JPH0321006A - Manufacture of solid electrolytic capacitor - Google Patents

Abstract

PURPOSE:To eliminate risk of damaging a chemically polymerized film and an oxide film by a method wherein electrolytic oxidation polymerization is performed with carbon fibers wound around a capacitor element as a power supply electrode and then the carbon fibers protruding from an electrolytic polymerized film are cut off. CONSTITUTION:Electrolytic oxidation polymerization with carbon fibers 7 wound around a capacitor element 5 as a power supply electrode is performed and then the carbon fibers 7 protruding from an electrolytic polymerized film 10 are cut off. That is, since the carbon fibers 7 used as the power supply electrode are soft, a chemically polymerized film and an oxide film are not damaged even if the fibers 7 are in contact with a chemically polymerized film 3 and the oxide film to contribute to effective formation of the electrolytic polymerized film 10 as well as the carbon fibers 7 in contact with the capacitor element 5 are not removed after the formation of the electrolytic polymerized film 10 with only portions protruding from the electrolytic polymerized film 10 to be cut off. Thus not only the electrolytic polymerized film 10 but also the chemically polymerized film 3 and the oxide film are free from damage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a method for manufacturing a solid electrolytic capacitor using a conductive polymer membrane as a solid electrolyte.

(Prior art) In recent years, Japanese Patent Application Laid-Open No. 60-24401-7 or Japanese Patent Application Laid-open No. 6
There is one disclosed in Publication No. 3-181308.

The techniques disclosed in these publications involve chemically converting a valve metal with a roughened surface to form an oxide film, and using the anode body as an anode, immersing it in an electrolytic solution and energizing it to form an oxide film on the oxide film. In this method, an electrolytic polymer membrane is used as a solid electrolyte.
Since the oxide film is an insulator, there is no effective electrical conduction with the cathode, and current concentrates in defective parts of the oxide film or in areas close to the cathode, making it difficult to obtain a uniform electrolytic polymer film as a solid electrolyte. It was extremely difficult.

Therefore, a thin chemical polymer film is formed in advance on the oxide film of the anode body by chemical oxidation polymerization, and a metal wire such as a platinum wire, nickel wire, or stainless steel wire is brought into contact with the chemical polymer film as a power supply electrode, and then placed in the electrolyte. By applying electricity to perform electrolytic oxidative polymerization, an electrolytically polymerized membrane as a solid electrolyte is formed.

However, since the metal wire used as the power supply electrode is sandy, there is a risk of damaging not only the chemically polymerized film but also the oxide film when it comes into contact with the oxide film. When separating, the electrolytic polymer film formed on the chemically polymerized film at the contact part of the power supply electrode may be damaged, as well as the chemically polymer film, resulting in an increase in leakage current and short-circuit failure. There is a risk that
It was not necessarily an effective method.

(Problems to be Solved by the Invention) As described above, the conventionally undisclosed means have resulted in problems that need to be solved in order to obtain a desired electrolytically polymerized membrane.

The present invention has been made in view of the above points, and is a solid electrolyte that can form an excellent electrolytic polymer film that becomes a solid electrolyte without damaging the oxide film, chemical polymer film, or electrolytic polymer film. The purpose of this invention is to provide a method for manufacturing denza.

[Structure of the Invention] (Means for Solving the Problems) The method for manufacturing a solid electrolytic capacitor of the present invention includes forming a chemical polymer film by chemical oxidation polymerization on an oxide film formed on a valve metal, and then performing the chemical polymerization. In a method for producing a solid electrolytic capacitor in which an electrolytic polymerized film is formed on the membrane by electrolytic oxidative polymerization, carbon fibers as a power supply electrode are wound around the capacitor element and subjected to electrolytic oxidative polymerization, and then carbon fibers protruding from the electrolytic polymeric film are formed. This method is characterized by cutting and removing carbon fibers.

(Function) According to the above configuration, since the carbon fiber used as the power supply N electrode is soft, even if it comes into contact with a chemical polymer film or oxide film, it will not damage the chemical polymer film or oxide film, and the electrolysis can be carried out efficiently. At the same time as it contributes to the formation of a polymerized film, the carbon fibers that have come into contact with the condenser element are not removed after the electrolytic polymerized film is formed, but only the parts that protrude from the electrolytic polymerized film are cut and removed.
It does not damage electrolytically polymerized membranes, chemically polymerized membranes, or oxidized 34 films.

(Example) An example of the present invention will be described below. That is, as shown in FIG. 2, an anode lead 1 is attached to a high-purity aluminum foil on which an oxide film is formed, and an anode foil 3 and a separator paper 4 on which a chemically polymerized film 2 is formed on the surface by chemical oxidation polymerization.
A laminated winding capacitor element 5 is obtained.

Next, the condenser element 5 is reformed to repair the oxide film, and then, as shown in FIG. ,] Carbon $117 is used as a power supply electrode for each of the capacitor elements 5, and the electrolytic cell 8 is placed in a state in which this carbon fiber 7 is continuously wound around each of the capacitor elements 5.
The condenser element 5 is immersed in the electrolytic solution 9 in the electrolyte solution 9 to perform electrolytic oxidative polymerization, and as shown in FIG. After that, the carbon fibers 7 protruding from the electrolytic polymer membrane 10 as power supply electrodes are cut and removed, and then a carbon layer is formed on the surface of the electrolytic polymer membrane 10 as a means for drawing out the cathode, and then silver A conductive coating film is formed by applying a conductive coating film, a cathode lead is taken out from a part of the coating film, and finally an exterior is applied.

According to the manufacturing method of the solid electrolytic capacitor having the above configuration, since the carbon fiber 7 used as the power supply electrode is soft,
Even if it wraps around the capacitor element 5 and comes into contact with the chemically polymerized film 2, the chemically polymerized film 2 itself is not damaged, the cause of short circuit failure due to damage to the oxide film is eliminated, and the electrolytic polymerized film 10 as a solid electrolyte is efficient. can be formed into

In addition, since the carbon m-string 7 that has come into contact with the 2 parts of the chemically polymerized film of the Ndenza element 5 is not removed after the electrolytic polymeric film 10 is formed, the carbon m-string 7 that is in contact with the chemically polymerized film 2 of the electrolytic polymeric film 10 of the electrolytic polymeric film 10 is not removed. It can greatly contribute to improving various properties without adding stress.

Next, a solid electrolytic capacitor obtained by the present invention,
The following table shows a comparison of the characteristics of solid electrolytic capacitors obtained by conventional methods in which metal wires are used as power supply electrodes and the metal wires are removed after electrolytic oxidation polymerization.

In both the example and the conventional example, the chemical oxidation polymerization means was 2 mol/
J) 0.5m after immersion in pyrrole/ethanol solution for 5 minutes
The electrolytic oxidative polymerization means produced pyrrole monomer-1 mOI/41 by immersion in an aqueous solution of ammonium persulfate for 5 minutes.
1 and acetonitrile containing 1 mol/J of sodium p-toluenesulfonate as a supporting electrolyte, and a constant current of 177 LA/cn was applied for 30 minutes.

The sample voltage was 35V-1.5μ for both the example and the conventional example.

As is clear from the above table, it was found that the products according to the present invention not only significantly contributed to the improvement of short-circuit defects, but also were effective in improving various characteristics, compared to the products according to the conventional example.

In the above embodiments, aluminum foil was used as the anode foil, but it can also be applied to valve metals such as tantalum foil or niobium strips, and these valve metal powders can be sintered. Of course, the present invention can be applied to a sintered anode body.

[Effects of the Invention] According to the present invention, there is no risk of damage to the chemically polymerized film or oxide film due to contact with the power supply electrode during the electrolytic oxidation polymerization process, and it not only greatly contributes to preventing short circuits but also It is possible to obtain a method for manufacturing a solid electrolytic capacitor that is effective in improving various characteristics without the risk of peeling off of polymer films, chemical polymer films, or oxide films.

[Brief explanation of drawings]

Figures 1 to 3 relate to one embodiment of the present invention;
The figure is a cross-sectional view showing a state in which a capacitor element is immersed in an electrolytic bath in an electrolytic oxidative polymerization method, Figure 2 is a developed perspective view showing a capacitor element before electrolytic oxidative polymerization, and Figure 3 is a configuration of a capacitor element after electrolytic oxidative polymerization. FIG. 2...Chemical polymer membrane patent application Hitomarukon Electronics Co., Ltd. Nippon Carlit Co., Ltd.

Claims (1)

[Claims] In the method for producing a solid electrolytic capacitor, in which a chemically polymerized film is formed by chemical oxidation polymerization on an oxide film formed on a valve metal, and then an electrolytically polymerized film is formed on this chemically polymerized film by electrolytic oxidation polymerization, the capacitor element is A method for producing a solid electrolytic capacitor, which comprises winding carbon fibers as a power supply electrode, performing electrolytic oxidation polymerization, and then cutting and removing carbon fibers protruding from an electrolytically polymerized film.