JP2741065B2 - Method for manufacturing solid electrolytic capacitor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a solid electrolytic capacitor using a thin film by a Langmuir-Blodgett method as a solid electrolyte membrane.

(Prior Art) In recent years, with the digitization of electric devices, there has been a growing demand for capacitors used therein to have low impedance, small size and large capacity in a high frequency range.

A capacitor formed by connecting a pair of lead-out terminals to each of a pair of anode and cathode foils made of aluminum foil that has been commonly used in the past, and wrapping a spacer made of kraft paper, manila paper, etc. between the two electrode foils and winding them By removing the spacers and converting the electrolyte to a tetracyanoquinodimethane (hereinafter abbreviated as TCNQ) complex or a conductive polymer from the capacitor that was impregnated with the electrolyte in the case, housed in the case, and sealed, In addition to the improvement of various characteristics, the miniaturization and the improvement of the manufacturing process are in further progress.

As an example of such a technique, a method of manufacturing a solid electrolytic capacitor in which a thin film (hereinafter abbreviated as LB film) is laminated on an electrode having a dielectric film on the surface by a Langmuir-Blodgett method (Japanese Patent Laid-Open No. -122207) has been proposed. This method will be described with reference to FIG. 3. A Langmuir-Blodget device (hereinafter abbreviated as LB device) 8
A monomolecular film (not shown) of a pyridinium-TCNQ complex is formed on the water surface in the inside, and an electrode plate 10 in which an aluminum thin film and its anodic oxide film are laminated on a plastic film substrate by pulleys 9 continuously up and down. The LB film is accumulated and laminated on the electrode plate by moving the floats 11 and 12 continuously in the direction of the electrode plate at the same time, and is simultaneously provided on the electrode plate. The LB film is used as a solid electrolyte of a capacitor.

(Problems to be Solved by the Invention) The above-mentioned method for manufacturing a solid electrolytic capacitor in which an organic semiconductor LB film is laminated on an electrode plate enables the manufacture of a small and large-capacity solid electrolytic capacitor. Two layers of the film required a float for controlling the surface pressure, and it was necessary to use a plurality of LB devices. In addition, in the above method, it is necessary to adopt a complicated method in terms of steps, such as providing a silver vapor deposition film on the LB film of the electrode plate on which the LB film is laminated to form a capacitor.

An object of the present invention is to eliminate the above-mentioned disadvantages and to make it simpler than before.
Using an LB device and one LB device to simultaneously apply two electrode plates
An object of the present invention is to provide a method for manufacturing a solid electrolytic capacitor which can be easily formed into a paperless type capacitor by laminating LB films and thereafter laminating the two films.

(Means for Solving the Problems) The present invention has been made to solve such problems, and is directed to the production of a solid electrolytic capacitor having a solid electrolyte film on an anode plate provided with a dielectric film on the surface. At least one of the two electrode plates having a dielectric film on the surface is opposed to the trough of the LB device in which the solid electrolyte membrane material has been developed, and the two electrode plates are simultaneously pulled up continuously and vertically, or lowered, And simultaneously moving the electrode plate so as to approach the horizontal direction continuously, thereby obtaining an electrode plate on which an LB film is laminated, and using the electrode plate as a constituent member of a solid electrolytic capacitor. Thus, it is possible to manufacture a small and large-capacity solid electrolytic capacitor by a simpler method than the conventional method.

The method of the present invention will be described with reference to the drawings. FIG. 1 and FIG. 2 show conceptual diagrams of a method of laminating an LB film on an electrode plate, where 1 is an LB device, and 2 and 3 are opposed. Two electrode plates, at least one of which has a dielectric film on the surface. 4 and 4 'are vector representations of the vertical lifting or lowering speed Y of the electrode plates, in which the two electrode plates 2 and 3 are continuously raised or lowered in the vertical direction at the same speed. It shows. 5 and 5 'are vector representations of the speed X of the approach of the electrode plate in the horizontal direction performed in parallel with the vertical lifting or lowering of the electrode plate. It indicates that they approach in the same direction at the same speed. Therefore, the two electrode plates continuously move in the a direction or the b direction while facing each other. The lower part of FIGS. 1 and 2 conceptually shows the state of accumulation of the monomolecular films 6, 6 ', 7, 7' on the electrode plate when the electrode plate is moved.

Various methods can be adopted as a method of laminating the LB film on the electrode plate. As shown in FIG. 1, a method in which opposing electrode plates are successively pulled up in the a direction and accumulated in close proximity as shown in FIG. 1, or as shown in FIG. Then, there is a method of successively pulling up in the a-direction while approaching and accumulating, or a method of repeating these laminating operations a plurality of times. However, the present invention is not limited to these methods.

The LB device used in the present invention may have various structures. For example, making the width of the electrode plate smaller than the width of the trough, making the width of the electrode plate the same as the width of the trough,
It is also possible to use a device provided with a zone heater capable of moving on a trough and applying zone heating to a monomolecular film on the water surface to convert it into a multilayer film.

Further, the method of the present invention can be carried out by changing the method of laminating the LB film on the electrode plate in accordance with the type of the solid electrode material used.

For example, (1) a method in which an organic semiconductor is developed on a water surface and then accumulated on an electrode plate, and (2) a monomer is developed on a water surface and accumulated on the electrode plate, and then chemically oxidized or polymerized by electrolytic oxidation. Method, (3) a method in which monomers are polymerized on the water surface and then accumulated on the electrode plate, (4) a method in which the polymer is spread on the water surface and accumulated on the electrode plate, (5) By dissolving the charged water-soluble polymer in the aqueous phase and turning the oppositely charged amphipathic molecules on the water surface, they accumulate on the electrode plate as a polyion complex, and then heat-treated. To form a polymer laminated film.

As the solid electrolyte membrane material used in the method (1),
TCNQ complexes, such as long-chain pyridium / TCNQ complex, long-chain pyridium / (TCNQ) ₂ complex, (tetramethyltetraliafulvalene) ₃ · (long-chain TCNQ) ₂ complex, etc., and 4-cano-
N-alkyl-pyridinium • (TCNQ) complex, N-alkylquinolinium • (TCNQ) complex, 4-amino • 2,3,
5,6-tetraalkylanilinium · (TCNQ) ₂ complex,
2,2'-bipyridinium. (TCNQ) ₂ complex, 4-hydroxy-N-benzylanilinium. (TCNQ) ₂ complex and the like can also be used.

Examples of the solid electrolyte membrane material used in the method (2) or (3) include an amphiphilic pyrrole monomer and an amphiphilic neophene monomer. For example, 4-methylpyrrole-3-carboxylic acid octadecyl ester,
Octadecylpyrrole, 3-octylthiophene, 3-
Hexylthiophene, 3-dodecylthiophene and the like can be used.

As the solid electrolyte membrane material used in the method (4),
Examples include an amphiphilic pyrrole polymer and an amphiphilic neophene polymer.

Examples of the solid electrolyte membrane material used in the method (5) include a soluble precursor of poly (p-phenylenevinylene) having a repeating unit represented by the following formula (1).

(Wherein R ¹ and R ² are lower alkyl groups, X is a perfluorocarboxylic acid anion, or [CH _3- (CH ₂ ) ₁₁ .O.CO] ₂
-CH ₂ -CHSO _3- and the like having an ability to form a bilayer film) The LB film laminated on the electrode plate by the method of the present invention can be doped as needed. As the doping, any of known chemical doping and electrochemical doping can be adopted.

Examples of the electrode plate used in the present invention include valve metal foils such as aluminum, tantalum, niobium, titanium, and tungsten. At least one of the two electrode plates has a dielectric film on its surface.
Normally, these electrode plates are formed by etching a valve metal foil to increase the surface area, and then, if necessary, oxidizing the surface to form a metal oxide dielectric film. In this case, the electrode used as the cathode of the capacitor may be oxidized. As the method of the oxidation treatment, various known methods, for example, a method of anodizing the valve metal foil at 60 to 80 V, and the like are used. Further, the electrode used for laminating the LB film in the present invention is not limited to the above, metal, plastic, metal on a substrate such as glass, electrode material such as conductive oxide vacuum deposition, It is also possible to use a thin film formed by means such as sputtering or ion plating and, if necessary, a dielectric film provided thereon by means such as vacuum deposition, sputtering, ion plating or electrode oxidation.

As shown in FIGS. 1 and 2, an electrode plate having an LB film laminated by the method of the present invention can easily produce a paperless solid electrolytic capacitor by laminating two produced electrode plates. be able to.

(Examples) Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

Example 1: A high-purity aluminum (purity: 99.99%) foil was used as a base material. After the surface of the aluminum foil was etched to increase the surface area, the surface was sufficiently washed with water. Next, anodizing treatment was performed at a voltage of about 70 V using the aluminum foil as an anode, and a dielectric film of aluminum oxide was formed on the surface. The operation shown in FIG. 1 was repeated using this electrode plate, and an (LB) film was accumulated and laminated on the electrode plate using (tetramethyltetrathiafulvalene) _3. (Tetradecyl TCNQ) ₂ complex.

This LB film showed a high value of conductivity of about 1 s / cm ² . Two electrode plates having the LB film laminated thereon were overlapped to prepare a paperless laminated solid electrolytic capacitor.

Example 2 Using the same electrode plate as in Example 1, the operation of FIG. 2 was repeated to accumulate LB films on the electrode plate.

As the solid electrolyte membrane material, 4-methyl-pyrrole-
A mixture of 3-carboxylic acid octadecyl ester and octadecane was used.

The electrode plate on which the LB film was accumulated was then subjected to electrolytic oxidation polymerization in an electrolytic solution using acetonitrile as a solvent and lithium perchlorate as a supporting electrolyte to obtain an electrode plate having the pyrrole polymer laminated thereon. The electrode plates were overlapped as shown in FIG. 2 to produce a paperless capacitor.

Example 3 Using the same electrode plate as in Example 1, the operation of FIG. 1 was repeated to accumulate LB films on the electrode plate. The oxidizing agent FeCl ₃ is dissolved in the aqueous phase in the trough of the LB device, and
-Octadecyl pyrrole developed. 3-octadecylpyrrole formed a polymer film on the water surface by the action of the oxidizing agent.

 Then, the polymer film was accumulated on the electrode plate.

The two electrode plates thus obtained were combined to prepare a paperless capacitor.

Example 4 Using the same electrode plate as in Example 1, the operation of FIG. 1 was repeated to accumulate LB films on the electrode plate.

For the solid electrolyte membrane material, a repeating unit of the following formula A precursor of poly (p-phenylenevinylene) having the following formula was used. The precursor was developed in a trough of an LB apparatus, a monomolecular film was formed on a water surface, and then accumulated on an electrode plate. Next, this electrode plate was heat-treated at about 200 ° C. for about 2 hours to obtain an electrode plate having a poly (phenylene vinylene) LB film. Since the LB film has a low conductivity, the conductivity was increased by doping with sulfuric acid, and the obtained electrode plates were combined to form a paperless capacitor.

(Effects of the Invention) As described in detail above, according to the method of the present invention, two LB film laminated electrode plates can be manufactured at a time, and the two electrode plates can be easily assembled by combining them. Since a paperless solid electrolytic capacitor can be manufactured, the production process can be simplified. Further, the LB apparatus used in the present invention does not require the float used in the conventional apparatus, so that the manufacturing apparatus can be simplified.

In addition, since the LB film is used, a small-sized and large-capacity capacitor can be manufactured.

Therefore, the present invention achieves extremely excellent effects in terms of the production process, the equipment, and the performance of the capacitor.

[Brief description of the drawings]

FIGS. 1 and 2 are conceptual diagrams showing a process of laminating a solid electrolyte LB film on an electrode plate in accordance with the method of the present invention. The lower part of each figure shows that the LB film is accumulated on the electrode plate in each process. It shows the status. FIG. 3 shows the LB in the conventional method of accumulating the LB film on the electrode plate.
FIG. 2 shows a conceptual diagram of the device. 1,8: LB device, 2, 3, 10: electrode plate, 4, 4 ': velocity vector indicating the vertical lifting or pulling speed of the electrode plate, 5,
5 ′: velocity vector indicating the approach speed of the electrode plate in the horizontal direction, 6, 6 ′, 7, 7 ′: monomolecular film, 9: pulley, 11, 12: float, a,
b: Moving direction of electrode plate

Continuation of the front page (56) References JP-A-2-309615 (JP, A) JP-A-2-21965 (JP, A) JP-A-1-218630 (JP, A)

Claims (5)

(57) [Claims] 1. A method for producing a solid electrolytic capacitor having a solid electrolyte film on an anode having a dielectric film provided on a surface thereof.
A Langmuir-Blodgett film is obtained by simultaneously raising or lowering two electrode plates having a dielectric film on the surface at the same time continuously in the vertical direction and simultaneously moving them in the horizontal direction. A method for producing a solid electrolytic capacitor, characterized by obtaining an electrode plate on which is laminated, and using the electrode plate as a component of the solid electrolytic capacitor. 2. The method according to claim 1, wherein the vertical lifting and the horizontal movement of the electrode plate are simultaneously and continuously performed in one lamination operation.
3. The method for manufacturing a solid electrolytic capacitor according to item 1. 3. The method for manufacturing a solid electrolytic capacitor according to claim 1, wherein in a single laminating operation, the raising and lowering of the electrode plate in the vertical direction and the moving in the horizontal direction are simultaneously and continuously performed. 4. The method for manufacturing a solid electrolytic capacitor according to claim 1, wherein the laminating operation is repeated a plurality of times. 5. The method according to claim 1, wherein said two electrode plates on which a Langmuir-Blodgett film is laminated are overlapped.
A method for producing an electrolytic capacitor according to any one of claims 4 to 6.