JPH10154638A - Method for manufacturing solid capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a solid capacitor that can form a conductive function macromolecular film layer with less leakage current even if a rated voltage is high, namely 10V or higher, by carefully designing the surface treatment method of an aluminum anodized film layer. SOLUTION: In a method for manufacturing a solid capacitor with a conductive function macromolecular film layer formed on an anodized film layer as a solid electrolyte, the anodized film layer is formed in a solution containing at least four constituents of each acid of boric acid, citric acid, adipic acid, and phosphoric acid or its salt by formation treatment, and the conductive function macromolecule film layer is formed in a solution containing dodecylbenzenesulfone acid, borodislicylic acid ammonium, and pyrrole by electrolytic oxidation polymerization. Also, a thin-film layer of γ- glycidoxypropyltrimetoxysilane or octadecyltrimetoxysilane is formed on the anodized film layer surface and then a conductive function macromolecular film layer is formed in a solution by electrolytic oxidation polymerization.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a solid capacitor using a conductive functional polymer film layer as a solid electrolyte.

[0002]

2. Description of the Related Art A solid-state capacitor in which a conductive functional polymer film layer is formed on an anodic oxide film layer formed on the surface of an aluminum foil and the conductive functional polymer film layer is a solid electrolyte is different from a conventional electrolytic capacitor. It is known that the solid-state capacitor has a low impedance and a low equivalent series resistance because the specific resistance is very small as compared with the electrolyte used (such as a driving electrolyte or manganese dioxide).

As described above, a solid capacitor using a conductive functional polymer film layer as a solid electrolyte has excellent capacitor characteristics. However, depending on the method of forming the conductive functional polymer film layer, the yield is poor or the leakage current is low. Because of the large value, various methods for forming a conductive functional polymer film layer have been proposed. However, these forming methods are effective for a solid capacitor having a low rated voltage of about 4 V to 8 V, but a leakage current value is large at a rated voltage of 10 V or more, and a leakage current value is large at a rated voltage of 10 V or more. At present, there is no effective and suitable forming method.

As a method for forming a conductive functional polymer film layer on the aluminum anodic oxide film, a chemical oxidation polymerization method and an electrolytic oxidation polymerization method have been proposed, and the effective method is an electrolytic oxidation polymerization method. . In this electrolytic oxidation polymerization method, for example, pyrrole is dissolved in an acetonitrile solvent, and as an electrolyte, a boron compound (ammonium borodi-salicylate, borodi-citric acid, etc.) or a sulfur compound (dodecylbenzenesulfonic acid, tetraethylammonium paratoluenesulfonic acid) The most effective method is to carry out electrolytic oxidative polymerization in a solution in which (E.

[0005]

The pyrrole is dissolved in the most effective acetonitrile solvent, and electrolytic oxidative polymerization is carried out in a solution in which a boron compound or a sulfur compound is dissolved as an electrolyte. However, even when a conductive functional polymer film layer is formed, there is a disadvantage that the leakage current value increases when the rated voltage increases.

[0006] The above-mentioned drawbacks include poor adhesion at the interface between the aluminum anodic oxide film layer and the conductive functional polymer film layer, and variations in the film quality of the conductive functional polymer film layer (film thickness, density, uniformity). Gender etc.). This is because as the thickness of the aluminum anodic oxide film increases, the electrolytic oxidation polymerization reaction becomes more difficult and the reaction does not proceed smoothly. Therefore, there is a demand for a method of forming a conductive functional polymer film layer in which the electrolytic oxidation polymerization reaction easily proceeds even when the thickness of the aluminum anodic oxide film is increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and by devising a surface treatment method of an aluminum anodic oxide film layer, a conductive function having a small leakage current even at a high rated voltage of 10 V or more. An object of the present invention is to provide a method for manufacturing a solid capacitor capable of forming a polymer film layer.

[0008]

According to a first aspect of the present invention, there is provided a method for forming an anodized film layer on a surface of an aluminum foil having a roughened surface by a chemical conversion treatment. Forming an insulating material layer on the aluminum foil surface, dividing the aluminum foil surface into two parts, using one of the divided parts as an external anode terminal joint, and forming a conductive functional polymer film on the other anodic oxide film layer, In the method for manufacturing a solid capacitor using the conductive functional polymer film layer as a solid electrolyte, the anodic oxide film layer is formed of an aqueous solution containing at least four components of boric acid, citric acid, adipic acid, phosphoric acid, or a salt thereof. The conductive functional polymer film layer is formed by electrolytic oxidation polymerization in an aqueous solution containing dodecylbenzenesulfonic acid, ammonium borodisalicylate and pyrrole.

According to a second aspect of the present invention, in the method for manufacturing a solid capacitor according to the first aspect, after forming the anodic oxide film layer, the surface of the anodic oxide film layer is coated with γ-glycidoxypropyltriethyl. A thin film layer of methoxysilane or octadecyltriethoxysilane is formed, and then a conductive functional polymer film layer is formed by electrolytic oxidation polymerization in an aqueous solution.

[0010]

Embodiments of the present invention will be described below. Table 1 is a table showing the composition of the chemical conversion solution used in the method for producing a solid capacitor of the present invention.

[Table 1]

In a chemical conversion solution having a composition name and a composition ratio shown in Table 1, the surface of an aluminum foil (aluminum-etched foil) having a roughened surface was subjected to a chemical conversion treatment, as shown in FIG.
An aluminum anodic oxide coating layer 2 is formed on the surface of an aluminum foil 1. When the composition and the composition ratio of the chemical conversion liquid are as shown in Table 1, a uniform aluminum anodic oxide film layer 2 can be formed on the surface of the aluminum foil 1, and when the electrolytic oxidation polymerization is performed later, the conductive functional polymer film Grows better.

An aluminum anodic oxide film layer 2 is formed on the surface.
As shown in FIG. 2, an insulating material (resin material) layer 3 is formed on a predetermined portion of the aluminum foil 1 on which is formed, and the surface of the aluminum anodic oxide coating layer 2 is divided into two portions. One of the portions is used as an external anode terminal connection portion as described later, and the aluminum anodic oxide film layer 2a of the other portion is
The aluminum anodic oxide film layer 2 was immersed in an alcohol solution of γ-glycidoxypropyltrimethoxysilane or octadecyltriethoxysilane of 2% by weight for 2 minutes.
The surface of a is surface-treated. Subsequently, a conductive functional polymer film layer 4 is formed on the surface-treated aluminum anodic oxide film layer 2a by electrolytic oxidation polymerization.

Table 2 shows the composition names and composition ratios of the electrolytic solutions for the electrolytic oxidation polymerization.

[Table 2] The electrolytic oxidation polymerization using the aqueous solution shown in Table 2 as the electrolytic solution is shown in FIG.
The aluminum anodic oxide coating layer 2a of one part divided by the insulating material layer 3 of the aluminum foil 1 surface-treated in the alcohol solution is immersed in the electrolytic solution 11 in the conductive container 10 as shown in FIG. Then, a predetermined voltage and current are applied from the DC power supply 12 using the aluminum foil 1 as an anode and the opposite electrode as a cathode.

As described above, the aluminum anodic oxide film layer 2a is immersed in an alcohol solution of γ-glycidoxypropyltrimethoxysilane or octadecyltriethoxysilane for 2 minutes to perform a surface treatment, thereby obtaining a conductive film by electrolytic oxidation polymerization. It was confirmed that the reactive growth of the functional polymer film was extremely good. This is because the silane agent 5 is vertically adsorbed on the aluminum anodic oxide film layer 2a as shown in FIG. 4 by performing the above-mentioned surface treatment, and the silane agent 5 Gap 1 of
4, as shown in FIG.
It is presumed that the conductive functional polymer film layer 4 grows upward from the surface of a.

As described above, the silane agent 5 is for allowing the conductive functional polymer film to grow perpendicularly to the surface of the aluminum anodic oxide film layer 2a. It is intended to grow horizontally with respect to the anodized film layer. This is because it is necessary to form a uniform conductive functional polymer film layer on the aluminum anodic oxide film layer 2 in a portion to be constituted as a solid capacitor by electrolytic oxidation polymerization.

However, when the conductive functional polymer film grows in the horizontal direction at the initial stage of electrolytic oxidation polymerization (0 to 2 minutes at the start of electrolytic oxidation polymerization), the conductive functional polymer film Since the polymerization reaction has a limit and the growth stops halfway, the aluminum anodic oxide film layer 2 is often not entirely covered. Thus, if the silane agent 5 is adsorbed on the surface of the aluminum anodic oxide coating layer 2 and electrolytic oxidation polymerization is performed as described above, growth occurs in various parts of the surface of the aluminum anodic oxide coating layer 2 in a vertical direction. By allowing the growth in the horizontal direction to occur, a uniform conductive functional polymer film layer 4 can be formed on the aluminum anodic oxide film layer 2.

The conductive functional polymer film layer 4 is formed on the aluminum anodic oxide film layer 2a as described above, and the graphite layer is formed on the conductive functional polymer film layer 4 as shown in FIG. 6, a silver paste layer 7 is formed, an anode external terminal 8 is connected to the other portion of the aluminum foil 1 divided by the insulating material layer 3, and a cathode external terminal 9 is connected to the silver paste layer 7; (Not shown), a solid capacitor using the conductive functional polymer film layer 4 as an electrolyte is completed.

It has been confirmed that the solid capacitor having the conductive functional polymer film layer 4 formed as described above has a small leakage current even when the rated voltage is 10 V or more.

For comparison with the above embodiment, an aluminum anodic oxide film was formed on the surface of an aluminum foil in a 10% by weight aqueous solution of ammonium adipate, which is a conventional chemical composition, and the aluminum anodic oxide film was formed. In order to form a conductive functional polymer film on the layer, 4.0 w
t.% dodecylbenzenesulfonic acid and 2.0 wt.%
Although the electrolytic oxidation polymerization was attempted in an aqueous solution of pyrrole, a conductive functional polymer film layer could not be formed.

[0020]

【The invention's effect】

(1) As described above, according to the first aspect of the present invention, a chemical conversion treatment is performed in an aqueous solution containing at least four components of each acid such as boric acid, citric acid, adipic acid, phosphoric acid or a salt thereof. Forming a conductive functional polymer film layer by electrolytic oxidation polymerization in an aqueous solution containing dodecylbenzene sulfonic acid, ammonium borodi-salicylate and pyrrole, thereby forming a high rated voltage. In such a case, a solid capacitor with low leakage current can be manufactured.

(2) According to the invention of claim 2, after forming an anodic oxide film on the surface of the aluminum foil, γ-glycidoxypropyltrimethoxysilane or octadecyl is formed on the surface of the anodic oxide film. A thin layer of triethoxysilane is formed, followed by electrolytic oxidation polymerization, so that the silane agent is vertically adsorbed on the anodic oxide film layer, and a conductive functional polymer film layer grows in the gap between the silane agents. In this case, the growth of the conductive functional polymer film is improved, and a solid capacitor with a small leakage current can be manufactured when the rated voltage is high as described above.

[Brief description of the drawings]

FIG. 1 is a view showing a cross section of an aluminum foil having an aluminum anodic oxide film layer formed on a surface thereof.

FIG. 2 is a sectional view showing a state where an aluminum anodic oxide film layer is formed and divided by an insulating material layer.

FIG. 3 is a diagram showing a schematic configuration example of an apparatus for performing electrolytic oxidation polymerization.

FIG. 4 is a prediction diagram showing a state in which a silane agent is adsorbed on an aluminum anodic oxide film layer.

FIG. 5 is a prediction diagram showing a state in which a conductive functional polymer grows in a gap between silane agents.

FIG. 6 is a diagram showing a cross-sectional configuration of a solid electrolytic capacitor manufactured by the manufacturing method of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 aluminum foil 2 aluminum anodic oxide film layer 3 insulating material layer 4 conductive functional polymer film layer 5 silane agent 6 graphite layer 7 silver paste layer 8 anode external terminal 9 cathode external terminal

Claims (2)

[Claims] An anodized film layer is formed on a surface of an aluminum foil having a roughened surface by a chemical conversion treatment, and then an insulating material layer is formed on a predetermined portion to divide the aluminum foil surface into two parts. One of the divided is an external anode terminal joint,
Forming a conductive functional polymer film layer by electrolytic oxidation polymerization on the other anodic oxide film layer, a method for manufacturing a solid capacitor using the conductive functional polymer film layer as a solid electrolyte, wherein the anodic oxide film layer is , Boric acid, citric acid, adipic acid, phosphoric acid, or a salt thereof, formed in an aqueous solution containing at least four components by an chemical conversion treatment, wherein the conductive functional polymer film layer is formed of dodecylbenzenesulfonic acid, -A method for producing a solid capacitor, characterized by being formed by electrolytic oxidation polymerization in an aqueous solution containing ammonium salicylate and pyrrole. 2. The method for manufacturing a solid capacitor according to claim 1, wherein after forming the anodic oxide film layer, γ-glycidoxypropyltrimethoxysilane or octadecyltriethoxysilane is formed on the surface of the anodic oxide film layer. Forming a thin film layer of
Thereafter, a conductive functional polymer film is formed by electrolytic oxidation polymerization in the aqueous solution.