US3881963A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Irradiation for fast switching thyristors
Assignee: Westinghouse Electric Corp
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Filing: 1973-01-18
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Granted: 1975-05-06
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Expires: 1993-01-18
Abstract
Abstract The switching speed of a thyristor is increased while maintaining low gate current (Ig) by irradiating with a radiation source. The thyristor is irradiated preferably with electron radiation of an intensity greater than 1 Mev and most desirably 2 Mev preferably to an electron dosage of from between 1 X 1013 and 2 X 1014 electrons/cm2.
Inventors
- 👤 Chang K Chu
- 👤 John Bartko
- 👤 Patrick E Felice
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:09
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/50; H10D62/53; H10P; H10P34/00; H10P95/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
67 words
A METHOD OF DECREASING THE TURN-OFF TIME OF THYRISTOR WITHOUT SIGNIFICANTLY EFFECTING OTHER ELECTRICAL CHARACTERISTICS THEREOF COMPRISING THE STEPS OF: A. POSITIONING A THYRISTOR SEMICONDUCTOR BODY WITH A MAJOR SURFACE THEREOF TO BE EXPOSED TO A RADIATION SOURCE; AND B. THEREAFTER IRRADIATING THE THYRISTOR SEMICONDUCTOR BODY WITH THE RADIATION SOURCE TO A DOSAGE LEVEL CORRESPONDING TO LESS THAN 2 X 10**14 ELECTRONS/CM2 WITH 2 MEV ELECTRON RADIATION.
Claim 2
Independent Claim
67 words
A METHOD OF DECREASING THE TURN-OFF TIME OF THYRISTOR WITHOUT SIGNIFICANTLY EFFECTING OTHER ELECTRICAL CHARACTERISTICS THEREOF COMPRISING THE STEPS OF: A. POSITIONING A THYRISTOR SEMICONDUCTOR BODY WITH A MAJOR SURFACE THEREOF TO BE EXPOSED TO A RADIATION SOURCE; AND B. THEREAFTER IRRADIATING THE THYRISTOR SEMICONDUCTOR BODY WITH THE RADIATION SOURCE TO A DOSAGE LEVEL CORRESPONDING TO LESS THAN 2 X 10**14 ELECTRONS/CM2 WITH 2 MEV ELECTRON RADIATION.
Claim 3
Dependent Claim
23 words
A method of decreasing the turn-off time of a thyristor as set forth in claim 1 wherein: the radiation source is electron radiation.
Claim 4
Dependent Claim
27 words
A method of decreasing the turn-off time of a thyristor as set forth in claim 2 wherein: the electron radiation has an intensity greater than 1 Mev.
Claim 5
Dependent Claim
33 words
A method of decreasing the turn-off time of a thyristor as set forth in claim 1 wherein: the dosage level corresponds to greater than 1 X 1013 electrons/cm2 with 2 Mev electron radiation.
Claim 6
Dependent Claim
33 words
A method of decreasing the turn-off time of a thyristor as set forth in claim 1 wherein: the dosage level corresponds to greater than 3 X 1013 electrons/cm2 with 2 Mev electron radiation.
Claim 7
Dependent Claim
36 words
A method of decreasing the turn-off time of a thyristor as set forth in claim 3 wherein: the dosage level corresponds to between 1 X 1013 and 2 X 1014 eleCtrons/cm2 with 2 Mev electron radiation.
Claim 8
Dependent Claim
32 words
A method of decreasing the turn-off time of thyristors as set forth in claim 6 wherein: the dosage level corresponds to less than 8 X 1013 electrons/cm2 with 2 Mev electron radiation.
Claim 9
Dependent Claim
32 words
A method of decreasing the turn-off time of thyristors as set forth in claim 1 wherein: the dosage level corresponds to less than 8 X 1013 electrons/cm2 with 2 Mev electron radiation.
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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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |