US3867129A - Anodically oxidizable metal powder - Google Patents

Anodically oxidizable metal powder Download PDF

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US3867129A
US3867129A US439805A US43980574A US3867129A US 3867129 A US3867129 A US 3867129A US 439805 A US439805 A US 439805A US 43980574 A US43980574 A US 43980574A US 3867129 A US3867129 A US 3867129A
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powder
metal
valve
powders
capacitor
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US439805A
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Gerard S Ronneau
Pierre D Debacker
Hugo L Carpentier
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TANTALUM PRODUCTION Inc A DE CORP
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Societe Generale Metallurgique de Hoboken SA
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Assigned to FANSTEEL INC.; A CORP. OF NY. reassignment FANSTEEL INC.; A CORP. OF NY. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: METALLURGIE HOBOKEN-OVERPELT
Assigned to FANSTEEL INC. 1 TANTALUM PLACE, N. CHICAGO, IL 60064 A CORP. OF NY reassignment FANSTEEL INC. 1 TANTALUM PLACE, N. CHICAGO, IL 60064 A CORP. OF NY ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: METALLURGIE HOBOKEN-OVERPELT A COMPANY OF BELGIUM
Assigned to TANTALUM PRODUCTION INC., A DE CORP. reassignment TANTALUM PRODUCTION INC., A DE CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: FANSTEEL INC.
Assigned to TANTALUM PRODUCTION INC., A DE CORP. reassignment TANTALUM PRODUCTION INC., A DE CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: FANSTEEL INC., A DE CORP.
Assigned to SIAM COMMERCIAL BANK, LTD., THE reassignment SIAM COMMERCIAL BANK, LTD., THE SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: TANTALUM PRODUCTION INC., A DE CORP.
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/004—Details
    • H01G9/04—Electrodes or formation of dielectric layers thereon
    • H01G9/042—Electrodes or formation of dielectric layers thereon characterised by the material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/922—Static electricity metal bleed-off metallic stock
    • Y10S428/923—Physical dimension
    • Y10S428/924—Composite
    • Y10S428/926—Thickness of individual layer specified
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12014—All metal or with adjacent metals having metal particles
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12181—Composite powder [e.g., coated, etc.]

Definitions

  • the new powders, object of the present invention provide the means of solving the above problem as will appear from the examples of comparable results set out in Table I hereafter.
  • a metal in powder form whose particles are made up of an anodically oxidizable metal, also recognized as valve metal or metal converting alternating current to direct current, such as .tantalum or niobium powder, containing molybdenum and/or vanadium and/or tungsten and/or hafnium in contents comprised between 0.06 and 2 per cent on an additive metal to tantalum or niobium metal basis, these additive metal contents referring to each additive metal separately or to the additive metals as a whole.
  • anodically oxidizable metal also recognized as valve metal or metal converting alternating current to direct current
  • .tantalum or niobium powder containing molybdenum and/or vanadium and/or tungsten and/or hafnium in contents comprised between 0.06 and 2 per cent on an additive metal to tantalum or niobium metal basis, these additive metal contents referring to each additive metal separately or to the additive metals as a whole.
  • the particles of another powder according to the invention are made up of a nucleus of anodically oxidizable metal covered with a surface layer of the same metal, such layer containing molybdenum and/or vanadium and/or tungsten and/or hafnium in contents comprised between 0.01 and 2 per cent on an additive metal to tantalum or niobium metal basis, these additive metal contents referring severally to each additive metal separately or to the additive metals as a whole.
  • the thickness ofsaid surface layer will preferentially be less than 3,000 Angstrom.
  • Still another powder according to the invention is one whose particles are made up a nucleus of anodically oxidizable metal covered with either a continuous or a noncontinuous surface layer, or one or more areas on the surface, made up of molybdenum and/or vanadium and/or tungsten and/of hafnium.
  • the thickness of said surface layer will preferentially be less than 3,000 Angstrom.
  • powders according to the invention improve the characteristics of the dielectric (electrolytic oxide) built up on the surface of the particles of which these powders are made up. Such improved characteristics give better performance to the capacitor manufactured from these powders.
  • the powders according to the present invention can be manufactured by a number of well known methods such as: co'fusion and embrittlement, sodiothermic reduction, fused electrolysis, hydrogen reduction on a fluidized bed.
  • One suitable powder which can be processed in accordance with the present invention is a tantalum powder obtained by electron-beam fusion and hydrogen embrittlement. Such high-purity powder is thoroughly blended with molybdenum powder in proportion of to .2 by weight. The powder blend is compacted in an isostatic press by a well-known technique and the resulting bars are melted in an electron beam furnace. The ingot is hydrided to a hydrogen content of about 0.4 per cent by weight, then it is crushed and pulverized and the powder obtained is degassed and submitted to chemical assay. The desired molybdenum content is traced back in the powder with more or less 10 per cent accuracy.
  • Another type of powder which can be prepared in accordance with the present invention is made by charging a quantity of potassium double fluoride into a sodiothermic reduction vessel. The reduction occurs at a temperature of about 800C in a fused salt solution containing sodium chloride: for instance 300 kg of potassium tantalum double fluoride in 10 kg'sodium chloride. A stoich-iometric quantity of sodium in liquid form is slowly added to the fuses salt mass; a dendritic tantalum powder is rapidly formed. When the reaction signs (exothermicity) tend to disappear, indicating that the chemical reaction has been completed, a quantity of 260 g of vanadium trichloride is charged into the sodiothermic reduction vessel, then g of sodium are added.
  • a tantalum powder which contains about 600 parts per million of vanadium, this latter metal being located on the surface of the powder particles.
  • Still another type of powder which can be prepared in accordance with the present invention is made by anoperating process similar to the one described just above.
  • the particles of this powder show a surface layer containing both the matrix metal, which is tantalum or niobium, and the doping element.
  • the reaction scheduled for reducing 300 kg of potassium tantalum double fluoride is stopped when 90 per cent. of the required quantity of sodium has been added; then a reducible compound, as in the process described above, is injected into the reaction vessel. Then the addition of sodium is resumed and the reduction together of the remaining 10 per cent. of the matrix metal and of the additive element occurs simultaneously on the surface of the powder particles obtained during the first phase of the reaction.
  • Table I below records the resultsof measurements made on electrolytic capacitors manufactured from two powders of the invention; more explicitly, one of these powders was made according to example (a) above; it is referenced in table I by the letter (a); it contains on average 2,100 parts per million by weight of molybdenum (0.21 per cent). The other powder was made according to example (c); it is referenced in table I by the letter (c); it contains on average 1050 parts per million by weight of molybdenum (0.105 per cent).
  • table I also includes the resultats of measurements made on capacitors manufactured from a powder such as can be found on the market, being powder P38 from Reframet-Hoboken.
  • This powder represents the status of performance that can presently be achieved without the improvements brought by the powders of the present invention; it was manufactured according to the procedure of example (a); nevertheless, contrary to the invention, it does not contain any traceable amount, added naturally, accidentally or intentionally, of molybdenum or vanadium or tungsten r hafnium that can be determined by chemical analysis.
  • the electrolytic capacitors manufactured from these three powders are of type C 40 volts and 50 volts with solid electrolyte (manganese dioxide) and manufactured by a strictly identical process, so as to lend results an absolute value for purposes of comparison.
  • Section B of Table I lists the main characteristics of finished electrolytic capacitors, such as capacitance, leakage current and dissipation factor, but the significant parameters of variance of capacitance in relation to capacitance at 25C for capacitances measured at these ratios being expressed in percentage points in Table I.
  • the significant advantage provided by the powders of the invention over another powder can clearly be seen; there isless capacitance variation.
  • capacitors made from the powders of the invention withstand higher reverse voltages (with negative polarization of tantalum) than capacitors made from other powders. This advantage is expressed in the leakage currents and 555C, 85C and 125C.
  • a valve-metal base powder for use in electronics the grains of which powder are made up of the said valve-metal containing between about 0.06 and about 2 percent by weight of at least one additive metal chosen in the group consisting of Mo, V, W, and Hf.
  • a valve-metal base powder for use in electronics the grains of which powder are made up of a nucleus of the said valve-meta] covered with a surface layer of the same valve-metal containing between about 0.01 and about 2 percent by weight of at least one additive metal chosen in the group consisting of No, V, W and Hf.
  • a valve-metal base powder for use in electronics the grains of which powder are made up of a nucleus of the said valve-metal covered with a surface layer consisting of at least one metal chosen in the group consisting of Mo, V, W and Hf.
  • valvemetal is chosen in the group consisting of tantalum and niobium.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Powder Metallurgy (AREA)

Abstract

An anodically oxidizable metal powder for use in electrolytic capacitor applications, the individual metal particles containing in depth and/or surface evenly or unevenly distributed amounts of the metals molybdenum and/or vanadium and/or tungsten and/or hafnium.

Description

Klimt] Katee [.1] tent [1 1 Ronneau et al.
[ 1 ANODICALLY OX1DIZABLE METAL POWDER [75] Inventors: Gerard S. lRonneau, Edegen; Pierre D. Debacker, Hoboken; Hugo L. Carpentier, Aartselaar, all of Belgium [73] Assignee: Metallurgie Hoboken-Overpelt [22] Filed: Feb. 5, 1974 [21] Appl. No.: 439,805
[52] US. Cl. 75/0.5 BB, 29/192 R, 29/192 CP,
75/174 [51] Int. Cl B221 9/00, C22c 27/00 [58] Field of Search 29/192 CP, 192 R, 182;
75/05 BB, 05 BA, 174
[4 .1 Feb. 18, 1975 [56] References Cited UNITED STATES PATENTS 3,203,793 8/1965 Hand 75/174 3,285,716 11/1966 Contant 75/174 3,415,639 12/1968 Daendliker et a1. 75/0.5 BB
Primary Examiner-W. Stallard Attorney, Agent, or Firm-Fred Philpitt [57] ABSTRACT 6 Claims, N0 Drawings I ANODICALLY OXIDIZAIBLE METAL POWDER The present invention relates to improvements in powders used in the manufacture of electrolytic capacitors.
It is well known that electrolytic capacitors have to meet a large number of conditions which it is difficult to obtain simultaneously as they are often contradictory. In the present state of the technique and taking into account the intrinsic characteristics of the powders used in building up a capacitor, such as tantalum or niobium powders, there is some difficulty in achieving an acceptable compromise amongst the various electrical characteristics demanded of a capacitor.
The new powders, object of the present invention, provide the means of solving the above problem as will appear from the examples of comparable results set out in Table I hereafter.
In accordance with the present invention there is provided a metal in powder form, whose particles are made up of an anodically oxidizable metal, also recognized as valve metal or metal converting alternating current to direct current, such as .tantalum or niobium powder, containing molybdenum and/or vanadium and/or tungsten and/or hafnium in contents comprised between 0.06 and 2 per cent on an additive metal to tantalum or niobium metal basis, these additive metal contents referring to each additive metal separately or to the additive metals as a whole.
The particles of another powder according to the invention are made up of a nucleus of anodically oxidizable metal covered with a surface layer of the same metal, such layer containing molybdenum and/or vanadium and/or tungsten and/or hafnium in contents comprised between 0.01 and 2 per cent on an additive metal to tantalum or niobium metal basis, these additive metal contents referring severally to each additive metal separately or to the additive metals as a whole. The thickness ofsaid surface layer will preferentially be less than 3,000 Angstrom.
Still another powder according to the invention is one whose particles are made up a nucleus of anodically oxidizable metal covered with either a continuous or a noncontinuous surface layer, or one or more areas on the surface, made up of molybdenum and/or vanadium and/or tungsten and/of hafnium. The thickness of said surface layer will preferentially be less than 3,000 Angstrom.
It has been found that powders according to the invention improve the characteristics of the dielectric (electrolytic oxide) built up on the surface of the particles of which these powders are made up. Such improved characteristics give better performance to the capacitor manufactured from these powders. In effect, it has been found on such capacitors manufactured from powders according to the invention a sizeable decrease of the capacitance variance as a function'of operating temperature; in addition, such capacitors withstand reverse voltages higher than those that can be withstood by capacitors manufactured from a powder that has not been treated according to the present invention and the performances under life test are better.
The powders according to the present invention can be manufactured by a number of well known methods such as: co'fusion and embrittlement, sodiothermic reduction, fused electrolysis, hydrogen reduction on a fluidized bed.
a. One suitable powder which can be processed in accordance with the present invention is a tantalum powder obtained by electron-beam fusion and hydrogen embrittlement. Such high-purity powder is thoroughly blended with molybdenum powder in proportion of to .2 by weight. The powder blend is compacted in an isostatic press by a well-known technique and the resulting bars are melted in an electron beam furnace. The ingot is hydrided to a hydrogen content of about 0.4 per cent by weight, then it is crushed and pulverized and the powder obtained is degassed and submitted to chemical assay. The desired molybdenum content is traced back in the powder with more or less 10 per cent accuracy.
b. Another type of powder which can be prepared in accordance with the present invention is made by charging a quantity of potassium double fluoride into a sodiothermic reduction vessel. The reduction occurs at a temperature of about 800C in a fused salt solution containing sodium chloride: for instance 300 kg of potassium tantalum double fluoride in 10 kg'sodium chloride. A stoich-iometric quantity of sodium in liquid form is slowly added to the fuses salt mass; a dendritic tantalum powder is rapidly formed. When the reaction signs (exothermicity) tend to disappear, indicating that the chemical reaction has been completed, a quantity of 260 g of vanadium trichloride is charged into the sodiothermic reduction vessel, then g of sodium are added. After crushing the sponge containing the tantalum, and washing the crushed sponge, a tantalum powder is obtained which contains about 600 parts per million of vanadium, this latter metal being located on the surface of the powder particles. c. Still another type of powder which can be prepared in accordance with the present invention is made by anoperating process similar to the one described just above. The particles of this powder show a surface layer containing both the matrix metal, which is tantalum or niobium, and the doping element. To this end, the reaction, scheduled for reducing 300 kg of potassium tantalum double fluoride is stopped when 90 per cent. of the required quantity of sodium has been added; then a reducible compound, as in the process described above, is injected into the reaction vessel. Then the addition of sodium is resumed and the reduction together of the remaining 10 per cent. of the matrix metal and of the additive element occurs simultaneously on the surface of the powder particles obtained during the first phase of the reaction.
EXAMPLES.
Table I below records the resultsof measurements made on electrolytic capacitors manufactured from two powders of the invention; more explicitly, one of these powders was made according to example (a) above; it is referenced in table I by the letter (a); it contains on average 2,100 parts per million by weight of molybdenum (0.21 per cent). The other powder was made according to example (c); it is referenced in table I by the letter (c); it contains on average 1050 parts per million by weight of molybdenum (0.105 per cent). For purposes of comparison, table I also includes the resultats of measurements made on capacitors manufactured from a powder such as can be found on the market, being powder P38 from Reframet-Hoboken. This powder represents the status of performance that can presently be achieved without the improvements brought by the powders of the present invention; it was manufactured according to the procedure of example (a); nevertheless, contrary to the invention, it does not contain any traceable amount, added naturally, accidentally or intentionally, of molybdenum or vanadium or tungsten r hafnium that can be determined by chemical analysis.
The electrolytic capacitors manufactured from these three powders are of type C 40 volts and 50 volts with solid electrolyte (manganese dioxide) and manufactured by a strictly identical process, so as to lend results an absolute value for purposes of comparison.
Under Section A of Table 1, characteristics of capacitor anodes will be found such as they can be measured in a liquid electrolyte of phosphoric acid before insertion into the capacitor case and before impregnation with manganese nitrate, each of these steps being well known by the trade.
Section B of Table I lists the main characteristics of finished electrolytic capacitors, such as capacitance, leakage current and dissipation factor, but the significant parameters of variance of capacitance in relation to capacitance at 25C for capacitances measured at these ratios being expressed in percentage points in Table I. The significant advantage provided by the powders of the invention over another powder can clearly be seen; there isless capacitance variation.
From Section C it can be seen that the advantage of powders of the invention is also obvious with respect to leakage current of electrolytic capacitors manufactured from these powders as capacitors breaking down during life tests are on average fewer.
From Section D it will be noticed that capacitors made from the powders of the invention withstand higher reverse voltages (with negative polarization of tantalum) than capacitors made from other powders. This advantage is expressed in the leakage currents and 555C, 85C and 125C.
the breakdown voltages.
TABLE I Performance of type C capacitors Powder of Untreated Powder of Powder of Untreated Powder of 1 reference the invention the invention reference the invention the invention Units powder 1050 ppm Mo 2100 ppm Mo powder 1050 ppm Mo 2100 ppm Mo on the surface in the matrix on the surface in the matrix (a) (c) A.- Anode characteristics (average of measurements on 500 anodes) Weight g l 1 1 1 1 1 Diameter mm 4.47 4.49 4.48 4.47 4.49 4.48 Height mm 7.36 7.32 7.33 7.36 7.32 7.33 Sintering temp. C 1850 1850 1850 1850 1850 1850 Sintering time min. 30 30 30 30 30 Dissipation 7r 14 14 14 14 14 14 Leakage #Amp/g 0.57 0.80 0.71 0.57 0.80 0.71 Capacitance uFV/g 3841 3858 3732 3841 3868 3732 B.- Characteristics of type C capacitors 40 V and V (average of 20 capacitors) C/40 V C/50 V Capacitance ,uF 21.5 22.0 22.2 17.7 17.2 17.2 Leakage uAmp/capacitor 0.087 0.141 0.084 0.166 1.08 0.25 Dissipation 72 1.67 0.88 0.86 1.38 0.86 0.88 A cap(-C) 4.36 2.32 1.84 -3.9 2.3 .1.74 A cap(+C) +5.1 +2.72 +2.7 +4.5 +2.9 +2.3 A cap(+125C) 7: +8.8 +5.0 +4.97 +7.90 +4.6 +4.8
' C.- Characteristics under life test (average of 10 capacitors) Test according to CCTU O2-12B C/40 V C/SO V 85C 1007(Vn(:) after 2000 h Leakage ,uAmp/capacitor 0.539 0.414 0.393 0.182 0.288 0.192 Breakdowns v 0 0 0 0 0 0 after 4000 h Leakage ,uAmp/capacitor 0.747 0.446 0.368 0.414 0.300 0.260 Breakdowns 1 .0 0 1 0 0 0 125C-667cVn(:) t
after 2000 h Leakage ,uAmp/capacitor 0.436 0.450 0.1 14' 0.378 0.966 0.385 Breakdowns 0 0 0 '1 0 0 after 4000 h Leakage ,uAmp/capacitor 0.867 0.623 0.235 0.247 t 0.440 0.26 Breakdowns 2 0 2 1 0' D.- Characteristics under direct (positive) and reverse (negative) voltages (average of 5 capacitors) C/40 V BDV C/40 V Leakage at POSITIVE POLARIZATION OF TANTALUM 120 V #Amp/capacitor 100 110 105 V V 80 V #Amp/capacitor 0.4 4 30 V #Amp/capacitor 0.1 0.4 3 V ,uAmp/capacitor 0.01 0.08 NEGATlVE POLARIZATION OF TANTALUM 10 V uAmp/capacitor 30 0.5 20 V #Amp/capacitor 1000 40 25 V 32 V 30 V #Amp/capacitor Breakdown BDV Breakdown voltage (z) Vn Nominal voltage What we claim is:
1. A valve-metal base powder for use in electronics, the grains of which powder are made up of the said valve-metal containing between about 0.06 and about 2 percent by weight of at least one additive metal chosen in the group consisting of Mo, V, W, and Hf.
2. A valve-metal base powder for use in electronics, the grains of which powder are made up of a nucleus of the said valve-meta] covered with a surface layer of the same valve-metal containing between about 0.01 and about 2 percent by weight of at least one additive metal chosen in the group consisting of No, V, W and Hf.
3. A powder as claimed in claim 2, in which the thickness of the surface layer is lower than 3,000 Angstroms.
4. A valve-metal base powder for use in electronics. the grains of which powder are made up of a nucleus of the said valve-metal covered with a surface layer consisting of at least one metal chosen in the group consisting of Mo, V, W and Hf.
5. A powder as claimed in claim 4, in which the thickness of the surface layer is lower than 3,000 Angstroms.
6. A powder as claimed in claim 1, in which the said valvemetal is chosen in the group consisting of tantalum and niobium.

Claims (6)

1. A VALVE E-METAL BASE POWDER FOR USE IN ELECTRONICS, THE GRAINS OF WHICH POWDER ARE MADE UP OF THE SAID VALVE-METAL CONTAINING BETWEEN ABOUT 0.06 AND ABOUT 2 PERCENT BY WEIGHT OF AT LEAST ONE ADDITIVE METAL CHOSEN IN THE GROUP CONSISTING OF MO, V, W, AND HF.
2. A valve-metal base powder for use in electronics, the grains of which powder are made up of a nucleus of the said valve-metal covered with a surface layer of the same valve-metal containing between about 0.01 and about 2 percent by weight of at least one additive metal chosen in the group consisting of No, V, W and Hf.
3. A powder as claimed in claim 2, in which the thickness of the surface layer is lower than 3,000 Angstroms.
4. A valve-metal base powder for use in electronics, the grains of which powder are made up of a nucleus of the said valve-metal covered with a surface layer consisting of at least one metal chosen in the group consisting of Mo, V, W and Hf.
5. A powder as claimed in claim 4, in which the thickness of the surface layer is lower than 3,000 Angstroms.
6. A powder as claimed in claim 1, in which the said valve-metal is chosen in the group consisting of tantalum and niobium.
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Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3984208A (en) * 1973-02-19 1976-10-05 Societe Lignes Telegraphiques Et Telephoniques Anodes for solid electrolyte capacitors
FR2305841A2 (en) * 1975-03-24 1976-10-22 Lignes Telegraph Telephon Electrolytic condenser mfr with molybdenum-doped tantalum anode - by adding pure molybdenum (cpd) before sintering, for adaptability (NL280976)
FR2313759A2 (en) * 1975-06-04 1976-12-31 Lignes Telegraph Telephon Electrolytic condenser mfr with molybdenum-doped tantalum anode - by adding pure molybdenum (cpd) before sintering, for adaptability (NL280976)
US4009007A (en) * 1975-07-14 1977-02-22 Fansteel Inc. Tantalum powder and method of making the same
US4097415A (en) * 1975-03-03 1978-06-27 Societe Lignes Telegraphiques Et Telephoniques Production of improved anodes for solid electrolyte capacitors
JPS5376848A (en) * 1976-12-20 1978-07-07 Toshiba Corp Electrochromic display device
FR2442499A1 (en) * 1978-11-25 1980-06-20 Matsushita Electric Ind Co Ltd ANODE FOR SOLID ELECTROLYTIC CAPACITOR AND METHOD FOR MANUFACTURING SUCH ANODE
DE3230219A1 (en) * 1981-08-24 1983-03-03 Fansteel Inc., 60064 North Chicago, Ill. ADDITION OF PHOSPHORUS IN SITU TO TANTAL
US4569693A (en) * 1982-08-30 1986-02-11 Hermann C. Starck Berlin Process for improving the flowability and increasing the bulk density of high-surface area valve metal powders
USRE32260E (en) * 1975-07-14 1986-10-07 Fansteel Inc. Tantalum powder and method of making the same
WO2001035428A1 (en) * 1999-11-09 2001-05-17 H.C. Starck Gmbh Capacitor powder
US6558737B1 (en) 2000-09-08 2003-05-06 Epcos Ag Method for producing an electrode, and for producing a capacitor with the electrode
EP1324359A1 (en) * 2000-08-10 2003-07-02 Showa Denko K.K. Niobium powder, sinter thereof, and capacitor employing the same
US20030205106A1 (en) * 2000-08-10 2003-11-06 Showa Denko K.K. Niobium powder, sintered body thereof, and capacitor using the same
US20050094354A1 (en) * 2000-06-21 2005-05-05 Karlheinz Reichert Capacitor powder
US20050270724A1 (en) * 2002-07-08 2005-12-08 Tadasu Kirihara Niobium powder, anode for solid electrolytic capacitor and solid electrolytic capacitor
DE10192560B4 (en) * 2000-06-21 2007-02-15 H.C. Starck Gmbh Capacitor used as an electrolytic capacitor comprises an anode based on niobium with a BIAS-independent capacitance
US20070137434A1 (en) * 2003-11-10 2007-06-21 Showa Denko K.K. Niobium powder for capacitor, niobium sintered body and capacitor

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* Cited by examiner, † Cited by third party
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US3203793A (en) * 1963-01-28 1965-08-31 Du Pont Porous columbium and tantalum materials
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US3285716A (en) * 1964-07-20 1966-11-15 Kawecki Chemical Company Etched tantalum foil
US3415639A (en) * 1965-05-25 1968-12-10 Ciba Ltd Method for the manufacture of tantalum and/or niobium powder

Cited By (34)

* Cited by examiner, † Cited by third party
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US3984208A (en) * 1973-02-19 1976-10-05 Societe Lignes Telegraphiques Et Telephoniques Anodes for solid electrolyte capacitors
US4097415A (en) * 1975-03-03 1978-06-27 Societe Lignes Telegraphiques Et Telephoniques Production of improved anodes for solid electrolyte capacitors
FR2305841A2 (en) * 1975-03-24 1976-10-22 Lignes Telegraph Telephon Electrolytic condenser mfr with molybdenum-doped tantalum anode - by adding pure molybdenum (cpd) before sintering, for adaptability (NL280976)
FR2313759A2 (en) * 1975-06-04 1976-12-31 Lignes Telegraph Telephon Electrolytic condenser mfr with molybdenum-doped tantalum anode - by adding pure molybdenum (cpd) before sintering, for adaptability (NL280976)
US4009007A (en) * 1975-07-14 1977-02-22 Fansteel Inc. Tantalum powder and method of making the same
USRE32260E (en) * 1975-07-14 1986-10-07 Fansteel Inc. Tantalum powder and method of making the same
JPS5376848A (en) * 1976-12-20 1978-07-07 Toshiba Corp Electrochromic display device
JPS6124693B2 (en) * 1976-12-20 1986-06-12 Tokyo Shibaura Electric Co
FR2442499A1 (en) * 1978-11-25 1980-06-20 Matsushita Electric Ind Co Ltd ANODE FOR SOLID ELECTROLYTIC CAPACITOR AND METHOD FOR MANUFACTURING SUCH ANODE
DE3230219A1 (en) * 1981-08-24 1983-03-03 Fansteel Inc., 60064 North Chicago, Ill. ADDITION OF PHOSPHORUS IN SITU TO TANTAL
US4569693A (en) * 1982-08-30 1986-02-11 Hermann C. Starck Berlin Process for improving the flowability and increasing the bulk density of high-surface area valve metal powders
KR100715408B1 (en) 1999-11-09 2007-05-08 하.체. 스타르크 게엠베하 Capacitor Powder
US6821314B1 (en) 1999-11-09 2004-11-23 H. C. Starck Gmbh Capacitor powder
JP4999135B2 (en) * 1999-11-09 2012-08-15 エイチ・シー・スタルク・ゲゼルシヤフト・ミツト・ベシュレンクテル・ハフツング Condenser powder
CZ301939B6 (en) * 1999-11-09 2010-08-04 H.C. Starck Gmbh Capacitor powder, process for its preparation, capacitor anode and electrolytic capacitor
WO2001035428A1 (en) * 1999-11-09 2001-05-17 H.C. Starck Gmbh Capacitor powder
JP2003514378A (en) * 1999-11-09 2003-04-15 エイチ・シー・スタルク・ゲゼルシヤフト・ミツト・ベシユレンクテル・ハフツング Condenser powder
AU770489B2 (en) * 1999-11-09 2004-02-26 H.C. Starck Gmbh Capacitor powder
AU2001269062B2 (en) * 2000-06-21 2006-07-20 H.C. Starck Gmbh Capacitor powder
KR100915729B1 (en) * 2000-06-21 2009-09-04 하.체. 스타르크 게엠베하 Capacitor Powder
US20050094354A1 (en) * 2000-06-21 2005-05-05 Karlheinz Reichert Capacitor powder
US7833511B2 (en) * 2000-06-21 2010-11-16 H.C. Starck Gmbh Capacitor powder
US20090278095A1 (en) * 2000-06-21 2009-11-12 H.C. Starck Gmbh Capacitor powder
DE10192560B4 (en) * 2000-06-21 2007-02-15 H.C. Starck Gmbh Capacitor used as an electrolytic capacitor comprises an anode based on niobium with a BIAS-independent capacitance
US7594947B2 (en) 2000-08-10 2009-09-29 Showa Denko K.K. Niobium powder, sintered body thereof, and capacitor using the same
EP1324359A4 (en) * 2000-08-10 2008-04-23 Showa Denko Kk Niobium powder, sinter thereof, and capacitor employing the same
US20030205106A1 (en) * 2000-08-10 2003-11-06 Showa Denko K.K. Niobium powder, sintered body thereof, and capacitor using the same
US6652619B2 (en) * 2000-08-10 2003-11-25 Showa Denko K.K. Niobium powder, sintered body thereof, and capacitor using the same
EP1324359A1 (en) * 2000-08-10 2003-07-02 Showa Denko K.K. Niobium powder, sinter thereof, and capacitor employing the same
EP2224462A3 (en) * 2000-08-10 2011-03-09 Showa Denko K.K. Niobium powder, sintered body and capacitor using the body
EP1316095B1 (en) * 2000-09-08 2004-09-22 Epcos Ag Method for producing an electrode for capacitors and for producing a capacitor
US6558737B1 (en) 2000-09-08 2003-05-06 Epcos Ag Method for producing an electrode, and for producing a capacitor with the electrode
US20050270724A1 (en) * 2002-07-08 2005-12-08 Tadasu Kirihara Niobium powder, anode for solid electrolytic capacitor and solid electrolytic capacitor
US20070137434A1 (en) * 2003-11-10 2007-06-21 Showa Denko K.K. Niobium powder for capacitor, niobium sintered body and capacitor

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