductive polymer layer by electrolytic polymerization.

Alternatively, as described in claim 22, a step of arranging a pair of electrodes facing each other, a step of forming a dielectric layer between the electrodes, and a step of forming a dielectric layer between the electrodes, wherein A first conductive polymer layer forming step of impregnating a first conductive polymer layer containing a thiophene derivative as a repeating unit shown in Chemical formula 2) with a conductive polymer solution, and a pyrrole or a derivative thereof as a repeating unit And a laminated conductive polymer layer forming step having a second conductive polymer layer forming step of forming a second conductive polymer layer by chemical polymerization.

Alternatively, as described in claim 23, a step of arranging a pair of electrodes facing each other, a step of forming a dielectric layer between the electrodes, and a step of forming a dielectric layer between the electrodes, wherein A first conductive polymer layer forming step of impregnating a first conductive polymer layer containing a thiophene derivative as a repeating unit shown in Chemical formula 2) with a conductive polymer solution, and a pyrrole or a derivative thereof as a repeating unit And a laminated conductive polymer layer forming step having a second conductive polymer layer forming step of forming a second conductive polymer layer by electrolytic polymerization.

In any of these manufacturing methods,
A laminated conductive polymer layer is surely formed to improve the characteristics and heat resistance of the capacitor.

Since the thiophene derivative used for the first conductive polymer layer has a lower polymerization rate than that of pyrrole, it penetrates deep into the pores of a capacitor using an etched foil or a porous sintered electrode. Since post-polymerization is performed, a capacitor having a higher capacity achievement ratio than when polypyrrole is formed alone can be easily obtained.

In addition, when the dielectric layer is composed of an oxide film of a valve metal and the conductive polymer layer is formed by chemical polymerization in a solution, the dielectric layer is heated by heat. Damage can be prevented.

In the formation of a manganese oxide layer by thermal decomposition, a solid electrolytic capacitor having a low leakage current can be easily obtained even if the restoration chemical treatment required for each of the thermal decomposition processes performed repeatedly is omitted. .

Further, as described in claim 24, in the step of forming a laminated conductive polymer layer, the third conductive polymer layer containing the thiophene derivative represented by the above-mentioned (Chemical Formula 2) as a repeating unit is formed by the third step. A second layer on the opposite side of the first conductive polymer layer;
And a third conductive polymer layer forming step of forming the conductive polymer layer adjacent to the conductive polymer layer.

According to such a configuration, the laminated conductive polymer layer including the third conductive polymer layer is surely formed.
Improve the characteristics and heat resistance of the capacitor.

The third conductive polymer layer forming step may be a step of forming by a chemical polymerization step as described in claim 25, or may be a step of forming a conductive polymer layer as described in claim 26. It may be a step of forming by impregnating a polymer solution.

With such a configuration, the laminated conductive polymer layer having the third conductive polymer layer is surely formed, and the characteristics and heat resistance of the capacitor are improved.

The third conductive polymer layer is preferably formed by solution impregnation, particularly when the inner polypyrrole layer is formed by chemical polymerization.

Here, the above-mentioned chemical polymerization step is defined in claim 2
As described in 7, it is preferable that the chemical polymerization step is performed in an aqueous medium, and as described in claim 28, the chemical polymerization step includes ferric sulfate and an anionic surfactant. It is preferable to form a conductive polymer layer using a solution.

As described above, the use of non-toxic and non-flammable water as the polymerization medium facilitates the construction of a production process.

Further, by including the iron surfactant in the thiophene derivative polymerization solution shown in the above (Chemical Formula 2), the wettability of the polymerization solution to the surface of the capacitor electrode element is improved, and the high coverage is obtained. , A high-capacity capacitor can be realized.

Further, in this case, fine precipitates composed of trivalent iron cations and surfactant anions are temporarily generated, and the thiophene monomer molecules are adsorbed on the surface and polymerized on the surface. This is preferable because it has an action of accelerating the polymerization, which tends to be slow.

Furthermore, since an anionic surfactant is used as the surfactant, the monovalent anion dissociated from the anion is used as the surface active agent of the transition metal polyvalent acid salt used as the oxidizing agent in the polymerized conductive polymer. Competitive incorporation with polyvalent anions.

The anion of the anionic surfactant contains a hydrophobic group and has a large ionic size.
Dedoping by diffusion at high temperature or high humidity is suppressed,
As a result, a conductive polymer having the thiophene derivative having a small deterioration in conductivity as a repeating unit is formed, and this effect appears in the same manner in the case of polypyrrole, and the heat resistance and the moisture resistance are excellent. A capacitor is obtained.

Further, since the anion of the surfactant is monovalent, the polyvalent anion generated from the oxidizing agent is more easily incorporated as a dopant into the conductive polymer composed of the thiophene derivative and pyrrole.

Therefore, the ratio of the monovalent anion to the total dopant depends more on the surfactant concentration than on the oxidant concentration, and the ratio can be adjusted by changing this concentration.

The electric conductivity of the conductive polymer having a dopant and the stability thereof tend to be improved as the doping ratio of the monovalent anion having a large molecular size based on the surfactant becomes higher.

Therefore, a capacitor having greatly improved high-frequency characteristics and loss characteristics can be easily produced as compared with a case where a conductive polymer polymerized using a transition metal polyvalent acid salt is used or a case where manganese dioxide is used. Is obtained.

In this case, it is preferable to use an anionic surfactant containing an anion having a sulfonic acid group.

As described in claim 30, in the chemical polymerization step, chemical polymerization may be further carried out using a solution containing phenol or a derivative thereof. It may be nitrophenol, cyanophenol, hydroxybenzoic acid, hydroxyphenol or acetophenol, or a combination thereof.

As described above, by adding phenol or a derivative thereof, the electric conductivity and the stability of the thiophene derivative and the conductive polymer obtained from pyrrole are improved.
Better.

This is because the phenolic compound is not incorporated as a dopant into the amphoteric conductive polymer,
This is thought to be due to the formation of a conductive polymer with a high degree of regularity and therefore a conjugated length.As a result, the initial characteristics and stability of capacitors using polypyrrole obtained from a polymerization system to which a phenolic derivative has been added. This is because the property is further improved.

Further, the above-mentioned electrolytic polymerization step is performed in a
As described in the above, it is preferable that the electrolytic polymerization step in an aqueous medium, as described in claim 33, in the electrolytic polymerization step, a solution containing a phenol or a derivative thereof in the same manner as in the chemical polymerization. The phenol derivative may be nitrophenol, cyanophenol, hydroxybenzoic acid, hydroxyphenol or acetophenol, or a combination thereof, as described in claim 34.

According to the above-described method for manufacturing a capacitor, the dielectric material forming step is as follows.
The dielectric may be formed by anodizing the valve metal, and the valve metal constituting one of the electrodes may be aluminum or tantalum.

On the other hand, as described in claim 37, the dielectric forming step may be a spin coating step of forming a dielectric using a polymer.
The polymer may be polyimide.

Hereinafter, each embodiment of the present invention will be described in detail. (Embodiment 1) In this embodiment, first, 2x
For a 1.4 × 0.9 mm ³ tantalum sintered body, a solution of 5 ml of phosphoric acid in 1000 ml of water
By applying 40 V at 0 ° C., an oxide film dielectric film was formed by anodic oxidation.

This structure was regarded as a capacitor, and the capacity in a chemical conversion solution was measured to be 18.0 μF.

Further, using this constitution, 0.1 mol / l of ethylenedioxythiophene (EDOT) and 0.75% by weight of sodium alkylnaphthalenesulfonate (average molecular weight: 338) which is an aromatic sulfonic acid-based surfactant
For 5 minutes, and then immersed in an oxidizing agent solution at 65 ° C. containing 0.75 mol / l of ferric sulfate for 60 minutes.

Here, EDOT is commercially available from Bayer AG in Germany, but EDOT may be synthesized by a general production method.

By this treatment, a conductive layer made of polyethylene dioxythiophene (PEDOT) doped with divalent sulfate ions and monovalent alkylnaphthalenesulfonate ions was converted to a tantalum sintered body having a dielectric film formed thereon. Formed on top.

FIG. 1 shows the yield of PEDOT and the change in electrical conductivity obtained when the amount of sodium alkylnaphthalenesulfonate was changed.

As shown in FIG. 1, it can be seen that the yield and electric conductivity of PEDOT are increased by gradually adding the sodium alkylnaphthalenesulfonate.

This is considered to be due to the fact that monovalent alkylnaphthalenesulfonate ions are doped in PEDOT.

On the other hand, when a sulfonate having no surface activity was added, the yield and electric conductivity of PEDOT did not significantly increase so far.

Therefore, it was also found that the addition of a sulfonate having a surfactant action has an effect of further accelerating the polymerization rate and increasing the yield.

In addition, elemental analysis confirmed that the polymerization product contained substantially no iron.

Then, 0.75 m of pyrrole monomer was placed on the tantalum sintered body on which the PEDOT layer was formed as described above.
ol / l and 0.75% by weight of sodium alkylnaphthalenesulfonate (average molecular weight: 338), immersed in a 25 ° C. aqueous monomer solution for 2 minutes, and immersed in an oxidizing agent solution of the composition used in PEDOT at 25 ° C. for 10 minutes did.

This process was repeated 14 times to form a conductive layer made of polypyrrole doped with divalent sulfate ions and monovalent alkylnaphthalenesulfonate ions.

The yield and electric conductivity of the polypyrrole are increased by gradually adding the polypyrrole to the one containing no sodium alkylnaphthalenesulfonate.

This is probably due to the fact that polypyrrole is doped with monovalent alkylnaphthalenesulfonate ions.

On the other hand, when a sulfonate having no surface activity was added, the yield of polypyrrole did not increase so far.

Therefore, it was found that the addition of a sulfonate having a surfactant action also has an effect of increasing the polymerization rate and increasing the yield of polypyrrole.

[0096] From an elemental analysis, it was found that the polymerization product contained substantially no iron.

Next, on the tantalum sintered body on which the polypyrrole layer was formed, a cathode was formed with a carbon layer and a silver paint layer, and a cathode lead was mounted thereon, so that a total of ten capacitor elements were formed. Obtained.

Further, the element was packaged using an epoxy resin, and an aging treatment at 13 ° C. was applied at 125 ° C. to complete a capacitor.

For each of these ten devices, the capacitance at 1 kHz, the loss factor, and the impedance at 400 kHz were measured, and the capacitance change rate and the loss factor after the load heat resistance test performed at 125 ° C. with 10 V applied were measured. The average values are shown in the following (Table 1).

[0100]

[Table 1]

(Embodiment 2) In this embodiment, a conductive polymer poly (3,3) which similarly contains a thiophene derivative represented by the following formula (2) as a repeating unit instead of PEDOT in the embodiment 1 Except for using 4- (1,2-propylene) dioxythiophene) (PPDOT), ten capacitor elements configured in the same manner as in Embodiment 1 were completed.

As with the first embodiment, the capacitance, the loss factor, and the
The impedance at 00 kHz, and the rate of change in capacity and loss factor after a load heat resistance test conducted by applying 10 V at 125 ° C. were measured, and their average values are shown in Table 1 above.

As can be understood from Table 1, it is understood that the present embodiment can also realize the same capacitor characteristics and heat resistance as those of the first embodiment.

This is because, even in the present embodiment, PEDO
A layer of a conductive polymer PPDOT having the same physical properties as the T layer is used to form a laminated conductive layer with a polypyrrole layer, and sodium dodecylbenzenesulfonate has a bulky monovalent sulfonate anion which is divalent. This is because such a conductive polymer and polypyrrole are doped in a form in which sulfate ions are partially substituted, and also have a function as a surfactant.

As described above, also in the present embodiment, a capacitor having high capacity achievement ratio, low loss, excellent high-frequency impedance characteristics, and high heat resistance can be efficiently obtained.

The same results were obtained with other thiophene derivatives shown in the above (Chemical Formula 2).

(Comparative Example 1) Next, Comparative Example 1 was used for comparison.
PEDOT without forming a polypyrrole layer at all
Ten capacitors were completed under the same conditions as in Embodiment 1 except that the operation of forming layers was repeated.

However, the number of repetitions required for forming the PEDOT layer was 30 times. Also for these ten elements, the capacity at 1 kHz,
Loss factor, and impedance at 400 kHz,
Furthermore, the capacity change rate and the loss coefficient after the load heat resistance test performed by applying 10 V at 125 ° C. were measured, and the average values were shown in the above (Table 1).

Examination of the results of Embodiment 1 and this comparative example shows that the capacitor characteristics and the heat resistance are equivalent to each other, but that the number of repetitions necessary for forming the PEDOT layer as the conductive layer is large.

In other words, in order to ensure the same characteristics and durability as in the first embodiment, a longer conductive layer formation time is required, resulting in an extremely long process holding time, which is not practical. You can see that.

As described above, by employing a laminated conductive layer in which a polypyrrole layer is combined with a PEDOT layer,
It has been found that a capacitor excellent in capacitor characteristics and heat resistance can be manufactured practically.

(Comparative Example 2) Next, Comparative Example 2 was used for comparison.
As a result, ten capacitors were completed under the same conditions as in Embodiment 1 except that sodium alkylnaphthalenesulfonate was not added.

As with the first embodiment, the capacitance, the loss coefficient, and the
The impedance at 00 kHz, and the rate of change in capacity and loss factor after a load heat resistance test conducted by applying 10 V at 125 ° C. were measured, and their average values are shown in Table 1 above.

When the results of Embodiment 1 and this comparative example were examined, the capacitor characteristics and heat resistance of this comparative example were extremely low.

This is presumably because, first of all, although the PEDOT layer and the polypyrrole layer are formed, bulky monovalent alkylnaphthalenesulfonate ions are not doped together.

Further, in the case of the first embodiment, since sodium alkylnaphthalenesulfonate which also acts as a surfactant is used, in this comparative example not using it, the capacitor characteristics and heat resistance are further improved. It is considered that a remarkable difference has occurred.

Furthermore, in the case of this comparative example, since sodium alkylnaphthalenesulfonate acting as a surfactant was not used, the state of the PEDOT layer formed on the dielectric surface could be visually observed. It is considered that the formation of the PEDOT layer was not enough to improve the capacitor characteristics and the heat resistance, which was merely an insignificant degree of formation.

As described above, by doping monovalent alkylnaphthalenesulfonate ions into the laminated conductive layer, PED
Not only the yield and electrical conductivity of the OT layer etc. increase,
It was found that capacitor characteristics and heat resistance were improved, and in particular, they could be further improved by using sodium alkylnaphthalenesulfonate which also acts as a surfactant.

(Comparative Example 3) Next, for comparison, Comparative Example 3
Except that no PEDOT layer was formed, only the polypyrrole layer was formed under the same conditions as in Embodiment 1 to complete 10 capacitors.

For these ten elements, as in the first embodiment, the capacitance at 1 kHz, the loss coefficient,
The impedance at 00 kHz, and the rate of change in capacity and loss factor after a load heat resistance test conducted by applying 10 V at 125 ° C. were measured, and their average values are shown in Table 1 above.

Examination of the results of the first embodiment and this comparative example showed that the capacitance of the capacitor tended to be small.

This is considered to be because the polymerization rate of polypyrrole is so high that the monomer is polymerized before the monomer reaches the deep part of the pores of the sintered body to form polypyrrole, which partially blocks the pores. .

On the other hand, in the first embodiment, although the surface-active agent sodium alkylnaphthalenesulfonate is applied to the EDOT monomer solution, the polymerization rate of EDOT is increased, Since the polymerization rate is moderately slow, PEDOT penetrates deeper into the sintered body where the dielectric film is formed and does not block pores.
Can be formed, it is considered that a larger capacitor capacity has been achieved.

As described above, it has been found that a capacitor having a large capacitance can be realized by adopting the laminated conductive layer having the PEDOT layer formed so as to be located on the sintered body side on which the dielectric film is formed.

From the results of comparison between the first embodiment and Comparative Examples 1 to 3, the first embodiment employs a laminated conductive layer containing PEDOT and polypyrrole.
That is, by combining a polypyrrole layer having a high polymerization rate, a capacitor having excellent capacitor characteristics and heat resistance can be produced more efficiently in a form suitable for practical use.

By doping monovalent alkylnaphthalenesulfonate ions into the laminated conductive layer having this structure, not only the yield and electric conductivity of the PEDOT layer and the like are increased, but also the capacitor characteristics and heat resistance are improved. In particular, they are further improved by using sodium alkylnaphthalenesulfonate which also acts as a surfactant.

Furthermore, if the PEDOT layer is formed on the side of the sintered body on which the dielectric film is formed, the PEDOT layer penetrates deep into the sintered body on which the dielectric film is formed, and the PEDOT layer is formed without closing the pores. As a result, the capacitance of the capacitor can be increased.

The above results were also confirmed for each conductive polymer shown in the second embodiment.

This is a conductive polymer containing a thiophene derivative represented by the following formula (2) as a repeating unit.
It is considered that the same action is obtained from the aromatic sulfonic acid-based surfactant and the like.

(Embodiment 3) In this embodiment, sodium dodecylbenzenesulfonate, which is also an aromatic sulfonic acid surfactant, is used in place of sodium alkylnaphthalenesulfonate in Embodiment 1. Except for this, ten capacitor elements configured in the same manner as in the first embodiment were completed.

As in the first embodiment, the capacitance, the loss coefficient, and the
The impedance at 00 kHz, and the rate of change in capacity and loss factor after a load heat resistance test conducted by applying 10 V at 125 ° C. were measured, and their average values are shown in Table 1 above.

As can be understood from Table 1, it is understood that the present embodiment can also realize the same capacitor characteristics and heat resistance as the first embodiment.

This is because PEDO is also used in this embodiment.
PEDOT and polypyrrole have a layered conductive layer of a T layer and a polypyrrole layer, and are also doped with sodium dodecylbenzenesulfonate, in which bulky monovalent sulfonate anions are partially substituted with divalent sulfate ions. And
Further, it has a function as a surfactant.

As described above, also in the present embodiment, a capacitor having high capacity achievement ratio, low loss, excellent high-frequency impedance characteristics, and high heat resistance can be efficiently obtained.

The above results were also confirmed for each conductive polymer described in the second embodiment.

(Embodiment 4) In this embodiment, the same conditions as in Embodiment 1 are used except that an etched aluminum foil electrode is used instead of the tantalum sintered body of Embodiment 1.
Completed 0 capacitors and evaluated the same characteristics.
The results are shown in the above (Table 1).

The number of repetitive treatments required for forming the polypyrrole layer was 12 times.

Here, a specific fabrication of an etched aluminum electrode foil was performed as follows. First, 4 × 10mm
A 1 mm wide polyimide tape was stuck on both sides so as to partition the aluminum-etched foil of No. ² into portions of 3 mm and 6 mm.

Next, the 4 × 3 aluminum-etched foil 1
The anode lead of the mm ² part was attached, and the 4 × 6 mm ² part of the aluminum-etched foil was applied with a 3% ammonium adipate aqueous solution at about 70 ° C. and 50 V was applied.
An oxide film dielectric layer was formed by anodic oxidation.

Here, this configuration is regarded as a capacitor,
When the volume in the chemical conversion solution was measured, it was 4.92 μF.

Also in this embodiment, each of the conductive polymers shown in Embodiment 2 was used in place of PEDOT, and sodium dodecylbenzenesulfonate was used in place of sodium alkylnaphthalenesulfonate. In these cases, similar results were obtained.

(Comparative Example 4) Next, Comparative Example 4
PEDOT without forming a polypyrrole layer at all
Ten capacitors were completed under the same conditions as in Embodiment 4 except that the operation of forming the layers was repeated.

The number of repetitions required for forming the PEDOT layer was 27 times. Also for these ten elements, the capacitance at 1 kHz,
Loss factor, and impedance at 400 kHz,
Furthermore, the capacity change rate and the loss coefficient after the load heat resistance test performed by applying 10 V at 125 ° C. were measured, and the average values were shown in the above (Table 1).

Examination of the results of Embodiment 4 and this comparative example shows that the capacitor characteristics and the heat resistance are equivalent to each other, but that the number of repetitions necessary for forming the PEDOT layer as the conductive layer is large.

In other words, in order to ensure the same characteristics and durability as in the fourth embodiment, a longer conductive layer formation time is required, resulting in an extremely long process holding time, which is not practical. You can see that.

As described above, by adopting a laminated conductive layer in which a polypyrrole layer is combined with a PEDOT layer,
It has been found that a capacitor excellent in capacitor characteristics and heat resistance can be manufactured practically.

(Comparative Example 5) Next, for comparison, Comparative Example 5
As a result, ten capacitors were completed under the same conditions as in Embodiment 4, except that sodium alkylnaphthalenesulfonate was not added.

As in the fourth embodiment, the capacitance, the loss coefficient, and the
The impedance at 00 kHz, and the rate of change in capacity and loss factor after a load heat resistance test conducted by applying 10 V at 125 ° C. were measured, and their average values are shown in Table 1 above.

Examination of the results of Embodiment 4 and this comparative example shows that in this comparative example, the capacitor characteristics and heat resistance were extremely low.

This is presumably because, first of all, although the PEDOT layer and the polypyrrole layer are formed, bulky monovalent alkylnaphthalenesulfonate ions are not doped together.

Furthermore, in the case of Embodiment 4, since sodium alkylnaphthalenesulfonate, which also acts as a surfactant, is used, in this comparative example not using such, the capacitor characteristics and heat resistance are further improved. It is considered that a remarkable difference has occurred.

Further, in the case of this comparative example, since the sodium alkylnaphthalenesulfonate acting as a surfactant was not used, the state of the PEDOT layer formed on the dielectric surface could be visually observed. It is considered that the formation of the PEDOT layer was not enough to improve the capacitor characteristics and the heat resistance.

As described above, by doping monovalent alkylnaphthalenesulfonate ions into the laminated conductive layer, the PED
Not only the yield and electrical conductivity of the OT layer etc. increase,
It was found that capacitor characteristics and heat resistance were improved, and in particular, they could be further improved by using sodium alkylnaphthalenesulfonate which also acts as a surfactant.

(Comparative Example 6) Next, for comparison, Comparative Example 6
Only the polypyrrole layer was formed under the same conditions as in Embodiment 4 except that the PEDOT layer was not formed, thereby completing ten capacitors.

As with the fourth embodiment, the capacity, the loss coefficient, and the
The impedance at 00 kHz, and the rate of change in capacity and loss factor after a load heat resistance test conducted by applying 10 V at 125 ° C. were measured, and their average values are shown in Table 1 above.

Examination of the results of the fourth embodiment and this comparative example showed that the capacitance of the capacitor tended to be small.

This is considered to be because the polymerization rate of polypyrrole is so high that the monomer is polymerized before the monomer reaches the deep part of the pores of the sintered body to form polypyrrole, which partially blocks the pores. .

On the other hand, in the fourth embodiment, although a surfactant, sodium alkylnaphthalenesulfonate, is applied to the EDOT monomer solution to increase the polymerization rate of EDOT, it is compared with pyrrole. If the polymerization rate is moderately slow, PEDOT penetrates deeper into the sintered body where the dielectric film is formed, and does not block pores.
Can be formed, it is considered that a larger capacitor capacity has been achieved.

From the above, it has been found that a capacitor having a large capacitor capacity can be realized by employing a laminated conductive layer in which a PEDOT layer is formed so as to be located on the sintered body side on which a dielectric film is formed.

From the results of comparison between Embodiment 4 and Comparative Examples 4 to 6, in Embodiment 4, first, a laminated conductive layer containing PEDOT and polypyrrole was adopted.
That is, by combining a polypyrrole layer having a high polymerization rate, a capacitor having excellent capacitor characteristics and heat resistance can be produced more efficiently in a form suitable for practical use.

By doping monovalent alkylnaphthalenesulfonate ions into the laminated conductive layer, PEDO
Not only the yield and electrical conductivity of the T layer and the like are increased, but also the capacitor characteristics and heat resistance are improved. In particular, those are further improved by using sodium alkylnaphthalenesulfonate which also acts as a surfactant. It is.

Furthermore, if the PEDOT layer is formed on the etched foil side on which the dielectric film is formed, the PEDOT layer is formed in close contact with the etched foil on which the dielectric film is formed, thereby increasing the capacitance of the capacitor. It was something that could be done.

(Embodiment 5) In this embodiment, a 20 mm x 20 mm aluminum smooth foil is used instead of the etched aluminum foil in the structure of the fourth embodiment.
In addition, substantially the same as Embodiment 3 except that an electrode having a polyimide dielectric layer formed of a polyimide thin film having a thickness of 0.5 μm on one surface is used instead of forming an oxide film dielectric by spin coating. Under the same conditions, a total of ten capacitors were produced.

The number of processing repetitions required for forming the polypyrrole layer was 10. These were evaluated in the same manner as in Embodiment 4, and the results are shown in the above (Table 1).

In the present embodiment, when the conductive polymer shown in Embodiment 2 is used instead of PEDOT,
Similar results were obtained when sodium dodecylbenzenesulfonate was used in place of the sodium alkylnaphthalenesulfonate.

(Comparative Example 7) Next, for comparison, Comparative Example 7
PEDOT without forming a polypyrrole layer at all
Ten capacitors were completed under the same conditions as in Embodiment 5, except that the operation of forming layers was repeated.

However, the number of repetitions required for forming the PEDOT layer was 22 times. Also for these ten elements, the capacitance at 1 kHz,
Loss factor, and impedance at 400 kHz,
Furthermore, the capacity change rate and the loss coefficient after the load heat resistance test performed by applying 10 V at 125 ° C. were measured, and the average values were shown in the above (Table 1).

Examination of the results of the fifth embodiment and the comparative example shows that the capacitor characteristics and the heat resistance are equal to each other, but that the number of repetitions necessary for forming the PEDOT layer as the conductive layer is large.

In other words, in order to ensure the same characteristics and durability as in the fifth embodiment, a longer conductive layer formation time is required, resulting in an extremely long process holding time, which is not practical. You can see that.

As described above, by adopting a laminated conductive layer in which a polypyrrole layer is combined with a PEDOT layer,
It has been found that a capacitor excellent in capacitor characteristics and heat resistance can be manufactured practically.

(Comparative Example 8) Next, for comparison, Comparative Example 8
As a result, ten capacitors were completed under the same conditions as in the fifth embodiment except that sodium alkylnaphthalenesulfonate was not added.

As with the fifth embodiment, the capacity, the loss coefficient, and the
The impedance at 00 kHz, and the rate of change in capacity and loss factor after a load heat resistance test conducted by applying 10 V at 125 ° C. were measured, and their average values are shown in Table 1 above.

Examination of the results of the fifth embodiment and this comparative example shows that the heat resistance of the capacitor was extremely low in this comparative example.

This is because although the PEDOT layer and the polypyrrole layer were formed, bulky monovalent alkylnaphthalenesulfonate ions were not doped at all, and the polypyrrole layer having low heat resistance was formed. It is considered to be caused.

As described above, by doping monovalent alkylnaphthalenesulfonate ions into the laminated conductive layer, the PED
Since not only the yield and electric conductivity of the OT layer and the like but also the heat resistance are improved, the heat resistance of the capacitor is improved. In particular, by using sodium alkylnaphthalenesulfonate which also acts as a surfactant, It turned out that it was able to be further improved.

From the results of comparison between Embodiment 5 and Comparative Examples 7 and 8, in Embodiment 5, first, a laminated conductive layer containing PEDOT and polypyrrole was employed, that is, polypyrrole having a high polymerization rate. By combining the layers, a capacitor having excellent capacitor characteristics and heat resistance can be manufactured more efficiently in a form suitable for practical use.

Then, PEDO is obtained by doping monovalent alkylnaphthalenesulfonate ions into the laminated conductive layer.
Not only the yield and electrical conductivity of the T layer and the like are increased, but also the capacitor characteristics and heat resistance are improved. In particular, those are further improved by using sodium alkylnaphthalenesulfonate which also acts as a surfactant. It is.

Although the description has been given of the case where polyimide is used as a polymer to be a dielectric, any material other than polyimide can be used as long as it is a dielectric polymer material capable of forming a thin film.

The case where a polyimide film serving as a dielectric is formed on a smooth aluminum foil by spin coating has been described. However, a polyimide film may be formed on the surface of an etched aluminum foil by, for example, electrodeposition. 5
In this case, a polymer dielectric can be applied.

(Embodiment 6) In the present embodiment, in the structure of the embodiment 1, 0.0%
Ten capacitor elements were completed in the same manner as in Embodiment 1 except that 5 mol / l of p-nitrophenol was added.

The same evaluation as in Embodiment 1 was performed on these, and the results are shown in the above (Table 1).

FIG. 2 shows the relationship between the amount of sodium alkylnaphthalenesulfonate added and the electric conductivity of polypyrrole, depending on whether P-nitrophenol was added or not.

FIG. 2 shows that the electric conductivity when p-nitrophenol was added was clearly higher than that when p-nitrophenol was not added.

From the elemental analysis, it was confirmed that the composition of the obtained polypyrrole was not changed by the addition of p-nitrophenol, so that it was not incorporated as a dopant.

On the other hand, in PEDOT, as in the case of polypyrrole, the improvement in electric conductivity due to the addition of p-nitrophenol was not clearly observed, but the polymerization rate was not so high as to close the pores. It was confirmed that it was further promoted.

Then, as understood from (Table 1),
The capacitor according to the present embodiment has almost the same results as the capacitors according to the first and second embodiments in terms of capacitor characteristics and heat resistance.

Therefore, in the present embodiment, the high capacity achievement ratio, the low loss, and the high frequency impedance characteristics are excellent,
In addition to realizing a high heat-resistant capacitor, adding p-nitrophenol to the polymerization solution
Since the polymerization reaction to EDOT is promoted and the yield increases while maintaining good permeability of PEDOT into the sintered body, it can be said that a capacitor can be realized more efficiently and practically.

In the second to fifth embodiments, the same effect was obtained by adding p-nitrophenol to the polymerization solution in addition to the anionic surfactant.

(Embodiment 7) In this embodiment, p-nitrophenol of Embodiment 6 is replaced with p-nitrophenol.
10 capacitors were added in the same manner as in Embodiment 6 except that cyanophenol (A), m-hydroxybenzoic acid (B), m-hydroxyphenol (C), and m-nitrophenol (D) were added. Completed.

The same evaluation as in Embodiment 1 was performed on these, and the results are shown in the above (Table 1).

As can be understood from Table 1, the capacitor according to the present embodiment also exhibited results similar to the capacitor characteristics and heat resistance of the sixth embodiment.

Therefore, also in the present embodiment, the high capacity achievement ratio, low loss, and excellent high-frequency impedance characteristics are achieved.
It can be said that a capacitor element having high heat resistance was efficiently obtained.

In the second to fifth embodiments, the same effect was obtained by adding the above phenol derivative to the polymerization solution in addition to the anionic surfactant.

(Embodiment 8) This embodiment is the same as Embodiment 1 except that cupric sulfate having the same concentration is used in place of ferric sulfate in Embodiment 1. The 10 capacitor elements thus configured were completed.

The same evaluation as in Embodiment 1 was performed on these, and the results are shown in the above (Table 1).

As can be understood from Table 1, although the capacitor in the present embodiment is slightly inferior to the capacitor characteristics and heat resistance of the first embodiment, the capacitor exhibited practically acceptable results.

Therefore, also in the present embodiment, a high capacity achievement ratio, a low loss, and excellent high-frequency impedance characteristics are achieved.
It can be said that a capacitor element having high heat resistance was efficiently obtained.

[0198] Also in Embodiments 2 to 7, similar effects were obtained by using cupric sulfate instead of ferric sulfate.

(Embodiment 9) In this embodiment, ten capacitors are formed in the same manner as in Embodiment 4, except that polypyrrole is formed by electrolytic polymerization instead of chemical polymerization. Was completed.

For these, the same evaluation as in Embodiment 4 was performed, and the results are shown in the above (Table 1).

Here, the conditions of the electrolytic polymerization of the present embodiment will be described. Pyrrole monomer concentration is 0.25 mol / l,
The concentration of the supporting electrolyte sodium alkylnaphthalenesulfonate was 0.1 mol / l, the element having the PEDOT layer formed was immersed in an aqueous solution containing them, and the stainless steel electrode for electrolytic polymerization was brought into contact with the electrode for electrolytic polymerization. A voltage of 2.5 V was applied between the electrode and the second electrode for electrolytic polymerization provided at a distance, and an electrolytically-polymerized polypyrrole layer was formed via a PEDOT layer.

As can be understood from Table 1, the capacitor according to the present embodiment also exhibited results similar to the capacitor characteristics and heat resistance of the fourth embodiment.

Further, in this embodiment, after the PEDOT layer forming step is performed once, the polypyrrole layer is formed by electrolytic polymerization via the PEDOT layer. As in the case where a layer is formed and this is used as a conductive layer, there is an effect that a capacitor having a small leakage current can be obtained without the need for a chemical conversion treatment for repairing a dielectric film before electrolytic polymerization.

More specifically, the leakage current of the capacitor according to the present embodiment two minutes after application of 10 V was 15 nA on average.

Therefore, also in this embodiment, the high capacity achievement rate, the low loss, and the high frequency impedance characteristics are excellent,
In addition to a capacitor element having high heat resistance, a capacitor having a small leakage current can be obtained.

In the first to third and fifth to eighth embodiments, the same effect was obtained by forming a polypyrrole layer by electrolytic polymerization.

Comparative Example 9 For comparison, as Comparative Example 9, instead of forming a PEDOT layer, a 3% aqueous solution of ammonium adipate was used after immersion in a 30% aqueous manganese nitrate solution and thermal decomposition at 250 ° C. Then, ten capacitors were completed in the same manner as in the ninth embodiment except that the repair formation was performed by applying 40 V at about 70 ° C.

Then, the leakage current was measured in the same manner as in the ninth embodiment, and an average of 37 nA was obtained.

Further, the same evaluation as in Embodiment 9 was performed on these, and the results are shown in (Table 1).

When the above-described ninth embodiment is compared with this comparative example, the comparative example shows that even when the dielectric film is repaired, the capacitor characteristics and the heat resistance are slightly inferior to the ninth embodiment. Has become.

Therefore, in the ninth embodiment, while obtaining a capacitor having high capacity achievement ratio, low loss, excellent high-frequency impedance characteristics and excellent leakage current characteristics, and having high heat resistance,
Furthermore, since there is no need to repair the dielectric film, a practical capacitor that can be manufactured very efficiently has been realized.

Comparative Example 10 For comparison, a ninth embodiment was performed as a comparative example 10 except that sodium perchlorate was used instead of sodium alkylnaphthalenesulfonate in the electrolytic polymerization of polypyrrole in the ninth embodiment. In the same manner as described above, ten capacitors were completed.

With respect to these, the same evaluation as in Embodiment 9 was performed, and the results are shown in (Table 1).

When the above-described ninth embodiment and this comparative example are compared and examined, this comparative example shows that the capacitor characteristics and the heat resistance are far inferior to the ninth embodiment.

[0215] This is because sodium perchlorate does not impart conductivity, does not have bulkiness, and does not act as a surfactant. Therefore, it lacks thermal stability and penetrates the polymerization solution into the etch pits. It is considered that the capacity was not sufficient and the capacity decreased.

Therefore, in the ninth embodiment, by using an aromatic sulfonic acid surfactant such as sodium alkylnaphthalenesulfonate also during electrolytic polymerization, a high capacity achievement ratio, a low loss, a high-frequency impedance characteristic and a leakage current A capacitor having excellent characteristics and high heat resistance was obtained.

(Embodiment 10) This embodiment is the same as Embodiment 9 except that P-nitrophenol is further added to the electrolytic polymerization solution of polypyrrole in an amount of 0.05 mol / l. Thus, ten capacitors were completed.

The same evaluation as in the ninth embodiment was performed on these, and the results are shown in the above (Table 1).

And, as understood from (Table 1),
The capacitor of the present embodiment has more improved results in terms of capacitor characteristics and heat resistance than the capacitor of the ninth embodiment.

It is considered that this is because the initial electric conductivity and environmental stability of the electrolytically-polymerized polypyrrole are further improved by the coexistence of P-nitrophenol.

Therefore, in this embodiment, the high capacity achievement ratio, the low loss, and the high frequency impedance characteristics are excellent,
It can be said that a capacitor with high heat resistance has been realized more remarkably.

Note that, as described in the seventh embodiment, P-
Similar effects were observed when other phenol derivatives were added instead of nitrophenol.

(Embodiment 11) In this embodiment, instead of forming the PEDOT of the embodiment 1 by chemical polymerization, a PEDOT solution doped with polystyrene sulfonate ions, which are sulfonic acid anions ( Concentration 0.
2% by weight), further added with 0.2% of sodium alkylnaphthalenesulfonate, immersed at room temperature for 5 minutes,
Embodiment 1 except that it was formed by drying at 105 ° C. for 15 minutes.
Under the same conditions as above, ten capacitors were completed.

Here, PEDOT doped with polystyrene sulfonate ions was prepared by electrolytic polymerization of EDOT using polystyrene sulfonate as a supporting electrolyte. Alternatively, PEDOT was prepared, for example, in the presence of polystyrene sulfonate in the presence of polystyrene sulfonate. It can be produced by oxidative polymerization of EDOT using an oxidizing agent containing a polyvalent anion such as ferric iron.

Then, the characteristics were evaluated in the same manner as in the first embodiment, and the results are shown in the above (Table 1).

From Table 1, it can be seen that the capacitor of the present embodiment has the same capacitor characteristics and heat resistance as those of the first embodiment.

The reason is that the polystyrene sulfonate ion is bulky, and the alkyl naphthalene sulfonate group obtained from sodium alkyl naphthalene sulfonate which is the aromatic sulfonic acid type surfactant doped in the first embodiment is used. It is considered that it plays a role substantially equivalent to the above.

Therefore, in this embodiment, since a PEDOT polymerized in advance is used, a capacitor having a high capacity achievement ratio, a low loss, a high frequency impedance characteristic, an excellent leakage current characteristic and a high heat resistance can be obtained very easily. It was something that could be done.

In the second to tenth embodiments,
The same effect was obtained by doping a polystyrene sulfonate ion, which is a sulfonate-based anion, into a PEDOT layer using a soluble PEDOT.

In addition, a conductive polymer can be used as a repeating unit using a thiophene derivative represented by (Chemical Formula 2) other than PEDOT if it is a soluble type, and a sulfonic acid other than polystyrene sulfonate can be used if it is bulky. A system anion can also be suitably doped.

(Embodiment 12) In this embodiment, in addition to the laminated conductive polymer layer described in the above embodiment,
Further, it has a configuration in which a third conductive polymer layer is added.

First, in the present embodiment, the PEDOT layer as the first conductive polymer layer and the polypyrrole layer as the second conductive polymer layer are Laminates were sequentially formed on the sintered electrodes.

However, the number of repetitive treatments for forming polypyrrole was limited to three. Then, after immersing in a PEDOT solution (concentration: 0.2% by weight) doped with polystyrene sulfonate ions for 5 minutes at room temperature,
Dry for 5 minutes.

Thereafter, in the same manner as in the first embodiment, a cathode is formed and an epoxy resin outer layer is formed to complete ten tantalum capacitors having a structure in which three layers of PEDOT / polypyrrole / PEDOT are stacked. I let it.

Then, the same characteristics as those of the first embodiment were evaluated, and the results are shown in the above (Table 1).

From Table 1, it can be seen that the capacitor of the present embodiment has the same capacitor characteristics and heat resistance as the two-layered PEDOT layer and polypyrrole layer of the first embodiment and the like. .

Further, in this embodiment, the number of times of chemical polymerization required for forming the polypyrrole layer, that is, the processing time is greatly reduced.

Therefore, in the present embodiment, PED
By adopting a laminated conductive polymer layer having a three-layer structure of an OT layer / polypyrrole layer / PEDOT layer, a capacitor having a high capacity achievement rate, a low loss, a high-frequency impedance characteristic, an excellent leakage current characteristic and a high heat resistance can be obtained. It was obtained efficiently.

In the present embodiment, the PEDOT layer as the first and third conductive polymer layers may be formed by immersion drying, or the polypyrrole layer as the second conductive polymer layer. May be formed by electrolytic polymerization.

Further, instead of the PEDOT layer which is the first or third conductive polymer layer, a conductive polymer layer containing any of the thiophene derivatives shown in the above (Chemical Formula 2) in the repeating unit is used. Alternatively, it is of course possible to appropriately include the configurations and steps in each of the above-described embodiments.

In each of the above embodiments, only the sulfate ion is described as the polyvalent anion. However, a transition metal polyvalent acid salt other than the sulfate may be used so as to be doped with other polyvalent anions. Can also.

In each of the above embodiments, only the case where iron (III) and copper (II) are used as transition metals has been described. However, transitions having an oxidation-reduction potential capable of oxidizing other pyrroles are described. Metals can also be used as well, and the invention is not limited to that type.

Further, in each of the above embodiments, only the case where pyrrole is used as a polymerizable monomer has been described, but a derivative thereof having a substituent may be used.

In the above embodiments, only the case where the valve metal is aluminum or tantalum has been described.
In addition, zirconium, niobium, hafnium and titanium, and their intermetallic compounds can also be used.

[0245]

As described above, in the present invention, first, a laminated conductive polymer layer in which a first layer represented by a PEDOT layer is combined with a second layer represented by a polypyrrole layer having a high polymerization rate. By employing such a capacitor, a capacitor having excellent capacitor characteristics and heat resistance can be manufactured more efficiently in a form suitable for practical use.

By doping a monovalent alkylnaphthalenesulfonate ion or the like into the laminated conductive layer having this structure, not only the yield and electric conductivity of the conductive polymer layer are increased, but also the capacitor characteristics and heat resistance are improved. Can be further improved, especially by using sodium alkylnaphthalenesulfonate which also acts as a surfactant.

Further, if the first layer is formed on the side of the sintered body on which the dielectric film is formed, the first layer penetrates to the deep part of the sintered body on which the dielectric film is formed, and the PED is formed without closing the pores.
By forming the OT layer, the capacitance of the capacitor can be increased.

Further, by adding p-nitrophenol or the like to the polymerization solution, the polymerization reaction of the first layer is promoted, and the yield is increased while maintaining good permeability into the sintered body such as PEDOT. Therefore, a capacitor can be realized more efficiently and practically.

Furthermore, a three-layer laminated conductive polymer layer of a first layer represented by a PEDOT layer / a second layer represented by a polypyrrole layer / a third layer represented by a PEDOT layer is employed. Thus, a capacitor having high capacity achievement ratio, low loss, excellent high-frequency impedance characteristics, and excellent leakage current characteristics and high heat resistance can be efficiently obtained.

Further, the first and third layers are formed by impregnating with a chemical polymerization or a conductive polymer solution, and the second conductive polymer layer is formed by a chemical polymerization or electrolytic polymerization. In addition, a capacitor excellent in heat resistance can be manufactured more efficiently and reliably in a form suitable for practical use.

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between the amount of a surfactant added to a conductive polymer, electric conductivity, and yield in a first embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between the amount of surfactant added to a conductive polymer and the electric conductivity corresponding to the presence or absence of P-nitrophenol in the fifth embodiment.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yasue Matsuya 3-10-1 Higashi Mita, Tama-ku, Kawasaki City, Kanagawa Prefecture Matsushita Giken Co., Ltd.

Claims (38)

[Claims] 1. A pair of electrodes provided to face each other, a dielectric layer provided between the electrodes, and a first layer provided between the electrodes and containing a thiophene derivative represented by the following formula (1) as a repeating unit. And a laminated conductive polymer layer having a second conductive polymer layer containing pyrrole or a derivative thereof as a repeating unit. Embedded image 2. The capacitor according to claim 1, wherein the first conductive polymer layer contains a monovalent anion as a dopant. 3. The capacitor according to claim 2, wherein the first conductive polymer layer further contains a polyvalent anion as a dopant. 4. The capacitor according to claim 1, wherein the second conductive polymer layer contains a monovalent anion as a dopant. 5. The capacitor according to claim 4, wherein the second conductive polymer layer further contains a polyvalent anion as a dopant. 6. The capacitor according to claim 1, wherein the first conductive polymer layer contains a sulfonic acid-based anion as a dopant. 7. The laminated conductive polymer layer according to claim 1, wherein the laminated conductive polymer layer is provided adjacent to the second conductive polymer layer on a side opposite to the first conductive polymer layer. 7. The capacitor according to claim 1, further comprising a third conductive polymer layer containing the thiophene derivative shown in 1) as a repeating unit. 8. The capacitor according to claim 7, wherein the third conductive polymer layer contains a monovalent anion as a dopant. 9. The capacitor according to claim 8, wherein the third conductive polymer layer further contains a polyvalent anion as a dopant. 10. The capacitor according to claim 8, wherein the third conductive polymer layer contains a sulfonic acid-based anion as a dopant. 11. The capacitor according to claim 2, wherein the monovalent anion is a sulfonic acid group. 12. The capacitor according to claim 11, wherein the sulfonic acid groups include those dissociated from an anionic surfactant. 13. The capacitor according to claim 3, wherein the polyvalent anion is a sulfate group. 14. The capacitor according to claim 6, wherein the sulfonic acid-based anion is a polystyrenesulfonic acid ion. 15. The capacitor according to claim 1, wherein the dielectric layer is an oxide film of a valve metal constituting one of the electrodes. 16. The capacitor according to claim 15, wherein the valve metal is aluminum or tantalum. 17. The capacitor according to claim 1, wherein the dielectric layer is a polymer dielectric. 18. The method according to claim 1, wherein the polymer is a polyimide.
7. The capacitor according to 7. 19. The capacitor according to claim 1, wherein the first conductive polymer layer is adjacent to the dielectric layer. 20. The thiophene according to claim 1, wherein a step of arranging a pair of electrodes facing each other, a step of forming a dielectric layer between the electrodes, and a step between the electrodes. A first conductive polymer layer forming step of forming a first conductive polymer layer containing a derivative as a repeating unit by chemical polymerization and a second conductive polymer layer containing pyrrole or a derivative thereof as a repeating unit; A method for manufacturing a capacitor, comprising: a laminated conductive polymer layer forming step having a second conductive polymer layer forming step formed by polymerization. 21. The thiophene according to claim 1, wherein a step of arranging a pair of electrodes facing each other, a step of forming a dielectric layer between the electrodes, and a step between the electrodes. A first conductive polymer layer forming step of forming a first conductive polymer layer containing a derivative as a repeating unit by chemical polymerization, and an electrolysis of a second conductive polymer layer containing pyrrole or a derivative thereof as a repeating unit. A method for manufacturing a capacitor, comprising: a laminated conductive polymer layer forming step having a second conductive polymer layer forming step formed by polymerization. 22. A thiophene according to claim 1, wherein a step of arranging a pair of electrodes facing each other, a step of forming a dielectric layer between the electrodes, and a step between the electrodes. A first conductive polymer layer forming step of impregnating a first conductive polymer layer containing a derivative as a repeating unit with a conductive polymer solution and forming a second conductive polymer layer containing pyrrole or a derivative thereof as a repeating unit A method of forming a laminated conductive polymer layer having a second conductive polymer layer forming step of forming a conductive polymer layer by chemical polymerization. 23. The thiophene according to claim 1, wherein a step of disposing a pair of electrodes facing each other, a step of forming a dielectric layer between the electrodes, and a step between the electrodes. A first conductive polymer layer forming step of impregnating a first conductive polymer layer containing a derivative as a repeating unit with a conductive polymer solution and forming a second conductive polymer layer containing pyrrole or a derivative thereof as a repeating unit A method of forming a laminated conductive polymer layer having a second conductive polymer layer forming step of forming a conductive polymer layer by electrolytic polymerization. 24. The laminated conductive polymer layer forming step further comprises the step of forming the third conductive polymer layer containing the thiophene derivative represented by the formula (1) as a repeating unit in the first conductive polymer layer.
24. The capacitor according to claim 20, further comprising a third conductive polymer layer forming step of forming a third conductive polymer layer adjacent to the second conductive polymer layer on the side opposite to the conductive polymer layer. Production method. 25. The method according to claim 24, wherein the third conductive polymer layer forming step is a step of forming by a chemical polymerization step. 26. The method according to claim 24, wherein the third conductive polymer layer forming step is a step of forming the conductive polymer layer by impregnating the conductive polymer solution. 27. The method according to claim 20, wherein the chemical polymerization step is a chemical polymerization step in an aqueous medium. 28. The method according to claim 27, wherein in the chemical polymerization step, the conductive polymer layer is formed using a solution containing ferric sulfate and an anionic surfactant. 29. The method for producing a capacitor according to claim 28, wherein an anionic surfactant containing an anion having a sulfonic acid group is used. 30. The method of manufacturing a capacitor according to claim 20, wherein in the chemical polymerization step, chemical polymerization is further performed using a solution containing phenol or a derivative thereof. 31. The method according to claim 30, wherein the phenol derivative is nitrophenol, cyanophenol, hydroxybenzoic acid, hydroxyphenol or acetophenol, or a combination thereof. 32. The method according to claim 21, wherein the electrolytic polymerization step is an electrolytic polymerization step in an aqueous medium. 33. The method for manufacturing a capacitor according to claim 21, wherein in the electrolytic polymerization step, electrolytic polymerization is further performed using a solution containing phenol or a derivative thereof. 34. The method according to claim 33, wherein the phenol derivative is nitrophenol, cyanophenol, hydroxybenzoic acid, hydroxyphenol or acetophenol, or a combination thereof. 35. The method for manufacturing a capacitor according to claim 20, wherein in the step of forming a dielectric, the dielectric is formed by anodic oxidation of a valve metal. 36. The method according to claim 20, wherein the valve metal forming one of the electrodes is aluminum or tantalum. 37. The method of manufacturing a capacitor according to claim 20, wherein the dielectric forming step is a spin coating step of forming a dielectric using a polymer. 38. The polymer according to claim 37, wherein the polymer is a polyimide.
A method for manufacturing the capacitor as described in the above.