JP3520688B2 - Capacitor and manufacturing method thereof - Google Patents

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-sized 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 electrical equipment,
Also for capacitors, small capacitors, large capacitors, and low impedance in a high frequency region are required.

Conventionally, capacitors used in the high frequency range include plastic capacitors, mica capacitors, and laminated ceramic capacitors, but these capacitors have a large shape and it is difficult to increase the capacity.

On the other hand, as a large-capacity capacitor, there is an aluminum dry electrolytic capacitor or an electrolytic capacitor such as an aluminum or tantalum solid electrolytic capacitor.

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

[0006] For example, in an aluminum dry capacitor, an etched anode and cathode aluminum foil is wound around a separator, and a liquid electrolyte is impregnated into the separator for use.

Since this liquid electrolyte has ionic conductivity and high specific resistance, it has a problem that loss is large and impedance frequency characteristics and temperature characteristics are extremely poor.

In addition, there is a problem that liquid leakage and evaporation are unavoidable, and the capacity decreases and the loss increases with the passage of time.

Further, in the tantalum solid electrolytic capacitor,
Since manganese oxide is used as an electrolyte, the problems of temperature characteristics and changes in capacity, loss, etc. over time are improved, but since the specific resistance of manganese oxide is relatively high, the frequency characteristics of loss and impedance are It was inferior to ceramic capacitors or film capacitors.

Further, in the tantalum solid electrolytic capacitor, in forming the electrolyte made of manganese oxide, the step of immersing it in a manganese nitrate solution and then thermally decomposing it at a temperature of about 300 ° C. is repeated several times to ten or more times. It was necessary and the forming process was complicated in the first place.

Further, in the tantalum solid electrolytic capacitor, since an electrolyte made of manganese oxide is repeatedly formed by thermal decomposition, it is necessary to carry out chemical conversion each time in order to repair the film damage that has occurred. Since then, the process has become complicated.

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

Further, there has been proposed a solid electrolytic capacitor formed by chemically polymerizing a conductive polymer polythiophene having a substituent at the 3- and 4-positions (Japanese Patent Publication No. 2-15).
No. 611).

Furthermore, a large-capacity film capacitor in which a conductive polymer layer is sequentially formed by chemical polymerization and electrolytic polymerization after forming a dielectric made of an electrodeposited polyimide thin film on an etched aluminum foil to form an electrode. Has been proposed (Abstracts of the 58th Conference of the Electrochemical Society of Japan, pp. 251-252 (1991)).

[0015]

However, in the case of forming an electrolytically polymerized polymer through a conductive pyrolytic metal oxide such as manganese oxide in a solid electrolytic capacitor, the dielectric film formed by heat is used. Since damage occurs, in order to obtain a high withstand voltage capacitor, it is also necessary to perform chemical conversion again before electrolytic polymerization and repair it, which further complicates the process.

In addition, when a conductive polymer layer is formed by chemical polymerization with polypyrrole, since it has a high polymerization rate at around room temperature, it penetrates deep into the pores of the etched aluminum foil or tantalum sintered body, which is one of the electrodes. As a result of polymerization during the process, the etch pits and the pores of the sintered body were partially blocked, and it was difficult to form a conductive polymer layer having a high filling rate.

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

Although this problem can be solved by reducing the concentration of the pyrrole monomer, a new problem arises that the number of times of polymerization required for coating is increased.

Furthermore, when the polypyrrole layer is formed by chemical polymerization, a powdery polymer is obtained, and the coating property of the edge portion on the surface and inside of the capacitor electrode is poor, and the polymerization time for complete coating is long. It was also an issue.

On the other hand, in the case of electropolymerized polypyrrole,
Since a film-shaped polymer is obtained, such a problem does not occur, but on the other hand, there is a problem that a film having a high coverage cannot be formed unless conductivity is given to the surface of the dielectric.

Furthermore, when a polythiophene having a substituent at the 3- and 4-positions is formed by chemical polymerization, it takes a long time for the polymerization because the polymerization rate is slow, or the polymerization time is shortened in order to shorten the polymerization time. It was necessary to raise the temperature.

Further, when the polymerization temperature is raised, the activating effect of the oxidizing agent becomes strong, and there is a problem that the dielectric film is damaged.

The present invention solves each of the problems in the prior art described above. It is possible to easily obtain a solid electrolytic capacitor having a high capacity achievement rate, high capacitor characteristics, and high heat resistance and humidity resistance, and a small size, large capacity, and high capacity. The purpose is to easily obtain a film capacitor having an achievement rate, high capacitor characteristics, and high heat and humidity resistance.

[0024]

The capacitor of the present invention comprises:
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. A layer and a laminated conductive polymer layer having a second conductive polymer layer containing pyrrole or a derivative thereof as a repeating unit, and the laminated conductive polymer layer further comprises:
The second conductive polymer layer on the opposite side of the first conductive polymer layer.
It is provided so as to be adjacent to the child layer and is shown in the following (Chemical formula 2).
Third conductivity containing a thiophene derivative as a repeating unit
It is a structure including a hydrophilic polymer layer .

[0025]

[Chemical 2]

This thiophene derivative is, for example, 3,4
-Reacting an alkali metal salt of dihydroxythiophene-2,5-dicarboxylic acid ester with a suitable alkylene-vic-dihalide, followed by hydrolysis to give 3,4 (alkylene-vic-dioxy) thiophene-2,5-carboxylic acid. It can be obtained by decarboxylating this (Polymer magazine, Vol. 35, No. 7 (1994).
1347 pages, Tetrahedron magazine, 23 volumes (1
967) 2437 p. Am. Chem. So
c. Vol. 67 (1945), page 2217).

The method of manufacturing the capacitor of the present invention is
Such a capacitor can be suitably manufactured, and particularly, as a laminated conductive polymer layer forming step for laminating the first conductive polymer layer and the second conductive polymer layer, And a second conductive polymer layer forming step of forming a second conductive polymer layer by chemical polymerization. A first conductive polymer layer forming step and a second conductive polymer which are formed by performing the conductive polymer layer forming step or impregnating the first conductive polymer layer with a conductive polymer solution. Performing a laminated conductive polymer layer forming step having a second conductive polymer layer forming step of forming a layer by chemical polymerization, or impregnating the first conductive polymer layer with a conductive polymer solution. Forming a first conductive polymer layer and a second conductive polymer layer And it has a configuration to execute a laminated conductive polymer layer formation step having a second conductive polymer layer formation step of forming a depolymerization.

With the above structure, it is possible to easily obtain a solid electrolytic capacitor having a high capacity achievement rate, a high capacitor characteristic and a high heat resistance and humidity resistance, and a small and large capacity, a high capacity achievement rate, a high capacitor characteristic, a high heat resistance and humidity resistance. The film capacitor can be easily obtained.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention according to claim 1 is provided with a pair of electrodes facing each other, a dielectric layer provided between the electrodes, and a space provided between the electrodes. 2)
First containing the thiophene derivative shown in
And a conductive polymer layer and pyrrole or multilayer electrically conductive polymer layer having a second conductive polymer layer containing the derivative as a repeating unit, further, the laminated conductive high content
A child layer is provided on the opposite side of the first conductive polymer layer.
It is provided so as to be adjacent to the second conductive polymer layer,
Using the thiophene derivative shown in Chemical formula 2 as a repeating unit
And a third conductive polymer layer included therein .

As described above, the laminated conductive polymer layer functions as an electrolyte that also functions as a true cathode in a capacitor whose dielectric is composed of an oxide film of a valve metal, while it is composed 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 and the like obtained from alpha olephene, and further 1, It may be a 2-cyclohexene, 2,3-butylene, 2,3-dimethylene 2,3-butylene, 2,3-pentylene group or the like. However, preferred examples are methylene, 1,
Examples include 2-ethylene and 1,2-propylene groups.

With such a structure, the capacitor characteristics and heat resistance are improved. Furthermore, 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 increased. 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, and as described in claim 10 , the monovalent anion is: It is preferably a sulfonic acid group.

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

Here, as described in claim 11 , it is preferable that the sulfonic acid group contains the sulfonic acid group dissociated from the anionic surfactant, and the capacitor property and heat resistance are further improved by the surfactant action. .

Further, as described in claim 12 , 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 oxidant, and 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 or the like can be used.

On the other hand, as described in claim 6, the first electroconductive polymer layer may contain a sulfonic acid type anion as a dopant, and as described in claim 13 , the sulfonic acid type anion is The polystyrene sulfonate ion is preferred.

Even with such a structure, the capacitor characteristics and heat resistance are improved. Further, as described in claim 4, it is preferable that the second conductive polymer layer also contains a monovalent anion as a dopant, and the capacitor characteristics and heat resistance are improved.

As described in claim 5, the second conductive polymer layer may further contain a polyvalent anion as a dopant, and as described in claim 10 , the monovalent anion is It is preferably a sulfonic acid group.

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

Here, as described in claim 11 , it is preferable that the sulfonic acid group contains a sulfonic acid group dissociated from the anionic surfactant, and the capacitor characteristics and heat resistance are further improved by the surfactant action. .

Further, as described in claim 12 , the polyvalent anion may be a sulfate group. Furthermore, the product layer conductive polymer layer, a second side opposite the first conductive polymer layer
The third conductive polymer layer may be provided so as to be adjacent to the conductive polymer layer, and the conductive polymer layer may include a third conductive polymer layer containing the thiophene derivative shown in Chemical formula 2 as a repeating unit.

[0044] The third conductive polymer layer, similarly to the first conductive polymer, as described in claim 7, comprises a monovalent anion as a dopant, as described in claim 8 , the third conductive polymer layer further may comprise a polyvalent anion as a dopant, as described in claim 10, monovalent anion, a sulfonate group, claim 11
It is preferable that the sulfonic acid group contains a group dissociated from an anionic surfactant, as described in 1.

Further, as described in claim 12 , the polyvalent anion may be a sulfate group. On the other hand, as described in claim 9 , the third conductive polymer layer may contain a sulfonic acid type anion as a dopant, and as described in claim 13 , the sulfonic acid type anion is polystyrene sulfonic acid. It may be an ion.

And in the above-mentioned constitution, claim 14
As described, the dielectric layer may be an oxide film of the valve metal constituting one of the electrodes, as described in claim 15, the valve metal include aluminum and tantalum.

On the other hand, as described in claim 16 , the dielectric layer may be a polymer dielectric, and as described in claim 17 , the polymer may be polyimide.

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

The present invention concerning a method of manufacturing a capacitor includes the step of disposing a pair of electrodes facing each other according to claim 19 , and the step of forming a dielectric layer between the electrodes. Between the electrodes, the first conductive polymer layer forming step of forming a first conductive polymer layer containing the thiophene derivative represented by the above (Chemical Formula 2) as a repeating unit by chemical polymerization, and pyrrole or its derivative And a laminated conductive polymer layer forming step including a second conductive polymer layer forming step of forming a second conductive polymer layer containing a repeating unit by chemical polymerization.

[0050]

Alternatively, as described in claim 20 , a step of disposing 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 are as described above. A first conductive polymer layer-forming step of forming a first conductive polymer layer containing a thiophene derivative shown in Chemical formula 2) as a repeating unit in a conductive polymer solution, and a repeating unit of pyrrole or a derivative thereof. 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 21 , a step of disposing a pair of electrodes facing each other, a step of forming a dielectric layer between the electrodes, and a step of forming the dielectric layer between the electrodes are the same as those described above. A first conductive polymer layer-forming step of forming a first conductive polymer layer containing a thiophene derivative shown in Chemical formula 2) as a repeating unit in a conductive polymer solution, and a repeating unit of pyrrole or a derivative thereof. 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.

By any of these manufacturing methods,
The 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 slower polymerization rate than that of pyrrole, it penetrates deep into the pores of the capacitor using the etched foil or the porous sintered body electrode. Since it is post-polymerized, a capacitor having a higher capacity achievement rate can be easily obtained as compared with the case where polypyrrole is formed alone.

In addition, in the case where 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.

When the manganese oxide layer is formed by thermal decomposition, a solid electrolytic capacitor having a low leakage current can be easily obtained even if the repair chemical conversion treatment required for each of the repeated thermal decomposition treatments is omitted. .

Further, as described in claim 22 , in the laminated conductive polymer layer forming step, the third conductive polymer layer containing the thiophene derivative represented by the above (formula 2) as a repeating unit A second layer on the opposite side of the first conductive polymer layer
The third conductive polymer layer forming step of forming the conductive polymer layer adjacent to the conductive polymer layer may be included.

With this structure, the laminated conductive polymer layer including the third conductive polymer layer can be surely formed,
The characteristics and heat resistance of the capacitor are improved.

The third conductive polymer layer forming step may be a step of forming by a chemical polymerization step as described in claim 23 , or as described in claim 24 , conductive layer It may be a step of forming by impregnating with a polymer solution.

With such a structure, 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 prepared by a solution impregnation method, especially when the inner polypyrrole layer is formed by chemical polymerization.

Here, the above chemical polymerization step is carried out according to claim 2.
It is preferable that it is a chemical polymerization process in an aqueous medium as described in 5, and as described in claim 26 , the chemical polymerization process includes ferric sulfate and an anionic surfactant. It is preferable to form the conductive polymer layer using a solution.

As described above, when nontoxic and nonflammable water is used as the polymerization medium, the production process can be easily constructed.

Further, by incorporating the iron surfactant into the thiophene derivative polymerization solution represented by the above (Chemical Formula 2), the wettability of the polymerization solution on the surface of the capacitor electrode element is improved and the high coverage is obtained. The conductive polymer can be formed to realize a high-capacity capacitor.

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 polymerize on the surface, which causes excessive reaction. It is suitable because it has the effect of promoting polymerization, which tends to be slow.

Furthermore, since an anionic surfactant is used as the surfactant, the monovalent anion dissociated from the anionic surfactant is used as the oxidant of the transition metal polyvalent acid salt used as the oxidizing agent in the polymerized conductive polymer. It is competitively incorporated with polyvalent anions.

The anion of the anionic surfactant contains a hydrophobic group and has a large ion size. However, due to this large ion size dopant,
Dedoping due to diffusion at high temperature or high humidity is suppressed,
As a result, a conductive polymer having a repeating unit of the thiophene derivative with less deterioration of conductivity is formed, and this effect is also exhibited in the case of polypyrrole, which is excellent in heat resistance and humidity resistance. A capacitor is obtained.

Since the anion of the surfactant is monovalent, it is more likely to be incorporated as a dopant into the conductive polymer composed of the thiophene derivative and pyrrole than the polyvalent anion generated from the oxidizing agent.

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

The electric conductivity and stability of the conductive polymer having the dopant tend to be improved as the doping ratio of the surfactant-based monovalent anion having a large molecular size is increased.

Therefore, as compared with the case of using a conductive polymer polymerized with a transition metal polyvalent acid salt or the case of using manganese dioxide, it is easy to form a capacitor having significantly improved high frequency characteristics and loss characteristics. Can be obtained.

Further, as described in claim 27 , it is preferable to use an anionic surfactant containing an anion having a sulfonic acid group.

[0073] Then, as described in claim 28, the chemical polymerization process, may additionally be a chemical polymerization using a solution containing a phenol or a derivative thereof, as claimed in claim 29, phenol derivative It may be nitrophenol, cyanophenol, hydroxybenzoic acid, hydroxyphenol or acetophenol, or a combination thereof.

Thus, by adding phenol or its derivative, the electrical conductivity and stability of the conductive polymer obtained from the thiophene derivative and / or pyrrole are improved.
To improve.

This is because the phenolic compound is not incorporated as a dopant in the above-mentioned both conductive polymers.
This is thought to be due to the formation of a conducting polymer with a high degree of regularity and therefore a conjugation length. As a result, the initial characteristics and stability of capacitors using polypyrrole obtained from a polymerization system with a phenol derivative added This is because the sex is further improved.

The above electropolymerization step is carried out according to claim 30.
It is preferable that the electropolymerization step is carried out in an aqueous medium as described in 1., and as in claim 31 , in the electropolymerization step, a solution containing phenol or a derivative thereof is added in the same manner as the chemical polymerization. It may be used for electropolymerization and the phenol derivative may be nitrophenol, cyanophenol, hydroxybenzoic acid, hydroxyphenol or acetophenol, or a combination thereof, as claimed in claim 32 .

According to the above method of manufacturing a capacitor, as described in claim 33 , the dielectric forming step includes:
The dielectric may be formed by anodic oxidation of the valve metal, and the valve metal forming one of the electrodes may be aluminum or tantalum as described in claim 34 .

On the other hand, as described in claim 35 , the dielectric forming step may be a spin coating step of forming a dielectric by using a polymer, and as described in claim 36 ,
The polymer may be polyimide.

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

When this structure was regarded as a capacitor and the capacity in the chemical conversion liquid was measured, it was 18.0 μF.

Further, using this constitution, ethylenedioxythiophene (EDOT) 0.1 mol / l and sodium alkylnaphthalene sulfonate (average molecular weight 338) 0.75 wt% which is an aromatic sulfonic acid type surfactant.
Was immersed in an aqueous monomer solution of 45 ° C. for 5 minutes and then immersed in an oxidizing agent solution containing ferric sulfate 0.75 mol / l at 65 ° C. for 60 minutes.

Here, as the EDOT, the one commercially available from Bayer AG of Germany was used, but the EDOT may be synthesized by a general production method.

By this treatment, a conductive layer made of polyethylenedioxythiophene (PEDOT) doped with divalent sulfate ions and monovalent alkylnaphthalene sulfonate ions was added to the tantalum sintered body having a dielectric film formed thereon. Formed on.

Here, FIG. 1 shows changes in the yield and electrical conductivity of PEDOT obtained when the amount of sodium alkylnaphthalene sulfonate added was changed.

As shown in FIG. 1, by gradually adding this sodium alkylnaphthalene sulfonate, the yield and electrical conductivity of PEDOT are increased.

It is considered that this is due to the fact that PEDOT was doped with monovalent alkylnaphthalene sulfonate ions.

On the other hand, when the sulfonate having no surface activity was added, the yield of PEDOT and the electric conductivity did not increase remarkably up to this point.

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

It was confirmed from the elemental analysis that the polymerization product did not substantially contain iron.

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

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

Also with respect to this polypyrrole, the surfactant and sodium alkylnaphthalene sulfonate are not added at all, and by gradually adding it, the yield and the electric conductivity are increased.

It is considered that this is due to the fact that polypyrrole is doped with monovalent alkylnaphthalenesulfonate ion.

On the other hand, when the 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 function also had an effect of accelerating the polymerization rate and increasing the yield of polypyrrole.

From the elemental analysis, iron was not substantially contained in this polymerization product.

Then, on the tantalum sintered body on which the polypyrrole layer was formed as described above, a cathode was formed with a carbon layer and a silver paint layer, and a cathode lead was attached on the cathode to form a total of 10 capacitor elements. Obtained.

Further, the device was packaged with an epoxy resin and further subjected to an aging treatment at 13 ° C. with 13 V applied to complete a capacitor.

For these 10 elements, the capacitance at 1 kHz, the loss factor, and the impedance at 400 kHz were measured, and the rate of change in capacitance and loss factor after a load heat resistance test conducted at 10 ° C. at 125 ° C. were measured. However, the average value thereof is shown in (Table 1) below.

[0100]

[Table 1]

(Embodiment 2) In this embodiment, instead of PEDOT in Embodiment 1, a conductive polymer poly (3,3) similarly containing a thiophene derivative represented by the following (Chem. 2) as a repeating unit is used. Ten capacitor elements configured in the same manner as in Embodiment 1 were completed except that 4- (1,2-propylene) dioxythiophene) (PPDOT) was used.

With respect to these 10 elements, the capacitance at 1 kHz, the loss coefficient, and the 4
The impedance at 00 kHz and the rate of change in capacity and loss coefficient after a load heat resistance test performed by applying 10 V at 125 ° C. were each measured, and the average values thereof are shown in the above (Table 1).

As can be seen from Table 1, this embodiment can also realize the same capacitor characteristics and heat resistance as those of the first embodiment.

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

As described above, also in the present embodiment, it was possible to efficiently obtain a capacitor having a high capacity achievement rate, a low loss, a high frequency impedance characteristic, and a high heat resistance.

Similar results were obtained for the other thiophene derivatives shown in the chemical formula 2 above.

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

However, the number of repetitions required to form the PEDOT layer was 30 times. As for the ten elements, the capacitance at 1 kHz, as in the first embodiment,
Loss factor and impedance at 400 kHz,
Further, the rate of change in capacity and the loss coefficient after a load heat resistance test performed by applying 10 V at 125 ° C. were measured, and the average values thereof are shown in (Table 1) above.

Examining the results of the first embodiment and this comparative example, although the capacitor characteristics and heat resistance were equivalent to each other, a large number of repetitions were required to form the PEDOT layer as the conductive layer.

That is, in order to secure the same characteristics and durability as those of the first embodiment, a longer conductive layer formation time is required, resulting in a very long process holding time, which is not practical. I understand.

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

Comparative Example 2 Next, for comparison, Comparative Example 2
As a result, 10 capacitors were completed under the same conditions as in Embodiment 1 except that sodium alkylnaphthalene sulfonate was not added.

As for the ten elements, the capacitance at 1 kHz, the loss coefficient, and the 4
The impedance at 00 kHz and the rate of change in capacity and loss coefficient after a load heat resistance test performed by applying 10 V at 125 ° C. were each measured, and the average values thereof are shown in the above (Table 1).

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

It is considered that, first of all, although the PEDOT layer and the polypyrrole layer were formed, neither was the bulky monovalent alkylnaphthalene sulfonate ion originally doped.

Furthermore, in the case of the first embodiment, since sodium alkylnaphthalene sulfonate which also acts as a surfactant is used, in this comparative example which does not use it, the capacitor characteristics and heat resistance are further improved. It is considered that there was a significant difference.

Furthermore, in the case of this comparative example, since sodium alkylnaphthalene sulfonate acting as a surfactant was not used, the PEDOT layer, in particular, the state formed on the dielectric surface can be visually observed. It is considered that the formation of the PEDOT layer was not sufficient to improve the capacitor characteristics and heat resistance, which is also an influence.

From the above, the PED was obtained by doping the laminated conductive layer with monovalent alkylnaphthalenesulfonate ion.
Not only does the yield and electrical conductivity of the OT layer increase,
It was found that the capacitor characteristics and heat resistance were improved, and in particular, by using sodium alkylnaphthalene sulfonate which also acts as a surfactant, it was possible to further improve them.

Comparative Example 3 Next, for comparison, Comparative Example 3
As a result, only the polypyrrole layer was formed under the same conditions as in Embodiment 1 except that the PEDOT layer was not formed, and 10 capacitors were completed.

As for the ten elements, the capacitance at 1 kHz, the loss coefficient, and the 4
The impedance at 00 kHz and the rate of change in capacity and loss coefficient after a load heat resistance test performed by applying 10 V at 125 ° C. were each measured, and the average values thereof are shown in the above (Table 1).

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

It is considered that this is because the polymerization rate of polypyrrole is high, so that the polypyrrole is polymerized to form polypyrrole before the monomer reaches the deep part of the pores of the sintered body, and the pores are partially blocked. .

On the other hand, in the first embodiment, the surface active agent sodium alkylnaphthalene sulfonate is applied to the EDOT monomer solution to increase the polymerization rate of EDOT. Since the polymerization rate is moderately slow, it penetrates deeper into the sintered body where the dielectric film is formed, and PEDOT without blocking the pores.
Therefore, it is considered that a larger capacitor capacity is achieved.

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

From the comparison results of the above-described first embodiment and Comparative Examples 1 to 3, in the first embodiment, by first adopting the 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 could be efficiently manufactured in a form suitable for practical use.

By doping a monovalent alkylnaphthalene sulfonate ion into the laminated conductive layer having this structure, not only the yield and electrical conductivity of the PEDOT layer etc. are increased, but also the capacitor characteristics and heat resistance are improved. In particular, the use of sodium alkylnaphthalene sulfonate, which also acts as a surfactant, further improves them.

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 to the deep part of the sintered body on which the dielectric film is formed, and the PEDOT layer is formed without blocking the pores. As a result, the capacitor capacity can be increased.

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

If this is a conductive polymer containing a thiophene derivative represented by the chemical formula 2 as a repeating unit,
It is considered that the same effect is exerted from an aromatic sulfonic acid type surfactant or the like.

(Embodiment 3) In the present embodiment, sodium dodecylbenzene sulfonate, which is also an aromatic sulfonic acid type surfactant, is used instead of sodium alkylnaphthalene sulfonate in the first embodiment. Except for the above, 10 capacitor elements configured in the same manner as in Embodiment 1 were completed.

As for the ten elements, the capacitance at 1 kHz, the loss coefficient, and the 4
The impedance at 00 kHz and the rate of change in capacity and loss coefficient after a load heat resistance test performed by applying 10 V at 125 ° C. were each measured, and the average values thereof are shown in the above (Table 1).

As can be seen from Table 1, this embodiment can also realize the same capacitor characteristics and heat resistance as those of the first embodiment.

This is also the case with this embodiment.
It has a laminated conductive layer of a T layer and a polypyrrole layer, and sodium dodecylbenzene sulfonate is also doped with PEDOT and polypyrrole in such a form that its bulky monovalent sulfonate anion partially replaces the divalent sulfate ion. And
This is because it also has a function as a surfactant.

As described above, also in the present embodiment, it is possible to efficiently obtain a capacitor having a high capacity achievement rate, a low loss, a high frequency impedance characteristic, and a high heat resistance.

The above results were also confirmed for each conductive polymer shown 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 in place of the tantalum sintered body of Embodiment 1.
Completed 0 capacitors and evaluated the same characteristics,
The results are shown in (Table 1) above.

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

Here, the concrete production of the etched aluminum electrode foil was carried out as follows. First, 4 x 10 mm
A polyimide tape having a width of 1 mm was attached to both sides of the etched aluminum foil of No. ² so as to be divided into 3 mm and 6 mm portions.

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

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

Also in this embodiment, when PEDOT is replaced by each conductive polymer shown in Embodiment 2, and sodium alkylnaphthalenesulfonate is replaced by sodium dodecylbenzenesulfonate. Similar results were obtained in these cases.

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

However, the number of repetitions required to form the PEDOT layer was 27 times. As for the ten elements, the capacitance at 1 kHz, as in the fourth embodiment,
Loss factor and impedance at 400 kHz,
Further, the rate of change in capacity and the loss coefficient after a load heat resistance test performed by applying 10 V at 125 ° C. were measured, and the average values thereof are shown in (Table 1) above.

Examining the results of the fourth embodiment and this comparative example, although the capacitor characteristics and heat resistance were equivalent to each other, a large number of repetitions were required to form the PEDOT layer as the conductive layer.

That is, in order to secure the same characteristics and durability as those of the fourth embodiment, a longer conductive layer formation time is required, resulting in a very long process holding time, which is not practical. I understand.

From the above, by adopting the laminated conductive layer in which the PEDOT layer and the polypyrrole layer are combined,
It has been found that a capacitor having excellent capacitor characteristics and heat resistance can be practically manufactured.

Comparative Example 5 Next, for comparison, Comparative Example 5
As a result, 10 capacitors were completed under the same conditions as in Embodiment 4 except that sodium alkylnaphthalene sulfonate was not added.

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

Examination of the results of the fourth embodiment and this comparative example revealed that the capacitor characteristics and heat resistance were extremely low in this comparative example.

This is probably because, first of all, although the PEDOT layer and the polypyrrole layer were formed, neither was the bulky monovalent alkylnaphthalene sulfonate ion doped in the first place.

Further, in the case of Embodiment 4, since sodium alkylnaphthalene sulfonate which also acts as a surfactant is used, in this comparative example which does not use it, the capacitor characteristics and heat resistance are further improved. It is considered that there was a significant difference.

Further, in the case of this comparative example, since sodium alkylnaphthalene sulfonate acting as a surfactant was not used, the PEDOT layer, in particular, the state formed on the dielectric surface can be visually observed. It is considered that the formation of the PEDOT layer to the extent that the PEDOT layer was not sufficiently formed to improve the capacitor characteristics and the heat resistance was also affected.

From the above, the PED can be obtained by doping the laminated conductive layer with monovalent alkylnaphthalenesulfonate ion.
Not only does the yield and electrical conductivity of the OT layer increase,
It was found that the capacitor characteristics and heat resistance were improved, and in particular, by using sodium alkylnaphthalene sulfonate which also acts as a surfactant, it was possible to further improve them.

(Comparative Example 6) Next, for comparison, Comparative Example 6
As a result, 10 capacitors were completed by forming only a polypyrrole layer under the same conditions as in Embodiment 4 except that the PEDOT layer was not formed.

As for the ten elements, the capacitance at 1 kHz, the loss coefficient, and the 4
The impedance at 00 kHz and the rate of change in capacity and loss coefficient after a load heat resistance test performed by applying 10 V at 125 ° C. were each measured, and the average values thereof are shown in the above (Table 1).

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

This is probably because the polymerization rate of polypyrrole is high, so that the polypyrrole is polymerized to form polypyrrole before the monomer reaches the deep part of the pores of the sintered body, thus blocking some of the pores. .

On the other hand, in the fourth embodiment, although the surfactant sodium alkylnaphthalene sulfonate is applied to the EDOT monomer solution to increase the polymerization rate of EDOT, it is compared with pyrrole. For example, because the polymerization rate is moderately slow, it penetrates deeper into the sintered body where the dielectric film is formed, and PEDOT without blocking the pores.
Therefore, it is considered that a larger capacitor capacity is achieved.

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

From the comparison results of the above-mentioned Embodiment 4 and Comparative Examples 4 to 6, in Embodiment 4, first, by adopting the 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 could be efficiently manufactured in a form suitable for practical use.

Then, the laminated conductive layer is doped with monovalent alkylnaphthalene sulfonate ions to obtain PEDO.
Not only the yield and electric conductivity of the T layer and the like are increased, but also the capacitor characteristics and heat resistance are improved, and in particular, by using sodium alkylnaphthalene sulfonate which also acts as a surfactant, those further improved. Is.

Further, when the PEDOT layer is formed on the side of the etched foil having the dielectric film formed thereon, the PEDOT layer is formed in good contact with the etched foil having the dielectric film formed thereon to increase the capacitance of the capacitor. I was able to do it.

(Embodiment 5) In this embodiment, in the structure of Embodiment 4, an aluminum smooth foil of 20 mm × 20 mm is used instead of the etched aluminum foil.
In addition, substantially the same as the third embodiment except that an electrode having a polyimide dielectric layer made of a polyimide thin film having a thickness of 0.5 μm formed on one surface by spin coating is used instead of forming an oxide film dielectric. Under the same conditions, a total of 10 capacitors were manufactured.

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

Also in this embodiment, when the conductive polymer shown in the second embodiment is used instead of PEDOT,
Similar results were obtained when sodium dodecylbenzenesulfonate was used instead of sodium alkylnaphthalenesulfonate.

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

However, the number of repetitions required to form the PEDOT layer was 22 times. As for the ten elements, the capacitance at 1 kHz, as in the fifth embodiment,
Loss factor and impedance at 400 kHz,
Further, the rate of change in capacity and the loss coefficient after a load heat resistance test performed by applying 10 V at 125 ° C. were measured, and the average values thereof are shown in (Table 1) above.

Examining the results of the fifth embodiment and this comparative example, although the capacitor characteristics and the heat resistance were equivalent to each other, a large number of repetitions were required to form the PEDOT layer as the conductive layer.

That is, in order to secure the characteristics and durability equivalent to those of the fifth embodiment, a longer conductive layer formation time is required, resulting in an extremely long process holding time, which is not practical. I understand.

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

Comparative Example 8 Next, for comparison, Comparative Example 8
As a result, 10 capacitors were completed under the same conditions as in Embodiment 5 except that sodium alkylnaphthalene sulfonate was not added.

As for the ten elements, the capacitance at 1 kHz, the loss coefficient, and the 4
The impedance at 00 kHz and the rate of change in capacity and loss coefficient after a load heat resistance test performed by applying 10 V at 125 ° C. were each measured, and the average values thereof are shown in the above (Table 1).

When the results of Embodiment 5 and this comparative example were examined, the heat resistance of the capacitor was extremely low in this comparative example.

This is because the PEDOT layer and the polypyrrole layer were formed, but the bulky monovalent alkylnaphthalene sulfonate ion was not doped in the first place and the polypyrrole layer having low heat resistance was formed. It is thought to be due to this.

As described above, by doping the laminated conductive layer with monovalent alkylnaphthalenesulfonate ion, the PED
Not only the yield and electrical conductivity of the OT layer and the like are increased, but also the heat resistance is improved, so that the heat resistance of the capacitor is improved, and in particular, by using sodium alkylnaphthalenesulfonate which also acts as a surfactant, It turned out that it could be improved further.

From the comparison results of the fifth embodiment and the comparative examples 7 and 8, in the fifth embodiment, the laminated conductive layer containing PEDOT and polypyrrole is first employed, that is, the polypyrrole having a high polymerization rate is used. By combining the layers, it was possible to more efficiently manufacture a capacitor having excellent capacitor characteristics and heat resistance in a form suitable for practical use.

Then, by doping the laminated conductive layer with monovalent alkylnaphthalenesulfonate ion, PEDO
Not only the yield and electric conductivity of the T layer and the like are increased, but also the capacitor characteristics and heat resistance are improved, and in particular, by using sodium alkylnaphthalene sulfonate which also acts as a surfactant, those further improved. Is.

Although the case where polyimide is used as the polymer serving as the dielectric has been described, any material other than polyimide may be used as long as it is a polymer material for the dielectric capable of forming a thin film.

The case where a polyimide film serving as a dielectric is formed on an aluminum smooth 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
The polymer dielectric can be applied also in.

(Embodiment 6) In the present embodiment, in the structure of Embodiment 1, the oxidizer solution is further added with 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.

These were evaluated in the same manner as in Embodiment 1, and the results are shown in (Table 1) above.

Here, FIG. 2 shows the relationship between the electrical conductivity of polypyrrole and the amount of sodium alkylnaphthalene sulfonate added with and without the addition of P-nitrophenol.

From FIG. 2, it can be seen that the electric conductivity when p-nitrophenol is added is obviously higher than that when p-nitrophenol is not added.

From the elemental analysis, it was confirmed that the polypyrrole obtained by addition of p-nitrophenol did not change in composition, and therefore it was not incorporated as a dopant.

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

And, as can be understood from (Table 1),
The capacitor of the present embodiment has substantially the same results as the capacitors of Embodiments 1 and 2 in the capacitor characteristics and heat resistance.

Therefore, in this embodiment, the high capacity achievement rate, the low loss and the high frequency impedance characteristics are excellent,
Not only can a capacitor with high heat resistance be realized, but by adding p-nitrophenol to the polymerization solution, P
It can be said that the capacitor was able to be realized more efficiently and practically because the polymerization reaction to EDOT was promoted and the yield increased while maintaining good permeability of PEDOT into the sintered body.

Also in Embodiments 2 to 5, the same effect was obtained by adding p-nitrophenol to the polymerization solution in addition to the anionic surfactant.

(Embodiment 7) In the present embodiment, p-nitrophenol is replaced by p-nitrophenol of Embodiment 6.
10 capacitors were prepared 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

These were evaluated in the same manner as in Embodiment 1, and the results are shown in (Table 1) above.

As can be seen from (Table 1), the capacitor according to the present embodiment also showed the same results as the capacitor characteristics and heat resistance of the sixth embodiment.

Therefore, also in this embodiment, the high capacity achievement rate, the low loss and the high frequency impedance characteristics are excellent,
It can be said that the capacitor element having high heat resistance could be efficiently obtained.

Also in Embodiments 2 to 5, 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 in Embodiment 1, cupric sulfate having the same concentration is used instead of ferric sulfate. The constructed 10 capacitor elements were completed.

These were evaluated in the same manner as in Embodiment 1, and the results are shown in (Table 1) above.

As can be seen from (Table 1), the capacitor according to the present embodiment also exhibited practically acceptable results, although it was slightly inferior to the capacitor characteristics and heat resistance of the first embodiment.

Therefore, also in this embodiment, the high capacity achievement rate, the low loss and the high frequency impedance characteristics are excellent,
It can be said that the capacitor element having high heat resistance could be efficiently obtained.

In Embodiments 2 to 7 as well, the same effect was obtained by using cupric sulfate instead of ferric sulfate.

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

The same evaluation as in Embodiment 4 was carried out on these, and the results are shown in (Table 1) above.

Here, the conditions of the electrolytic polymerization of this embodiment are shown. Pyrrole monomer concentration is 0.25 mol / l,
The concentration of the supporting electrolyte sodium alkylnaphthalene sulfonate was 0.1 mol / l, the element on which the PEDOT layer was formed was immersed in an aqueous solution containing these, and the electrode for electrolytic polymerization made of stainless steel was brought into contact with the electrode for electrolytic polymerization. A voltage of 2.5 V was applied between the second electrode and the second electrode for electrolytic polymerization, which were provided apart from each other, and an electrolytic polymerization polypyrrole layer was formed via a PEDOT layer.

As can be seen from (Table 1), the capacitor according to the present embodiment also showed the same results as the capacitor characteristics and heat resistance of the fourth embodiment.

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

Specifically, the leakage current of the capacitor according to the present embodiment 2 minutes after applying 10 V was 15 nA on average.

Therefore, also in the present embodiment, the high capacity achievement rate, the low loss and the high frequency impedance characteristic are excellent,
In addition to being able to obtain a capacitor element with high heat resistance, a capacitor with a small leakage current could be obtained.

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

Comparative Example 9 For comparison, as Comparative Example 9, instead of forming the PEDOT layer, after immersing in a 30% aqueous solution of manganese nitrate, it was thermally decomposed at 250 ° C. and a 3% aqueous solution of ammonium adipate was used. Then, 10 capacitors were completed in the same manner as in Embodiment 9 except that 40 V was applied at about 70 ° C. to perform repair formation.

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

The same evaluations as those of the ninth embodiment were carried out on these, and the results are shown in (Table 1).

When the above-described Embodiment 9 and this comparative example are compared and examined, it is found that in this comparative example, even if the dielectric film is repaired and formed, the capacitor characteristics and heat resistance are slightly inferior to those of the ninth embodiment. Has become.

Therefore, in the ninth embodiment, while obtaining a capacitor having a high capacity achievement rate, a low loss, a high frequency impedance characteristic and a leakage current characteristic and a high heat resistance,
Furthermore, since there is no need to repair the dielectric film, we have realized a practical capacitor that can be manufactured extremely efficiently.

(Comparative Example 10) For comparison, as Comparative Example 10, Embodiment 9 is different from Embodiment 9 except that sodium perchlorate was used in place of sodium alkylnaphthalenesulfonate during electrolytic polymerization of polypyrrole. 10 capacitors were completed in the same manner as in.

The same evaluations as in Embodiment 9 were performed on these, and the results are shown in (Table 1).

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

[0215] This is because sodium perchlorate does not impart conductivity, is not bulky, and does not act as a surfactant, so that it lacks thermal stability and penetrates into the etch pit of the polymerization solution. It is considered that the capacity is not sufficient and the capacity has decreased.

Therefore, in the ninth embodiment, by using the aromatic sulfonic acid type surfactant such as sodium alkylnaphthalene sulfonate even in the electrolytic polymerization, high capacity achievement rate, low loss and high frequency impedance characteristics and leakage current are obtained. It was possible to obtain a capacitor having excellent characteristics and high heat resistance.

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

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

Then, as understood from (Table 1),
The capacitor of the present embodiment has further improved results in capacitor characteristics and heat resistance as compared with the capacitor of the ninth embodiment.

It is considered that this is because the coexistence of P-nitrophenol significantly improves the initial electrical conductivity and environmental stability of the electrolytically polymerized polypyrrole.

Therefore, in the present embodiment, the high capacity achievement rate, the low loss and the high frequency impedance characteristic are excellent,
It can be said that the capacitor with high heat resistance was realized more remarkably.

Incidentally, 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 PEDOT of Embodiment 1 by chemical polymerization, a PEDOT solution (polystyrenesulfonate ion, which is a sulfonate anion, is doped). Concentration 0.
2% by weight), 0.2% of sodium alkylnaphthalenesulfonate is further added, and after immersion at room temperature for 5 minutes,
Embodiment 1 other than being formed by drying at 105 ° C. for 15 minutes
Ten capacitors were completed under the same conditions as above.

Here, the PEDOT doped with polystyrene sulfonate ion was prepared by electrolytically polymerizing EDOT using polystyrene sulfonate as a supporting electrolyte. Alternatively, for example, in the presence of polystyrene sulfonate, sulfuric acid was used. It can be prepared by oxidatively polymerizing EDOT using an oxidizing agent containing a polyvalent anion such as ferric iron.

Then, with respect to these, the same characteristic evaluation as in the first embodiment was carried out, and the results are shown in the above (Table 1).

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

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

Therefore, in this embodiment, since the pre-polymerized PEDOT is used, a capacitor having a high capacity achievement rate, a low loss, a high frequency impedance characteristic and a leakage current characteristic and a high heat resistance can be obtained very easily. I was able to do it.

In the second to tenth embodiments as well,
A similar effect was obtained by using a soluble PEDOT to dope the PEDOT layer with polystyrene sulfonate ion, which is a sulfonate-based anion.

If it is a soluble type, a conductive polymer can be used with a thiophene derivative represented by (formula 2) other than PEDOT as a repeating unit, and if it is bulky, a sulfonic acid other than polystyrenesulfonate ion can be used. The system anion can also be suitably doped.

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

First, in the present embodiment, the PEDOT layer that is the first conductive polymer layer and the polypyrrole layer that is the second conductive polymer layer are made of porous tantalum in the same manner as in the first embodiment. Layers were sequentially formed on the sintered electrode.

However, the repeating treatment for forming polypyrrole was limited to 3 times. Then, it was immersed in a PEDOT solution (concentration: 0.2% by weight) further doped with polystyrene sulfonate ion at room temperature for 5 minutes, and then at 1
It was dried for 5 minutes.

Thereafter, in the same manner as in Embodiment 1, a cathode is formed and an epoxy resin outer layer is formed to complete 10 tantalum capacitors having a structure in which conductive polymer layers are laminated in three layers of PEDOT / polypyrrole / PEDOT. Let

Then, with respect to these, the same characteristic evaluation as in the first embodiment was carried out, and the result is shown in the above (Table 1).

From Table 1, it can be seen that the capacitor of the present embodiment exhibits the same capacitor characteristics and heat resistance as those of the first embodiment and the like in which two layers of the PEDOT layer and the polypyrrole layer are laminated. .

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

Therefore, in this embodiment, the PED
By adopting a laminated conductive polymer layer having a three-layer structure of OT layer / polypyrrole layer / PEDOT layer, a capacitor with high heat resistance and high capacity achievement rate, low loss, high frequency impedance characteristics and leakage current characteristics can be obtained. It was possible to obtain it efficiently.

In this embodiment, the PEDOT layers which are the first and third conductive polymer layers may be formed by immersion drying, or the polypyrrole layer which is 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 represented by the above (formula 2) as a repeating unit is used. Of course, it is also possible to appropriately include the aspects of the configurations and steps in each of the above-described embodiments.

Further, in each of the above embodiments, only the sulfate ion was described as the polyvalent anion, but a transition metal polyvalent acid salt other than sulfate is used so that other polyvalent anions are doped. You 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, but other transitions having a redox potential capable of oxidizing other pyrroles. Metals can be used as well and the invention is not limited to that type.

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

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

[0245]

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

By doping a monovalent alkylnaphthalene sulfonate 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 improved, especially by using sodium alkylnaphthalene sulfonate 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, it penetrates to the deep part of the sintered body on which the dielectric film is formed, and PED without blocking the pores.
Since the OT layer is formed, the capacitance of the capacitor can be increased.

Furthermore, 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, the capacitor can be realized more efficiently and practically.

Further, by adopting a laminated conductive polymer layer having a three-layer structure of a first layer typified by a PEDOT layer / a second layer typified by a polypyrrole layer / a third layer typified by a PEDOT layer. It is possible to efficiently obtain a capacitor having a high capacity achievement rate, a low loss, a high frequency impedance characteristic and a leakage current characteristic, and high heat resistance.

Furthermore, by forming the first layer and the third layer by impregnating them in a chemical polymerization or conductive polymer solution and forming the second conductive polymer layer by chemical polymerization or electrolytic polymerization, the capacitor characteristics can be improved. Also, a capacitor having excellent heat resistance can be manufactured more efficiently and in a form suitable for practical use.

[Brief description of drawings]

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

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

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Matsue Yasue 3-10-1 Higashisanda, Tama-ku, Kawasaki City, Kanagawa Prefecture Matsushita Giken Co., Ltd. (56) Reference JP-A-4-42912 (JP, A) JP-A-2-15611 (JP, A) JP-A-4-87316 (JP, A) JP-A-4-315412 (JP, A) JP-A-5-175082 (JP, A) JP-A-5-175081 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01G 9/028

Claims (36)

(57) [Claims] 1. A pair of electrodes provided opposite to each other, a dielectric layer provided between the electrodes, and a thiophene derivative shown in Chemical formula 1 as a repeating unit provided between the electrodes. and a conductive polymer layer and pyrrole or multilayer electrically conductive polymer layer having a second conductive polymer layer containing the derivative as a repeating unit, further, the product
The conductive polymer layer is opposite to the first conductive polymer layer.
So as to be adjacent to the second conductive polymer layer on the side
The thiophene derivative shown in the chemical formula 1 is provided.
A capacitor including a third conductive polymer layer included as a return unit . [Chemical 1] 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 type anion as a dopant. 7. The capacitor according to claim 1, wherein the third conductive polymer layer contains a monovalent anion as a dopant. 8. The capacitor according to claim 7 , wherein the third conductive polymer layer further contains a polyvalent anion as a dopant. 9. The capacitor according to claim 7 , wherein the third conductive polymer layer contains a sulfonic acid anion as a dopant. 10. The capacitor according to claim 2, 4 or 7 , wherein the monovalent anion is a sulfonic acid group. 11. The capacitor according to claim 10 , wherein the sulfonic acid group contains a sulfonic acid group dissociated from an anionic surfactant. 12. The capacitor according to claim 3, 5 or 8 , wherein the polyvalent anion is a sulfate group. 13. sulfonic acid anion, a capacitor of claim 6 or 9 wherein the polystyrene sulfonic acid ion. 14. A dielectric layer capacitor according to any one of claims 1 13 is an oxide film of the valve metal constituting one of the electrodes. 15. The capacitor according to claim 14 , wherein the valve metal is aluminum or tantalum. 16. The dielectric layer capacitor according to any one of 15 claims 1 is a polymeric dielectric. 17. The polymer is a polyimide as claimed in claim 1.
6. The capacitor according to 6 . 18. The first conductive polymer layer capacitor according to any one of claims 1 to 17 adjacent to the dielectric layer. 19. The thiophene represented by (Chemical Formula 1) 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 are performed. 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 a pyrrole or its derivative as a repeating unit are chemically formed. And a laminated conductive polymer layer forming step having a second conductive polymer layer forming step formed by polymerization. 20. The thiophene represented by (Chemical Formula 1) 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 of forming a dielectric layer between the electrodes. First conductive polymer layer forming step of forming a first conductive polymer layer containing a derivative as a repeating unit by impregnating a conductive polymer solution, and a second conductive containing 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 conductive polymer layer by chemical polymerization. 21. A thiophene represented by (Chemical Formula 1) 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 of forming a dielectric layer between the electrodes. First conductive polymer layer forming step of forming a first conductive polymer layer containing a derivative as a repeating unit by impregnating a conductive polymer solution, and a second conductive containing 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 conductive polymer layer by electrolytic polymerization. 22. Further, in the step of forming the laminated conductive polymer layer, the third conductive polymer layer containing a thiophene derivative represented by (Chemical Formula 1) as a repeating unit is used as a first conductive layer.
22. The capacitor according to claim 19 , further comprising a third conductive polymer layer forming step of forming the third conductive polymer layer adjacent to the second conductive polymer layer on the side opposite to the conductive polymer layer. Production method. 23. The method for manufacturing a capacitor according to claim 22, wherein the third conductive polymer layer forming step is a step of forming by a chemical polymerization step. 24. The method for manufacturing a capacitor according to claim 22, wherein the third conductive polymer layer forming step is a step of forming the conductive polymer layer by impregnating the conductive polymer solution. 25. The method for producing a capacitor according to claim 19 , 20 or 23 , wherein the chemical polymerization step is a chemical polymerization step in an aqueous medium. 26. The method for producing a capacitor according to claim 25 , wherein in the chemical polymerization step, the conductive polymer layer is formed using a solution containing ferric sulfate and an anionic surfactant. 27. The method for producing a capacitor according to claim 26 , wherein an anionic surfactant containing an anion having a sulfonic acid group is used. In 28. chemical polymerization process, further phenol or method according capacitor to claim 19, 20, 23 from 27 to the chemical polymerization using a solution containing a derivative thereof. 29. The method for producing a capacitor according to claim 28 , wherein the phenol derivative is nitrophenol, cyanophenol, hydroxybenzoic acid, hydroxyphenol or acetophenol, or a combination thereof. 30. The method for producing a capacitor according to claim 21 , wherein the electrolytic polymerization step is an electrolytic polymerization step in an aqueous medium. 31. The method for producing 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. 32. The method for producing a capacitor according to claim 31 , wherein the phenol derivative is nitrophenol, cyanophenol, hydroxybenzoic acid, hydroxyphenol or acetophenol, or a combination thereof. 33. The dielectric forming step, the manufacturing method of a capacitor according to any one of claims 19 to form the dielectric by anodic oxidation of the valve metal 32. 34. A method for producing a capacitor according valve metal constituting one of the electrodes to one of claims 19 is aluminum or tantalum 33. 35. The method according to claim 19 , wherein the dielectric forming step is a spin coating step of forming a dielectric using a polymer.
34. The method for manufacturing the capacitor according to any one of 34 . 36. The polymer as claimed in claim 35.
A method for manufacturing the described capacitor.