JPS6266616A - Manufacturing 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] [Industrial Field of Application] The present invention provides a method for converting a conductive polymer compound into a solid conductor. This paper describes a method for producing solid electrolytic content 4 with good performance, which was used as a quality material.

[Prior Art] Conventional solid electrolytic capacitors, such as aluminum cum electrolytic capacitors, are made by providing an aluminum oxide layer as a dielectric on etched porous aluminum cum foil with a large specific surface area, and then forming a layer between the cathode foil and the aluminum oxide layer. The structure consists of electrolytic paper impregnated with a liquid electrolyte, but since the electrolyte is liquid, it causes a problem of liquid leakage, which is not desirable. Attempts have been made to replace it with electrolytes. Those solid electrolytic capacitors are
PAis coating gold-coated aluminum, tantalum?
It has a structure in which a solid electrolyte is attached to the Li film-forming metal, and is the solid electrolyte of this type of solid capacitor? 1 mainly uses manganese dioxide formed by thermal decomposition of manganese nitrate. However, due to the high heat required during thermal decomposition and the meltening effect of the NOx gas generated, solid electrolyte capacitors are difficult to use due to the dielectric material aluminum.
There is damage to the oxide film of metals such as tantalum, which lowers the withstand voltage, increases leakage current, and deteriorates the electrical characteristics, which is a very big drawback. 'I is considered essential.

To compensate for these shortcomings, high heat is added! As a method for forming a solid electrolyte layer in the field, a method has been attempted in which a solid electrolyte is made of a very high-performance semiconductor material. For example, as described in JP-A-52-79255, a conductive organic compound containing a 7.7.8.8-tetracyanoquinodimethane (TCNQ) complex salt is used as the main component of a solid electrolyte. Solid electrolytic capacitors are known. However, in this solid electrolytic capacitor υ, the TCNQ complex salt has poor adhesion to the anodic oxide film, and the degree of connectivity is 10-3~
Since it is 10'S/cm, it has a length of 10'S/cm.
The fi value is small, the induced Ti loss is large, and the thermal stability over time is also poor, resulting in low reliability. Also, TCN Qta
Since salt is expensive, there has been a problem in that the manufacturing cost of the entire solid electrolytic capacitor is high.

In recent years, Ti has high conductivity and good adhesion with dielectric coatings.
Attempts have also been made to provide solid electrolytic capacitors using inexpensive conductive polymer compounds as solid electrolytes. In this attempt, a conductive polymer compound was skillfully introduced into the pores of the porous metal oxide when adhering the wiping polymer compound onto the porous metal oxide film used as the dielectric. The most important challenge is to stabilize the environment.

Generally, conductive polymer compounds are insoluble and infusible, and have extremely poor formability and processability. For this reason, most conductive polymer compounds cannot be molded by melt molding or casting methods, so while they have excellent performance as solid electrolytes, they cannot be introduced into the pores of porous 111M compounds. Therefore, in many cases, it could not be used for solid electrolytic capacitors.

[Problem to be solved by the invention 1 The purpose of the present invention is to solve the problems of the prior art described above,
A conductive polymer compound with excellent performance as a solid electrolyte can be easily introduced into the pores of a porous dielectric, and the adhesion with the dielectric coating is approximately 9%, and the manufacturing cost is low. It is an object of the present invention to provide a method for manufacturing a solid electrolytic capacitor using a solid electrolytic polymer compound having a low M m property as a solid conductive material.

[Means for Solving the Problems] According to the present invention, in manufacturing a solid electrolytic capacitor using a conductive polymer compound as a solid electrolyte, the conductive polymer compound is formed into a porous dielectric layer by sputtering. Provided is a method for producing a β1-electrolytic condenser, which comprises adhering the same to a β-1 electrolytic condenser.

Solid electrolysis in the present invention! The conductive polymer compound used as 1 is a polymer compound having a π-electron conjugated system, and preferably has an electrical conductivity of 1O-2S/cIR or more. Typical examples of such conductive polymer compounds include polyacetylene, polyparaphenylene, polypyrrole, polythiophene, polycyanoacetylene, polyisothianaphthene, polydiacetylene, polyaniline, polyphthalocyanine, and monomers constituting these polymers. Examples include polymers of derivatives of. Among these conductive polymer compounds, a preferable conductive polymer compound is polyparaphenylene.

Some of the above conductive polymer compounds contain 10
Some have electrical conductivity of S/1 or higher, while others have electrical conductivity of 1O-2S/cIR or higher by doping with electron-donating or electron-withdrawing dopants. Both can be used as solid electrolytes.

In the case of one, either chemical doping or electrochemical doping may be used for doping. Chemically doped dopant iodide, halogens such as bromine and Q-iodide, <II) arsenic pentafluoride, antimony pentafluoride, silicon tetrafluoride, J-rich phosphorus, phosphorous pentafluoride, aluminum chloride , metal halides such as aluminum bromide and aluminum fluoride, (III) sulfuric acid, nitric acid, full 4-sulfuric acid,
Protonic acids such as trifluoromethane sulfuric acid and chlorosulfuric acid, (TV) oxidizing agents such as sulfur trioxide, nitrogen dioxide, difluorosulfonyl bar'A, (V) AgC4+
04, (■) Tetracyanoeblene, Tetracyanoquinodimethane, Floranil, 2,3-dichloro-5,6-
Dicyatsubara benzoquinone, 2,3-dibrome-5,6
-Alkali metals such as benzoquinone, (■) Li, Na, and Ni, etc. can be used. On the other hand, electrochemically doped dopane [- is (I)
PFii, SbFi, AsFe, SbCρ
Halide anions of Va group elements such as i, BFi
Ha[]genide anions of elements of the 1lia group, such as ■
-(Ii), anionic dopants such as halogen anions such as Br-, C, O-, perchlorate anions such as 090i, and (TI)Li", Na", and +.

Rh+, alkali metal ion such as Cs, general formula RM
+1-1 or RM'' (in the formula, [ is 4-
x x 3 1C to C1
o alkyl group, ) [nyl, 80) [nyl, al: - aryl group such as ruphenyl, M is 'N, P, As, M1 is O or S, × represents 0 or 1; )'r-Cation and dopants such as tetraalkyl ammonium ion, detraalkyl small sulfonium ion, tetraalkyl ammonium ion, trifluorol A4 sonium, trialkylsul small nium ion, etc. can be mentioned, but these are not necessarily included. It is not limited to.

The dopant is generally formed by sputtering a conductive polymer compound onto the porous dielectric layer and then doped with the dopant (1-i).

When using metal cations such as Na+ as a dopant, it is possible to sputter a conductive polymer compound doped with these metal cations in advance, and any conventional doping method can be used. . When Bolivaraf T-nylene is used as a conductive polymer compound, doping with an electron-accepting compound, an electron-loving compound, an anion dopant, or a cation dopant is possible, but it is preferably doped in air. Doping with stable electron-accepting compounds and anionic dopants.

The type of porous dielectric material used in the present invention is not particularly limited, but oxides of metals such as aluminum, kuntal, and niobium can be suitably used.

In the present invention, the sputtering equipment used to deposit the Ti conductive polymer compound onto the porous dielectric layer by sputtering includes a DC two-pole sputtering method, an RF 2 K sputtering method, and a three-pole plasma sputtering method. , 41 Plasma sputtering method, AC sputtering method, bias sputtering 6 types, reactive twin sputtering method, ion beam sputtering method, DC magnetron sputtering method, R "Apparatus using sputtering methods such as magnetron sputtering method, coaxial magnetron sputtering method, etc. Among these sputtering methods, magnetron sputtering is preferred because it has high productivity of thin films.

In the present invention, the device i? For example, examples include a method of pressure molding conductive polymer compound powder onto a copper plate F, and a method of adhering it onto a copper plate using an adhesive such as EVO 1 adhesive or Teflon. However, it is not particularly limited to these.

The sputtering method used in the present invention is generally (1) capable of obtaining films of the same composition by using targets of complex compositions such as compounds, alloys, etc. under appropriate conditions.

■ There are fewer restrictions on the area and shape of the object to be coated.

■ There is no υ1 difference in the relative positional relationship between the substrate and the target, so b can be deposited in any direction.

■ Film thickness 1. II is easy to control.

■ Since the kinetic energy V- of the sputtered atoms incident on the substrate is high, the force applied to the film on the substrate is small.

It has the right features such as: By using this in the manufacturing method of the solid electrolytic capacitor of the present invention, the electrical conductivity is high,
An inexpensive conductive polymer compound that has good Jn properties with a dielectric film and good high frequency characteristics can be used as the solid electrolyte.

[Effect of explanation] The solid electrolyte produced by the method of the present invention has a higher capacity than the conventional solid electrolyte using an inorganic oxide semiconductor. Bamboo has outstanding performance in terms of dielectric loss, stability under shuttle.

Furthermore, the solid electrolytic capacitor manufactured by the method of the present invention has the following characteristics compared to the conventionally known solid electrolytic capacitor:
It has the following advantages.

■ Since a conductive polymer compound can be formed on the porous RI dielectric layer without heating it to high temperatures, there is no scratch on the oxide film of the anode, and there is no need to perform anodization (reformation) for repair. . Therefore, the rated voltage can be increased to several times that of the conventional capacitor, and the shape can be made smaller compared to the conventional capacitor, even though the capacitor has the same capacity and the same rated voltage.

(2) Leakage current is small because the adhesion between the ffi-conducting fi polymer compound and the dielectric coating is good.

^ Since the pressure-resistant condensate V can be made of fi and is sufficiently high, there is no need to provide 13ffil of graphite or the like, and the process for this can be simplified.

■Good frequency characteristics.

■ Low manufacturing cost.

[Examples] Hereinafter, the present invention will be explained in further detail by giving Examples and Comparative Examples.

Note that the characteristic values of each solid electrolytic capacitor are shown in the table.

Example 1 Aluminum foil with a thickness of 100 μm (purity 99.99%)
was designated as giI4i, and the surface of the foil was electrochemically etched by alternating direct current and alternating current to produce a porous aluminum foil with an average pore diameter of 2 μm and a specific surface area of 12 m 2 /g. The etched aluminum foil was then immersed in a 111M ammonium solution to electrochemically form a thin dielectric layer on the aluminum foil in the solution.

Benzene is mixed with a Lewis acid (AJ (J 3 )) and an oxidizing agent (
The mixture was stirred in the presence of (Cu CJ 2 ) (polymerization by Freel-Crauff reaction), and then, after washing low molecular weight components and impurities, it was vacuum dried to obtain a brown powder of polyparaphenylene. This powder was adhesively press-molded onto a copper plate using an epoxy adhesive to form a target. This target was installed in a Pelger equipped for planar type RF magnetron sputtering, and the aluminum foil having the dielectric layer obtained as described above was placed as a substrate. Sputter output 1'47cm2~3 α2, argon pressure 5
x 10 torr ~2 x 10'torr (7
) range, and set the rate (adhesion speed) from 10 to 100.
Sputtering was performed as a person/■in. This conclusion,
A thin film of polyparaphenylene with strong adhesion was obtained on the substrate.

This polyparaphenylene 1111 was doped by exposing it to BF3 gas. The electrical conductivity of polyparaphenylene at this time was 2S/1. A solid electrolytic capacitor was prepared by using aluminum foil as a cathode and fixing it with rubber.

Example 2 Li+ was added to the brown powder of polyparaphenylene obtained in Example 1.
was doped. Electrical conduction +ff at this time is 1S/C
It was IR. This pre-doped polyparaphenylene is bonded and pressed onto a copper plate using an epoxy adhesive.1! A solid electrolytic capacitor was produced by sputtering in the same manner as in Example 1, except that the same aluminum foil as in Example 1 was used as the target.

Comparative Example A solid electrolytic capacitor was fabricated using the same aluminum foil as in Example 1 for the dielectric layer, conventional manganese dioxide as the solid electrolyte, and aluminum foil as the cathode.

table

Claims (1)

[Claims] A method for manufacturing a solid electrolytic capacitor, which comprises depositing the conductive polymer compound on a porous dielectric layer by sputtering, in manufacturing a solid electrolytic capacitor using a conductive polymer compound as a solid electrolyte.