JPH06181144A - Solid electrolytic capacitor and manufacture thereof - Google Patents

Abstract

PURPOSE:To control the equivalent series resistance of a solid electrolytic capacitor to a desired value to contrive to suppress a loss by impregnating a capacitor element with an electrolyte, in which two kinds or more of TCNQ salts are mixed and the mixture ratio of the salts is adjusted arbitrarily. CONSTITUTION:A capacitor element 4 used in a solid electrolytic capacitor is a winding element, around which element anode side and cathode side electrode foils composed of a solid-state component or metal such as aluminum together with separator paper interposed between both foils are wound, and an anode lead 6 constituting an anode terminal is drawn out to the end face of the capacitor element. The capacitor element 4 is impregnated with TCNQ salt 3 and time TCNQ salt 3 is attached to the surface of the electrode. In the TCNQ salt 3, two kinds or more of TCNQ salts are mixed and the mixture ratio is set arbitrarily. A graphite layer 8 constituting a conductor layer is formed on the surface of the capacitor element 4 and a silver coating layer 10 constituting a conductor layer is formed on the graphite layer 8. The capacitor element 4 is fixed inside a container 12 while solder 14 and synthetic resin 16 are interposed between.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid electrolytic capacitor using a TCNQ salt as a solid electrolyte and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, solid electrolytic capacitors using one type of TCNQ salt as an electrolyte are known. Here, the TCNQ salt means a salt composed of 7,7,8,8 tetracyanoquinodimethane.

In the production of an electrolytic capacitor using this TCNQ salt, when a so-called high-magnification etching foil subjected to high etching is used as an electrode, needle-like crystals are easily formed in the crystallization process of the TCNQ salt, and the electrode and TCNQ Contact with the salt interface may be insufficient.

Usually, the TCNQ salt is a. A method of melting at a high temperature and adhering to an electrode, cooling it to crystallize, b. A method in which a solvent is added to form a solution, and the solution is attached to recrystallize, c. It is crystallized by a method of crystallization using a solvent.

[0005]

By the way, when the TCNQ salt penetrates into the etching pits of the electrode and crystallizes in the pits, when crystals are formed by short-circuiting the inner walls of the pits, Since the crystal substantially functions as a cathode, the crystal is effective, but the TCNQ salt adhering to the wall of the etching pit becomes a needle crystal and its tip slightly contacts another wall, or If there is no contact, the part does not function as a cathode,
Alternatively, even if it functions as a cathode, it will have a large contact resistance. This is the equivalent series resistance ESR of the electrolytic capacitor.
To increase product loss and decrease product value.

Therefore, an object of the present invention is to provide a solid electrolytic capacitor which controls the crystallization process of TCNQ salt, suppresses the generation of needle-like crystals, and has improved electrical characteristics, and a method for producing the same.

[0007]

The solid electrolytic capacitor of the present invention is a mixture of two or more types of TCNQ salt (3), and
A capacitor element (4) impregnated with an electrolyte obtained by arbitrarily adjusting the mixing ratio is used.

Also, in the solid electrolytic capacitor of the present invention, the TCNQ salt contains iso-propyl-iso-quinolinium (TCNQ) ₂ , n-propyl-n-quinolinium (TCNQ).
It is characterized by using CNQ) ₂ .

The solid electrolytic capacitor manufacturing method of the present invention comprises a step of forming a capacitor element (4) having an anode terminal (anode lead 6) and two or more kinds of TCNQ salt (on the electrode surface of the capacitor element). 3) adhering an electrolyte formed by mixing, and a conductor layer (graphite layer 8, on the surface of the capacitor element to which the electrolyte is adhered).
The method is characterized by comprising a step of forming a silver paint layer 10), a step of forming a cathode terminal on the conductor layer, a step of drawing out the anode terminal and enclosing the capacitor element in a container (12).

[0010]

The solid electrolytic capacitor of the present invention comprises two or more T
By mixing a CNQ salt to form an electrolyte and adhering it to the electrode surface of a capacitor element, the crystallization process is controlled to impregnate a solid electrolyte containing a large amount of amorphous. The mixing ratio of salt is controlled arbitrarily. Therefore, in the solid electrolytic capacitor of the present invention, due to the amorphous solid electrolyte, the contact with the inside of the etching pit is improved, and the contact resistance can be reduced or controlled to any value that does not pose a practical problem, and the loss can be reduced. can do.

Further, in the method for producing a solid electrolytic capacitor of the present invention, two or more kinds of TC to be impregnated into the capacitor element are used.
By arbitrarily controlling the mixing ratio of NQ salt, a solid electrolytic capacitor having a desired equivalent series resistance value can be easily realized.

[0012]

The present invention will be described in detail below with reference to the embodiments shown in the drawings.

FIG. 1 shows an embodiment of the solid electrolytic capacitor of the present invention. The capacitor element 4 used in this solid electrolytic capacitor is a winding element in which a solid element or an anode-side and cathode-side electrode foil made of a metal such as aluminum is wound together with separator paper interposed therebetween. There is an anode lead 6 which forms an anode terminal on its end face.
Has been pulled out. This capacitor element 4 has TCN
The Q salt 3 is impregnated, and the TCNQ salt 3 is attached to the electrode surface. This TCNQ salt 3 is a mixture of two or more types of TCNQ salts, and the mixing ratio thereof is set arbitrarily. A graphite layer 8 forming a conductor layer is formed on the surface of the capacitor element 4, and a silver coating layer 1 forming a conductor layer is formed thereon.
0 is formed.

Capacitor element 4 which has been subjected to such processing
Is fixed inside the container 12 with the solder 14 and the synthetic resin 16 interposed therebetween, and the solder 14 is provided with a cathode lead 18 forming a cathode terminal. The cathode lead 18 is pulled out from the container 12 together with the anode lead 6. ing.

Therefore, this solid electrolytic capacitor is
A desired equivalent series resistance is set by controlling the mixing ratio of two or more types of TCNQ salts to be impregnated in the capacitor element.

Next, FIGS. 2 to 4 show an embodiment of the method for manufacturing a solid electrolytic capacitor of the present invention. Figure 2
As shown in Fig. 3, the solid electrolytic capacitor is a capacitor element that forms a winding element together with a separator paper having a solid element or an anode-side and cathode-side electrode foil made of a metal such as aluminum interposed therebetween. 4 is used, and an anode lead 6 forming an anode terminal electrically connected to the electrode foil on the anode side is drawn out from an end portion of the capacitor element 4.

This capacitor element 4 has two or more types of TCs.
An electrolyte obtained by mixing NQ salt at an arbitrary mixing ratio is impregnated. As shown in FIG. 3, the container 2 is filled with a molten TCNQ salt 3 serving as a solid electrolyte. This T
CNQ salt 3 is a mixture of two or more types of TCNQ salts, such as iso-propyl-iso-quinolinium (TCNQ).
₂ and n-propyl-n-quinolinium (TCNQ) ₂
It is composed of a mixed system of both complex salts or two or more kinds of TCNQ salts. The melting method of the TCNQ salt 3 is a method of only heating, or a method of adding a solvent and heating to form a solution.

The capacitor element 4 is immersed in the thus liquefied TCNQ salt 3 and the TCNQ salt is formed on the electrode surface.
Add salt 3.

Next, the capacitor element 4 subjected to such a TCNQ salt bath is cooled. By this cooling, the TCNQ salt 3 adhering to the electrode surface of the capacitor element 4 is solidified and its crystallization is achieved.

Next, as shown in FIG. 4, a conductor layer is formed on the surface of the capacitor element 4. That is, the capacitor element 4
A graphite layer 8 forming a conductor layer is formed on the outer surface of, and a silver paint layer 10 forming a conductor layer is formed thereon as well.

Next, after this surface treatment, the capacitor element 4 is fixed inside the container 12 with the solder 14 and the synthetic resin 16 interposed therebetween, and the cathode lead 18 is installed on the solder 14 and pulled out from the container 12. As a result, a solid electrolytic capacitor as a product is obtained.

When the solid electrolytic capacitor is formed in this manner, the solid electrolyte composed of the TCNQ salt 3 is interposed between the electrode foils on the anode side and the cathode side, and this solid electrolyte substantially functions as a cathode. Since the cathode lead 18 is electrically connected to the cathode via the graphite layer 8 and the solder 14, a desired capacitance is formed between the leads 6 and 18.

The solid electrolyte contains two or more kinds of T.
Since the CNQ salt is mixed, as a result of suppressing the crystallization process, a large amount of amorphous is contained. This can be confirmed by experiments.

Therefore, there is no inconvenience due to needle-like crystals in the conventional etching pits, the contact with the inside of the etching pits is good, and the adhesion with the inner wall of the pits is high, so that the contact resistance is reduced or practically used. It can be controlled to a value that does not cause a problem, and loss can be reduced.

Next, FIG. 5 shows the experimental results of the solid electrolytic capacitor of the present invention. The results of this experiment show that iso-propyl-iso-quinolinium (TCNQ) ₂ {= IP-
IQ} and n-propyl-n-quinolinium (TCN
Q) ₂ {= NP-Q} shows the relationship between the composition of both salts and the ESR of the solid electrolytic capacitor in the mixed system of both complex salts, and shows that iso-propyl-iso-quinolinium (TCN).
The concentration of Q) ₂ is 20 to 98% by weight (wt%), n
-Propyl-n-quinolinium (TCNQ) ₂ concentration in the range of 2 to 80 wt% (wt%), ESR
Is observed.

In the examples, iso-propyl-iso-quinolinium (TCNQ) ₂ and n-propyl-n-
Although a mixed system of both quinolinium (TCNQ) ₂ complex salts has been described, such characteristics can be controlled to a value that does not pose a problem in practical use when ESR is decreased when two or more kinds of TCNQ salts are mixed. Guessed.

[0027]

As described above, according to the present invention,
By mixing two or more types of TCNQ salts and impregnating the capacitor element with an electrolyte whose mixing ratio is arbitrarily adjusted, the crystallization process is controlled to impregnate the solid electrolyte containing a large amount of non-crystal, so the equivalent series The resistance can be controlled to a desired value, and loss can be suppressed.

Further, according to the method for manufacturing a solid electrolytic capacitor of the present invention, a solid electrolytic capacitor having an arbitrary equivalent series resistance can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a solid electrolytic capacitor of the present invention.

FIG. 2 is a side view showing a capacitor element before a TCNQ salt bath in one embodiment of the method for manufacturing a solid electrolytic capacitor of the present invention.

FIG. 3 is a diagram showing a TCNQ salt bath of a capacitor element in one example of the method for manufacturing a solid electrolytic capacitor of the present invention.

FIG. 4 is a vertical cross-sectional view showing a capacitor element in one example of the method for manufacturing a solid electrolytic capacitor of the present invention.

FIG. 5 is a mixed system T in the solid electrolytic capacitor of the present invention.
FIG. 7 is a diagram showing equivalent series resistance for a CNQ salt.

[Explanation of symbols]

 2 container 3 TCNQ salt 4 capacitor element 6 anode lead (anode terminal) 8 graphite layer (conductor layer) 10 silver paint layer (conductor layer) 12 container 18 cathode lead (cathode terminal)

Claims (3)

[Claims] 1. A mixture of two or more TCNQ salts, and
A solid electrolytic capacitor characterized by using a capacitor element impregnated with an electrolyte obtained by arbitrarily adjusting the mixing ratio. 2. The TCNQ salt contains iso-propyl-
Iso-quinolinium (TCNQ) ₂ , n-propyl-n
-The solid electrolytic capacitor according to claim 1, wherein quinolinium (TCNQ) ₂ is used. 3. A step of forming a capacitor element having an anode terminal, and two or more types of TCNQ on the electrode surface of the capacitor element.
Depositing an electrolyte formed by mixing salt, forming a conductor layer on the surface of the capacitor element to which the electrolyte is attached, forming a cathode terminal on the conductor layer and pulling it out, and pulling out the anode terminal And a step of encapsulating the capacitor element in a container, and a method of manufacturing a solid electrolytic capacitor, comprising: