US3889357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screen printed solid electrolytic capacitor
Assignee: Vishay Sprague Inc
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Filing: 1973-07-05
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Granted: 1975-06-17
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Expires: 1993-07-05
Abstract
Abstract A solid tantalum capacitor is made by screen printing on a tantalum substrate, a thick mixture of tantalum powder and a binder, sintering the printed layer, forming a dielectric oxide, and forming a counterelectrode. A large number of capacitors may be so made on a single substrate and thereafter individual or groups of capacitors are separated, and may have leads attached thereto. The planar geometries provide simple packaging in conventional DIP''s and in hybrid integrated circuits.
Inventors
- 👤 Richard J Millard
- 👤 David R Poat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:48
CPC Classifications
H; H01; H01G; H01G9/00; H01G9/0029
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
242 words
A METHOD FOR MANUFACTURING A SOLID ELECTROLYTIC CAPACITOR HAVING A HIGH VOLT-MICROFARAD PRODUCT PER UNIT VOLUME COMPRISING: A. PREPARING A MIXTURE COMPRISING FINELY DIVIDED VALVE METAL POWDER, AND A BINDER TO ACHIEVE AN INK EXHIBITING ESSENTIALLY NO FLOW IN HORIZONTAL THICK FILM FORM UNDER CONDITIONS OF ZERO AGITATION; B. SCREEN PRINTING SUCCESSIVE LAYERS FORMING A COMPOSITE LAYER OF SAID MIXTURE ON A SUBSTRATE SO THAT SAID COMPOSITE LAYER HAS A ROUGH OUTER SURFACE REFLECTING THE PATTERN OF SAID SCREEN, SAID SUBSTRATE HAVING AT LEAST ONE FACE MADE OF SAID VALVE METAL AND SAID VALVE METAL FACE COMPRISING THE ANODE CONNECTIVE MEANS FOR SAID CAPACITOR; C. HEATING TO SOLIDIFY EACH SAID SCREENED LAYER AFTER EACH SAID SCREENING STEP; D. SINTERINING SAID SCREENED COMPOSITE LAYER AT A TEMPERATURE BETWEEN 1550*C AND 2000*C, THEREBY TRANSFORMING SAID COMPOSITE LAYER INTO A POROUS VALVE METAL PAD BEING SINTER BONDED TO SAID VALVE METAL FACE E. FORMING BY AN ELECTROLYTIC PROCESS, A VALVE METAL OXIDE FILM OVER ALL EXPOSED REGIONS OF SAID VALVE METAL FACE AND SAID POROUS VALVE METAL PAD; F. DIPPING SAID SUBSTRATE AND SAID VALVE METAL PAD INTO AN AQUEOUS SOLUTION OF MANGANOUS SALT; G. REMOVING SAID SUBSTRATE FROM SAID SALT SOLUTION; H. HEATING SAID PAD AND SAID SALT SOLUTION ADHERING THERETO TO CAUSE SAID SALT TO PERMEATE SAID POROUS PAD AND TO TRANSFORM SAID SALT INTO MANGANESE DIOXIDE BY PYROLYSIS; I. APPLYING A CONDUCTIVE COUNTERELECTRODE OVER SAID COMPOSITE LAYER TO FORM A CATHODE CONNECTION.
Claim 2
Independent Claim
242 words
A METHOD FOR MANUFACTURING A SOLID ELECTROLYTIC CAPACITOR HAVING A HIGH VOLT-MICROFARAD PRODUCT PER UNIT VOLUME COMPRISING: A. PREPARING A MIXTURE COMPRISING FINELY DIVIDED VALVE METAL POWDER, AND A BINDER TO ACHIEVE AN INK EXHIBITING ESSENTIALLY NO FLOW IN HORIZONTAL THICK FILM FORM UNDER CONDITIONS OF ZERO AGITATION; B. SCREEN PRINTING SUCCESSIVE LAYERS FORMING A COMPOSITE LAYER OF SAID MIXTURE ON A SUBSTRATE SO THAT SAID COMPOSITE LAYER HAS A ROUGH OUTER SURFACE REFLECTING THE PATTERN OF SAID SCREEN, SAID SUBSTRATE HAVING AT LEAST ONE FACE MADE OF SAID VALVE METAL AND SAID VALVE METAL FACE COMPRISING THE ANODE CONNECTIVE MEANS FOR SAID CAPACITOR; C. HEATING TO SOLIDIFY EACH SAID SCREENED LAYER AFTER EACH SAID SCREENING STEP; D. SINTERINING SAID SCREENED COMPOSITE LAYER AT A TEMPERATURE BETWEEN 1550*C AND 2000*C, THEREBY TRANSFORMING SAID COMPOSITE LAYER INTO A POROUS VALVE METAL PAD BEING SINTER BONDED TO SAID VALVE METAL FACE E. FORMING BY AN ELECTROLYTIC PROCESS, A VALVE METAL OXIDE FILM OVER ALL EXPOSED REGIONS OF SAID VALVE METAL FACE AND SAID POROUS VALVE METAL PAD; F. DIPPING SAID SUBSTRATE AND SAID VALVE METAL PAD INTO AN AQUEOUS SOLUTION OF MANGANOUS SALT; G. REMOVING SAID SUBSTRATE FROM SAID SALT SOLUTION; H. HEATING SAID PAD AND SAID SALT SOLUTION ADHERING THERETO TO CAUSE SAID SALT TO PERMEATE SAID POROUS PAD AND TO TRANSFORM SAID SALT INTO MANGANESE DIOXIDE BY PYROLYSIS; I. APPLYING A CONDUCTIVE COUNTERELECTRODE OVER SAID COMPOSITE LAYER TO FORM A CATHODE CONNECTION.
Claim 3
Dependent Claim
57 words
The method of claim 1 wherein said mixture is prepared by homogeneously combining said finely divided valve metal powder, having particle sizes from 3 to 10 microns; said binder being polyisobutyl methacrylate; and a vehicle of a glycol butyl ether; in the approximate proportions by weight of 85 percent, 2 1/2 percent and 12 1/2 percent, respectively.
Claim 4
Dependent Claim
17 words
The method of claim 1 wherein said substrate is composed of a sheet of said valve metal.
Claim 5
Dependent Claim
35 words
The method of claim 1 comprising the additional step of sputtering a coating of said valve metal onto a ceramic body, to form said substrate having at least one face made of said valve metal.
Claim 6
Dependent Claim
60 words
The method of claim 1 wherein said screen is partially masked permitting said mixture to be selectively screened through certain predetermined regions of said screen; and wherein said screening includes the simultaneous screen printing of two or more porous composite layers on said valve metal face, such that each said composite layer becomes the anode portion of a discrete capacitor.
Claim 7
Dependent Claim
31 words
The method of claim 5 comprising the additional step of selectively depositing a barrier coating on portions of said oxidized valve metal face between said discrete pads prior to said dipping.
Claim 8
Dependent Claim
51 words
The method of claim 1 whereIn said applying of a conductive counterelectrode is accomplished by applying a first coating of graphite, a second coating of conductive silver paste and a third coating of solder; and whereby said application of said counterelectrode coatings is accomplished at least in part by screen printing.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |