Patent US3852877A successfully refreshed from Google Patents.
US3852877A
Expired / Lapsed
US
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Multilayer circuits
Assignee: International Business Machines Corp
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Filing: 1974-04-02
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Granted: 1974-12-10
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Expires: 1994-04-02
Abstract
Abstract Multilevel ceramic high conductivity circuit structures are formed by depositing a metallizing media on surfaces of green ceramic sheets, including on walls of holes which extend through the sheets. The metallizing media includes metals and compounds which convert to a metal during firing. The sheets are stacked in registry, laminated into a monolithic structure and heated in a reducing atmosphere to sinter the ceramic to a dense body, and simultaneously fire the metallizing media to form an adherent metal capillary within the body. A high conductivity, low melting point conductor fills the capillary thereby forming a highly conductive circuit member within the multilevel ceramic structure.
Inventors
- 👤 D Wilcox
- 👤 J Ahn
- 👤 B Schwartz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:11
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/10; H05K3/101; H01; H01B; H01B1/00; H01G; H01G4/00; H01G4/30; H01G4/302; H10; H10N; H10N97/00; H05K2201/00; H05K2201/03; H05K2201/0302; H05K2201/0305; H05K2203/00; H05K2203/12; H05K2203/128; Y; Y10; Y10T; Y10T29/00; Y10T29/43; Y10T29/435; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/49126; Y10T29/49155; Y10T29/49163; Y10T428/00; Y10T428/24; Y10T428/24273; Y10T428/24322; Y10T428/24628
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
209 words
A METHOD FOR MANUFACTUREING A MULTIFILAYER CERAMIC CIRCUIT BOARD WITH INTERCONNECTED CONDUCTORS DISPOSED IN DIFFERENT LAYERS, SAID METHOD COMPRISING THE STEPS OF: PREPARING A PLURALITY OF GREEN CERAMIC SHEETS OF CERAMIC MATERIAL DISPERSED IN A HEAT VOLATILE BINDER; FORMING HOLES AT PREDETERMINED LOCATIONS IN SAID SHEETS, PREPARING A PASTE COMPOSITION COMPRISING A METALLIZING MEDIA DISPERSED IN A HEAT COLATILE BINDER, SAID MEDIA BEING SELECTED FROM THE GROUP CONSISTING OF REFRACTORY METALS AND COMPOUNDS THEREOF WHICH DENSITY WHEN SINTERED AT A TEMPERATURE HIGHER THAN THE TEMPERATURE AT WHICH SAID CERMAIC DENSIFIES WHEN SINTERED; DEPOSITING SAID PASTE COMPOSITION ON SURFACE AREAS OF SAID GREEN SHEETS INCLUDING SURFACE AREAS WITHIN SAID HOLES, STACKING SAID SHETS ONE UPON ANOTHER IN REGISTRY SUCH THAT PATTERNS ON AND HOLES IN DIFFERENT SHEETS ARE SUPERPOSED IN A DESIRED CIRCUIT PATTERN; LAMINATING SAID SHEETS; HEATING SAID LAMINATE AT A TEMPERATURE HIGH ENOUGH TO DRIVE OFF SAID BINDERS, SINTER SAID CERAMIC TO A DENSE STATE AND BOND SAID METAL TO SAID CERAMIC BUT LOWER THAN A TEMPERATURE AT WHICH SAID METAL DENSIFIES WHEN SINTERED TO FORM THEREBY A CONTINUOUS POROUS METALLIC CAPILLARY PATH IN COINCIDENCE WITH SAID CIRCUIT PATTERN; AND FILLING SAID CAPILLARY PATH WITH A MOLTEN CONDUCTOR IN A REDUCED, PRESSURE ATMOSPHERE TO COMPLETE SAID CIRCUIT PATTERN.
Claim 2
Independent Claim
209 words
A METHOD FOR MANUFACTUREING A MULTIFILAYER CERAMIC CIRCUIT BOARD WITH INTERCONNECTED CONDUCTORS DISPOSED IN DIFFERENT LAYERS, SAID METHOD COMPRISING THE STEPS OF: PREPARING A PLURALITY OF GREEN CERAMIC SHEETS OF CERAMIC MATERIAL DISPERSED IN A HEAT VOLATILE BINDER; FORMING HOLES AT PREDETERMINED LOCATIONS IN SAID SHEETS, PREPARING A PASTE COMPOSITION COMPRISING A METALLIZING MEDIA DISPERSED IN A HEAT COLATILE BINDER, SAID MEDIA BEING SELECTED FROM THE GROUP CONSISTING OF REFRACTORY METALS AND COMPOUNDS THEREOF WHICH DENSITY WHEN SINTERED AT A TEMPERATURE HIGHER THAN THE TEMPERATURE AT WHICH SAID CERMAIC DENSIFIES WHEN SINTERED; DEPOSITING SAID PASTE COMPOSITION ON SURFACE AREAS OF SAID GREEN SHEETS INCLUDING SURFACE AREAS WITHIN SAID HOLES, STACKING SAID SHETS ONE UPON ANOTHER IN REGISTRY SUCH THAT PATTERNS ON AND HOLES IN DIFFERENT SHEETS ARE SUPERPOSED IN A DESIRED CIRCUIT PATTERN; LAMINATING SAID SHEETS; HEATING SAID LAMINATE AT A TEMPERATURE HIGH ENOUGH TO DRIVE OFF SAID BINDERS, SINTER SAID CERAMIC TO A DENSE STATE AND BOND SAID METAL TO SAID CERAMIC BUT LOWER THAN A TEMPERATURE AT WHICH SAID METAL DENSIFIES WHEN SINTERED TO FORM THEREBY A CONTINUOUS POROUS METALLIC CAPILLARY PATH IN COINCIDENCE WITH SAID CIRCUIT PATTERN; AND FILLING SAID CAPILLARY PATH WITH A MOLTEN CONDUCTOR IN A REDUCED, PRESSURE ATMOSPHERE TO COMPLETE SAID CIRCUIT PATTERN.
Claim 3
Dependent Claim
38 words
The method as defined in claim 1 wherein said paste composition further includes a solid material that is not volatile at the laminating temperature of said sheets but is at the temperature at which said sheets are sintered.
Claim 4
Dependent Claim
24 words
The method defined by claim 1 wherein said metallizing media comprises a minor proportion by volume, of the total solids of said paste composition.
Claim 5
Dependent Claim
42 words
The method according to claim 1 wherein said metallizing media is selected from the group consisting of molybdenum, molybdenum-manganese, tungsten, titanium, tantalum, zirconium, iron, niobium and compounds thereof, and said molten conductor is selected from the group consisting of aluminum and copper.
Claim 6
Dependent Claim
16 words
The method according to claim 1 wherein said heating is carried out in a reducing atmosphere.
Claim 7
Dependent Claim
26 words
The method as defined in claim 1 wherein said reducing atmosphere has water added thereto to prevent the oxidization of the ceramic particles in said sheets.
Claim 8
Dependent Claim
26 words
The method according to claim 6 wherein said metallizing media includes an oxide compound of the metal which reduces to the metal during the heating step.
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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) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |