JPH0374030B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a solid electrolytic capacitor, and particularly to a method for manufacturing a solid electrolytic capacitor impregnated with TCNQ salt.

[Conventional technology]

Conventionally, in a solid electrolytic capacitor using a wound type element, the element winding process and the electrolyte impregnation process are performed separately.

A solid electrolytic capacitor has a structure in which an anode-side electrode is formed by forming an anodized film on a film-forming metal such as aluminum, and a solid electrolyte is attached to this.

Manganese dioxide has been used as a solid electrolyte in conventional solid electrolytic capacitors, but the oxide film on the anode side electrode is damaged due to thermal decomposition during the formation of the manganese dioxide layer. It has drawbacks such as poor repairability of the anodic oxide film.

Therefore, the use of TCNQ salt, an organic semiconductor, as a solid electrolyte has been proposed and put into practical use. This TCNQ salt refers to a salt of 7,7,8,8 tetracyanoquinodimethane.

This TCNQ salt usually forms powder-like crystals, and exhibits high conductivity and film repair properties that cannot be obtained with manganese dioxide, but because it is a powder-like crystal, it is difficult to process. In particular, deterioration tends to occur during the process of attaching TCNQ salt to an electrode, so it is difficult to perform a process such as winding a foil-shaped electrode to which TCNQ salt is attached.

Conventionally, attempts have been made to liquefy powdered TCNQ salt by heating and melting it, and immerse electrodes in this to form a solid electrolytic capacitor element.

[Problems to be Solved by the Invention] Although this method allows TCNQ salt to adhere to the electrolytic capacitor element, heating and melting the TCNQ salt turns it into an electrical insulator and does not function as a solid electrolyte. It is not suitable for mass production of electrolytic capacitor elements with stable electrical characteristics due to time constraints on element formation such as attachment work. Particularly, in the case of winding the electrode foil, although it is possible experimentally, there is a drawback in that the yield rate decreases in manufacturing.

In addition, after forming an electrolytic capacitor element, immersing the element in molten TCNQ salt is possible for small electrolytic capacitor elements, but for large electrolytic capacitor elements, the impregnation time may be too long. However, there is a risk that the impregnation will be insufficient.

Therefore, the present invention provides a method for manufacturing a solid electrolytic capacitor with stable electrical characteristics by simultaneously performing TCNQ salt impregnation treatment and element winding treatment, without impairing the function of TCNQ salt as a solid electrolyte. For the purpose of providing.

[Means for solving problems]

The method for manufacturing a solid electrolytic capacitor of this invention includes:
While impregnating the anode side electrode foil 14, the cathode side electrode foil 10, and electrolytic paper (first electrolytic paper 8, second electrolytic paper 12) with TCNQ salt 15 dissolved by heating under reduced pressure, the anode side A solid electrolytic capacitor element 26 is formed by overlapping and winding the electrode foil, the cathode side electrode foil, and the electrolytic paper.

Specifically, the anode side electrode foil,
A cathode side electrode foil and electrolytic paper as a separator are installed, and powdered TCNQ salt is individually supplied and transferred to these, and then wound to form a solid electrolytic capacitor element.

Next, this solid electrolytic capacitor element is cooled in a vacuum cooling furnace, and then in a normal pressure cooling furnace.

[Effect]

In this way, impregnation with the TCNQ salt is improved, and the winding of the element can be performed at the same time, thereby avoiding the inconvenience caused by separate steps as in the conventional method.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

FIG. 1 shows an embodiment of the method for manufacturing a solid electrolytic capacitor according to the present invention.

This manufacturing method includes a vacuum heating furnace 2, a vacuum cooling furnace 4
and a normal pressure cooling furnace 6 are installed adjacent to each other, and the element constituent materials and the electrolytic capacitor elements to be manufactured can be quickly transferred to these furnaces 2, 4, and 6 in this order. The vacuum heating furnace 2 and the vacuum cooling furnace 4 are maintained at a predetermined reduced pressure state.

In this embodiment, a first electrolytic paper 8, a cathode-side electrode foil 10, a second electrolytic paper 12, and an anode-side electrode foil 14 are installed at regular intervals in the vacuum heating furnace 2, and the device is manufactured. It is in the form of a roll that can be rewound. The first and second electrolytic paper 8, 12 are
It functions as a separator interposed between the cathode side and anode side electrode foils 10 and 14.

In addition, the cathode side and anode side electrode foils 10 and 14 are
It is composed of film-forming metals such as aluminum, niobium, and tantalum, each of which has been subjected to surface enlargement treatment by etching, and the anode side electrode foil 14 is
An anodic oxide film is formed by chemical conversion treatment.

Then, the first electrolytic paper 8, the cathode side electrode foil 10,
Above the flat plate-shaped portion of the second electrolytic paper 12 and the anode side electrode foil 14, there is a layer of fine powder.
Supply means 16, 18 for supplying TCNQ salt 15,
20 and 22 are installed in sequence.

Further, inside the vacuum heating furnace 2, an element winding section 24 is installed in which the first electrolytic paper 8, the cathode side electrode foil 10, the second electrolytic paper 12, and the anode side electrode foil 14 are assembled and wound. has been done.

A method for manufacturing a solid electrolytic capacitor with the above configuration will be described.

The vacuum heating furnace 2 is set at a temperature at which the TCNQ salt 15 is heated and melted, for example, about 200°C. Therefore, under reduced pressure, the first electrolytic paper 8, the cathode electrode foil 10, the second electrode paper 12, and the anode electrode foil 14 are heated, and each first electrolytic paper 8, anode electrode foil 1
0, the second electrolytic paper 12 and the anode side electrode foil 14 are individually supplied from the supply means 16 to 22
A fine powder of TCNQ salt 15 is also heated. As a result,
The first electrolytic paper 8, the cathode electrode foil 10, the second electrolytic paper 12, and the anode electrode foil 14 are well impregnated with the TCNQ salt 15.

While impregnating with TCNQ salt 15 like this,
The first electrolytic paper 8, the cathode side electrode foil 10, the second electrolytic paper 12, and the anode side electrode foil 14 are connected to the element winding portion 24.
The solid electrolytic capacitor element 26 is formed by transferring the solid electrolytic capacitor element 26 to a solid electrolytic capacitor element 26 and winding it into a predetermined shape. In addition, in the formation of one element, the time from the start of winding to the end of winding until transfer to the vacuum cooling furnace 4 is TCNQ salt 15
In order to prevent thermal decomposition, the heating time is, for example, within 3 minutes.

This solid electrolytic capacitor element 26 is transferred to the vacuum cooling furnace 4 and vacuum cooled to avoid deterioration of the TCNQ salt 15. Next, the normal pressure cooling furnace 6
A final cooling process is carried out at .

FIG. 2 shows a solid electrolytic capacitor element 26 manufactured by the above manufacturing method, and the cathode side and anode side tabs 28, 30 are attached to the corresponding electrode foils 10, 14 during the element winding process. shall be electrically connected.

As explained above, according to this manufacturing method,
In the vacuum heating furnace 2, the first electrolytic paper 8, the cathode side electrode foil 10, the second electrolytic paper 12, and the anode side electrode foil 14.
Since the TCNQ salt 15 is individually impregnated while being heated and the element is wound at the same time, the impregnation process and the element winding process can be performed simultaneously, simplifying and speeding up the manufacturing process. Furthermore, by performing the winding process of the element and the impregnation process with the TCNQ salt 15 at the same time, it is possible to prevent the TCNQ salt 15 from deteriorating, and since the cooling is also performed in the vacuum cooling furnace 4, the TCNQ salt 15 Electrolytic capacitors having extremely stable and reliable electrical characteristics without impairing their function as a solid electrolyte can be manufactured in large quantities and at a high yield.

In addition, since the TCNQ salt 15 is heated under reduced pressure, the thermal decomposition temperature is lowered, so the impregnation time is extended, and the TCNQ salt 15 is heated under reduced pressure.
The impregnation efficiency of salt 15 can be increased.

Although the embodiments have been explained using a wound type electrolytic capacitor element as an example, the same effect can be expected even if the present invention is applied to a solid electrolytic capacitor composed of a multilayer electrode that is not wound. .

〔Effect of the invention〕

As explained above, according to the present invention, the following effects can be obtained.

(1) It is possible to simplify the manufacturing process and prevent characteristic deterioration during the impregnation process of the solid electrolyte composed of TCNQ salt, making it possible to efficiently manufacture electrolytic capacitors with stable electrical characteristics and improving reliability. It is possible to provide high-quality products at low prices.

(2) In particular, for large wound elements, compared to the method of immersing the element in molten TCNQ salt, the impregnation with TCNQ salt is better, and the improved impregnation efficiency improves electrical performance. Stability of characteristics can be improved.

[Brief explanation of drawings]

FIG. 1 is an explanatory view showing an embodiment of the method for manufacturing a solid electrolytic capacitor according to the present invention, and FIG. 2 is a perspective view showing a solid electrolytic capacitor element. 2...Vacuum heating furnace, 4...Vacuum cooling furnace, 8...
First electrolytic paper, 10... Cathode side electrode foil, 12...
Second electrolytic paper, 14... Anode side electrode foil, 15...
TCNQ salt, 26...Solid electrolytic capacitor element.

Claims (1)

[Claims] 1. While impregnating the anode side electrode foil, the cathode side electrode foil, and the electrolytic paper with TCNQ salt heated and melted under reduced pressure, the anode side electrode foil, the cathode side electrode foil, and the electrode A method for manufacturing a solid electrolytic capacitor, comprising forming a solid electrolytic capacitor element by overlapping and winding papers. 2. The method for manufacturing a solid electrolytic capacitor according to claim 1, wherein the solid electrolytic capacitor element impregnated with the TCNQ salt is cooled under reduced pressure and then cooled under normal pressure.