JPS5817609A - Solid electrolytic condenser and method of pruducing same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solid electrolytic capacitor and a method for manufacturing the same.

A solid electrolytic capacitor has a structure in which a solid electrolyte is attached to a film-forming metal such as aluminum having an anodized film. In this type of capacitor, which has been mass-produced in the past, the solid wi electrolyte that constitutes it is mostly manganese dioxide.

In recent years, solid electrolytes have been developed to improve the weaknesses of manganese dioxide, such as the damage to the anodic oxide film of the film-forming metal during thermal decomposition to form manganese dioxide, and the poor repairability of the anodic oxide film by manganese dioxide. It has been proposed to use organic semiconductors, mainly TCNQ stacks, as a solution. Here, 〒CNQ means 7.7.8.8 Tetracyanoquinodimethane.

However, TeCNQ wood is usually a powdered crystal, and although the crystal itself exhibits high conductivity and good repairability of the above-mentioned film, it is difficult to process because it is a powdered crystal.

That is, there is a problem in how to attach the crystals of CNQ to the skin-olfactory gold. In particular, film-forming metals used in solid electrolytic capacitors are often porous, but it is extremely difficult to uniformly impregnate and adhere TCNq salt to such porous metals. What is more important is that the TeCNQ tomb itself is always at risk of being damaged due to poor quality during the attachment work.

Conventionally proposed methods for attaching T CN Q woodcutter can be classified into the following three types.

T in a solvent such as 1110Mr (dimethylformamide)
A method in which a solution containing a CNQ salt is applied to the metal, and then dried to remove the solvent by scattering.

(2) A method in which JTCNQ powder is finely milled using a ball mill, etc., the crystals are dispersed in alcohol, etc., and the crystals are applied to the metal and dried.

A method of vacuum depositing 131TelIQ deposits on the above metals.

In the method (1) above, DMF, which has high solubility for TCNQ salt, is used as a solvent, and such a solvent is
Even if it is heated, the solute is limited to 1095. This means that it is necessary to apply and dry the solid electrolyte many times in order to adhere the necessary thickness of the solid electrolyte to the metal covered with foil, or to apply the solid electrolyte to the porous metal in a sufficient impregnation manner. It means something. For example, rating I
In the case of porous metals for jIF, the impregnation rate that can be achieved by applying 5 to 10 times and drying is at most 5 Qll, assuming that the impregnation rate when manganese dioxide is used as the solid electrolyte is 100 or more. With such a low impregnation rate, the capacitance value of the capacitor cannot be increased even though the metal is porous.The metal coated with a solvent is exposed to high temperature during the above-mentioned drying process. , At this time, the TCNQ salt more or less degrades, leading to deterioration of the conductivity of the solid electrolyte. In addition, the solid electrolyte thus deposited on the metal is TCNQ.
Since it consists of fine crystals of salt, a coagulating resin such as polyvinylpyrrolidone is actually added to 1 g of the coating solution to strengthen the adhesion strength of the fine crystals. Due to this, the conductivity of the solid electrolyte becomes even lower (approximately 800Ω (at 25° C.)) due to the deterioration of the conductivity described above.

In the above method (2+), there is a limit to the thinning of the 'I'CNQ salt, and the adhesion strength to the above metal is particularly weak. It might peel off.

Deterioration of characteristics 1 For example, an increase in tarlδ and a decrease in capacity are observed. The above-mentioned bond strength can be improved to some extent by employing a coagulating resin as described above.

Similarly, this leads to a decrease in the conductivity of the solid electrolyte. Also, TCNQ
Since a dispersion solution of microcrystals consisting of fi is used, the impregnation rate into the porous wire mesh is particularly poor (even if an ultrasonic diffusion impregnation method is used, the impregnation rate is at most the same as the method +11 above.

The above method (31) is not only complicated in vacuum evaporation work but also completely unsuitable for adhesion to porous metals.

The present invention relates to a novel solid electrolytic capacitor and a method for manufacturing the same, and more specifically, to a novel solid electrolytic capacitor and a method for manufacturing the same. Create a liquid consisting of and bring the metal into contact with the liquid.

The present invention provides a solid electrolytic capacitor obtained by cooling and solidifying the above liquid, and a method for manufacturing the same.

IC) The most practical way to obtain a liquid consisting only of IC wood is to liquefy the powdered TCNQ wood in its original form by heating and melting it. But still.

Simply heating and melting the IC will thermally decompose the IC and turn it into almost an electrical insulator, completely eliminating the function of the solid electrolyte for the capacitor.

The present invention is applicable to certain TCMQ managers, specifically.

N-isopropylquinoline, M-n-propylquinoline,
T CN QI of N-n-propylisoquinoline, N-isopropylisoquinoline! ! Even if it is heated and melted, it will take a short time for reeds to decompose thermally, but it will provide enough time for attachment work, so if it is cooled and solidified within that time, it will be possible to make an ICNQ tomb that maintains high conductivity. This is based on the completely new knowledge that it is possible to obtain a solid electrolyte consisting of

Furthermore, the present invention provides that, among the above TeCNQ salts, N-n-propylisoquinoline or N-isopropylinquinoline'
! 'CN Q Woodcutter is selected.

That is, the melting point of N-n-propylisoquinoline and TCNQ complex of N-isopropylisoquinoline is 210 to 220°C, but it is liquefied and maintained at a temperature above the melting point and below about 280°C, and before thermal decomposition, that is, after the completion of liquefaction. If cooling is started within 4 minutes, it will crystallize again and form a solid electrolyte that exhibits a high electrical conductivity of 20 to 50 Ω-(25°C).

At temperatures above about 280℃, or even at temperatures below about 1
If the TCHQ clay is kept in a liquid state for more than 4 minutes, i<4 minutes, the TCNQ clay will smoke violently and become an electrical insulator.

The solid electrolyte obtained by the present invention is not a collection of fine crystals of -%TC1iQjJl as in the case of the conventional methods 11) and (2), but is close to an amorphous state. Furthermore, the solid electrolyte obtained by the present invention has properties inherent to IC) IQ salt.

For example, it maintains excellent repairability against oxide films on film-forming metal surfaces.

According to the present invention, since the solution in which 100% of IC) iQ is dissolved is the same as that used to attach TCNQ to the film-forming metal, it is different from the conventional method (1) described above. , with only one adhesion operation.

In addition to improving the quality, the conventional drawbacks such as deterioration of TQNQ wood every time it is dried are overcome. Furthermore, according to the present invention, since the solid electrolyte is close to an amorphous body, the adhesion force to the metal is sufficiently large.

There is no need to use plum fat for coagulation as in the past, and an undesirable decrease in the electrical conductivity of the solid electrolyte can be avoided.

Further, the electrolytic capacitor according to the present invention using TCNQ of N-propyl (or N-isopropyl) isoquinoline can be prepared using other TCNQ salts, namely, TCNQ of N-isopropyl (or N-n-propyl) quinoline. Compared to the case where salt is used, this shows an improvement effect of making the capacitance value (ie, impregnation rate) larger and making the capacitance change rate smaller at high temperature (+85° C.).

Examples of the present invention will be described below.

First, a TCNQ layer of N-n-propylisoquinoline is prepared. The creation of CIIQ woodcutter itself.

J, Am, Chew, Soo,, Vol, aa, PP5
574-5587 (1962), but briefly, n-propylisoquinoline iodite obtained by reacting n-propyliodo and inquinoline with TECNQ is excavated in acetonitrile. A powder crystalline N-n-propyl isoquinoline TCMQ is produced by equimolar reaction.

From now on, just use this salt? It is called CN Q*.

On the other hand, 1. In accordance with the usual manufacturing method of an aluminum sintered solid electrolytic capacitor, a sintered body of aluminum powder is anodized as shown in FIG. 1, and a porous capacitor element as a film-forming metal having an oxide film is produced (1) is created.

After the above preparation, the steps to be performed include the capacitor element (1
) is impregnated with a solid electrolyte made of IC. As shown in Figure 2, the prepared powder cane TCHQ was stored in an aluminum container (2) under moderate pressure, and the container (2) was heated to melt and liquefy it. A bath (31) is provided. The temperature of the C bath is maintained at 250° C. to 260° C. It should be noted that the pressure applied to the aluminum container (2) during storage of the CNQ salt is not essential.

(In the process, as shown in Figure 6, the temperature is 250℃~26℃)
What about the capacitor element (1) that is heated and maintained at 0℃? C
Immerse it in the NQ salt bath (31) and immediately cool the entire container (2) naturally at room temperature. As a result, the TCNQ salt impregnated into the porous capacitor element (1) cools and solidifies, forming the desired solid electrolyte. The time required from the liquefaction of the 'f'cNQ salt to the start of cooling is about 5 seconds.The time required from the start of cooling to the temperature below the melting point is within several seconds (for example, 4 seconds).

In the remaining steps, the container 121 is peeled off from the capacitor element (1) impregnated with the 1ei1 electrolyte, and then a graphite layer (4 ), paint 1fj
151 are sequentially deposited, and finally such element +11 is the cathode lead #! (It is housed in an aluminum container (7) together with 61 and fixed with solder (8) and epoxy resin 19+.

When a conventional capacitor using manganese dioxide as a solid electrolyte has a capacitance of 1 μF as the element (1), the capacitance of the completed capacitor was approximately 1 μF.
It was F. This means that the impregnation rate for manganese dioxide is 1
00% means the same degree of impregnation.

Table u51 and Table +ig2 show the temperature characteristics and high temperature load characteristics of the capacitors of this example. The characteristics of the capacitor obtained by modifying quinoline TCNQ are also shown. still.

N-n-propyl quinoline fCNQ was prepared in the same manner, but the liquefaction holding temperature was 260°C to 2.
The temperature is 70° C., and the time from liquefaction to cooling is about 10 seconds.

Table 1 Temperature Characteristics Table 2 High Temperature Load Characteristics Ratings at 10V applied According to the table, in the case of the reference example, the capacitance value is approximately 0.8 μF (
20℃), so the impregnation rate with manganese dioxide is 100
%, the impregnation rate is 80%.

It can be seen that the impregnation rate (100%) of this example is excellent. Also, in terms of temperature characteristics, the superiority of this example is clear on the high temperature side.

In the present invention, instead of using the powder sintered element (1) as in the above embodiment, an etched aluminum foil is used as the cathode,
The same method can also be effectively applied when using a winding element in which chemically formed foil is used as an anode and these are wound up with separator paper in between. In other words, a solid electrolyte made of TCNQ wood is used in the same manner as in the above example. By impregnating the wound element c and sealing it with resin, it is possible to create an electrolytic capacitor having temperature characteristics and high temperature load characteristics similar to those of the unsintered type (IF).

In this case, it is necessary to chemically convert the cut part of the chemically formed foil, the anode lead, etc. before impregnation, but the container 1
21 can be used as it is as a capacitor outer case, and a graphite layer or a silver paint layer is not required.

The above unwinding element (conventional dry electrolytic capacitor 50V, 2
．． The characteristics of the completed capacitor are 1.4 5 s.
P, j a na 1,89, L
C/30 replacement 0.04 sm.

In the above example e, the metal of the 1g element (1) was aluminum, but other film-forming metals 1, such as tantalum or niobium, may be used. Furthermore, as a solid electrolyte.

Of N-isopropylisoquinoline? A capacitor can be manufactured using a CM Q woodcutter in the same manner as in the embodiment.

As is clear from the above description, one aspect of the present invention is as follows.

In solid electrolytic capacitors using solid electrolytes made of organic semiconductors, the solid electrolyte can be attached to film-forming metals with a simple process, and there is little deterioration of the solid electrolyte during such operations, making it an unprecedented technology. As for the characteristics as a capacitor, a sufficiently practical capacitor having a large capacitance value and excellent A degree characteristics can be obtained.

[Brief explanation of the drawing]

1 to 4 are step-by-step diagrams illustrating a method according to an embodiment of the present invention, where FIG. 1 is a side view and FIGS. 2 to 4 are sectional views. (1)...Capacitor element, (3...T CN Q
Fi bath. Procedural amendment (spontaneous) May tF3, 1980 Mr. Commissioner of the Japan Patent Office1, Indication of the case, 1982 Patent Application No. 1168612, Name of the invention Solid electrolytic capacitor and its manufacturing method3, Person making the amendment Patent applicant address 2-18 Keihan Hondori, Moriguchi City Name (188) Sanyo Electric Co., Ltd. Representative Kaoru Iue 4, agent address 2-18 Keihan Hondori, Moriguchi City Contact information: Telephone (Tokyo) 835-1111 Kamata 4, resident at Patent University, amended column 5 of detailed explanation of the European invention, contents of the amendment (2) In the 10th line of page 13 of the specification, amended rAJ to ``rA (25V applied)''. do.

Claims (1)

[Claims] 111N-n-propyl (or N-iso-propyl) isoquinoline? A solid electrolytic capacitor whose solid electrolyte is an organic semiconductor composed of CNQ. 121) i-n-propyl (or N-iso-propyl)
With isoquinoline? A method for manufacturing a solid electrolytic capacitor, characterized in that an organic semiconductor consisting of CIQ is melted and liquefied, solidified by cooling, and used as a solid electrolyte.