JPS6054423A - Method of producing solid electrolytic condenser - 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 method for manufacturing a solid electrolytic capacitor.

In general, solid electrolytic capacitors are made by forming a dielectric ridge by growing an oxide film on the surface of a metal W electrode such as A/, Ta, etc., attaching a solid electrolyte to this, and then forming a conductive 14L layer of gelaphite, silver, etc. The cathode is led out through the structure. In this type of capacitor, manganese dioxide is generally used as the solid electrolyte layer in many cases. The method used is to immerse the material in a manganese nitrate bath solution, then heat it to decompose it and deposit it on the electrode as manganese dioxide. According to this method, in the case of AJ, for example, the dielectric A/gos film is damaged during thermal decomposition treatment, resulting in a large drop in breakdown voltage. In this method, the dielectric film is dissolved with nitric acid and manganese dioxide is attached thereto, which strongly bonds the electrode and manganese dioxide and also works to lower the contact resistance between the solid and the solid body. There is. Therefore, various methods have been investigated to improve the manganese dioxide method, particularly to improve the film deterioration and the drop in pressure resistance, but no fundamental solution has been found in any of them.

On the other hand, there is an increasing trend toward miniaturization of electronic components, and a decrease in Cv due to low pressure and weight must be avoided at all costs. In addition, the trend towards chips is becoming more prominent, and the shift from conventionally used liquid electrolytes to solid electrolytes is becoming inevitable. It can be easily assumed that these requirements will be transformed into new capacitor assembly technology as lamination technology advances.

The present invention was provided as part of this background.

The gist of the invention is that while conventional liquid electrolytes have been used to perform iontophoresis such as OR in living organisms when anodizing electrodes, it is currently necessary to apply this function to a solid state. Since the situation is still difficult even after considering all materials, we applied the mechanism of ion exchanger reaction and proton conduction at the interface.

The basic reaction form of the present invention is shown by the following formula. For example, in the reaction with A7, MOX-n HgO+A l → Mo X (n 3 )
HxO+Al (HgO)g・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・・・・(1)
At (HsOh −+Al (OH)a + 3 H
＋・・・・・・・・・・・・・・・・・・・・・・・・
(2) At (OH)m→1A 1m On + 3
/ 2 H*Kano・・・・・・・・・・・・・・・・・・
(3) MOx-n H! If O is proton conducting (2
) 3H+ generated by the formula migrates in MOc-nHlo,
Under the condition of voltage application, the reaction proceeds, and in fact, anodic oxidation takes place.

The best condition is when the reaction shown by equation K (3) proceeds and the produced water is incorporated again into the MOX crystal as crystal water or adsorbed water.

Furthermore, as for application to the solid electrolyte of capacitors: (1) Crystal water or adsorbed water must not scatter up to around 20C1.

■ Considering soldering, there should be no deterioration in quality by immersion treatment at 260°C for 10 seconds.

■ Do not damage the electrode.

■ Easily oxidized by heat treatment.

(Sh) It must be relatively inexpensive.

There are conditions such as Therefore, it satisfies the conditions in F, has crystal water or @water landing, and has proton readability? This means that the gold lN41Jf compound V has the functionality as a solid electrolyte.

The next problem is how to attach it to 1c@%. The method of depositing gold with nitric acid while melting the film with 1 m tM tr provides good electrical adhesion between the visiting body film and the solid electrolyte, but the melting of the film greatly impairs the characteristics of the capacitor. This is not a good idea as it reduces the

Therefore, crystal water or eA, which is the electrolyte used in the present invention,
Considering the Q of the proton-conducting bonded oxide that conducts water tfJ, gold maple oxide is first applied onto the electric body and film by vapor deposition, sputtering, electroless plating, etc., and then gold maple oxide is applied by heat treatment. year.

It has been found that heat treatment in steam is effective in producing a gold M#1 compound containing crystal water or adsorbed water.

Hereinafter, we will congratulate the embodiments shown in Figs. 1 to 8g4.

A chemically formed foil obtained by anodizing a 99.99%, 90 μm high-purity aluminum foil with an ammonium borate solution to 150 V is used.

Example 1 Using a vacuum evaporation apparatus, the above film was deposited with a thickness of 1.5 μm.
3n is deposited. Next, a steam sword was placed in a cylindrical heating furnace, and heated to 220°C while maintaining the saturated steam pressure inside the heating furnace.
Heat treatment was performed for 1 hour. As shown in FIG. 1, the resulting sample was coated with colloidal carbon 4, silver paste 5 was further adhered, and lead wires 7 were soldered to produce a solid electrolytic capacitor sample. In Figure 1, 1
is aluminum foil, 2 is aluminum oxide, and 3 is 5nol-n (Snow O) as a solid electrolyte.

Next, the capacitor sample K O, 5mA10J shown in Figure 1
A constant current was applied to measure the voltage rise characteristics, and the A/*Oa film forming ability was adjusted.

Curve a in FIG. 2 shows the result. In addition, the curved line in FIG. 2 shows the A/gos film forming ability of Snug without heating in water vapor, that is, without crystallization water. As is clear from this figure, the presence of crystal water or adsorbed water significantly increases the so-called aging property, and the solid electrolyte effect is greatly enhanced.

In addition, this capacitor sample'fr10℃ in an atmosphere of 150℃
A 00-hour no-load test was conducted to fully investigate the state of water scattering in 5n01.nHaO, but the film-forming ability was hardly impaired. The results are shown in FIG. Curve a in Figure 3 is for one crop, and curve A is 1501.
:'] (This is the voltage increase characteristic after 100 hours. This is the voltage increase characteristic measured by applying a constant current of 0.117 IA/l?Jl.

“Also, the 5nOj・nH,0 deposited at this time is 2 μm, and the specific resistance in the rq direction is approximately 60Ω (-JnC25'C
) and had the same function as the W layer liquid.

Example 2 Vacuum deposition equipment for 150V chemical aluminum foil as described in 1.
1 μm of 191 nm) was deposited using the same method. Next, water vapor is sent into the cylindrical heating furnace, and f saturation 1 is achieved in the heating furnace.
Heat treatment was performed at 150° C. for 30 minutes while maintaining the pressure at 1°C. Next, a capacitor sample was manufactured in the same manner as in Example 1.

As a result of measuring the voltage rise characteristics by applying a constant current of 0.5 mA/cd and investigating the AJxOs film generation ability, the same characteristics as shown in Fig. 3 were obtained, and the same good film formation ability as 5n02/nHlo was obtained. It was found that it has.

In0g/nHlO at this time is approximately 15 μm,
The specific resistance in the thickness direction was 40Ω-c+++ (25'C), which was lower than that of S n 01·nHHO2.

Further, for 7.n, the same results as for the above-mentioned Sn,:[n were obtained.

In addition, Example]: I-? Table 1 shows the capacitance, -1, and leakage current characteristics of the capacitor samples manufactured by the method of Example 2. Figure 4 shows the temperature characteristics of the same capacitor.

Table 1 *: After 5 minutes of application of 50V, a solid ゛dissolution is formed at 0, Curve B is I n O,・n
Solid city with H2O, the solution is +19 bsl, song! 1JIC is the case of conventional liquid electrolysis.

As is clear from FIG. 4, the rate of change in Wbl at -40'C to +105"C is significantly reduced compared to that of conventional dispersed electrolytes. In addition, various studies of processing conditions have been conducted. This also provided better impedance than those using liquid material.

In addition, in the above-mentioned example, if the metal that was exposed to the oxide skin 1IIJ was Sn, the heating temperature in steam was set to 10
0 to 240'c, 1 for In (10 to 1fiO'c
.

In the case of Zn, it is desirable to treat it within the range of 100 to 420'c. This is because if the temperature is less than 100, the necessary water vapor cannot be obtained, and the reason for the limitation on the high temperature side is that it exceeds the melting point of the F metal.

As described above, the solid electrolytic capacitor produced by the method of the present invention has a low resistivity comparable to or lower than that of conventional liquid electrolytes, has great advantages in terms of temperature change and high frequency impedance characteristics, and can be easily adapted to be made into a chip. It has great industrial and practical value.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of a capacitor sample manufactured by the manufacturing method of the solid electrolytic capacitor of the present invention, Figure 2 is a comparison diagram of the aging characteristics of the same capacitor, and Figure 3 is the aging of the same capacitor before and after a no-load test. Characteristic Comparison Chart FIG. 4 is a comparison diagram of capacitor accuracy characteristics comparing a capacitor manufactured by the l'i manufacturing method of a solid electrolytic capacitor of the present invention and a conventional product. 1. Aluminum oxide 2: Aluminum oxide 3: 14'' Body width Determination patent entry Nippon Capacitor Industries Co., Ltd. Figure 2 Figure 1-・ ? 1. Indication of the case 1982 Patent Application No. 163856'F: 2. Name of the invention Method for manufacturing solid electrolytic capacitors 3. Person making the amendment Relationship to the case Patent applicant 4. Subject of the amendment ``Invention in the specification 5 Contents of the amendment (1) Mei 111]ll An, page 5, line 19 is amended as follows. For example.'' (2) Correct the 17th line of page 6 of 明帷蔵 as follows.

Claims (2)

[Claims] (1) Oxide film generation A method for manufacturing a solid electrolytic capacitor in which an oxide film layer is formed on the surface of synthetic fibers, and a solid electrolyte layer and a cathode groove %LPin are sequentially formed thereon, by a method such as vacuum evaporation or sputtering. , S ” s I
``%zn'' is grown on the oxide film, and then reacted by heating in water vapor to form sno, HnHxOl.
InOx・nHsO, Zn0t-nHt. A method for manufacturing a solid electrolytic capacitor, comprising forming a solid electrolytic II layer made of a duck oxide having adsorbed water or crystallized water. (2) The solid electrolytic capacitor according to claim 1, characterized in that the heating temperature in the water vapor is 10 liters or more and is below the melting point of the metal formed on the oxide film. manufacturing method.