JPH11312626A - Capacitor and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitor provided with a conductive layer composed of a polythiophene derivative, which is excellent in stability under high temperature and high humidity, and a method of manufacturing the same. SOLUTION: A pair of electrodes are provided facing the dielectric layer,
At least one of the electrodes has a benzenesulfonic acid ion having at least one sulfonic acid group, an alkylbenzenesulfonic acid ion having at least one alkyl group and a sulfonic acid group, or a naphthalenesulfonic acid ion having at least one sulfonic acid group. A polythiophene derivative doped with at least one of them and at least one of alkylnaphthalenesulfonate ions having at least one alkyl group and a sulfonic acid group, or at least one anthraquinonesulfonate ion having at least one sulfonic acid group And a method for manufacturing the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to capacitor characteristics,
In particular, the present invention relates to a small and large-capacity capacitor excellent in frequency characteristics and moisture resistance and a method of manufacturing the same, and at least one of the dielectric surfaces has a benzenesulfonate ion, an alkylbenzenesulfonate ion or a naphthalenesulfonate ion having a small bulk molecular structure. Provided with a conductive layer composed of a polythiophene derivative doped with at least one of alkylnaphthalenesulfonate ions having a bulky molecular structure or an anthraquinonesulfonate ion, and its production It is about the method.

[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 a high-frequency region include plastic capacitors, mica capacitors, and multilayer ceramic capacitors. However, these capacitors have large shapes 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 up through a separator, and the separator is impregnated with an electrolytic solution.

This electrolytic solution has a large loss due to ionic conductivity and a large specific resistance.
There is a problem that the temperature characteristics are extremely poor.

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 over 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.

In addition, in the case of a tantalum solid electrolytic capacitor, when forming an electrolyte composed of manganese oxide,
After immersion in a manganese nitrate solution, the step of thermally decomposing at a temperature of about 300 ° C. must be repeated several times to several tens of times, and the forming step is complicated.

Therefore, in recent years, a conductive polymer such as a metal, a conductive metal oxide, or polypyrrole has been formed on a dielectric film, and then, via these conductive layers, electrolytic polymerization has been carried out. (Japanese Patent Laid-Open No. 63-1)
58829, JP-A-63-173313, JP-A-1-253226 and the like.

Further, a capacitor has been proposed in which a conductive polymer containing 3,4-ethylenedioxythiophene as a repeating unit and p-toluenesulfonic acid anion as a dopant is formed by chemical polymerization on aluminum provided with a dielectric film. (JP-A-2-15611).

Further, there is disclosed a capacitor in which a chemically polymerized polypyrrole is formed on a surface of a tantalum sintered body provided with a dielectric film using ferric dodecylbenzenesulfonate as an oxidizing agent (Japanese Patent Application Laid-Open No. 7-94368). Gazette).

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, when an electropolymerized polymer is formed via a conductive pyrolytic metal oxide such as manganese oxide, the dielectric film is damaged by heat. In order to obtain a capacitor with a withstand voltage, it is necessary to carry out chemical formation again before electrolytic polymerization and to repair it, which has a problem that the process becomes complicated.

Furthermore, in a tantalum solid electrolytic capacitor, an electrolyte made of manganese oxide is formed by repeating thermal decomposition, and a chemical conversion is required each time to repair the generated film damage, which complicates the process. Had issues.

Furthermore, as described above, the method of forming an appropriate conductive layer in advance and then forming an electropolymerized conductive polymer layer via the conductive layer also has a problem that the process becomes complicated. I was

In addition, for forming the conductive polymer layer by chemical polymerization, for example, as disclosed in JP-A-63-173313 and JP-A-2-15611,
When persulfate or p-toluenesulfonate is used as an oxidizing agent, the dielectric film of aluminum is particularly eroded, resulting in a significant increase in leakage current or a decrease in capacity when exposed to high temperature and high humidity. There is a problem that the loss increases and the characteristics deteriorate.

FIG. 2 shows the effect of p-toluenesulfonic acid ions on the anodic oxide film during the formation of a constant current. It can be seen that the growth of the anodic oxide film is hindered even in a small amount. This indicates that the anodic oxide film was dissolved by the p-toluenesulfonic acid ion.

When ferric naphthalenesulfonate is used as an oxidizing agent to form a conductive polymer layer made of polyethylenedioxythiophene by chemical polymerization, in the completed capacitor, the naphthalenesulfonate ion becomes dielectric. The leakage current characteristics are good because it is hard to corrode the body film, and the heat resistance is also good, but when exposed to high temperature and high humidity, the capacity decreases and the loss increases, resulting in deterioration of the characteristics. I was having.

The present invention solves the above-mentioned problems of the prior art, and it is easy to obtain a solid electrolytic capacitor having a high capacity achievement ratio, excellent leakage current characteristics, and high heat and moisture resistance.
It is another object of the present invention to easily obtain a small and large-capacity film capacitor having a high capacity achievement rate, a small leakage current and high environmental stability.

[0022]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and comprises a benzenesulfonate ion having at least one sulfonic acid group having a small molecular structure, and at least one alkyl group and a sulfonic acid group. Alkyl benzene sulfonic acid ion having, or at least one of naphthalene sulfonic acid ions having at least one sulfonic acid group, and alkyl naphthalene sulfonic acid ion having at least one alkyl group and a sulfonic acid group having a bulky molecular structure, or Using a conductive layer made of a polythiophene derivative containing at least one of anthraquinone sulfonic acid ions having at least one sulfonic acid group as a dopant, at least one electrode of a capacitor provided to face each other is formed. What you did A.

When a conductive layer composed of a polythiophene derivative is formed by chemical polymerization using a transition metal salt having a small bulk benzenesulfonate ion, alkylbenzenesulfonate ion or naphthalenesulfonate ion as an anion as an oxidizing agent. Since the bulk of the transition metal salt or dopant is small, a high capacity achievement rate can be obtained. However, since the bulk of the dopant is small, it is easy to remove the dopant, and when exposed to high temperature and high humidity, the capacity is reduced and the loss is increased. Furthermore, when anions easily attack the dielectric film, there is a problem that the leakage current is significantly increased.

Since a dopant having a bulky molecular structure, such as an alkylnaphthalenesulfonate ion or anthraquinonesulfonate ion, is difficult to undo, it is composed of a polythiophene derivative doped with such a dopant. A capacitor having a conductive layer is excellent in heat resistance and moisture resistance. In addition, since the anions hardly invade the dielectric layer, the leakage current characteristics are also good. However, when a conductive layer made of a polythiophene derivative is formed by chemical polymerization using these transition metal salts as an oxidizing agent, a problem that a high capacity achievement rate cannot be obtained due to a large bulk of the transition metal salt or the dopant. was there.

Therefore, by doping an anion having a small bulk molecular structure and an anion having a large bulk molecular structure as a dopant into a conductive polymer made of a polythiophene derivative, the capacity achievement rate is reduced. Punt earns,
Leakage current characteristics and stability under high temperature and high humidity can be obtained by a bulky dopant, and a highly reliable capacitor can be realized.

Specifically, a step of preparing a dielectric layer;
A step of preparing a thiophene derivative monomer, and a benzenesulfonic acid transition metal salt having at least one sulfonic acid group, an alkylbenzenesulfonic acid transition metal salt having at least one alkyl group and a sulfonic acid group, or at least one sulfonic acid group At least one of the naphthalene sulfonic acid transition metal salts having, and an alkyl naphthalene sulfonic acid transition metal salt having at least one alkyl group and a sulfonic acid group, or an anthraquinone sulfonic acid transition metal salt having at least one sulfonic acid group. A step of preparing at least one oxidizing agent from among the above, and a conductive layer made of a conductive polymer obtained by chemically polymerizing the polymerizable monomer using the oxidizing agent on at least one of the surfaces of the dielectric layer. Forming a capacitor It is a manufacturing method.

Further, by using an additive selected from a phenol derivative or a nitrobenzene derivative in the polymerization solution, it is possible to promote the polymerization reaction and to facilitate the formation of a conductive layer made of a conductive polymer. Can be.

An efficient manufacturing method for easily obtaining a capacitor having a high capacity achievement ratio, excellent leakage current characteristics, and high heat and moisture resistance was provided.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION
A pair of electrodes are provided facing the dielectric layer, and at least one of the electrodes has a benzenesulfonic acid ion having at least one sulfonic acid group, or an alkylbenzenesulfonic acid ion having at least one alkyl group and a sulfonic acid group. A polythiophene derivative doped with at least one of them and at least one of alkylnaphthalenesulfonate ions having at least one alkyl group and a sulfonic acid group, or at least one anthraquinonesulfonate ion having at least one sulfonic acid group This is a capacitor provided with a conductive layer composed of:

In a capacitor in which the dielectric layer is composed of a valve metal oxide film, the conductive layer functions as an electrolyte also serving as a cathode, while in a film capacitor in which it is composed of a polymer thin film, it functions as a simple electrode. I do.

The conductive layer is formed of at least one of benzenesulfonate ions having at least one sulfonic acid group having a small bulk or at least one alkylbenzenesulfonate ion having at least one alkyl group and a sulfonic acid group. An alkylnaphthalenesulfonic acid ion having one alkyl group and a sulfonic acid group, or a polythiophene derivative in which at least one of anthraquinonesulfonic acid ions having at least one sulfonic acid group is doped, The achievement rate is achieved by a small-volume dopant, and the leakage current characteristics and the stability under high temperature and high humidity are achieved by a large-volume dopant, and a highly reliable capacitor can be realized.

Here, the benzenesulfonate ion having at least one sulfonic acid group includes a benzenesulfonate ion and a benzenedisulfonate ion, and the benzenesulfonate ion is preferably used.

The alkylbenzenesulfonate having at least one alkyl group and a sulfonic acid group includes ethylbenzenesulfonate, dodecylbenzenesulfonate, p-toluenesulfonate and the like. -Toluenesulfonic acid ions are used.

The alkylnaphthalenesulfonic acid ion having at least one alkyl group and a sulfonic acid group includes monoisopropylnaphthalenesulfonic acid ion,
Examples thereof include n-butylnaphthalenesulfonic acid ion, dibutylnaphthalenesulfonic acid ion, triisopropylnaphthalenesulfonic acid ion, and triisopropylnaphthalenedisulfonic acid ion. Triisopropylnaphthalenesulfonic acid ion is preferably used.

The anthraquinone sulfonic acid ion having at least one sulfonic acid group includes anthraquinone-2-sulfonic acid ion and anthraquinone-2,6
-Disulfonate ion and the like, and preferably anthraquinone-2-sulfonate ion.

According to a second aspect of the present invention, there is provided a pair of electrodes opposed to the dielectric layer, wherein at least one of the electrodes is provided with at least one naphthalenesulfonate ion having a sulfonic acid group. A conductive layer comprising a polythiophene derivative doped with at least one alkylnaphthalenesulfonate ion having two alkyl groups and a sulfonic acid group, or at least one anthraquinonesulfonate ion having at least one sulfonic acid group; Capacitor.

The conductive layer comprises a naphthalenesulfonic acid ion having at least one bulky sulfonic acid group, an alkylnaphthalenesulfonic acid ion having at least one bulky alkyl group and a sulfonic acid group, or at least one sulfonic acid ion. It is composed of a polythiophene derivative in which at least one of the anthraquinone sulfonate ions having a group is doped, and the capacity attainment rate is that a bulky dopant is obtained, and the stability at high temperature and high humidity is high. A bulky dopant is obtained, and a highly reliable capacitor can be realized.

The naphthalene sulfonic acid ion having at least one sulfonic acid group includes naphthalene sulfonic acid ion, naphthalene disulfonic acid ion, naphthalene trisulfonic acid ion and the like. Preferably, naphthalene sulfonic acid ion is used. Used.

Here, the dielectric layer may be an oxide of a valve metal.

Further, aluminum or tantalum can be used as the valve metal.

Further, the dielectric layer may be formed of a polymer film.

Further, as described in claim 6, the polymer film can be constituted by a polyimide film.

Further, as described in claim 7, poly (3,4-ethylenedioxythiophene) can be suitably used as the polythiophene derivative. Further, the substitutable alkylene group is preferably a 1,2-alkylene group such as ethene, 1-propene, 1-hexene or the like, which is obtained from alpha olefin, and furthermore, 1,2-cyclohexene , 2,3-butylene, 2,3-
It may be a dimethylene 2,3-butylene or 2,3-pentylene group. Most preferred examples include a methylene, 1,2-ethylene, 1,2-propylene group and the like.

The invention according to claim 8 of the present invention comprises a step of preparing a dielectric layer, a step of preparing a thiophene derivative monomer, and a step of preparing a benzenesulfonic acid transition metal salt having at least one sulfonic acid group, or At least one alkyl benzene sulfonic acid transition metal salt having one alkyl group and a sulfonic acid group, and an alkyl naphthalene sulfonic acid transition metal salt having at least one alkyl group and a sulfonic acid group, or at least one sulfonic acid group; Preparing an oxidizing agent comprising at least one of an anthraquinone sulfonic acid transition metal salt having; and at least one of the surfaces of the dielectric layer, the polymerizable monomer was chemically polymerized using the oxidizing agent. Forming a conductive layer made of a conductive polymer. The method is a method for producing a benzenesulfonic acid ion having at least one sulfonic acid group having a small bulk, or at least one alkylbenzenesulfonic acid ion having at least one alkyl group and a sulfonic acid group, and having a large bulk. A conductive layer comprising a polythiophene derivative doped with at least one alkylnaphthalenesulfonate ion having at least one alkyl group and a sulfonic acid group, or at least one anthraquinonesulfonate ion having at least one sulfonic acid group; Capacitor can be manufactured.

The capacity achievement rate is obtained by a small bulk dopant, and the leakage current characteristics and stability under high temperature and high humidity are achieved by a large bulk dopant, and a highly reliable capacitor can be obtained. .

The invention according to claim 9 of the present invention comprises a step of preparing a dielectric layer, a step of preparing a thiophene derivative monomer, and a step of preparing at least one transition metal salt of naphthalenesulfonic acid having at least one sulfonic acid group. A step of preparing an oxidizing agent comprising at least one alkylnaphthalenesulfonic acid transition metal salt having one alkyl group and a sulfonic acid group, or at least one anthraquinonesulfonic acid transition metal salt having at least one sulfonic acid group; Forming, on at least one of the surfaces of the dielectric layer, a conductive layer made of a conductive polymer obtained by chemically polymerizing the polymerizable monomer using the oxidizing agent. A naphthalenesulfonate ion having at least one sulfonic acid group having a small bulk; A conductive layer comprising a polythiophene derivative doped with at least one of alkylnaphthalenesulfonate ions having at least one alkyl group and a sulfonic acid group, or at least one anthraquinonesulfonate ion having at least one sulfonic acid group; Can be manufactured. The capacity achievement rate is achieved by a small-volume dopant, and the stability under high temperature and high humidity is achieved by a large-volume dopant, so that a highly reliable capacitor can be obtained.

Here, the dielectric layer may be an oxide of a valve metal.

Further, aluminum or tantalum can be used as the valve metal.

Further, the dielectric layer may be composed of a polymer film.

Also, the polymer film can be constituted by a polyimide film.

Further, as described in claim 14, poly (3,4-ethylenedioxythiophene) can be suitably used as the polythiophene derivative.

Further, iron (III), copper (II) or ruthenium (III) can be used as the transition metal.

The invention according to claim 16 of the present invention comprises the step of preparing a dielectric layer, the step of preparing a thiophene derivative monomer, and the step of preparing a transition metal salt of benzenesulfonic acid having at least one sulfonic acid group, At least one alkyl benzene sulfonic acid transition metal salt having one alkyl group and a sulfonic acid group, and an alkyl naphthalene sulfonic acid transition metal salt having at least one alkyl group and a sulfonic acid group, or at least one sulfonic acid group; Providing an oxidizing agent comprising at least one of an anthraquinone sulfonic acid transition metal salt having; an additive preparing agent selected from a phenol derivative or a nitrobenzene derivative; and at least one of the surfaces of the dielectric layer. In addition, the polymerizable monomer and the oxidizing agent Forming a conductive layer made of a conductive polymer that has been chemically polymerized, the method comprising: using an additive selected from a phenol derivative or a nitrobenzene derivative to perform a polymerization reaction. It is possible to facilitate the formation of a conductive layer made of a conductive polymer.

The invention according to claim 17 of the present invention comprises a step of preparing a dielectric layer, a step of preparing a thiophene derivative monomer, and a step of preparing at least one transition metal salt of naphthalenesulfonic acid having at least one sulfonic acid group. Preparing an oxidizing agent comprising at least one transition metal salt of an alkyl naphthalene sulfonic acid having one alkyl group and a sulfonic acid group, or an anthraquinone sulfonic acid transition metal salt having at least one sulfonic acid group; A step of preparing an additive selected from a phenol derivative or a nitrobenzene derivative, and at least one of the surfaces of the dielectric layer, comprising a conductive polymer obtained by chemically polymerizing the polymerizable monomer using the oxidizing agent. Forming a conductive layer. The use of additives selected from le derivative or nitrobenzene derivative, it is possible to promote the polymerization reaction, the formation of the conductive layer made of a conductive polymer can be facilitated.

Here, nitrophenol, cyanophenol, hydroxybenzoic acid or hydroxyphenol may be used as the phenol derivative.

As described in claim 19, nitrobenzene, nitrobenzoic acid, or nitrobenzyl alcohol can be used as the nitrobenzene derivative.

Hereinafter, each embodiment of the present invention will be described in detail. (Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to FIG.

The aluminum-etched foil 1 having a length of 8 mm and a width of 3.3 mm is partitioned into 4 mm and 3 mm portions.
A polyimide tape 2 having a width of 1 mm was stuck on both sides.

Next, an aluminum etched foil of 3 mm ×
The anode lead 5 was attached to the 3.3 mm portion, and the 4 mm × 3.3 mm portion of the aluminum-etched foil 1 was
Using a 3% aqueous solution of ammonium adipate at
The voltage was increased from 0 to 10 V at a rate of 0 mV / sec, and a constant voltage of 10 V was continuously applied for 40 minutes to form an oxide film dielectric layer 3 by anodic oxidation.

After washing with running deionized water for 10 minutes, drying was performed at 105 ° C. for 5 minutes. This configuration was regarded as a capacitor, and the capacity in the chemical conversion solution was measured to be 18 μF.

Ferric benzenesulfonate, a transition metal salt having a small bulk benzenesulfonate ion as anion, and triisopropylnaphthalenesulfonic acid, a transition metal salt having a large bulk triisopropylnaphthalenesulfonate ion as anion. Iron was used as the oxidizing agent. Each was dissolved in ethanol to prepare a ferric benzenesulfonate solution and a ferric triisopropylnaphthalenesulfonate solution having a solid content of 40% by weight.

Next, 1.34 g of the ferric benzenesulfonate solution and 0.44 g of the ferric triisopropylnaphthalenesulfonate solution in 1.44 g of ethanol were used.
And mixed. Further, a thiophene derivative monomer
3,4-ethylenedioxythiophene monomer
0.8 g was mixed and stirred to prepare a polymerization solution.

The electrode provided with the dielectric layer is immersed in the polymerization solution for 1 minute, pulled up, heated in an oven at 105 ° C. for several seconds, and then in an oven at 70 ° C. for 10 minutes. Heated. Chemical polymerization proceeded while the solvent was evaporated, and a conductive layer 4 made of a conductive polymer was formed on the dielectric layer.

Next, the substrate was washed with running deionized water for 15 minutes, and then dried at 105 ° C. for 5 minutes. The number of polymerizations from dip coating to drying was repeated 12 times until the conductive layer 4 had a predetermined thickness.

In order to prolong the life of the polymerization solution, it is effective to lower the temperature to lower the polymerization rate. In order to reduce the excess amount of the polymerization solution, brush coating, screen printing, spray coating, or the like may be used instead of dip coating.

After the formation of the conductive layer, a cathode 7 was formed thereon with a carbon layer and a silver paint layer, and a cathode lead 6 was mounted thereon.

Further, the element was packaged with an epoxy resin, and then subjected to an aging treatment to complete a total of ten capacitor elements.

For these ten elements, the capacitance and the loss factor at 1 kHz, and the impedance at 400 kHz
The dance and the leakage current two minutes after the application of the rated voltage of 6.3 V were measured. Exposure to 85% 85% atmosphere
A load heat / moisture resistance test with 6.3 V applied is performed.
The capacity, loss factor, impedance, and leakage current were measured. The average values are shown in the following (Table 1).

[0069]

[Table 1]

Comparative Example 1 As Comparative Example 1, only ferric benzenesulfonate, a transition metal salt having a small bulky benzenesulfonate ion as an anion, was used as an oxidizing agent. It was dissolved in ethanol to prepare a ferric benzenesulfonate solution having a solid content of 40% by weight. Next, ethanol 1.
In 27 g, the ferric benzenesulfonate solution 1.
55 g was added and mixed.

Further, 0.8 g of 3,4-ethylenedioxythiophene monomer was mixed and stirred to prepare a polymerization solution. Embodiment 1 except that this composition was used.
A capacitor element was produced in the same manner as in the above. The number of polymerizations at this time was 10 times. The results of measuring the characteristics are shown in the above (Table 1).

In Comparative Example 1, when only ferric benzenesulfonate which is a transition metal salt having a small benzenesulfonate ion as an anion was used as the oxidizing agent, the capacity achievement ratio was high and good initial characteristics were obtained. Was done. However, 85 ° C /
As a result of a load heat / moisture resistance test in an 85% atmosphere,
As shown in (Table 1), de-doping under high temperature and high humidity,
In addition, the corrosion of the oxide film dielectric layer by the undoped anions causes a decrease in capacity, an increase in the loss factor, an increase in impedance, and an increase in leakage current, resulting in an increase in stability under high temperature and high humidity. It was bad.

(Comparative Example 2) As Comparative Example 2, only ferric triisopropylnaphthalenesulfonate, a transition metal salt having a bulky triisopropylnaphthalenesulfonate ion as an anion, was used as an oxidizing agent. It was dissolved in ethanol to prepare a ferric triisopropylnaphthalenesulfonate solution having a solid content of 40% by weight.

Next, the ferric triisopropylnaphthalenesulfonate solution was added to 2.42 g of ethanol.
95 g was added and mixed. Further, 3,4-ethylenedioxythiophene monomer-0.8 g was mixed and stirred to prepare a polymerization solution. Except using this composition,
A capacitor element was manufactured in the same operation as in the first embodiment. The number of polymerizations at this time was 17 times. The results of measuring the characteristics are shown in the above (Table 1).

In Comparative Example 2, when only ferric triisopropylnaphthalenesulfonate, a transition metal salt having a bulky triisopropylnaphthalenesulfonate ion as an anion, was used as an oxidizing agent, as shown in Table 1 high temperature·
The characteristics were hardly deteriorated under high humidity, and the stability was good.

However, the capacity achievement ratio was low. Similar results were obtained with ferric diisopropylnaphthalenesulfonate other than ferric triisopropylnaphthalenesulfonate, for example, ferric dibutylnaphthalenesulfonate and ferric monoisopropylnaphthalenesulfonate.

As is apparent from the comparison between Comparative Examples 1 and 2 and Embodiment 1 in Table 1 above, Embodiment 1
In this case, the capacity achievement rate can be achieved with a small bulk dopant, and the leakage current characteristics and stability under high temperature and high humidity are large
It turned out that the punt earned and a highly reliable capacitor was obtained.

(Embodiment 2) Ferric p-toluenesulfonate, a transition metal salt having a small bulk p-toluenesulfonic acid ion as an anion, and a large bulk anthraquinone-2-sulfonic acid ion as an anion The transition metal salt and ferric anthraquinone-2-sulfonate were used as the oxidizing agent. Each was dissolved in ethanol to obtain a solid content of 40%.
A weight% ferric p-toluenesulfonic acid solution and a ferric anthraquinone-2-sulfonic acid solution were prepared.

Next, 1.5 g of ethanol contained the above p
-1.43 g of the ferric toluenesulfonic acid solution and 0.4 g of the ferric anthraquinone-2-sulfonic acid solution were added and mixed. Further, 3,4-ethylenedioxythiophene monomer-0.8 g was mixed and stirred to prepare a polymerization solution.

Except that this composition was used, ten capacitor elements were produced in the same manner as in the first embodiment. The number of polymerizations at this time was 13 times. The same characteristic evaluation as in the first embodiment was performed, and the average values thereof are shown in (Table 1).

As described above, according to the present embodiment, ferric p-toluenesulfonate, which is a transition metal salt having p-toluenesulfonic acid ion of small bulk as an anion, and anthraquinone-2-large of bulky The capacity achievement rate is increased by chemically polymerizing poly (3,4-ethylenedioxythiophene) using a transition metal salt anthraquinone-2-ferrous sulfonate having a sulfonate ion as an anion as an oxidizing agent. The small donut earns, and the stability under high temperature and high humidity is gained by the bulky dough (Table 1).
As shown in (1), a highly reliable capacitor can be obtained.

(Embodiment 3) A transition metal salt of ferric naphthalenesulfonate having a small bulky naphthalenesulfonate ion as an anion and a transition metal salt of a transition metal salt having a large bulky triisopropylnaphthalenesulfonate ion as an anion. Ferric isopropyl naphthalene sulfonate was used as the oxidizing agent. Each was dissolved in ethanol, a ferric naphthalene sulfonate solution having a solid content of 40% by weight,
And a ferric triisopropylnaphthalenesulfonate solution.

Next, 1.57 g of the ferric naphthalenesulfonate solution and 0.44 g of the ferric triisopropylnaphthalenesulfonate solution in 1.65 g of ethanol were used.
g was mixed. Further, 3,4-ethylenedioxythiophene monomer-0.8 g was mixed and stirred to prepare a polymerization solution. A capacitor element was manufactured in the same manner as in Embodiment 1 except that this composition was used. The number of polymerizations at this time was 14 times. The results of measuring the characteristics are shown in the above (Table 1).

Comparative Example 3 As Comparative Example 3, only a transition metal salt of ferric naphthalene sulfonate having a small bulk naphthalene sulfonate ion as an anion was used as an oxidizing agent. It was dissolved in ethanol to prepare a ferric naphthalene sulfonate solution having a solid content of 40% by weight. Next, 1.99 g of the ferric naphthalenesulfonate solution was added to 1.63 g of ethanol and mixed. Furthermore, 3,4-
A polymerization solution was prepared by mixing and stirring with 0.8 g of ethylenedioxythiophene monomer. A capacitor element was manufactured in the same manner as in Embodiment 1 except that this composition was used. The number of polymerizations at this time was 10 times. The results of measuring the characteristics are shown in the above (Table 1).

In Comparative Example 3, when only ferric naphthalenesulfonate, a transition metal salt having a small bulk naphthalenesulfonate ion as the anion, was used as the oxidizing agent, the capacity achievement ratio was high and good initial characteristics were obtained. Was done. However, 85
As shown in (Table 1), as a result of the load heat resistance / moisture resistance test in an atmosphere of
The capacity, loss factor, and impedance
Dance increased and stability under high temperature and high humidity was poor.

As is clear from the comparison between Comparative Example 3 and Embodiment 3 in (Table 1), in Embodiment 3,
It has been found that a capacitor with a small bulk gains in achieving the capacity, and a large bulk gains in stability under high temperature and high humidity, and a highly reliable capacitor can be obtained.

(Embodiment 4) Ferric naphthalenesulfonate, a transition metal salt having a small bulk naphthalenesulfonic acid ion as an anion, and a large bulk anthraquinone-2
A transition metal salt of anthraquinone-2-iron sulfonate having a sulfonate ion as an anion; Each was dissolved in ethanol to prepare a ferric naphthalenesulfonic acid solution and a ferric anthraquinone-2-sulfonic acid solution each having a solid content of 40% by weight.

Next, 1.57 g of the ferric naphthalenesulfonate solution and 0.4 g of the ferric anthraquinone-2-sulfonate solution were mixed in 1.62 g of ethanol. Further, 3,4-ethylenedioxythiophene monomer-0.8 g was mixed and stirred to prepare a polymerization solution. Embodiment 1 except that this composition was used.
A capacitor element was produced in the same manner as in the above. The number of polymerizations at this time was 11 times. The results of measuring the characteristics are shown in the above (Table 1).

As described above, according to the present embodiment, the transition metal salt of ferric naphthalenesulfonate having a small bulk naphthalenesulfonic acid ion as an anion and the large bulk anthraquinone-2-sulfonic acid ion are used. By chemically polymerizing poly (3,4-ethylenedioxythiophene) using a transition metal salt of ferric anthraquinone-2-sulfonate as an anion as an oxidizing agent, the capacity attainment rate is reduced by a small volume of The punt gains, and the stability under high temperature and high humidity increases the bulk of the punt, and a highly reliable capacitor can be obtained as shown in Table 1.

(Embodiment 5) Ferrous transition metal salt p-toluenesulfonate having a small bulk p-toluenesulfonate ion as an anion and transition having a large bulk triisopropylnaphthalenesulfonate ion as an anion A metal salt of ferric triisopropylnaphthalenesulfonate was used as the oxidizing agent. Dissolve each with ethanol,
A ferric p-toluenesulfonate solution having a solid content of 40% by weight and a ferric triisopropylnaphthalenesulfonate solution were prepared. Then, 1.5 g of ethanol, p-
1.44 g of the ferric toluenesulfonic acid solution, 0.48 g of the ferric triisopropylnaphthalenesulfonic acid solution
g, and 3,4-ethylenedioxythiophene monomer
0.8 g of the polymerization solution (A), ethanol 1.
5 g of the ferric p-toluenesulfonate solution 0.96
g, a polymerization solution (B) having a composition of 0.96 g of the ferric triisopropylnaphthalenesulfonate solution and 0.8 g of 3,4-ethylenedioxythiophene monomer, 1.5 g of ethanol, and 1.5 g of the p- A polymerization solution (C) having a composition of 0.48 g of a ferric toluenesulfonic acid solution, 1.44 g of the ferric triisopropylnaphthalenesulfonic acid solution, and 0.8 g of 3,4-ethylenedioxythiophene monomer was prepared. did.

Except that this composition was used, ten capacitor elements were manufactured in the same manner as in the first embodiment. The number of polymerizations at this time was (A) 11 times, (B) 12 times, and (C) 15 times. The same characteristic evaluation as in the first embodiment was performed, and the average values thereof are shown in (Table 1).

As shown in Table 1, when the ratio of the bulky oxidizing agent is large in the composition ratio of the small bulky oxidizing agent to the large bulking oxidizing agent, the composition is stable at high temperature and high humidity. And the capacity achievement ratio tends to be low. Further, it has been found that even when the ratio of the oxidizing agent having a small bulk is large, sufficient stability under high temperature and high humidity can be obtained.

(Embodiment 6) In the structure of Embodiment 1, copper (II) benzenesulfonate and triiron (II) benzenesulfonate are replaced by ferric benzenesulfonate having a small bulk and ferric triisopropylnaphthalenesulfonate. Ten capacitor elements were formed in the same manner as in Embodiment 1 except that cupric isopropylnaphthalenesulfonate (A) and ruthenium benzenesulfonate and ruthenium triisopropylnaphthalenesulfonate (B) were used, respectively. Produced. The number of polymerizations at this time was 13 for (A) and 13 for (B). The results of measuring the characteristics are shown in Table 1 above.
Shown in

According to the present embodiment, even when the above-mentioned oxidizing agent is used, the capacity achievement ratio is small.
The punt is earned, and the leakage current characteristics and stability under high temperature and high humidity are increased by the bulky punt, and a highly reliable capacitor can be obtained as shown in Table 1.

(Embodiment 7) Next, a seventh embodiment of the present invention will be described.

A method for manufacturing a capacitor using a tantalum sintered body as an electrode will be described. The size is 3.6X2.9X
1.4mm, weight of about 9 with tantalum lead wire
First, first chemical conversion is performed on 0 mg of a tantalum sintered body.

Using a solution of 5 ml of phosphoric acid dissolved in 1000 ml of deionized water at about 90 ° C.,
The voltage was increased from 0 to 42 V at a speed of, and a constant voltage of 42 V was continuously applied for 180 minutes, and an oxide film dielectric layer was formed by anodic oxidation. After washing with running deionized water, 31 V is applied at about 25 ° C. for 20 minutes using deionized water as a second formation, and then 0.05 ml of acetic acid is added as a third formation in 1 ml.
Using a solution dissolved in 000 ml of deionized water, about 25
At 30 ° C., a voltage of 30 V was applied for 30 minutes to repair the defective portion of the oxide film dielectric layer by anodic oxidation in two stages of second formation and third formation.

Then, the substrate was washed with running deionized water and dried. This configuration was regarded as a capacitor, and the capacity in the chemical conversion solution was 68 μF.

A monomer solution was prepared by mixing 50 g of thiophene derivative monomer and 50 g of 3,4-ethylenedioxythiophene in 50 g of ethyl alcohol.

Ferric transition metal salt p-toluenesulfonate having a small bulk p-toluenesulfonate ion as an anion and triisopropylnaphthalene transition metal salt having a large bulky triisopropylnaphthalenesulfonate ion as an anion Ferric sulfonate was used as the oxidizing agent.

Each was dissolved in ethanol, and a solution of ferric p-toluenesulfonate having a solid content of 40% by weight was prepared.
And a ferric triisopropylnaphthalenesulfonate solution. Next, 48 g of the ferric p-toluenesulfonate solution and 15 g of the ferric triisopropylnaphthalenesulfonate solution were mixed in 50 g of ethanol, and the mixture was stirred to prepare an oxidizing agent solution.

The electrodes of the tantalum sintered body provided with the dielectric layer were immersed in the monomer solution for 10 minutes,
For 20 minutes. A conductive layer made of poly (3,4-ethylenedioxythiophene) was formed on the dielectric layer by chemical polymerization. And
After washing with running water with deionized water for 10 minutes, 105
Dry at 5 ° C. for 5 minutes. Until the conductive layer reaches the specified thickness
The number of polymerizations from dipping in the monomer solution to drying was repeated 40 times.

After forming the conductive layer, a cathode was formed thereon with a carbon layer and a silver paint layer, and a cathode lead was mounted thereon.

Further, the element was packaged with an epoxy resin and then subjected to an aging treatment to complete a total of ten capacitor elements. For these 10 elements, the capacity at 1 kHz, the loss factor, 400 kHz
And the leakage current 2 minutes after application of a rated voltage of 10 V were measured. Further, the film was exposed to an atmosphere of 85 ° C./85% and subjected to a load heat / moisture resistance test at a voltage of 10 V, and the capacity, the loss coefficient, the impedance, and the leakage current were measured. The average values are shown in (Table 1).

In the seventh embodiment, the service life of these solutions can be extended by dividing into two solutions, namely, a monomer solution and an oxidizing agent solution.

According to this embodiment, ferric p-toluenesulfonate, which is a transition metal salt having p-toluenesulfonate having a small bulk as an anion, and triisopropylnaphthalenesulfonate having a large bulk as anion. The chemical polymerization of poly (3,4-ethylenedioxythiophene) using the transition metal salt triisopropylnaphthalenesulfonate and ferric oxide as an oxidizing agent leads to the achievement of a small volume bulky dopant. As for the leakage current characteristics and stability under high temperature and high humidity, a bulky dopant can be obtained, and a highly reliable capacitor can be obtained as shown in Table 1.

(Embodiment 8) Instead of forming an oxide film dielectric on a 20 mm × 20 mm aluminum smooth foil as in Embodiment 1, a polyimide made of a 0.5 μm thick polyimide thin film is formed by spin coating. A total of ten capacitor elements were manufactured under substantially the same conditions as in Embodiment 1 except that the electrode on which the dielectric layer was formed was used. The number of polymerizations at this time was 12 times. The same characteristic evaluation as in Embodiment 1 was performed, and the average value thereof was calculated (Table 1)
It was shown to.

The capacity obtained here was 87% in capacity achievement rate. According to the present embodiment, ferric benzenesulfonate of a transition metal salt having a small bulky benzenesulfonate ion as anion and triisopropyl of a transition metal salt having a large bulky triisopropylnaphthalenesulfonate ion as an anion. By chemically polymerizing poly (3,4-ethylenedioxythiophene) using ferric naphthalenesulfonate as an oxidizing agent, the capacity attainment rate can be improved by producing a bulky dopant under high temperature and high humidity. As for the leakage current characteristics and stability, a bulky dopant can be obtained, and a highly reliable capacitor can be obtained as shown in Table 1.

(Embodiment 9) In the first embodiment,
Ten capacitor elements were produced in the same manner as in Embodiment 1, except that 10% by weight of p-nitrophenol of 3,4-ethylenedioxythiophene monomer was further added to the polymerization solution. At this time, the number of polymerizations was eight. The same characteristic evaluation as in the first embodiment was performed, and the average values thereof are shown in (Table 1).

Since the polymerization rate was accelerated by the addition of p-nitrophenol, the number of polymerizations required for forming the conductive layer was reduced.

According to the present embodiment, ferric benzenesulfonate which is a transition metal salt having a small bulk benzenesulfonate ion as an anion, and a transition metal salt having a large bulk triisopropylnaphthalenesulfonate ion as an anion Of poly (3,4-ethylenedioxythiophene) using ferric triisopropylnaphthalenesulfonate as an oxidizing agent and further using p-nitrophenol as an additive to achieve a capacity achievement rate. As shown in (Table 1), a large-volume dopant gains a small bulk, and a leakage current characteristic and stability under high temperature and high humidity have a large bulk. Obtainable.

(Embodiment 10) Instead of p-nitrophenol of Embodiment 9, m-nitrophenol (A), p-cyanophenol (B), m-hydroxybenzoic acid (C), m-hydroxybenzoic acid (C) In the same manner as in the ninth embodiment except that hydroxyphenol (D), nitrobenzene (E), p-nitrobenzoic acid (F), and p-nitrobenzyl alcohol (G) were added, the capacitor elements were set in units of ten. Produced. The number of polymerizations at this time was (A) 8 times, (B)
9 times, (C) 8 times, (D) 8 times, (E) 8 times,
(F) was 7 times and (G) was 8 times. The same characteristic evaluation as in Embodiment 1 was performed, and the average value thereof was calculated (Table 1)
It was shown to.

In any of the additives, as is clear from the comparison with the first embodiment, the number of times of polymerization for forming the conductive layer was reduced.

According to this embodiment, ferric benzenesulfonate, a transition metal salt having a small bulk benzenesulfonate ion as an anion, and a transition metal salt having a large bulk triisopropylnaphthalenesulfonate ion, as an anion Poly (3,4-ethylenedioxythiophene) by using a ferric triisopropylnaphthalenesulfonate as an oxidizing agent and using a phenol derivative having an electron-withdrawing substituent or a nitrobenzene derivative as an additive. By chemically polymerizing the compound, the capacity achievement rate can be obtained with a small bulk dopant, and the leakage current characteristics and stability under high temperature and high humidity can be obtained with a large bulk dopant, as shown in Table 1. Thus, a highly reliable capacitor can be easily obtained.

In the eighth embodiment, the case where polyimide is used as the polymer to be a dielectric has been described. However, any polymer material other than polyimide can be used as long as it can form a thin film. Is not limited to that type. Also, the case of forming a polyimide film to be a dielectric by spin coating on an aluminum smooth foil has been described, but as one electrode of a film capacitor using a polyimide film as a dielectric provided on an etched aluminum foil surface, for example, by electrodeposition. The present invention is not limited to the forming method.

In the embodiment, a polymerizable monomer is used.
Has been described only for the case where 3,4-ethylenedioxythiophene is used, but derivatives having other substituents can also be used.

In the above embodiment, only the case where the valve metal is aluminum and tantalum has been described, but zirconium, niobium, hafnium and titanium, and intermetallic compounds thereof can also be used.

In the above embodiment, only the capacitor in which the conductive polymer layer is formed on only one electrode of the capacitor has been described. However, both electrodes may be formed of a conductive polymer.

[0119]

As described above, the present invention comprises a pair of electrodes facing the dielectric layer, and at least one of the electrodes has
At least one of benzenesulfonic acid ions having at least one sulfonic acid group having a small bulk, alkylbenzenesulfonic acid ions having at least one alkyl group and a sulfonic acid group, or naphthalenesulfonic acid ions having at least one sulfonic acid group When,
It is composed of a polythiophene derivative in which at least one bulky alkylnaphthalenesulfonic acid ion having at least one alkyl group and a sulfonic acid group, or at least one anthraquinonesulfonic acid ion having at least one sulfonic acid group is doped. And a method for manufacturing the same.

[0120] The capacity achievement ratio is advantageous in that a small-volume dopant gains, and the leakage current characteristics and stability under high temperature and high humidity can achieve a large-volume dopant, and a highly reliable capacitor can be realized. Effects can be obtained.

Furthermore, the addition of the phenol derivative and the nitrobenzene derivative promotes the polymerization reaction, so that the formation of the conductive layer made of the polythiophene derivative can be facilitated.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a capacitor of the present invention.

FIG. 2 is a diagram showing the relationship between the concentration of sodium p-toluenesulfonate and the ability to form an aluminum anodic oxide film in the prior art

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Aluminum etched foil 2 Polyimide tape 3 Oxide film dielectric layer 4 Conductive layer 5 Anode lead 6 Cathode lead 7 Cathode

Claims (19)

[Claims] A pair of electrodes facing the dielectric layer,
A capacitor having a conductive layer on at least one of the electrodes, wherein the conductive layer is a benzenesulfonic acid ion having at least one sulfonic acid group, or an alkylbenzenesulfonic acid ion having at least one alkyl group and a sulfonic acid group. Polythiophene doped with at least one of the above, and at least one alkylnaphthalenesulfonate ion having at least one alkyl group and a sulfonic acid group, or at least one anthraquinonesulfonate ion having at least one sulfonic acid group A capacitor comprising a derivative. A pair of electrodes opposed to the dielectric layer,
A capacitor having a conductive layer on at least one of the electrodes, wherein the conductive layer is a naphthalenesulfonic acid ion having at least one sulfonic acid group, and an alkylnaphthalenesulfonic acid having at least one alkyl group and a sulfonic acid group. A capacitor comprising a polythiophene derivative doped with ions or at least one of anthraquinone sulfonic acid ions having at least one sulfonic acid group. 3. The capacitor according to claim 1, wherein the dielectric layer is an oxide of a valve metal. 4. The capacitor according to claim 1, wherein the valve metal is aluminum or tantalum. 5. The method according to claim 1, wherein the dielectric layer is a polymer film.
2. The capacitor according to 2. 6. The polymer film according to claim 5, wherein the polymer film is a polyimide film.
The capacitor as described. 7. The polythiophene derivative is poly (3,4-
7. The capacitor according to claim 1, wherein said capacitor is ethylenedioxythiophene. 8. A step of preparing a dielectric layer, a step of preparing a thiophene derivative monomer, and a step of preparing a transition metal salt of benzenesulfonic acid having at least one sulfonic acid group, or at least one alkyl group and a sulfonic acid group. At least one of alkyl benzene sulfonic acid transition metal salts having at least one alkyl group and an alkyl naphthalene sulfonic acid transition metal salt having at least one sulfonic acid group or at least one anthraquinone sulfonic acid transition metal salt having at least one sulfonic acid group A step of preparing an oxidizing agent comprising at least one from: a conductive layer made of a conductive polymer obtained by chemically polymerizing the polymerizable monomer using the oxidizing agent on at least one of the surfaces of the dielectric layer. Forming a capacitor. 9. A step of preparing a dielectric layer, a step of preparing a thiophene derivative monomer, a step of preparing a transition metal salt of naphthalene sulfonic acid having at least one sulfonic acid group, at least one alkyl group and a sulfonic acid group. Preparing an oxidizing agent comprising at least one of an alkylnaphthalene sulfonic acid transition metal salt having, or an anthraquinone sulfonic acid transition metal salt having at least one sulfonic acid group, and at least one of the surfaces of the dielectric layer Forming a conductive layer made of a conductive polymer obtained by chemically polymerizing the polymerizable monomer using the oxidizing agent. 10. The method according to claim 8, wherein the dielectric layer is an oxide of a valve metal. 11. The method according to claim 8, wherein the valve metal is aluminum or tantalum. 12. The method according to claim 8, wherein the dielectric layer is a polymer film. 13. The method according to claim 12, wherein the polymer film is a polyimide film. 14. The polythiophene derivative is poly (3,4).
-Ethylenedioxythiophene).
3. The method for manufacturing a capacitor according to 3. 15. The method according to claim 8, wherein the transition metal is iron (III), copper (II) or ruthenium (III). 16. A step of preparing a dielectric layer, a step of preparing a thiophene derivative monomer, and a step of preparing a transition metal salt of benzene sulfonic acid having at least one sulfonic acid group or at least one alkyl group and a sulfonic acid group. At least one of alkyl benzene sulfonic acid transition metal salts having at least one alkyl group and an alkyl naphthalene sulfonic acid transition metal salt having at least one sulfonic acid group or at least one anthraquinone sulfonic acid transition metal salt having at least one sulfonic acid group A step of preparing an oxidizing agent comprising at least one of the following: a step of preparing an additive selected from a phenol derivative or a nitrobenzene derivative; and the step of preparing the polymerizable monomer on at least one of the surfaces of the dielectric layer. Conductivity chemically polymerized using oxidants Method of manufacturing the capacitor and a step of forming a conductive layer made of molecules. 17. A step of preparing a dielectric layer, a step of preparing a thiophene derivative monomer, a step of preparing a transition metal salt of naphthalenesulfonic acid having at least one sulfonic acid group, and a step of preparing at least one alkyl group and a sulfonic acid group. Preparing an oxidizing agent comprising at least one of a transition metal salt of an alkylnaphthalenesulfonic acid having at least one or a transition metal salt of anthraquinonesulfonic acid having at least one sulfonic acid group; and a phenol derivative or a nitrobenzene derivative. A step of preparing an additive; and a step of forming a conductive layer of a conductive polymer obtained by chemically polymerizing the polymerizable monomer using the oxidizing agent on at least one of the surfaces of the dielectric layer. Manufacturing method of capacitor. 18. The method according to claim 16, wherein the phenol derivative is nitrophenol, cyanophenol, hydroxybenzoic acid, or hydroxyphenol. 19. The method according to claim 16, wherein the nitrobenzene derivative is nitrobenzene, nitrobenzoic acid, or nitrobenzyl alcohol.