JPH02303017A - Manufacture of solid state electrolytic capacitor - Google Patents

Abstract

PURPOSE:To form a chemical polymerization film into a uniform electrolytic polymerization film and to prevent the shortcircuit failure by a method wherein in the case an electrolytic oxidation polymerization is performed after a chemical oxidation polymerization is performed, a feeder electrode is brought into contact to the chemical polymerization film formed on an insulating layer to perform the electrolytic oxidation polymerization. CONSTITUTION:An anode foil 1 having an anode lead-out terminal 2 and an insulating layer 4 is immersed in a pyrrole/ethanol solution for five minutes and moreover, is immersed in an ammonium persulfate aqueous solution for five minutes to form a polypyrrole film 5, which is a conductive high-molecular film, by a chemical oxidation polymerization. Then, a spacer paper 6 is superposed on this foil to wind spirally and after a wound element 7 is manufactured, a dielectric oxide film is restored by reformation. Moreover, a platinum wire 8 is used as a feeder electrode and the film 5 formed on the layer 4 is brought into contact to the electrode to perform an electrolytic oxidation polymerization. In such a way, the feed electrode dissolves and contributes to the formation of a stable electrolyte without contaminating a polymeric electrolyte.

Description

[Detailed Description of the Invention] [Objective of the Invention 1 (Field of Industrial Application) The present invention provides a solid electrolytic capacitor in which a solid electrolyte is formed on the surface of a dielectric fertilized film! '! J n method.

(Conventional technique v11) Solid electrolytic capacitors are usually aluminum.

A dielectric oxide film is formed on the film-forming metal surface of tantalum, and manganese dioxide, TCN
Solid electrolyte such as Q complex 1e1 fCi and 2J? It is constructed by sequentially forming Tf body layers. Capacitors using manganese dioxide as a solid electrolyte have drawbacks such as the dielectric oxide film being easily damaged during the manufacturing process;
Condensate υ using a CNQ button body has drawbacks such as poor thermal stability.

In addition, a capacitor has been proposed in which a polymer of a heterocyclic compound such as beer is formed on a dielectric oxide film by electrolytic polymerization to make it a prisoner-electric material. Therefore, it was not very difficult to form an electrolytically polymerized film on the surface, but it was possible (2).

The method for forming a polymer film on a dielectric oxide film is to form a polymer film in advance on the oxide film of the anode body by chemical oxidation, and use this chemical polymer film as an electrode during electrolytic polymerization. There has been a method in which a conductive material such as a metal is brought into contact with the membrane and electricity is applied in an electrolytic solution to form a polymeric membrane.

When performing electrolytic polymerization on an anode foil with a good oxide film formation as described above, the presence of the oxide film, which is an insulator, prevents efficient conduction of electricity with the 12 electrode, making it impossible to form a polymer film.
Or, even if it can be formed, the current will concentrate in the defective parts of the oxide film or in the places where the anode foil and the cathode foil are close, making it impossible to obtain a uniform conductive polymer film. In addition, a chemically oxidized 10-layer film was formed on the oxide film of the anode foil in advance, and gold I! When performing electrolytic polymerization by contacting a conductive material such as as a power supply electrode for electrolytic polymerization, the dielectric oxide film or chemical polymer film may be damaged or warm, and the contact state of the power supply electrode may be different. There were variations in the formation of the electrolytic polymer film, and there are still areas for improvement such as large leakage current and large tan δ, and furthermore, the formed polymer film was damaged by the mechanical shock when the power supply electrode was peeled off. There were problems such as.

In addition, when forming a polymer film as described above, if the gold electrolyte creeps up and comes into contact with weak points in the dielectric oxide film or unformed parts for electrode extraction, it will cause a short circuit and become unusable. There were drawbacks. For this reason, lead wires and lead frames for drawing out electrodes are sometimes provided with an insulating material such as resin near the surface of the electrolyte for the table to prevent contact with the electrolyte. Since the capacitor itself is very small, the application of the insulator is difficult and inefficient, and there is also the disadvantage that the applied insulator may be uneven.

(Problems to be Solved by the Invention) As stated above, conventionally it has been difficult to form an electrolytic layer on a film-forming metal surface on which a dielectric oxide film has been formed, and chemical When forming a polymer film and performing electrolytic polymerization using the chemically polymerized film as an electrode, the state of formation of the electropolymer film may vary depending on the contact state of the power supply electrode, and the polymer film may be damaged when the supply ffi electrode is peeled off. Furthermore, during polymerization, the film-forming metal is immersed in the polymer solution, but if the solution creeps up and forms a polymer film in areas other than the dielectric oxide film, a short circuit will occur, so An insulating material is applied to cover the area from the liquid level to the F part, but there are problems in that the application of this insulating material is difficult, inefficient, and the insulating material is uneven.

The present invention has been made in view of the above points, and it is possible to easily form a conductive polymer film uniformly on a dielectric oxide film, and also to reduce the damage (13
The purpose of this work is to provide a method for manufacturing solid electrolytic capacitors that is easy to use and has excellent workability.

Structure of the Invention] (Means for Solving the Problems) The solid electrolytic capacitor of the present invention is manufactured by chemical conversion treatment, chemical oxidation polymerization, electrolytic oxidation polymerization, etc. In the method for manufacturing a flat plate type one-volume solid electrolytic capacitor of the same type, sintered type or laminated type, in which a carbon layer is formed and a conductive coating film serving as a cathode is applied on the carbon layer, the chemical oxidation polymerization is performed at the anode lead-out part. Chemical oxidation polymerization is carried out by applying an insulating layer that covers the surface from the liquid level to the top.
The electrolytic oxidation polymerization is carried out using a chemical polymer film formed on the insulating layer or below the insulating layer as an anode.

(Function) In the method for manufacturing a solid electrolytic capacitor according to the present invention, a chemically polymerized film is formed on a dielectric oxide film and an insulating layer formed on the dielectric oxide film, and electrolytic oxidative polymerization is performed on this insulating layer. Metal wires or other conductive substances are brought into contact with the chemically polymerized film formed as a power supply electrode and polymerized, but since this contact is performed outside the m mixture, the power supply electrode cannot be used during or after polymerization. When peeling off, no mechanical shock is applied to the dielectric oxide film or conductive polymer film (chemical polymer film, electrolytic polymer film) on the pA electrode, and the power supply electrode dissolves and contaminates the polymer electrolyte. This can contribute to the formation of a stable electrolyte. Furthermore, if a silicone tube is used as the insulating layer and inserted into the anode lead wire to form an insulating layer, there is no need to apply the coating to minute areas, so there is the advantage that the work can be done more efficiently.

(Example) Practical III/41 As shown in Fig. 1, the anode lead terminal 2 was caulked to a high-purity aluminum foil with a roughened surface and a dielectric oxide film formed on it and a diameter of 60 μm and a width of 3 IMR. After installation, place the anode foil 1 in a bright place at 25*.
- After inserting the tube, the insulation layer 4 was formed by heating and shrinking it.

The anode foil 1 having the PA electrode output terminal 2 and the insulating layer 4 thus produced was immersed in a virol/ethanol solution of 2 m01/J for 5 minutes. The conductive polymer film 5 was formed by chemical oxidative polymerization by immersion in a 0.5 mol/j ammonium persulfate aqueous solution for 5 minutes.

These operations are performed without submerging the insulating layer 4 in the solution. Next, spacer paper 6 was layered on this anode foil 1 and wound in a spiral shape to produce a wound element 7, after which the dielectric oxide film was repaired by re-forming.

Further, as shown in FIG. 2, a platinum wire 8 having a diameter of 0.1#I was brought into contact with the polypyrrole film 5 formed on the insulating layer 4 as an RFI electrode to carry out electrolytic oxidation polymerization. Ti electrolytic oxidation polymerization To explain in detail, virol monomer 1 is used as an electrolyte.
Using acetonitrile containing 1 mol/J of sodium p-toluenesulfonate as m0I/j and supporting electrolyte i, platinum $98 was brought into contact with the insulating layer 4 without being immersed in the electrolytic solution, and formed on the anode foil 1 by chemical oxidation polymerization. Constant electric R electrolytic oxidative polymerization (1 mA/cd, 1:15 J) was performed between the polypyrrole film 5 prepared as an anode and an external cathode to form a polypyrrole film by electrolytic oxidative polymerization. This element was immersed in colloidal carbon to form a carbon layer, and then silver paste was applied to form a conductive coating, from which a cathode was taken out. This element is sealed in a case and rated at 10V.
A -6.7 μF solid electrolytic capacitor was completed.

As shown in Table 1, this capacitor showed improvements in capacitance, ta, nδ, leakage current, and a reduction in the incidence of short-circuit defects compared to conventional capacitors.

Example 2 Everything was the same as in Example 1 except that a silicone resin was applied instead of the silicone dupe in Example 1, and the insulating layer was formed by heating and curing this. The characteristics of this capacitor are shown in Table 1.1゜Example 3 Similar to the one used in Example 1, a silicone tube was inserted into the lead wire, and then an anode foil connected to the heat-shrinked anode lead terminal was wound. A polypyrrole film was formed from this by chemical oxidative polymerization under the same conditions as in Example 1, and a power supply electrode was brought into contact with the polypyrrole film formed on the silicone to form a polypyrrole film by electrolytic oxidative polymerization.

The characteristics of the solid electrolytic capacitor with a rating of 10V-6.7μF produced in this way are as shown in Table 1.

In addition, in such a manufacturing method, an appropriate spacer may be provided between the anode foils.

Conventional example The surface is roughened and a dielectric oxide film is formed60
After attaching the anode lead-out terminal by caulking to a high-purity alpha aluminum foil with a width of 3 m2 μm2, cut the anode foil to 25N4 (9).

The anode foil was then immersed in a 2rnol/j beer/ethanol solution for 5 minutes. Furthermore, it was immersed in a 0.5 m01/J ammonium persulfate aqueous solution for 5 minutes to form a polypylene film, which is a conductive a1 molecular film, by chemical oxidative polymerization. After winding a spacer paper around this anode foil into an m-wound shape to form an element, the dielectric oxide film was repaired by reconversion.Furthermore, a platinum wire with a diameter of 0.1 #I was used as a power supply electrode. Chemistry of this device: Acetonitrile containing 1 mol/N of virol monomer as an electrolyte and 1 mol/Jl of sodium paratoluenesulfone as a supporting electrolyte is used in contact with the gold film, and is connected to the external cathode by electrostatic Fi electrolytic oxidative polymerization (
1 mA/cIi, 11 L'i), and after forming a polypil [1-l crotch] by electrolytic and deoxidative polymerization, a capacitor was completed according to the method of Example 1.

The characteristics of this capacitor are shown in Table 1.

Table 1 Examples As shown in Fig. 3, aluminum P111 with a size of 3 tea x 6 m x 60 μm in thickness was roughened and subjected to chemical conversion treatment with a voltage of 49 V applied. ti (A M chemically formed film 12 was formed. After applying silicone resin to this aluminum foil 11 to form an insulating layer 13, Example 1
Under the same conditions as above, the chemical small gold film 14 with a thickness of 0.5 μm rL was immersed in the chemical oxidation mixture so that the $i layer 13 would not be buried.
Using the gold film 14 as wANA, a conductive film of silver paste 416 was formed on the gold film 15 and the electropolymerized film 15-E to a thickness of 10 μm, and the structure as shown in FIG. is. Table 2 shows the characteristics of a capacitor with a rating of 10V-1 .mu.F, which was prepared by taking out the anode lead terminal from an appropriate location on the top n1 of the R layer 13 and the F2 pole lead terminal from the conductive layer 16.

Table 2 Note that the insulating layer 13 was formed by applying silicone resin, but a silicone ring-shaped material may be fitted and heat-shrinked.

Example 5 Continuing with Example 4, we will now describe an actual 18 PA in which a plurality of prepared capacitor elements are laminated as shown in FIG.

After laminating 7 sheets of 6 formed up to the electrolytic assembly 15 of the capacitor element shown in FIG.
Silver paste was applied to the common cathode, and an appropriate lead terminal was connected to this to form a 112-rod lead-out end. On the other hand, the anode lead-out terminal is also coated with an insulating layer 13 and a gold film 14. The above 1i24 is applied to the aluminum 9511 isolated from the gold film 15.
Connect the anode lead terminal by the same means as in the case of 4i =
1 Ndenri was constructed. Table 3 shows the characteristics of this multilayer solid electrolytic capacitor.

Table 3 Note that the lead terminal is generally connected to a conductive layer such as a cathode paste using a cathode lead terminal, using a suitable shape such as a lead wire or a lead frame. In addition, the anode lead-out terminal may also be connected by the company's method or by various welding methods.Also, the required sheets of aluminum foil with an insulating layer are placed side by side at an appropriate interval, and the connection is made at the same time. Fi 171 of the invention of Mugi, which was formed by chemical oxidation polymerization, electrolytic oxidation polymerization, and electrolytic oxidation Φ polymerization to form a common conductive layer.
This is Shino in 1.

Example 6 As shown in FIG. 5, a 0.3 order φ tantalum wire 21 is implanted and tantalum powder is molded to obtain an element 22 of 3.2 mm φ x 5 gN, which is sintered at 1600°C. A type tantalum capacitor element was fabricated.

After applying 70V to this capacitor element 22 to perform a chemical conversion treatment, epoxy resin was applied to the area above the element end face of the tantalum wire 21 to form an insulating layer 23. This capacitor element 22 was immersed in a chemical polymerization solution for chemical oxidation polymerization, but this immersion was carried out without submerging the insulating layer 23 in the solution, thereby forming a chemical polymerization film 24. The capacitor element 22 on which the chemically polymerized film 24 has been formed in this manner is immersed in an electrolytic polymerization solution to perform electrolytic oxidative polymerization. A power supply electrode made of a platinum wire 25 is brought into contact with the power supply electrode, and the following is referred to as real/J1! ! Solid electrolytic condenser 1) was produced according to Example 1.

In addition, in this example, the case where epoxy resin was applied as an insulating layer was described, but it is also possible to apply silicone resin, fluororesin, etc., which are i8 aqueous substances, or to
) When the insulating layer is formed by inserting a washer-shaped material into the insulating layer, electrolytic oxidation polymerization may be performed using the chemically polymerized film formed under the insulating layer as an anode. These techniques can also be used for aluminum sintered solid electrolytic capacitors made of sintered aluminum powder.

[Effect of the invention] The prisoner lightning decomposition capacitor of the present invention! I! According to the J manufacturing method, when carrying out electrolytic oxidative polymerization after chemical oxidative polymerization, the chemical polymer film formed on the insulating layer is touched with a power supply electrode to perform electrolytic oxidative polymerization. Since the electrolytic polymer film can be peeled off and the mechanical shock required when peeling off the power supply electrode is reduced by 2, a uniform electrolytic polymer film can be produced.

Further, in the above method, since the chemically polymerized film and the electrolytically polymerized film are formed by applying an insulating layer, it is possible to prevent short circuit failures occurring between these polymerized films and the anode.

When a silicone tube or washer-like material is used, the workability is good and the insulating layer does not become uneven.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, with Fig. 1 showing an open view of a wound layer capacitor element, Fig. 2 a perspective view showing a power supply method in electrolytic oxidation polymerization, and Fig. 3 showing a flat plate capacitor element. 4 is a cross-sectional view showing the capacitor element after electrolytic oxidative polymerization, and FIG. 5 is a cross-sectional view showing the electrolytic oxidative polymerized state of the sintered capacitor element. 1... Positive ( i foil 2... anode lead terminal 3
... Lead wire 4 ... Insulating layer 5 ... Polypyrrole film 6 ... Spacer paper 7 ... Winding element
8...Platinum wire 11...Aluminum foil 1
2...Dielectric oxide film 13...Insulating layer 1
4...Chemical polymerization membrane 15...Electrolytic polymerization membrane 16.
...Conductive layer 21...Tantalum wire 22...CON+1 wire 23...Insulating layer 24...Chemical polymer film 25...Platinum wire Patent application Marcon Electronics Co., Ltd. Nippon Carlit Co., Ltd.

Claims (5)

[Claims] (1) A flat plate formed by forming a carbon layer on a film-forming metal that has produced a dielectric oxide film through chemical conversion treatment, chemical oxidation polymerization, electrolytic oxidation polymerization, and applying a conductive coating film to serve as a cathode on the carbon layer. , a method for manufacturing a wound type, sintered type, or laminated solid electrolytic capacitor, in which the chemical oxidation polymerization is performed by applying an insulating layer covering the area above the chemical oxidation polymerization liquid level of the anode lead-out part, and the electrolytic oxidation polymerization A method for manufacturing a solid electrolytic capacitor, characterized in that step 1 is carried out using a chemically polymerized film formed on or below the insulating layer as an anode. (2) The method for manufacturing a solid electrolytic capacitor according to claim (1), wherein the anode lead-out portion is a lead wire or a lead frame connected to a film-forming metal. (3) The method for manufacturing a solid electrolytic capacitor according to claim (1) or claim (2), wherein the insulating layer is formed of silicone resin, fluororesin, or epoxy resin. (4) Claims (1) to 10 in which the insulating layer is formed by heat-shrinking a silicone tube or fitting a washer-like member into the insulating layer.
The method for manufacturing a solid electrolytic capacitor according to claim (3). (5) The solid according to any one of claims (1) to (4), wherein the electrolytic oxidative polymerization is performed by bringing a power supply electrode into contact with a chemical polymer film formed on the insulating layer or under the insulating layer. Method of manufacturing electrolytic capacitors.