CN101866754B - Capacitor electrode, capacitor, manufacturing method thereof, electronic circuit and electronic device - Google Patents

Abstract

The present invention provides: (1) a capacitor electrode comprising niobium sintered body, wherein a plurality of pore diameter peak tops are in the pore distribution of the niobium sintered body; (2) a capacitor which comprises one electrode using the capacitor electrode, a counter electrode and dielectric material therebetween; (3) manufacturing method of the capacitor; and (4) an electronic circuit and electronic device using the above capacitor.

Description

Electrode for capacitors, capacitor and production method thereof, electronic circuit and electronic instrument

The application be in the application number that on May 14th, 2002 submits to be 02801689.0, name is called the dividing an application of patent application of " capacitor of niobium powder, niobium sintered body and this sintered body of use ".

The cross reference of related application

This application is the application of the regulation based on 35 U.S.C. the 111st (a) joint, it is according to the regulation of 35 U.S.C. the 119th (e) (1) joint, requirement is according to the U.S. Provisional Application No.60/291 that propose May 21 calendar year 2001 that is defined in of 35U.S.C.111 (b), 925 and the No.60/331 that proposes in November 9 calendar year 2001, the rights and interests of 200 the applying date.

Technical field

The present invention relates to niobium powder and sintered body thereof, it can stably be produced has unit mass high capacitance, the capacitor of good leak current characteristic and excellent moisture-proof, and relate to use niobium powder and the capacitor of sintered body and the manufacture method of niobium powder, sintered body and capacitor.

Background technology

For electronic instrument, require to have small size and high capacitance as the capacitor of portable phone and PC.In these capacitors, tantalum capacitor is preferred, because with respect to its size, capacitance is large and performance good.

In addition, in recent years, require electronic device to operate under low-voltage and high-frequency, and there is low noise, and for solid electrolyte capacitators, also require lower equivalent parallel resistance (ESR).

In this tantalum capacitor, the sintered body of tantalum powder is generally used as anode part.By this powder forming, sintering then, thus make described powder integration and make the electrode that is called as sintered body.This sintered body inside is formed the structure of 3 D complex by electricity and the powder particle of mechanical link each other, comprise the surface on internal void surface at this sintered body, forms dielectric film layer, floods the material of conduct to electrode, thereby prepares a kind of capacitor.As long as dielectric film layer is evenly attached to inner surface or the outer surface of described sintered body, the capacitance of the capacitor of manufacturing just depends primarily on the contact condition to electrode material and dielectric film layer on microcosmic.

In order to improve the capacitance of tantalum capacitor, must improve the quality of sintered body or use the sintered body that has increased surface area by broken tantalum powder.

The method that improves Sintered Quality must relate to the expansion of capacitor shape, and can not meet the requirement of miniaturization.On the other hand, in the method at broken tantalum powder with increasing specific surface area, the aperture of tantalum sintered object reduces or increases in sintering stage blind bore gap, result, and in subsequent step, the dipping of negative electrode reagent becomes difficult.

For example, suppose when using phosphate aqueous solution when to electrode material, the contact condition of described solution and dielectric film layer is completely, and capacitance is now apparent is 100% than (also referred to as negative electrode reagent-impregnated ratio), in use, have full-bodied to electrode material, particularly, in the situation of solid electrode material, almost can not obtain 100% the apparent ratio of capacitance.Especially, when the particle mean size sintered body little or that manufactured by tantalum powder of tantalum powder has large shape, difficulty increases and under extreme case, the apparent ratio of capacitance even may not reach 50%.Have the apparent ratio of such low-voltage capacity, the capacitor of manufacturing can not have sufficiently high moisture-proof.

In the situation that produce the tantalum powder of tantalum sintered object, have small-bore, it causes the small-bore of tantalum sintered object and the low apparent ratio of capacitance substantially.Therefore, produce the irreducible problem of ESR.

As one of measure addressing these problems, can consider to use sintered body as the capacitor of an electrode, this sintered body is used has the dielectric material production that dielectric constant is greater than tantalum, and provides the apparent ratio of high-capacitance.

As can be at this class electrode material of industrial supply, the dielectric constant of known niobium be greater than tantalum, and has large storage capacity.

JP-A-55-157226 (term used herein " JP-A " refers to " not examining open Japanese patent application ") discloses a kind of sintering device of producing capacitor, wherein, it by granularity, is the rectified action metal dust press molding of 2.0 microns or less reunion, then sintering, the base substrate of formed thereby and sintering is cut into tiny sheet, by conductor part and its link, and again sintering these.But, in this patent is open, the details of manufacture method and the character of niobium capacitor are not described.

United States Patent (USP) 4,084,965 disclose that to use particle mean size be the capacitor of sintered body of the niobium powder of 5.1 microns, and described niobium powder is by hydrogenation and pulverize niobium ingot and obtain.But disclosed capacitor has gross leak electric current (below sometimes referred to as " LC ") value, and has very little practical use.

JP-A-10-242004 (WO 98/38660) discloses a kind of part nitrided niobium powders and has therefore improved the technology of LC value.

The tap density that is used for the niobium powder of capacitor is the key factor of niobium powder shaping operation.The tap density of tradition niobium powder is 2.5g/ml or larger, is specifically about 4g/ml, and this is inadequate for shaping.

That is, if be shaped and the such niobium powder of sintering is prepared sintered body, niobium powder flow to metal die from the hopper of forming machine indigently, and the niobium powder of the constant basis that is difficult to weigh it is flow in metal die.As a result, it produces some problems, as not enough in the dimensionally stable of molded article, the undercapacity of molded article and sintered body, and often produce the capacitor with inferior LC.If use and also can process the special former with inferior mobility, the cost that is shaped too increases, and this is unpractical.

Like this, the conventionally known niobium powder for capacitor exists this powder can not adapt to the low problem of productivity ratio of progressive forming and capacitor completely.

Disclosure of an invention

The object of this invention is to provide the capacitor that a kind of unit mass capacitance is large, leakage current is little and moisture-proof is high; A kind of sintered body that can be used as the electrode material of this capacitor and can obtain the apparent ratio of high-capacitance; A kind of material as this sintered body is preferred, in shaping operation, show good fluidity, promote progressive forming and niobium powder that can steady production capacitor; Manufacture method with described capacitor, described sintered body and described niobium powder.

Result as the broad research addressing the above problem, the inventor has been found that, when thering is specific pore size distribution, the niobium powder that preferably has a plurality of apertures peak value in pore-size distribution is during for electrode for capacitors, the apparent ratio of high-capacitance can be obtained, and the capacitor that leakage current is little and moisture-proof is good can be produced.The inventor also finds, the tap density preferably with 0.5-2.5g/ml, more preferably particle mean size is 10～1, the niobium powder of 000 micron, show good mobility, can progressive forming and be preferred as the material of above-mentioned sintered body, when using this niobium powder, can stablize and produce the little capacitor of leakage current.The inventor has been found that more preferably, and using and a plurality of apertures peak value wide by pore size distribution range is all the capacitor as electrode of the niobium sintered body produced of 0.5 micron or larger niobium powder, can obtain the apparent ratio of high-capacitance and low ESR simultaneously.Based on these inventions, completed the present invention.

More particularly, the present invention relates to following niobium powder, niobium sintered body and the capacitor that uses it, and relate to the manufacture method of niobium powder, niobium sintered body and capacitor.

(1), for a niobium powder for capacitor, having tap density is 0.5～2.5g/ml.

(2) the niobium powder described in above-mentioned 1, wherein, particle mean size is 10～1,000 micron.

(3) the niobium powder as described in above-mentioned 1 or 2, wherein, angle of repose is 10 °～60 °.

(4) the niobium powder described in above-mentioned 1～3 any one, wherein, BET specific area is 0.5～40m ²/ g.

(5) the niobium powder described in above-mentioned 1～4 any one, has the pore-size distribution of aperture peak value in 0.01～500 micrometer range.

(6) the niobium powder described in above-mentioned 5, wherein, pore-size distribution has a plurality of apertures peak value.

(7) the niobium powder described in above-mentioned 5 or 6, wherein, any of aperture peak value is in 0.5～100 micrometer range.

(8) the niobium powder described in above-mentioned 1～7 any one, wherein, the content that is selected from least one element of nitrogen, carbon, boron and element sulphur is 200,000 quality ppm or still less.

(9) sintered body, it uses the niobium powder described in above-mentioned 1～8 any one.

(10) sintered body described in above-mentioned 9, it has aperture peak value at the pore-size distribution of 0.01～500 micron.

(11) for a niobium sintered body for electrode for capacitors, wherein, the pore-size distribution of niobium sintered body has a plurality of apertures peak value.

(12) niobium sintered body described in above-mentioned 11, wherein, pore-size distribution has two aperture peak values.

(13) niobium sintered body described in above-mentioned 11 or 12, wherein, in the peak value of a plurality of apertures, has the peak value at two peaks of high relative intensity and is present in respectively in 0.2～0.7 micrometer range and in 0.7～3 micrometer range.

(14) niobium sintered body described in above-mentioned 11～13 any one, wherein, in the peak value of a plurality of apertures, has the peak value at the peak of high relative intensity and is present in than having time side of the peak value larger diameter at the peak of high relative intensity.

(15) niobium sintered body described in above-mentioned 9～14 any one, wherein, the volume of sintered body is 10mm ³or larger, comprise the volume of hole.

(16) niobium sintered body described in above-mentioned 9～15 any one, wherein, the specific area of sintered body is 0.2～7m ²/ g.

(17) niobium sintered body described in above-mentioned 9～16 any one, wherein, a part of sintered body has been nitrided.

(18) niobium sintered body described in above-mentioned 12～17 any one, wherein, described sintered body is the sintered body being obtained by a kind of niobium formed body, described niobium formed body produce a kind of when 1300 ℃ of sintering CV value be the sintered body of 40,000～200,000 μ FV/g.

(19) capacitor, comprise use as above-mentioned 9～18 any one described in an electrode, of niobium sintered body to electrode and intervenient dielectric material.

(20) capacitor described in above-mentioned 19, wherein, dielectric material mainly comprises niobium oxide.

(21) capacitor described in above-mentioned 19 wherein, is at least one material that is selected from electrolyte solution, organic semiconductor and inorganic semiconductor to electrode.

(22) capacitor described in above-mentioned 21, wherein, to electrode, be organic semiconductor, and organic semiconductor is at least one material that is selected from the organic semiconductor that comprises benzopyrrole quinoline tetramer and chloranil, the organic semiconductor that mainly comprises four thio naphthacene, the organic semiconductor that mainly comprises four cyano quinone bismethane and electric conductive polymer.

(23) capacitor described in above-mentioned 22, wherein, electric conductive polymer is at least one composition that is selected from polypyrrole, polythiophene, polyaniline and substitutive derivative thereof.

(24) capacitor described in above-mentioned 22, wherein, electric conductive polymer is in the polymer by the repetitive to containing following formula (1) or (2) expression, to mix the electric conductive polymer that dopant obtains:

(wherein, R ¹～R ⁴saturated or unsaturated alkyl, alkoxyl or the alkyl ester group group, halogen atom, nitro, cyano group, primary, secondary or tertiary amino, the CF that represent independently of one another the straight or branched be selected from hydrogen atom, contain 1～10 carbon atom ₃the univalent perssad of the phenyl of group, phenyl and replacement; Every a pair of R ¹and R ², R ³and R ⁴can be at an arbitrary position in conjunction with forming divalence chain, for by R ¹and R ²or by R ³and R ⁴the carbon atom replacing forms at least one 3-, 4-, the saturated or unsaturated hydrocarbons ring structure of 5-, 6-or 7-unit together; The chain of ring-type combination can contain carbonyl, ether, ester, acid amides, thioether, sulfinyl, sulfonyl or imino group at an arbitrary position; X represents oxygen atom, sulphur atom or nitrogen-atoms; R ⁵only when being nitrogen-atoms, X just exists, and the straight or branched that represents independently hydrogen atom or contain 1～10 carbon atom, saturated or unsaturated alkyl).

(25) capacitor described in above-mentioned 24, wherein, electric conductive polymer is the electric conductive polymer that contains the repetitive being represented by following formula (3):

(wherein, R ⁶and R ⁷saturated or the unsaturated alkyl of the straight or branched that represents independently of one another hydrogen atom, contains 1～6 carbon atom, or a substituting group, is used to form at least one 5-, the 6-that contain two oxygen atoms or the 7-unit saturated hydrocarbons ring structure that by the alkyl that mutually combines at an arbitrary position, are obtained; And circulus comprises having the structure of can substituted ethenylidene key, can substituted phenylene structure).

(26) capacitor described in above-mentioned 22, wherein, electric conductive polymer is by mix the electric conductive polymer that dopant obtains in poly-(3,4-ethylidene dioxy thiophene).

(27) capacitor described in above-mentioned 19, wherein, is made by the material at least partly with layer structure electrode.

(28) capacitor described in above-mentioned 19, wherein, contains organic sulfonic acid root anion as dopant to the material of electrode.

(29) produce a method for the niobium powder described in above-mentioned 1～8 any one, it comprises the activation processing of niobium or niobium compound.

(30) method of the production niobium powder described in above-mentioned 29, wherein, the activation processing of niobium or niobium compound is that the step that is selected from sintering step and broken step by least one is carried out.

(31) method of the production niobium powder described in above-mentioned 29 or 30, wherein, the mixture of use niobium or niobium compound and activator carries out the activation processing of niobium or niobium compound.

(32) method of the production niobium powder described in above-mentioned 29～31 any one, wherein, carrying out the niobium of activation processing processing or the particle mean size of niobium compound is 0.01～10 micron.

(33) method of the production niobium powder described in above-mentioned 29～32 any one, wherein, described niobium or niobium compound contain at least one element that is selected from nitrogen, carbon, boron and sulphur, and its content is 200,000ppm or still less.

(34) method of the production niobium powder described in above-mentioned 29～33 any one, wherein, niobium compound is to be selected from least one of hydrogenated niobium, niobium alloy and hydrogenated niobium alloy.

(35) method of the production niobium powder described in above-mentioned 34, wherein, in niobium alloy or hydrogenated niobium alloy, the contained composition except niobium is that to be selected from atomic number be 88 or at least one element of less element, but does not comprise hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, iodine, niobium, helium, neon, argon, krypton, xenon and radon.

(36) method of the production niobium powder described in above-mentioned 31, wherein, the mixture that contains niobium or niobium compound and activator is by being used these compositions of solvent to obtain.

(37) method of the production niobium powder described in above-mentioned 36, wherein, described solvent is at least one solvent that is selected from water, alcohol, ether, cellosolve, ketone, aliphatic hydrocarbon, aromatic hydrocarbon and halogenated hydrocarbons.

(38) method of the production niobium powder described in above-mentioned 31, wherein, by the total amount of niobium or niobium compound, the consumption of activator is 1～40 quality %.

(39) method of the production niobium powder described in above-mentioned 31 or 38, wherein, the particle mean size of activator is 0.01～500 micron.

(40) method of the production niobium powder described in above-mentioned 31,38 and 39 any one, wherein, activator has a plurality of granularity peak values.

(41) method of the production niobium powder described in any one of above-mentioned 31,38-40, wherein, activator be a kind of 2,000 ℃ or following temperature with the removed material of gas form.

(42) method of the production niobium powder described in above-mentioned 41, wherein, activator is to be selected from naphthalene, anthracene, quinone, camphor, polyacrylic acid, polyacrylate, polyacrylamide, polymethylacrylic acid, polymethacrylates, PMAm, polyvinyl alcohol, NH ₄cl, ZnO, WO ₂, SnO ₂and MnO ₃at least one.

(43) method of the production niobium powder described in any one of above-mentioned 31,38-40, wherein, activator is to be selected from water-soluble substances, organic solvent solable matter, acid solution solable matter, aqueous slkali solable matter, forms complex compound and becomes the material of the material of water-soluble, organic solvent, acid solution or aqueous slkali, becomes at least one in the material of material of water-soluble, organic solvent, acid solution or aqueous slkali at 2000 ℃ or lower temperature.

(44) method of the production niobium powder described in above-mentioned 43, wherein, activator is the compound that is selected from metal and carbonic acid, sulfuric acid, sulfurous acid, halogen, perhalogeno acid, hypohalogenous acids, nitric acid, nitrous acid, phosphoric acid, acetic acid, oxalic acid or boric acid, metal, at least one of metal hydroxides and metal oxide.

(45) method of the production niobium powder described in above-mentioned 43, wherein, activator is to be selected from least one of lithium, sodium, potassium, rubidium, caesium, francium, beryllium, magnesium, calcium, strontium, barium, radium, scandium, yttrium, cerium, neodymium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, molybdenum, tungsten, manganese, rhenium, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, silver, gold, zinc, cadmium, boron, aluminium, gallium, indium, thallium, silicon, germanium, tin, lead, arsenic, antimony, bismuth selenium tellurium, polonium and compound thereof.

(46) method of the production niobium powder described in above-mentioned 29～40 and 43～45 any one, wherein, activation processing is by the processing of heating and/or under reduced pressure removing activator before sintering step or in sintering step.

(47) method of the production niobium powder described in above-mentioned 29～40 and 43～45 any one, wherein, described activation processing is by the processing that makes solvent contact to remove activator composition with the product of sintering or fragmentation after sintering step and in shattering process or after shattering process.

(48) method of the production niobium powder described in above-mentioned 47, wherein, described solvent is at least one in the solution that is selected from water, organic solvent, acid solution, aqueous slkali and contains the part that forms soluble complexes.

(49) method of the production niobium powder described in above-mentioned 48, wherein, acid solution is at least one solution being selected from nitric acid, sulfuric acid, hydrofluoric acid and hydrochloric acid.

(50) method of the production niobium powder described in above-mentioned 48, wherein, aqueous slkali contains at least one composition that is selected from alkali metal hydroxide and ammonia.

(51) method of the production niobium powder described in above-mentioned 48, wherein, described part is to be selected from least one of ammonia, glycine and ethylenediamine tetra-acetic acid.

(52) method of the production niobium powder described in above-mentioned 48, wherein, described organic solvent is methyl iso-butyl ketone (MIBK).

(53) produce a method for nitrogenous niobium powder, it comprises by least one method that is selected from bath nitriding, ionic nitriding and gas nitriding processes at the niobium powder described in above-mentioned 1～7 any one.

(54) produce a method for carbon containing niobium powder, it comprises by least one method that is selected from solid phase carbonization and liquid phase carbonization processes at the niobium powder described in above-mentioned 1～7 any one.

(55) produce a method for boracic niobium powder, it comprises by least one method that is selected from gas phase boronation and solid phase boronation processes at the niobium powder described in above-mentioned 1～7 any one.

(56) produce a method for sulfur-bearing niobium powder, it comprises by least one method that is selected from gas phase sulfuration, ion sulfuration and solid phase vulcanizing processes at the niobium powder described in above-mentioned 1～7 any one.

(57) the niobium powder that the manufacture method described in any one of a kind of use above-mentioned 29～56 obtains.

(58) production method for niobium sintered body, is used the niobium powder described in above-mentioned 1～8 and 57 any one.

(59) a kind of method of producing capacitor, described capacitor comprise one use electrode, the dielectric material forming on sintered body surface of niobium sintered body and on dielectric material, provide to electrode, wherein, niobium sintered body is to obtain at the niobium powder described in above-mentioned 1～8 and 57 any one by sintering.

(60) method of the production capacitor described in above-mentioned 59, wherein, dielectric material forms by electrolytic oxidation.

(61) a kind of method of producing capacitor, described capacitor comprise one use electrode, the dielectric material forming on described sintered body surface of niobium sintered body and on described dielectric material, provide to electrode, wherein, described niobium sintered body is at the niobium sintered body described in above-mentioned 9～18 any one.

(62) a kind of electronic circuit that uses the capacitor described in above-mentioned 19～28 any one.

(63) a kind of electronic instrument that uses the capacitor described in above-mentioned 19～28 any one.

Brief description of drawings

Fig. 1 is the enlarged drawing that signal explanation has the niobium powder of the present invention of two or more apertures peak value.

Fig. 2 is the sketch map of the pore-size distribution of the niobium powder measured by mercury injection method.

Implement mode of the present invention

Below describe have good leak current characteristic and excellent moisture-proof capacitor, can make it to there are these performances and provide the niobium sintered body of the apparent ratio of high-capacitance, preferably as this sintered material and there is good fluidity and can the niobium powder of progressive forming and the manufacture method of this capacitor, niobium sintered body and niobium powder.

In the present invention, the capacitor niobium powder that tap density is 0.5～2.5g/ml (sometimes referred to as " niobium powder ") is used as the niobium powder that meets the above-mentioned performance of capacitor and improve the productivity ratio in capacitor production.

Niobium powder for capacitor used herein refers to the niobium powder that mainly comprises niobium energy conduct production capacitor material.This niobium powder can contain, and for example, can form with niobium the composition of alloy, i.e. composition except niobium, as nitrogen and/or oxygen.

By using following methods shaping and sintering niobium powder for capacitor to obtain the niobium sintered body (sometimes referred to as niobium sintered body) for capacitor, then form dielectric layer thereon and to electrode layer, can produce capacitor.

Niobium powder for capacitor is joined by described adhesive being dissolved in to organic solvent below as in toluene or methyl alcohol and use shaking mixer or V-type mixer fully to mix in the solution being obtained.Then, use drier under reduced pressure to distill out organic solvent as circular cone drier, prepare the niobium mixed-powder that contains adhesive.This mixed-powder is put in the hopper of automatic forming machine, weighed and make niobium powder flow through the feed pipe from the metal die of hopper arrival metal forming machine, make it automatically fall into metal die, and be shaped together with wire.After removing adhesive, this molded article is 500～2, and 000 ℃ of sintering under reduced pressure, to manufacture niobium sintered body.

This niobium sintered body forms through electrochemical treatments, for example, in concentration, be in 0.1 phosphoric acid of quality % and the electrolyte solvent of adipic acid, at 30～90 ℃, under the voltage of 20～60V, processes 1～30 hour, to form the dielectric layer that mainly comprises niobium oxide.On this dielectric layer, form solid electrolyte layer as manganese dioxide, brown lead oxide and electric conductive polymer and graphite linings and silver paste layer.After cathode leg being connected thereon by soldering, with resin-sealed to prepare solid electrolyte capacitators.

When being shaped, do not have in the situation of mixed-powder at proper flow or angle of repose, this powder can not flow to metal die glibly from hopper, and can not stably form.Especially, because the methods such as use as vibration are carried this mixed-powder from hopper, excessive or the too small tap density of mixed-powder or particle mean size cause the intensity of molded article quality or sintered body or shape dispersed large, and in some cases, cause producing breach (chipping) or cracking, cause leakage current value difference.Therefore, the tap density of mixed-powder, particle mean size, mobility and angle of repose are the key factors of producing good sintered body and good capacitors.

These physical propertys of mixed-powder seldom change before and after mixing with adhesive, but determined by the physical property of niobium powder for capacitor used.Therefore, the importantly tap density of niobium powder used, particle mean size, mobility and angle of repose.The mobility of niobium powder and angle of repose are mainly subject to tap density or average particle size influences, and therefore, tap density and particle mean size become important factor.

In the present invention, in order to improve productivity ratio and the intensity of sintered body, and improve liquidity or angle of repose, thereby obtain the effect that reduces leakage current, tap density is 0.5～2.5g/ml preferably, more preferably 0.8～1.9g/ml.Preferably 10～1,000 micron of the particle mean size of niobium powder of the present invention, more preferably 50～200 microns.

For niobium powder can freely be dropped to the metal die of forming machine from hopper, preferably 10 °～60 °, the angle of repose of niobium powder of the present invention, more preferably 10 °～50 °.

By carrying out successively at least one sintering step and broken step, with the mixture (hereinafter referred to as " raw mixture ") that contains niobium powder or niobium compound powder (hereinafter referred to as " raw material niobium powder ") and activator (also referred to as " hole formation material ", and be below sometimes referred to as " additive "), can produce the niobium powder with above-mentioned physical property.

Produce niobium powder process of the present invention from raw mixture, at sintering step or broken step, remove deactivator.The removal of activator is also independent of described sintering step or broken step is carried out.

According to the chemical property of activator, can use arbitrarily the whole bag of tricks except deactivator.Can use and can easily remove a method of activator or combine multiple these methods of using.

The example that removes the method for deactivator comprises evaporation, distillation or thermal decomposition activator the method for removing with gas form, and by making it be dissolved in the method for removing activator in solvent.

In the situation that removing activator with gas form, can remove at sintering step, or a step except deactivator under heating and/or decompression was set before sintering.

The in the situation that of making it remove activator in being dissolved in solvent after by raw mixture sintering or in shattering process or after shattering process, the solvent of the following stated is contacted with sintered product or breakdown products, thereby dissolve and remove activator.

Can any stage in produced niobium powder process of the present invention by raw mixture nitrogenize, boronation, carbonization be set or vulcanize the step of a part of niobium powder.

Below describe the method for producing niobium powder of the present invention in detail.

Raw material niobium powder can be at least one powder being selected from niobium, hydrogenated niobium, niobium alloy and hydrogenated niobium alloy.Part powder can be nitrided, sulfuration, carbonization or boronation.In the present invention, " alloy " used comprises the solid solution with other alloying component.

The particle mean size of raw material niobium powder is preferably 0.01～10 micron, and more preferably 0.02～5 micron, more preferably 0.05～2 micron.

The example that obtains the method for the niobium that is used as raw material niobium powder comprises the method for hydrogenation, fragmentation and dehydrogenation niobium ingot, niobium particle or niobium powder; method with the reduction potassium niobate fluorides such as sodium broken reduzate; use the method for at least one reduction-oxidation niobium the broken reduzate of hydrogen, carbon, magnesium and aluminium, and the method for hydrogen reduction halogenation niobium.

The example that obtains the method for the hydrogenated niobium that is used as raw material niobium powder comprises the method for hydrogenation broken niobium ingot, niobium particle or niobium powder.

The example that obtains the method for the hydrogenated niobium alloy that is used as raw material niobium powder comprises the method for the hydride of broken niobium alloy ingot, niobium alloy particle or niobium alloy powder.Obtain example as the method for the niobium alloy of raw material niobium powder and comprise the method that makes the hydrogenated niobium alloy dehydrogenation that as above obtains.

As the alloying component except niobium, niobium alloy or hydrogenated niobium alloy contain that to be selected from atomic number be 88 or at least one element of less element, do not comprise hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, iodine, niobium, helium, neon, argon, krypton, xenon and radon.

Activator is the material of can any step in the process by raw mixture production niobium powder of the present invention removing.In niobium powder of the present invention, conventionally except in the part of deactivator, forming hole.

The aperture of the particle size influences niobium powder of the present invention of activator, the aperture of niobium powder affects the aperture of niobium sintered body, and the aperture of niobium sintered body affects the dipping ability of negative electrode agent in the capacitance of capacitor and capacitor production stage.

The dipping ability of negative electrode agent has a significant impact in the capacitor of producing high power capacity and low ESR.When the niobium powder that is shaped under by decompression is produced sintered body, the aperture of niobium sintered body is less than the aperture of niobium powder naturally.Owing to being difficult to impregnated cathode agent in the niobium sintered body of being produced by the little niobium powder in aperture, therefore, the average pore size of niobium powder is preferably 0.5 micron or larger, more preferably 1 micron or larger.

The average pore size of niobium powder is preferably 0.01～500 micron, and more preferably 0.03～300 micron, more preferably 0.1～200 micron.In order to have the aperture within the scope of this, the particle mean size of activator is preferably 0.01～500 micron, and more preferably 0.03～300 micron, more preferably 0.1～200 micron.

The average pore size of niobium powder most preferably is 0.5～100 micron, and the particle mean size of activator most preferably is 0.5～100 micron.

Use the activator of small grain size can reduce aperture diameter, and the activator of use coarsegrain can hole diameter enlargement.

By regulating the particle size distribution of activator, can adjustment aperture distribute.

In order to obtain, to there is enough high capacitances and do not have negative electrode agent dipping ability aspect to relate to the capacitor of problem, the capacitance that preferably suitably provides enough little hole to wish with generation according to the physical property of negative electrode agent in niobium sintered body, suitably provides enough large hole to flood to guarantee the satisfied of negative electrode agent.

In order to regulate the pore-size distribution of niobium powder or niobium sintered body, for example, by use, there is the activator (powder) of the particle size distribution of two or more peak values, can make niobium powder there is the pore-size distribution of two or more peak values.By this niobium powder of sintering, can obtain the niobium sintered body in the equal aperture in pore-size distribution with two or more peak values.In this case, described aperture peak value is preferably present in 0.01～500 micrometer range, more preferably 0.03～300 micron, further preferably 0.1～200 micron, particularly preferably 0.1～30 micron, most preferably is 0.2～3 micron.

The niobium powder of producing above niobium sintered body has two or more peak values in particle size distribution.Preferably 0.5 micron or larger of any of described two or more peak values.For example, in order to produce the niobium sintered body that has two peak values 0.7 and 3 microns in particle size distribution, two peak values of niobium powder can be adjusted to approximately 1.5 and approximately 2.5 microns.In order to obtain the wide-aperture niobium powder that has the small-bore of 1.5 microns and have 25 microns, need to use respectively average pore size is the activator of 1.5 microns and 25 microns.In general, when there is the hole of minor diameter and large diameter hole in niobium powder, in press molding process, large diameter hole diminishes.So large diameter peak value is preferably 20 microns or larger.Preferred all 30 volume % of pore volumes or there are 20 microns or larger aperture, more preferably 40 volume % or more also more.

Based on accompanying drawing, describe above embodiment in detail below.Fig. 1 is the enlarged drawing of signal explanation niobium powder of the present invention.Niobium powder in Fig. 1 is pelletizing, and it comprises the starting powder with the special pore size distribution being formed by activator.Use respectively the activator of approximately 1.5 microns of average diameters and approximately 25 microns to form hole (A) and (B).Like this, can make efficiently starting powder mutually condense.Fig. 2 is the sketch map of the niobium powder pore-size distribution measured by mercury injection method.Peak (A) is the hole (A) forming corresponding to the activator by approximately 1.5 microns of average diameters, the hole (B) that peak (B) forms corresponding to the activator by approximately 25 microns of average diameters.Peak (B) is than peak (A) height, and all pore volumes 44% there is 20 microns or larger aperture.

For example, by being blended in two or more activators in particle size distribution with different peak values, can obtain the activator in particle size distribution with two or more peak values.

As the example of the material of activator, be included in sintering temperature or become the material of gas and at least after sintering, dissolve in the material in solvent below.

In sintering temperature or the following example that becomes the material of gas, comprise the material that becomes gas by evaporation, distillation or thermal decomposition.The cheap material that also can easily become gas even at low temperatures and not leave residue is preferred.The example comprises that aromatic compound is as naphthalene, anthracene and quinone, camphor, NH ₄cl, ZnO, WO ₂, SnO ₂, MnO ₃and organic polymer.

The example of organic polymer comprises polyacrylic acid, polyacrylate, polyacrylamide, polymethylacrylic acid, polymethacrylates, PMAm and polyvinyl alcohol.

At least after sintering, soluble material is that residue or its thermal decomposition product of activator dissolves in the material in solvent.The material that can easily be dissolved in solvent described below after sintering or in shattering process or after fragmentation is particularly preferred.Such material can be selected from many materials according to the combination of solvent.

The example comprises compound, metal oxide, metal hydroxides and the metal of metal and carbonic acid, sulfuric acid, sulfurous acid, halogen, perhalogeno acid, hypohalogenous acids, nitric acid, nitrous acid, phosphoric acid, acetic acid, oxalic acid or boric acid.

Wherein, preferably solvent described below as acid, alkali or ammonium salt solution in the large compound of solubility.The example comprises the compound that contains at least one composition that is selected from lithium, sodium, potassium, rubidium, caesium, francium, beryllium, magnesium, calcium, strontium, barium, radium, scandium, yttrium, cerium, neodymium, erbium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, molybdenum, tungsten, manganese, rhenium, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, silver, gold, zinc, cadmium, aluminium, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth selenium tellurium, polonium, boron, silicon and arsenic.Wherein, preferable alloy salt, more preferably for example barium monoxide, manganese nitrate (II) and calcium carbonate.

These activators can use separately or its two or more be used in combination.

In order effectively to form special pore size distribution, the material that the solid form of usining under sintering temperature exists is preferred as activator material.Reason is under sintering temperature, with the solid-state activator existing, to hinder the excessive reunion of original niobium powder, and niobium powder only can be fused mutually at contact point place.If activator exists with liquid or gas form under sintering temperature, it is little and may form the less hole than hope to hindering the effect of this reunion.Therefore, with comprising more high-melting-point substances, than comprising low melting point, as can making aperture, the activator of aluminum metal, magnesium metal, magnesium hydride and calcium metal becomes more stable as barium monoxide, calcium carbonate, aluminium oxide and magnesian activator.

If add on a small quantity activator, it is large that tap density and angle of repose become, and if add in a large number, tap density diminishes, and increases at the sintering stage hole of remaining silent.In order to obtain the tap density of 60 ° or less angle of repose and 0.5～2.5g/ml and there is no the problem of the hole of remaining silent in sintering stage, the addition of activator is generally 1～40 quality % or still less (unless otherwise indicated, quality % is hereinafter referred to as %), be preferably 5～25%, more preferably 10～20%, by raw material niobium, still, this can change according to the particle mean size of activator.

By not using solvent respectively the do for oneself activator of powder type and niobium raw material or by using suitable solvent activator and niobium raw material dry this mixture, can obtain raw mixture.

The example of operable solvent comprises water, alcohol, ether, cellosolve, ketone, aliphatic hydrocarbon, aromatic hydrocarbon and halogenated hydrocarbons.

Can use mixer to mix.About mixer, can use common equipment as shaking mixer, V-Mixer and Nauter mixer and without any problem.Temperature during mixing is limited by the boiling point of solvent and solidifying point, but is generally-50～120 ℃, is preferably-50～50 ℃, more preferably-10～30 ℃.Mix restriction especially of time used, as long as it is 10 minutes or more, still, mixes preferably and to use inert gas to carry out 1～6 hour in as the oxygen-free atmosphere of nitrogen or argon gas.

In the situation that using solvent, lower than 80 ℃, preferably lower than 50 ℃, use the mixture of the dry gained of circular cone drier or chamber dryer.If dry described mixture at 80 ℃ or higher temperature, in niobium or hydrogenated niobium powder, contained oxygen adversely increases.

At activator in sintering temperature or following become gas in the situation that, activator can be removed when sintering, but the condition of removal can be arranged on independently the step that makes activator form gas and remove before sintering by the condition such as temperature, pressure and time being set as promoting according to the chemical property of activator.In this case, activator under reduced pressure evaporates at 100～800 ℃ within a few hours.

In the situation that using hydrogenated niobium or hydrogenated niobium alloy as raw material niobium, by carrying out above-mentioned steps, can realize dehydrogenation, and irrelevant with the kind of activator.

500～2,000 ℃, preferably 800～1,500 ℃, more preferably 1,000～1300 ℃, under reduced pressure or at reducing atmosphere carry out sintering step in as argon gas.After sintering completes, sintered product is preferably cooled to the temperature (sometimes referred to as " product temperature ") of niobium to become 30 ℃ or lower, add gradually and contain 0.01～10 volume %, be preferably the inert gas of 0.1～1 volume % oxygen as nitrogen or argon gas, make product temperature be no more than 30 ℃, and standing 8 hours or more how after, take out sintered product, obtain sintering agglomerate.

In broken step, use disintegrating machine sintering agglomerate to be crushed to suitable granularity as roll-type granulation machine.

In the situation that activator at least dissolves in solvent after sintering step, make suitable solvent with after sintering agglomerate or sintering and before fragmentation, among or broken powder afterwards or when a plurality of these steps contact, thereby described activator is dissolved and remove.Owing to removing easily, activator component is preferably dissolved and removes in the broken powder from fragmentation.

Here solvent used is the solvent that activator to be dissolved has enough high-dissolvabilities therein.Cheap and hardly residual solvent be preferred.For example, the in the situation that of water-soluble activator, can make water; The in the situation that of organic solvent solubility activator, can use organic solvents such as methylisobutylketone, ethanol or methyl-sulfoxide (DMSO); The in the situation that of solubility in acid activator, can use acid solutions such as nitric acid, sulfuric acid, phosphoric acid, boric acid, carbonic acid, hydrofluoric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid or organic acid; The in the situation that of alkali solubility activator, can use aqueous slkalis such as alkali metal hydroxide, alkaline earth metal hydroxide or ammonia; In the situation that form the activator of soluble complexes, can use become the amine aqueous solutions such as ammonia or ethylenediamine of complex compound part, such as amino acid such as glycine, such as the polyphosphoric acid such as sodium phosphate trimer, crown ether, such as thiosulfates such as sodium thiosulfate or such as chelating agents such as ethylenediamine tetra-acetic acids.

Also can suitably use ammonium salt solution, cation exchange resin and anion exchange resin such as ammonium chloride, ammonium nitrate and ammonium sulfate.Preferably dissolve at a lower temperature and remove activator.If activator at high temperature dissolves and removes, the surface of niobium is oxidized, because the affinity of niobium and oxygen is high.Therefore, dissolving and the temperature of removing are preferably 50 ℃ or lower, and more preferably-10 ℃-40 ℃, more preferably 0 ℃-30 ℃.According to above reason, be preferably chosen in the method that produces little heat in dissolving and removal process.For example, when using metal oxide or metal as activator, the high heat of neutralization of the general generation of the dissolving of carrying out with acid and removal.So, preferably select a kind of method that produces little heat, be for example dissolved in water and organic solvent, by using the solvent of ammonium salt and edetate form soluble complexes and be dissolved in the solvent that contains ion exchange resin.

The instantiation of the combination of activator and solvent comprises barium monoxide and water, calcium oxalate and hydrochloric acid, aluminium oxide and sodium hydrate aqueous solution, hafnium oxide and methylisobutylketone and magnesium carbonate and the tetrasodium ethylenediamine tetraacetate aqueous solution.

Dissolving and removing after activator, fully washing and dry residue.For example, at water, remove in barytic situation, use ion exchanged soln fully to wash residue until the conductivity of washing lotion is reduced to 5 μ S/cm or less.Subsequently, at product described in 50 ℃ or lower product temperature drying under reduced pressure.Here, remaining activator or the amount of solvent composition are generally 100ppm or less, but this changes along with wash conditions.

In order to improve LC value, the niobium powder so obtaining, sintering group is fast and niobium raw material powder can be through nitrogenize, boronation, carbonization or the sulfuration of a part of niobium powder, or multiple these processing.

Niobium powder of the present invention can be containing the niobium nitride obtaining to some extent, niobium (Nb) boride, niobium carbide or sulfuration niobium or multiple these materials.The total amount of nitrogen, boron, carbon and each element of sulphur changes along with the shape of niobium powder, but it is 0～200, and 000ppm, is preferably 50～100,000ppm, more preferably 200～20,000ppm.If total content surpasses 200,000ppm, the condenser capacity characteristic degradation of producing, is not suitable for capacitor.

The nitrogenize of niobium powder can by liquid phase nitrogenize, ionic nitriding and Gaseous Nitriding any or by its combination, undertaken.Wherein, the Gaseous Nitriding in blanket of nitrogen is preferred, because its equipment is simple and processing ease.For example,, by making above-mentioned niobium powder standing Gaseous Nitriding that can realize in blanket of nitrogen in blanket of nitrogen.With 2,000 ℃ or following nitriding atmosphere temperature and 100 hours or shorter time of repose, can obtain the niobium powder with target nitrogenize amount.At higher temperature, process and can shorten the processing time.

The boronation of niobium powder can be gas phase boronation or solid phase boronation.For example, can, by making itself and boron source for example, if boron particles or halogenation boron (boron trifluoride) were 2,000 ℃ or following temperature under reduced pressure standing 1 minute～100 hours, make niobium powder boronation.

The carbonization of niobium powder can be any of gas carburization, solid phase carbonization and liquid phase carbonization.For example, can by make its with carbon source for example, as within standing 1 minute～100 hours, under reduced pressure made the carbonization of niobium powder 2,000 ℃ or following temperature together with the organic materials of material with carbon element or carbon containing (methane).

The sulfuration of niobium powder can be any of gas phase sulfuration, ion sulfuration and solid phase vulcanizing.For example,, by niobium powder standing gas phase that can realize in sulphur atmosphere in sulphur atmosphere is vulcanized.With 2,000 ℃ or following vulcanized gas temperature and 100 hours or shorter time of repose, can obtain the niobium powder with target sulfuration amount.By processing and can shorten the processing time under higher temperature.

The BET specific area of the niobium powder of the present invention so obtaining is generally 0.5～40m ²/ g, preferably 0.7～10m ²/ g, more preferably 0.9～2m ²/ g.

The mixture of the niobium powder of the present invention niobium powder that can be tap density, granularity, angle of repose, BET specific area, pore-size distribution different with processing by nitrogenize, boronation, carbonization or sulfuration.

Can preferably by for example sintering above-mentioned niobium powder of the present invention, produce as the sintered body of the present invention of electrode for capacitors.For example, by niobium powder is compressed and molded into reservation shape, then at 500 ℃～2,000 ℃, preferably 800 ℃～1,500 ℃, more preferably 1,000 ℃～1300 ℃ 10 ^-5～10 ²pa makes its heating 1 minute～10 hours.

The pore-size distribution of the sintered body being obtained by niobium powder of the present invention has aperture peak value conventionally in 0.01～500 micrometer range.

By the impressed pressure when being shaped, be adjusted to specific force value, described sintered body can have the aperture peak value larger than niobium powder.This impressed pressure value with press molding condition as variations such as the shape of the physical property of niobium powder, molded article and forming machines, but in the pressure limit that pressure that can press molding is not closed to sintered body hole.By preliminary experiment basis, such as the conditions such as physical property of niobium powder to be formed, determine that preferred force value is to make it have a plurality of apertures peak value.For example, the forming machine load that is applied to molded article by control can be controlled impressed pressure value.

The pore-size distribution of sintered body preferably has at least two aperture peak values, so as to contain enough little with obtain wish capacitance hole and according to the physical property of negative electrode agent enough greatly to obtain the satisfied hole flooding of negative electrode agent.By this sintered body that has a plurality of peak values in pore-size distribution, can produce and there is the excellent capacitor to the dipping ability of electrode and the apparent ratio of high-capacitance.

When in a plurality of pore-size distribution peak values, respectively in 0.2～0.7 micrometer range and in 0.7～3 micrometer range, when preferably in 0.2～0.7 micron and 0.9～3 micrometer range, existence has the peak value at two peaks of high relative intensity respectively, the capacitor of being produced by this sintered body can have good moisture-proof.In a plurality of pore-size distribution peak values, there is the peak value at the peak of high relative intensity and be preferably present in than an inferior side of the peak value larger diameter at the peak of high relative intensity, because capacitor can have more excellent moisture-proof.

The specific area of the sintered body of so producing is generally 0.2～7m ²/ g.

Conventionally, the shape of sintered body is larger, more difficult to the dipping of electrode.For example, at sintered body, there is 10mm ³or in the situation of larger size, can especially effectively use the sintered body of the present invention in pore-size distribution with a plurality of peak values.

Sintered body of the present invention can part nitrogenize.About nitriding method, can use said method and reaction condition about niobium powder.Nitrogenize in advance part nitrogen powder, a part of sintered body of being produced by this niobium powder for the production of sintered body and nitrogenize.

Such sintered body contains the oxygen of 500～70,000 quality ppm conventionally, because there is the oxygen of the autoxidation containing before sintering and the oxygen adding by autoxidation after sintering in niobium powder.In sintered body of the present invention, the content of the element except niobium, alloy forming element, oxygen and nitrogen is generally 400 quality ppm or still less.

As an example, when sintered body of the present invention is during at 1300 ℃ of sintering, CV value (80 ℃ in 0.1 quality % phosphoric acid solution the electrochemical shaping electrochemical shaping voltage of 120 minutes and at the product of the capacitance of 120Hz) be 4,000～200,000 μ FV/g.

The production of capacitor devices is below described.

For example, the metal that preparation comprises rectified action is as niobium or tantalum and have the wire of suitable shape and length, when the press molding of niobium powder, by this wire integral forming, make a part of wire insert the inside of molded article, thereby make wire can be used as the lead-out wire of sintered body.Or be shaped and sintered niobium powder and use lead-in wire, then, by welding, wait the lead-in wire of preparing separately coupled.

Use this sintered body as an electrode, by inserting a kind of dielectric material at this electrode with between to electrode, can produce capacitor.For example, by using niobium sintered body as an electrode, on this sintered body surface (inner surface that comprises hole), above form dielectric material and provide electrode on this dielectric material, preparing capacitor.

Dielectric material for this capacitor preferably mainly comprises the dielectric material of niobium oxide, more preferably mainly comprises the dielectric material of niobium pentaoxide.For example, by electrolytic oxidation, as the niobium sintered body of an electrode, can obtain the main dielectric material containing niobium pentaoxide.For niobium electrode described in electrolytic oxidation in electrolyte, generally use protonic acid aqueous solution, for example 0.1% phosphate aqueous solution, aqueous sulfuric acid, 1% acetic acid aqueous solution or the adipic acid aqueous solution.In the situation that obtaining niobium oxide dielectric material by electrochemical shaping niobium electrode in electrolyte like this, capacitor of the present invention is that a kind of electrolytic capacitor and niobium electrode are used as anode.

In capacitor of the present invention, to described niobium sintered body to restriction especially of electrode, for example can use in aluminium electrolytic capacitor technology known at least one to be selected from the material (compound) of electrolyte, organic semiconductor and inorganic semiconductor.

The instantiation of electrolyte comprises the isobutyl carbonate propyl ester-ethylene glycol mixed solution that wherein dissolves 5 quality % isobutyl group tripropyl ammonium tetrafluoroborate electrolytical dimethyl formamide-ethylene glycol mixed solutions and wherein dissolve 7 quality % tetraethyl ammonium tetrafluoroborates.

Organic semi-conductor instantiation comprises, the organic semiconductor that comprises benzene pyrrolin tetramer and chloranil, the organic semiconductor that mainly contains four thio naphthacene, the organic semiconductor that mainly contains four cyano quinone bismethane and the electric conductive polymer that contains the repetitive being represented by following formula (1) or (2):

Wherein, R ¹～R ⁴saturated or unsaturated alkyl, alkoxyl or the alkyl group, halogen atom, nitro, cyano group, primary, secondary or tertiary amino, the CF that represent independently of one another the straight or branched be selected from hydrogen atom, contain 1～10 carbon atom ₃the univalent perssad of the phenyl of group, phenyl and replacement; Every a pair of R ¹and R ², R ³and R ⁴can be at an arbitrary position in conjunction with forming divalence chain, for by R ¹and R ²or by R ³and R ⁴the carbon atom replacing forms at least one 3-, 4-, the saturated or unsaturated hydrocarbons ring structure of 5-, 6-or 7-unit together; The chain of annular combination can contain carbonyl, ether, ester, acid amides, thioether, sulfinyl, sulfonyl or imino group at an arbitrary position; X represents oxygen atom, sulphur atom or nitrogen-atoms; R ⁵only when being nitrogen-atoms, X just exists, and the straight or branched that represents independently hydrogen atom or contain 1～10 carbon atom, saturated or unsaturated alkyl.

In the present invention, the R in formula (1) or (2) ¹～R ⁴the alkyl straight or branched that preferably represents hydrogen atom independently of one another or contain 1～6 carbon atom, saturated or undersaturated or alkoxyl, and every couple of R ¹and R ², R ³and R ⁴can be in conjunction with forming ring.

In the present invention, the electric conductive polymer that contains the repetitive being represented by formula (1) preferably contains the construction unit that represented by following formula (3) as the electric conductive polymer of repetitive:

Wherein, R ⁶and R ⁷saturated or the unsaturated alkyl of the straight or branched that represents independently of one another hydrogen atom, contains 1～6 carbon atom, or a substituting group, is used to form at least one 5-, the 6-that contain two oxygen atoms or the 7-unit saturated hydrocarbons ring structure that by the alkyl mutually combining at an arbitrary position, are obtained; And circulus comprises having the structure of can substituted ethenylidene key, can substituted phenylene structure.

The electric conductive polymer that contains such chemical constitution a kind of dopant that adulterates, and for described dopant, can use known dopant and not restriction.

The instantiation of inorganic semiconductor comprises the inorganic semiconductor that mainly comprises brown lead oxide or manganese dioxide, and the inorganic semiconductor that comprises tri-iron tetroxide.These semiconductors can be used separately, or its two or more be used in combination.

The example of the polymer of the repetitive that contains formula (1) or (2) expression comprises polyaniline, polyphenylene oxide, polyphenylene sulfide, polythiophene, poly-furans, polypyrrole, poly-methyl pyrrole, and substitutive derivative and copolymer.Wherein, preferred polypyrrole, polythiophene and substitutive derivative thereof (for example poly-(3,4-ethylidene dioxy thiophene)).

When the semi-conductive conductivity of organic or inorganic used is 10 ^-2s/cm～10 ³during S/cm, the capacitor of producing can have less resistance value and can increase high-frequency electrical capacity.

For example, under the oxidant effect of the oxidation reaction being oxidized by two electronics carrying out satisfactorily dehydrogenation, polymerization polymerizable compound, as the method for aniline, thiophene, furans, pyrroles, methylpyrrole or their substitutive derivative, can be produced electric conductive polymer.The example of the polymerization reaction of polymerizable compound (monomer) comprises gas-phase polymerization and polymerisation in solution.Electric conductive polymer layer has thereon on the niobium sintered body surface of niobium sintered body of dielectric material and forms.In the situation that electric conductive polymer be can solution coat organic solvent soluble polymer, use on described sintered body surface coated polymeric to form the method for electric conductive polymer layer.

A preferred example that uses the manufacture method of polymerisation in solution is a kind ofly the niobium sintered body that forms dielectric layer to be immersed in the solution (solution 1) that contains oxidant thereon, subsequently this sintered body is immersed in the solution (solution 2) that contains monomer and dopant, thereby carry out polymerization, to form electric conductive polymer layer on this sintered body surface.Also can be after it be immersed in solution 2, then this sintered body is immersed in solution 1.The solution 2 using in said method can be not contain the monomer solution of dopant.In the situation that using dopant, can make this dopant exist together with the solution that contains oxidant.

The operation of being carried out these polymerization procedures by the sintered body that has dielectric material on it repeats one or many, and preferably 3～20 times, thus can easily form the electric conductive polymer layer of densification and layering.

In the manufacture method of capacitor of the present invention, can use any oxidant, as long as the conductivity that its reducing agent that can not adversely affect capacitor performance and oxidant can become dopant and improve electric conductive polymer.When producing, the industrial cheap compound of easy to handle is preferred.

The instantiation of oxidant comprises that Fe (III) based compound is as FeCl ₃, FeClO ₄and Fe (organic anion) salt; Anhydrous Aluminum chloride/stannous chloride; Alkali metal persulphate; Ammonium persulfate; Peroxide; Manganese class is as potassium permanganate; Quinone is as 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), tetrachloro-Isosorbide-5-Nitrae-benzoquinones and four cyano-Isosorbide-5-Nitrae-benzoquinones; Halogen is as iodine and bromine; Peracid; Sulfonic acid is as sulfuric acid, oleum, sulfur trioxide, chlorosulfonic acid, fluosulfonic acid and sulfamic acid; Ozone; Mixture with multiple these oxidants.

The example of basic compound that forms the organic anion of above-mentioned Fe (organic anion) salt comprises organic sulfonic acid, organic carboxyl acid, organic phosphoric acid and organic boronic.The instantiation of organic sulfonic acid comprises benzene sulfonic acid, p-methyl benzenesulfonic acid, methanesulfonic acid, ethyl sulfonic acid, alpha-sulfo naphthalene, β-sulfo group naphthalene, naphthalenedisulfonic acid and alkyl naphthalene sulfonic acid (example of alkyl comprises butyl, triisopropyl and di-t-butyl).

The instantiation of organic carboxyl acid comprises acetic acid, propionic acid, benzoic acid and oxalic acid.In addition, can also use in the present invention polymer dielectric anion as polyacrylic acid, polymethylacrylic acid, polystyrolsulfon acid, polyvinylsulfonic acid, poly--Alpha-Methyl sulfonic acid, polyvinyl sulfuric acid and polyvinyl sulfonic acid and polyphosphoric acid.These organic sulfuric acid and organic carboxyl acid are only examples, and the invention is not restricted to these.The example of the counter cation of above-mentioned anion comprises that alkali metal ion is as H ⁺, Na ⁺and K ⁺, and the ammonium ion being replaced by hydrogen atom, tetramethyl, tetraethyl, the tetrabutyl or tetraphenyl, still, the invention is not restricted to these.In these oxidants, preferably contain trivalent Fe-based compound, stannous chloride, alkali metal persulphate, ammonium persulfate or quinone.

In producing for the polymer composition at electric conductive polymer, the anion with dopant ability that can exist together as required (anion except the reducing agent anion of oxidant), can use by above-mentioned oxidant, produced contain oxidant anion (reducing agent of oxidant) as electrolytic anion or other electrolytic anion of counter anion.Its instantiation comprises Bronsted acid anion, comprises that the halide anions of 5B family element is as PF ₆ ^-, SbF ₆ ^-and AsF ₆ ^-; The halide anions of 3B group element is as BF ₄ ^-; Halide anion is as I ^-(I ₃ ^-), Br ^-and Cl ^-; Perhalogeno hydrochlorate ion is as ClO ₄ ^-; Lewis acid anion is as AlCl ₄ ^-, FeCl ₄ ^-and SnCl ₅ ^-; Inorganic anion is as NO ₃ ^-and SO ₄ ^2-; The naphthalene sulfonic acids (hereinafter referred is " Cl-5 ") that sulfonic acid anion replaces as p-methyl benzenesulfonic acid, naphthalene sulfonic acids and the alkyl that contains 1～5 carbon atom; Organic sulfonic acid root anion is as CF ₃sO ₃ ^-and CH ₃sO ₃ ^-; With carboxylate anion as CH ₃cOO-and C ₆h ₅cOO ^-.

Other example comprises that polymer dielectric anion is as polyacrylic acid, polymethylacrylic acid, polystyrolsulfon acid, polyvinylsulfonic acid, polyvinyl sulfuric acid, poly--Alpha-Methyl sulfonic acid, polyvinyl sulfonic acid and polyphosphoric acid.Yet, the invention is not restricted to these.In these anion, preferred macromolecule or low molecule organic sulfonic acid compound or polyphosphoric acid compound.Preferably, aromatic sulfonic acid compound (for example neopelex, sodium naphthalene sulfonate) is as anion supplying compound.

In organic sulfonic acid root anion, more effective dopant is to contain one or more sulfonate anion group (SO at molecule ₃ ^-) and there is the sulfo group naphtoquinone compounds of quinone structure and rylnthracene sulfonin root anion.

The example of the basic framework of the sulfo group quinone anion of above-mentioned sulfo group naphtoquinone compounds comprises 1,4-benzoquinone, adjacent benzoquinones, 1,2-naphthoquinones, 1,4-naphthoquinone, 2,6-naphthoquinones, 9,10-anthraquinone, Isosorbide-5-Nitrae-anthraquinone, 1,2-anthraquinone, 1,4-bends quinone, 5,6-bends quinone, 6, and 12-bends quinone, acenaphthenequinone, acenaphthene quinone, camphorquinone, 2,3-camphane diketone, 9,10-phenanthrenequione and 2,7-pyrene quinone.

In the situation that electrode is solid, conductive layer can be set, for example, to obtain and good the electrically contacting of outer conductor (lead frame) of using on demand thereon.

For example by curing conductive, stick with paste, electroplate, metallize or form heat-resisting conductive resin membrane, can form conductive layer.The preferred embodiment of electroconductive paste comprises silver paste, copper paste, aluminium paste, carbon paste and nickel paste; These can use separately or its two or more be used in combination.In the situation that using two or more pastes, these pastes can mix or can be overlapped with independent stratum form.The example of electroplating comprises nickel plating, copper plating, silver plating and aluminium plating.The example of the metal of steam deposition comprises aluminium, nickel, copper and silver.

More specifically, for example, successively carbon paste and silver paste are stacked on second electrode, and these are used to the material forming such as epoxy resin, thereby prepare a kind of capacitor.This capacitor can have niobium or the tantalum lead-in wire with niobium sintered body integral sintering and shaping or welding afterwards.

For example with the dipping of resin die, resin enclosure, metal shell, resin or stacked film, to the capacitor of the present invention of preparation like this, add casing, then as capacitor product for various uses.

In the situation that electrode is liquid, for example, the prepared capacitor that comprises above-mentioned two electrodes and dielectric material is contained in to one with the shell that electrode is electrically connected to, to complete this capacitor.In this case, the electrode side of niobium sintered body is guided to outside by above-mentioned niobium or tantalum, uses electro-insulating rubber etc. and described casing insulation simultaneously.

By using according to the niobium powder of producing in previously described embodiment of the present invention, produce for the sintered body of capacitor and produce capacitor from described sintered body, can obtain the capacitor with little leakage current and good reliability.

Capacitor of the present invention has larger volume static capacity than traditional tantalum capacitor, so can obtain the capacitor product of more miniaturization.

The capacitor of the present invention with such character can be applied to, and for example, as being conventionally used in by-pass capacitor or the coupling capacitor in analog circuit and digital circuit, and can be used for traditional tantalum capacitor.

In general, such capacitor is used in electronic circuit conventionally, and when using capacitor of the present invention, the restriction of the discharge aspect of electronic unit arrangement or heat reduces, therefore the electronic circuit that, has a high reliability can be arranged in than in the required narrower space of conditional electronic circuit.

In addition, when using capacitor of the present invention, can obtain than traditional electronic instrument and there is smaller szie and the electronic instrument of high reliability more, for example, for example, as computer, computer peripheral (PC card), mobile device (portable phone), housed device, be arranged on equipment, artificial satellite and communication apparatus on the vehicles.

Implement best mode of the present invention

Below with reference to embodiment and comparative example, describe the present invention in detail, still, the invention is not restricted to these examples.

In each embodiment, the ESR value of the capacitance of the tap density of niobium powder, angle of repose, granularity and aperture and capacitor, leakage current, the apparent ratio of capacitance, moisture-proof and capacitor is all measured by the following method.

(1) mensuration of tap density

Tap density is according to using method and the determining instrument of compaction device to measure in the apparent specific gravity determination method of the industrial monohydrate of stipulating in JIS (Japanese Industrial Standards' version in 2000) K1201-1.

(2) mensuration at angle of repose

Angle of repose is to use fluidity determining instrument and the sample size in JIS (Japanese Industrial Standards' version in 2000) Z2504, stipulated to measure.More particularly, the hopper that is 6cm from hopper lower height with respect to the horizontal plane makes niobium monoxide powder fall to horizontal plane, and using the summit of generated circular cone to the inclined-plane of horizontal plane, angle is with respect to the horizontal plane as angle of repose.

(3) mensuration of granularity

The equipment that uses Microtrack (HRA 9320-X100) to manufacture, measures particle size distribution by laser diffraction and scattering method.Granularity (the D that is equivalent to 50 volume % at accumulative total volume % ₅₀; Micron) be designated as particle mean size.

(4) mensuration in aperture

The Poresizer 9320 that use is manufactured by Micromeritics, measures pore-size distribution by mercury injection method.

In the present invention, by the rate of change that is pressed into use level (press-fitted amount), determine maximum and by aperture shown in maximum is defined as to peak value, using the size of maximum relative intensity at peak under this peak value.

(5) mensuration of condenser capacity

In room temperature, between the terminal of the sheet of made, connect the LCR analyzer that Hewlett-Packard manufactures, the electric capacity using the solid measure value when the 120Hz as processing capacitor in blocks.

(6) mensuration of capacitor leakage electric current

At room temperature, using between the terminal of the sheet at made, apply current value that 6.3V direct voltage measures after 1 minute as the leakage current values of processing capacitor in blocks.

(7) the apparent ratio of the capacitance of capacitor

Capacitance while supposing under the condition that is determined at 80 ℃ and 20V in 30% sulfuric acid in the 0.1% phosphoric acid solution electrochemical shaping sintered body of 1,000 minute is 100%, and the ratio value representation of the capacitance after capacitor is used and produced to the apparent ratio of capacitance.

(8) the moisture-proof value of capacitor

By produced capacitor capacitance after standing 500 hours under 60 ℃ and 95% relative humidity be less than initial value 110% or be less than 120% number and represent moisture-proof value.Be less than 110% number more, illustrate that moisture-proof value is better.

(9) mensuration of the ESR value of capacitor

In room temperature, between the terminal of the sheet of made, connect the LCR analyzer that Hewlett-Packard manufactures, the ESR using the ESR measured value under 100kHz, 1.5VDC and 0.5Vrms as capacitor.

Embodiment 1

To packing 5,000 grams in nickel crucible, at 80 ℃ of abundant vacuum drying fluoro potassium niobates and mole, be the sodium of 10 times of fluoro potassium niobates, and make its under argon atmospher 1,000 ℃ of reduction reaction of carrying out 20 hours.After reacting completely, reduzate is cooling, wash with water successively, the sulfuric acid scrubbing with 95%, then washes with water, and vacuumize is also used the oxidation aluminium pot ball mill that contains silica alumina ball to pulverize 40 hours.Crushed products is flooded and stirred in 3: 2 (by mass) of 50% nitric acid and 10% aqueous hydrogen peroxide solution mixed solution.Then, crushed products water is fully washed, until pH value reaches 7, to remove impurity, then vacuumize.The particle mean size of raw material niobium powder is 1.2 microns.

In niobium tank, place 500 grams of this raw material niobium powder and add wherein 50 grams of polybutyl methacrylates and 1 liter of toluene.In addition, add zirconia ball and use shaking mixer by contents mixed 1 hour.After removing zirconia ball, this mixture is placed in circular cone drier and 1 * 10 ²vacuumize under the condition of Pa and 80 ℃.

Subsequently, by this niobium powder at 250-400 ℃ 1 * 10 ^-2pa heating 12 hours, to decompose and to remove polybutyl methacrylate, then 4 * 10 ^-3under the decompression of Pa 1,150 ℃ of sintering 2 hours.Niobium powder sintering agglomerate is cooling until product temperature is reduced to 30 ℃ or lower, then use roll pelletizer broken, take and obtain the broken powder of niobium that particle mean size is 100 microns.

The broken powder of this niobium, by passing into nitrogen through the nitrogen treatment at 300 ℃, 2 hours adding to depress, obtains the niobium powder of approximately 450 grams.Nitrogen content is 0.22%.

The physical property of this niobium powder represents as tap density, particle mean size, angle of repose, BET specific area and aperture peak value in table 1.

Pack the niobium powder (approximately 0.1 gram) so obtaining into tantalum device automatic forming machine (TAP-2R, by Seiken, manufactured) hopper in, and with automatic forming together with the niobium silk of 0.3mm φ, come manufacturing dimension to be about the molded article of 0.3cm * 0.18cm * 0.45cm.The qualitative dispersiveness of outward appearance and molded article represents in table 1.

This molded article is 4 * 10 ^-3in the vacuum of Pa 1,250 ℃ standing 30 minutes, to obtain sintered body.Prepare this sintered body of 100, and each uses 0.1% phosphate aqueous solution electrochemical shaping 200 minutes under 20V voltage, to form from the teeth outwards oxide dielectric film.

Subsequently, repeat this sintered body to be immersed in and in 60% manganese nitrate aqueous solution, then to make it in 220 ℃ of heating operations of 30 minutes, to form manganese dioxide layer as to electrode layer on oxide dielectric film.This to electrode layer on, stack gradually carbon-coating and silver is stuck with paste layer.After lead frame being installed thereon, this device is shaped with epoxy resin as a whole, to manufacture chip capacitor.Average electrical capacity and the average leakage current (hereinafter referred is " LC ") of the apparent ratio of capacitance of this capacitor and chip capacitor (n=100) represent in table 1.LC value is by applying 1 minute value at room temperature measuring of voltage of 6.3V.

Embodiment 2

In the reactor of SUS 304 systems, put into 1,000 gram of niobium ingot, and pass into continuously wherein hydrogen 10 hours at 400 ℃.After cooling, the niobium ingot of hydrogenation be placed in SUS 304 tank processed that contains zirconia ball and pulverize 10 hours.Then, make this hydride and water form the slurry of 20 volume %, pack spike mill into together with zirconia ball and at 40 ℃ or lower temperature wet pulverizing 7 hours, to obtain the hydrogenated niobium slurry of pulverizing.The particle mean size of this raw material hydrogenation niobium powder is 0.9 micron.

In SUS tank processed, packing this slurry (slurry concentration is 98%) into and adding wherein the particle mean size of 200 grams is the barium monoxide of 1 micron.In addition, add zirconia ball and use shaking mixer by contents mixed 1 hour.After removing zirconia ball, this mixture is placed in the bucket of niobium system, and 1 * 10 ²vacuumize under the condition of Pa and 50 ℃.

Subsequently, 1 * 10 ^-2under Pa, at 400 ℃ of mixtures by gained, heat 4 hours, to make hydrogenated niobium dehydrogenation, then 4 * 10 ^-3under the decompression of Pa 1,100 ℃ of sintering 2 hours.By the mixing of gained barytic niobium sintering agglomerate cooling until product temperature is reduced to 30 ℃ or lower, then use roll pelletizer broken, take the broken powder of barytic niobium that obtained mixing that particle mean size is 95 microns.

To this that packs 500 grams in polytetrafluoroethylcontainer container into, mixed barytic niobium broken powder and 1,000 gram-ion exchanged water and be cooled to 15 ℃ or lower.Preparation is by mixing 600 gram of 60% nitric acid, 150 gram of 30% hydrogen peroxide and 750 gram-ion exchanged waters and being cooled to 15 ℃ or lower the obtained aqueous solution separately.Then under stirring condition, having suspended wherein to have mixed in the aqueous solution of the broken powder of barytic niobium drips this aqueous solution of 500 grams, and notes not making water temperature surpass 20 ℃.After being added dropwise to complete, by this solution continuous stirring 1 hour again, standing 30 minutes, decant then.Add wherein 2,000 gram-ion exchanged waters, and the solution of gained is stirred 30 minutes, standing 30 minutes, decant then.This operation repeats 5 times.Then, the broken powder of niobium is packed in teflon post processed, and wash 4 hours with water and make deionized water mobile simultaneously.Now, washing electrical conductivity of water is 0.9 μ S/cm.

After washing completes, by the broken powder of niobium, at 50 ℃ of drying under reduced pressure, and by passing through the nitrogen treatment of 300 ℃ 3 hours adding to depress by nitrogen, result, obtains the niobium powder of approximately 350 grams.Nitrogen content is 0.28%.

The physical property of this niobium powder represents as tap density, particle mean size, angle of repose, BET specific area and aperture peak value in table 1.

Pack the niobium powder (approximately 0.1 gram) so obtaining into tantalum device automatic forming machine (TAP-2R, by Seiken, manufactured) hopper in, and with automatic forming together with the niobium silk of 0.3mm φ, come manufacturing dimension to be about the molded article of 0.3cm * 0.18cm * 0.45cm.The qualitative dispersiveness of outward appearance and molded article represents in table 1.

This molded article is 4 * 10 ^-3in the vacuum of Pa 1,250 ℃ standing 30 minutes, to obtain sintered body.Prepare this sintered body of 100, and each uses 0.1% phosphate aqueous solution electrochemical shaping 200 minutes under 20V voltage, to form from the teeth outwards oxide dielectric film.

Subsequently, oxide dielectric film is contacted with the mixed in equal amounts solution of 0.5% anthraquinone sulfonic acid solution with 10% ammonium persulfate aqueous solution, then the operation contacting with pyrroles's steam repeats at least 5 times, so as on oxide dielectric film, to form comprise polypyrrole to electrode.

This to electrode layer on, stack gradually carbon-coating and silver is stuck with paste layer.After lead frame being installed thereon, this device is shaped with epoxy resin as a whole, to manufacture chip capacitor.The average electrical capacity peace of the apparent ratio of capacitance of this capacitor and chip capacitor (n=100) all LC value represents in table 1.LC value is by applying 1 minute value at room temperature measuring of voltage of 6.3V.

Embodiment 3～10

By the method identical with embodiment 1, produce niobium powder, its molded article, sintered body and capacitor, but change the addition of particle mean size and polybutyl methacrylate, or use the method identical with embodiment 2 to produce, but change particle mean size and barytic addition.The dispersiveness of the physical property of niobium powder and outward appearance and molded article quality, and the capacitance of capacitor and LC represent in table 1.

Embodiment 11～22

With the method production example 11～14 identical with embodiment 1 and 16～18 niobium powder, molded article and sintered body, with the method production example 15 identical with embodiment 2 and 19～22 niobium powder, molded article and sintered body, but the activator that use table 1 makes in each case replaces polybutyl methacrylate or barium monoxide.The dispersiveness of the physical property of niobium powder and outward appearance and molded article quality, and the capacitance of capacitor and LC represent in table 1.

These molded articles then at 1,250 ℃ 4 * 10 ^-3under the decompression of Pa standing 30 minutes, to obtain sintered body.Prepare every kind of sintered body of 100, and use 0.1% phosphate aqueous solution electrochemical shaping 200 minutes under 20V voltage, to form from the teeth outwards oxide dielectric film.

Subsequently, the every kind of sintered body that has formed oxide dielectric film on it is immersed in the aqueous solution (solution 1) of the ammonium persulfate that contains 25 quality %, pull out, at 80 ℃, be dried 30 minutes, be immersed in and contain 3 of 18 quality %, in the aqueous isopropanol (solution 2) of 4-ethylidene dioxy thiophene, pull out, then in the atmosphere of 60 ℃ standing 10 minutes, thus carry out oxidation polymerization.This sintered body is immersed in solution 1 again, then uses with above identical method and process.From flooding solution 1 until the operation of oxidation polymerization repeats 8 times.Then, by the warm water washing of 50 ℃ 10 minutes for sintered body, and 100 ℃ dry 30 minutes, thereby form comprise conductive poly (3,4-ethylidene dioxy thiophene) to electrode.

This to electrode on, stack gradually carbon-coating and silver is stuck with paste layer.After lead frame being installed thereon, this device is shaped with epoxy resin as a whole, to manufacture chip capacitor.Average electrical capacity and the average LC value of the apparent ratio of capacitance of this capacitor and chip capacitor (n=100) represent in table 1.LC value is by applying 1 minute value at room temperature measuring of voltage of 6.3V.

Embodiment 23～25

By the method identical with embodiment 2, produce niobium powder, sintered body and capacitor, but as raw material, in embodiment 23, use niobium-tin alloy powder, in embodiment 24, use hydrogenated niobium-rhenium alloys powder, in embodiment 25, use hydrogenated niobium-yttrium-boron alloy powder.The physical property of capacitor, capacity and LC represent in table 1.

Comparative example 1～3

To packing 2,000 grams in nickel crucible, at 80 ℃ of abundant vacuum drying potassium niobate fluorides and mole, be the sodium of 10 times of potassium niobate fluorides, and make its under argon atmospher 1,000 ℃ of reduction reaction of carrying out 20 hours.After reacting completely, reduzate is cooling, washing in order, the sulfuric acid scrubbing with 95%, then washes with water, and vacuumize is also used the oxidation aluminium pot ball mill that contains silica-alumina ball to pulverize, and changes grinding time.Crushed products is flooded and stirred in 3: 2 (by mass) of 50% nitric acid and 10% aqueous hydrogen peroxide solution mixed solution.Then, every kind of crushed products water is fully washed, until pH value reaches 7, to remove impurity, then vacuumize.The particle mean size of the niobium powder of producing is 1.3 microns～10 microns.

Subsequently the niobium powder of 50 grams of gained is placed in SUS304 reactor processed, and passes into wherein continuously nitrogen 2～4 hours at 300 ℃, to obtain niobium nitride.

The physical property of every kind of niobium powder represents as tap density, particle mean size, angle of repose, BET specific area and aperture peak value in table 1.

The niobium powder (approximately 0.1 gram) so obtaining is packed in the hopper of tantalum device automatic forming machine (TAP-2R is manufactured by Seiken), and attempt automatic forming together with the niobium silk with 0.3mm φ.Acquired results represents in table 1.

Comparative example 4～9

By the method identical with embodiment 2 but changing particle mean size is the barytic addition of 1 micron, having obtained tap density is the niobium powder of 0.2～0.4g/ml or 2.6～3.3g/ml.Its physical property represents in table 1.

Pack the niobium powder (approximately 0.1 gram) so obtaining into tantalum device automatic forming machine (TAP-2R, by Seiken, manufactured) hopper in, and with automatic forming together with the niobium silk of 0.3mm φ, come manufacturing dimension to be about the molded article of 0.3cm * 0.18cm * 0.45cm.The qualitative dispersiveness of outward appearance and molded article represents in table 1.

These molded articles are 4 * 10 ^-3in the vacuum of Pa 1,250 ℃ standing 30 minutes, to obtain sintered body.Prepare every kind of sintered body of 100, and use 0.1% phosphate aqueous solution electrochemical shaping 200 minutes under 20V voltage, to form from the teeth outwards oxide dielectric film.

Subsequently, oxide dielectric film is repeated at least 5 times with the operation that the mixed in equal amounts solution of 10% ammonium persulfate aqueous solution and 0.5% anthraquinone sulfonic acid solution contacts and then contacts with pyrroles's steam, so as on oxide dielectric film, to form comprise polypyrrole to electrode.

This to electrode on, stack gradually carbon-coating and silver is stuck with paste layer.After lead frame being installed thereon, this device is shaped with epoxy resin as a whole, to manufacture chip capacitor.Average electrical capacity and the average LC value of the apparent ratio of capacitance of this capacitor and chip capacitor (n=100) represent in table 1.LC value is by applying 1 minute value at room temperature measuring of voltage of 6.3V.

Embodiment 26～31

The hydride of niobium ingot is pulverized and dehydrogenation be take and obtained the primary granule that particle mean size is 0.8 micron.By the primary granule sintering of gained pulverizing, to obtain niobium prilling powder.Then, together with the niobium silk of this prilling powder of 0.1 gram and the long 10mm of independent preparation, thick 0.3mm, be contained in (4.0mm * 3.5mm * 1.8mm) in metal die, and use tantalum device automatic forming machine (TAP-2R, by Seiken, manufactured) it is applied to load as shown in table 2, to produce molded article.Then by each molded article 1300 ℃ of sintering 30 minutes, to obtain target sintered body.The load applying by controlling forming machine, has produced the sintered body with the pore-size distribution shown in table 2.The size of the sintered body of embodiment 26, specific area and CV value are respectively 24.7mm ³, 1.1m ²/ g and 85,000 μ FV/g.In other embodiments, each value embodiment 26 ± 2% scope in.

Embodiment 32～34

By the method identical with embodiment 26～28, obtain sintered body, but be 0.5 micron by making primary granule classification change particle mean size.The size of the sintered body of embodiment 32, specific area and CV value are respectively 24.9mm ³, 1.5m ²/ g and 125,000 μ FV/g.In other embodiments, each value embodiment 32 ± 1% scope in.The pore-size distribution of each sintered body of producing represents in table 2.

Embodiment 35

By the method identical with embodiment 31, obtain sintered body, but the niobium powder that uses method in the same manner as in Example 4 to obtain replaces described pelletizing.The size of the sintered body of embodiment 35, specific area and CV value are respectively 24.8mm ³, 1.2m ²/ g and 78,000 μ FV/g.The pore-size distribution of the sintered body of producing represents in table 2.

Comparative example 10～12

By the method identical with embodiment 26～28, produce sintered body, but use niobium pelletizing used in the prepared niobium powder replacement embodiment 26～28 of magnesium-reduced niobium chloride is used in 1,100 ℃ of heat treatment.The size of the sintered body of comparative example 10, specific area and CV value are respectively 24.3mm ³, 0.8m ²/ g and 84,000 μ FV/g.In other comparative example, each value comparative example 10 ± 2% scope in.The pore-size distribution of each sintered body of producing represents in table 2.

Embodiment 36

60 of the various sintered bodies of producing by the method identical with embodiment 26～35 with embodiment 21, each is in the phosphate aqueous solution of 80 ℃ 0.1% and 20V electrochemical shaping 1,000 minute, to form oxide dielectric film on sintered body surface.By the sintered body grouping after these electrochemical shapings, every group forms by 30.By two kinds of negative electrode agent A shown in tables 3 and B dipping for 30 sintered bodies in every group.Stack gradually carbon paste and silver paste thereon, and this device is shaped with epoxy resin, to prepare chip capacitor.The apparent ratio of capacitance and the moisture-proof value of each capacitor of manufacturing represent in table 4.

Comparative example 13

60 of the various sintered bodies of producing by the method identical with comparative example 9～12, each is in the phosphate aqueous solution of 80 ℃ 0.1% and 20V electrochemical shaping 1,000 minute, to form oxide dielectric film on sintered body surface.By the sintered body grouping after these electrochemical shapings, every group forms by 30.By the negative electrode agent A dipping shown in table 3 for 30 sintered bodies in every group.Stack gradually carbon paste and silver paste thereon, and this device is shaped with epoxy resin, to prepare chip capacitor.The apparent ratio of capacitance and the moisture-proof value of each capacitor of manufacturing represent in table 4.

Embodiment 37

By the method identical with embodiment 2, pulverize raw material hydrogenation niobium powder, obtain slurry.The particle mean size of this hydrogenant agent powder is 0.6 micron.After pulp centrifuged sedimentation, by decant, remove supernatant liquor.Adding wherein anhydrous propanone to make slurry concentration is 40 quality % well suspended.After the solution centrifugal sedimentation of gained, by decant, remove supernatant liquor.Add wherein anhydrous propanone, making slurry concentration is 60 quality % well suspended.This slurry is contained in SUS tank processed, and to add respectively wherein 15 quality % of niobium quality and the particle mean size of 10 quality % be the barium monoxide of 1.4 microns and 23 microns.In addition, add zirconia ball and use shaking mixer to mix 1 hour content.After removing zirconia ball, this mixture is placed in niobium bucket and 1 * 10 ²vacuumize under Pa and 50 ℃ of conditions.

By the method identical with embodiment 2, obtain and mixed barytic niobium sintering agglomerate and the broken powder of niobium.

Under agitation this of 500 grams having been mixed to the broken powder of barytic niobium joins and is cooled in 15 ℃ or lower 1,000 gram-ion exchanged water and notes not making water temperature surpass 20 ℃.After having added, by this solution continuous stirring 1 hour again, standing 30 minutes, decant then.Add wherein 2,000 gram-ion exchanged waters, and the solution of gained is stirred 30 minutes, standing 30 minutes, decant then.This operation repeats 5 times.Then, the broken powder of niobium is packed in teflon post processed, and wash 4 hours with water and make deionized water mobile simultaneously.Now, washing electrical conductivity of water is 0.5 μ S/cm.

After washing completes, the broken powder of niobium to be passed through the nitrogen treatment of 300 ℃ 3 hours at 50 ℃ of drying under reduced pressure and adding to depress by nitrogen, result, obtains the niobium powder of approximately 350 grams.Nitrogen content is 0.30%.

The physical property of this niobium powder represents as tap density, particle mean size, angle of repose, BET specific area and aperture peak value in table 5.

By the method identical with embodiment 2, manufacture molded article.The outward appearance of molded article and quality dispersiveness represent in table 5.

Then use the method identical with embodiment 2 to form thin dielectric film on the surface of the sintered body of molded article.Then also stacked carbon-coating and silver are stuck with paste layer to shape paired electrode thereon successively.Install thereon after lead frame, this device is shaped with epoxy resin as a whole, to prepare chip capacitor.The apparent ratio of capacitance of this capacitor and the average electrical capacity of chip capacitor (n=100) peace all LC value represent in table 5.

Embodiment 38～44

By changing the kind of the activator add, average pore size and the consumption of two kinds of niobium powder to be mixed, use and method identical in embodiment 37 obtains the broken powder of niobium with activator mix.The solution that the solvent of dissolve activating agent is selected from water, acid, alkali, the solvent that contains ion exchange resin, ammonium nitrate solvent and contains edetate.With the method dissolve activating agent with identical in embodiment 37 to obtain niobium powder.The physical property of this niobium powder represents in table 5.

By the method with identical in embodiment 37, manufacture molded article and sintered body, to prepare chip capacitor.The capacitance of the outward appearance of molded article and quality dispersiveness and capacitor and average LC value represent in table 5.

Embodiment 45～47

As raw material, in embodiment 45, use respectively niobium-neodymium alloy powder, in embodiment 46, use niobium-tungsten alloy powder, in embodiment 47, use niobium-tantalum alloy powder, use with method identical in embodiment 37 and obtain niobium alloy powder.The physical property of niobium alloy powder represents in table 5.

With preparing molded article and sintered body with method identical in embodiment 37, prepare chip capacitor.The capacitance of the outward appearance of molded article and quality dispersiveness and capacitor and average LC value represent in table 5.

Embodiment 48～58

The niobium powder that use obtains in embodiment 37～47, uses the method identical with embodiment 2 to produce niobium sintered body.The pore-size distribution of sintered body represents in table 6.

Embodiment 59～69

100 of every kind of sintered bodies that preparation obtains in embodiment 48～58, and use 0.1 quality % phosphate aqueous solution 20V and 80 ℃ of electrochemical shapings 1,000 minute, to form from the teeth outwards oxide dielectric film.Negative electrode agent dipping shown in table 3 for these sintered bodies.Stack gradually carbon-coating thereon and with epoxy resin, be shaped to prepare chip capacitor with silver paste layer integral body.The apparent ratio of capacitance and the ESR of prepared capacitor represent in table 7.

Comparative example 14～17

100 of every kind of sintered bodies that preparation obtains in comparative example 9～12, and use 0.1 quality % phosphate aqueous solution 20V and 80 ℃ of electrochemical shapings 1,000 minute, to form from the teeth outwards oxide dielectric film.Negative electrode agent dipping shown in table 3 for these sintered bodies.Stack gradually carbon-coating thereon and with epoxy resin, be shaped to prepare chip capacitor with silver paste layer integral body.The apparent ratio of capacitance and the ESR of prepared capacitor represent in table 7.

Table 2

Table 3

Method	Negative electrode agent	The method of impregnated cathode agent
			A	Polypyrrole	Repeat the sintered body of having ammonium persulfate and anthraquinone sulfonic acid thereon to carry out gas-phase polymerization with pyrroles's steam
B	The mixture of brown lead oxide and lead sulfate (brown lead oxide: 98 quality %)	Repeat sintered body to flood in the mixed liquor of lead acetate and ammonium persulfate

Table 4

Table 6

Table 7

Embodiment and comparative example	Obtain the method for sintered body	The apparent ratio of capacitance	Electric capacity	ESR Ω
					Embodiment 59	Embodiment 48	98	592	0.024
Embodiment 60	Embodiment 49	97	587	0.023
					Embodiment 61	Embodiment 50	93	557	0.022
Embodiment 62	Embodiment 51	93	556	0.022
					Embodiment 63	Embodiment 52	98	585	0.023
Embodiment 64	Embodiment 53	98	589	0.023
					Embodiment 65	Embodiment 54	97	581	0.024
Embodiment 66	Embodiment 55	98	590	0.022
					Embodiment 67	Embodiment 56	98	592	0.024
Embodiment 68	Embodiment 57	98	587	0.023
					Embodiment 69	Embodiment 58	98	587	0.025
Comparative example 14	Comparative example 9	22	64	0.158
					Comparative example 15	Comparative example 10	71	305	0.083
Comparative example 16	Comparative example 11	73	314	0.081
					Comparative example 17	Comparative example 12	68	291	0.090

Industrial applicibility

Tap density is that 0.5～2.5g/ml, particle mean size are that 10～1000 microns, angle of repose are that 10～60 ° and BET specific area are 0.5～40m ²the niobium powder of the present invention of/g is excellent and can progressive forming aspect mobility.That by niobium powder described in sintering, obtain and in 0.01～500 micrometer range, have aperture peak value and preferably in pore-size distribution, have the niobium sintered body of a plurality of apertures peak value for electrode for capacitors, the apparent ratio of high-capacitance can be obtained and the capacitor of the low and excellent moisture resistance of leakage current can be produced.

Claims (18)

1. an electrode for capacitors that comprises niobium sintered body, wherein, the pore-size distribution of niobium sintered body has a plurality of apertures peak value, in the peak value of a plurality of apertures, has the peak value at the peak of high relative intensity and is present in than having time side of the peak value larger diameter at the peak of high relative intensity.

2. the electrode for capacitors described in claim 1, wherein, described pore-size distribution has two aperture peak values.

3. the electrode for capacitors described in claim 1, wherein, the volume of described sintered body is 10mm ³or larger, comprise the volume of hole.

4. the electrode for capacitors described in claim 1, wherein, a part of sintered body has been nitrided.

5. the electrode for capacitors described in claim 1, wherein, described sintered body is the sintered body being obtained by a kind of niobium formed body, described niobium formed body produce a kind of when 1300 ℃ of sintering CV value be the sintered body of 40,000～200,000 μ FV/g.

6. a capacitor, comprises an electrode that right to use requires the electrode for capacitors described in 1～5 any one, one to electrode and intervenient dielectric material.

7. the capacitor described in claim 6, wherein, described dielectric material mainly comprises niobium oxide.

8. the capacitor described in claim 6, wherein, is at least one material that is selected from electrolyte solution, organic semiconductor and inorganic semiconductor to electrode.

9. the capacitor described in claim 8, wherein, to electrode, be organic semiconductor, and organic semiconductor is at least one material that is selected from the organic semiconductor that comprises benzopyrrole quinoline tetramer and chloranil, the organic semiconductor that mainly comprises four thio naphthacene, the organic semiconductor that mainly comprises four cyano quinone bismethane and electric conductive polymer.

10. the capacitor described in claim 9, wherein, electric conductive polymer is at least one composition that is selected from polypyrrole, polythiophene, polyaniline and substitutive derivative thereof.

Capacitor described in 11. claims 9, wherein, electric conductive polymer is in the polymer by the repetitive to containing following formula (1) or (2) expression, to mix the electric conductive polymer that dopant obtains:

Wherein, R ¹～R ⁴the univalent perssad of phenyl that represents independently of one another saturated or unsaturated alkyl, alkoxyl or alkyl ester group group, halogen atom, nitro, cyano group, primary, secondary or tertiary amino, CF3 group, phenyl and the replacement of the straight or branched be selected from hydrogen atom, contain 1～10 carbon atom; Every a pair of R ¹and R ², R ³and R ⁴can be at an arbitrary position in conjunction with forming divalence chain, for by R ¹and R ²or by R ³and R ⁴the carbon atom replacing forms at least one 3-, 4-, the saturated or unsaturated hydrocarbons ring structure of 5-, 6-or 7-unit together; The chain of ring-type combination optionally contains carbonyl, ether, ester, acid amides, thioether, sulfinyl, sulfonyl or imino group at an arbitrary position; X represents oxygen atom, sulphur atom or nitrogen-atoms; R ⁵only when being nitrogen-atoms, X just exists, and the straight or branched that represents independently hydrogen atom or contain 1～10 carbon atom, saturated or unsaturated alkyl.

Capacitor described in 12. claims 11, wherein, electric conductive polymer is the electric conductive polymer that contains the repetitive being represented by following formula (3):

Wherein, R ⁶and R ⁷saturated or the unsaturated alkyl of the straight or branched that represents independently of one another hydrogen atom, contains 1～6 carbon atom, or a substituting group, is used to form at least one 5-, the 6-that contain two oxygen atoms or the 7-unit saturated hydrocarbons ring structure that by the alkyl mutually combining at an arbitrary position, are obtained; And circulus comprises having the structure of can substituted ethenylidene key, can substituted phenylene structure.

Capacitor described in 13. claims 9, wherein, electric conductive polymer is by mix the electric conductive polymer that dopant obtains in poly-(3,4-ethylidene dioxy thiophene).

Capacitor described in 14. claims 6, wherein, is made by the material at least partly with layer structure electrode.

Capacitor described in 15. claims 6, wherein, contains organic sulfonic acid root anion as dopant to the material of electrode.

16. 1 kinds of methods of producing capacitor, described capacitor comprises and uses an electrode of niobium sintered body, the dielectric material forming on described sintered body surface and on described dielectric material, provide one to electrode, wherein, described niobium sintered body is at the included niobium sintered body of electrode for capacitors described in any one of claim 1～5.

The electronic circuit of the capacitor described in any one of 17. 1 kinds of right to use requirements 6～15.

The electronic instrument of the capacitor described in any one of 18. 1 kinds of right to use requirements 6～15.

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