US3074887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for adjusting the electrical characteristics of silicon carbide crystals
Assignee: Unifrax I LLC
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Filing: 1959-03-27
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Granted: 1963-01-22
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Expires: 1979-03-27
Abstract
No abstract record available.
Inventors
- 👤 Paul E Carroll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:49
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/10; H01C7/105; H01C7/118; C; C01; C01B; C01B32/00; C01B32/90; C01B32/914; C01B32/956; C30; C30B; C30B29/00; C30B29/10; C30B29/36; C30B31/00; C30B31/06; Y; Y10; Y10S; Y10S148/00; Y10S148/148
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
106 words
A PROCESS FOR ADJUSTING THE ELECTRICAL CHARACTERISTICS OF SILICON CARBIDE CRYSTALS SELECTED FROM THE GROUP CONSISTING OF GREEN AND COLORLESS SILICON CARBIDE CRYSTALS AND COMPRISING HEATING THE CRYSTALS TO A TEMPERATURE OF AT LEAST 1500* C. AND BELOW THE TEMPERATURE OF RECRYSTALLIZATION WHILE MAINTAINING THE CRYSTALS AS SUBSTANTIALLY DISCRETE CRYSTALS, IN AN ENVIRONMENT THAT SUPPLIES TO THE CRYSTALS AN ELEMENT SELECTED FROM THE GROUP CONSISTING OF SILICON AND OF ELEMENTS FROM THE THIRD AND FIFTH COLUMNS OF THE MENDELEEFF PERIODIC TABLE FOR A PERIOD OF TIME IN THE RANGE FROM ABOUT 0.5 TO ABOUT 5 HOURS TO EFFECT A DESIRED CHANGE IN THE ELECTRIAL CHARACTERISTICS THEREOF.
Claim 2
Dependent Claim
106 words
A PROCESS FOR ADJUSTING THE ELECTRICAL CHARACTERISTICS OF SILICON CARBIDE CRYSTALS SELECTED FROM THE GROUP CONSISTING OF GREEN AND COLORLESS SILICON CARBIDE CRYSTALS AND COMPRISING HEATING THE CRYSTALS TO A TEMPERATURE OF AT LEAST 1500* C. AND BELOW THE TEMPERATURE OF RECRYSTALLIZATION WHILE MAINTAINING THE CRYSTALS AS SUBSTANTIALLY DISCRETE CRYSTALS, IN AN ENVIRONMENT THAT SUPPLIES TO THE CRYSTALS AN ELEMENT SELECTED FROM THE GROUP CONSISTING OF SILICON AND OF ELEMENTS FROM THE THIRD AND FIFTH COLUMNS OF THE MENDELEEFF PERIODIC TABLE FOR A PERIOD OF TIME IN THE RANGE FROM ABOUT 0.5 TO ABOUT 5 HOURS TO EFFECT A DESIRED CHANGE IN THE ELECTRIAL CHARACTERISTICS THEREOF.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-01-21 | 1966-07-23 | 1967-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-01-21 | 1970-07-23 | 1971-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-01-21 | 1974-07-23 | 1975-01-22 | $7700.00 | Window Closed / Lapsed |