US3990091A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low forward voltage drop thyristor
Assignee: Westinghouse Electric Corp
•
Filing: 1975-01-10
•
Granted: 1976-11-02
•
Expires: 1995-01-10
Abstract
Abstract A thyristor is provided with a low forward voltage drop (Vf) while providing a typical gate current to trigger (Ig). The working point in the cathode-base region of the thyristor has an impurity concentration less than 5 x 1015 and preferably less than 1 x 1015 per cm3. The gating portion of the device is selectively irradiated, preferably with electron radiation, to maintain the gate current. The forward blocking voltage (VBO) and rate of rise of application of forward voltage (dV/dt) of the thyristor may also be maintained at typical values by a fine shunt pattern and/or doping of the shunt portions.
Inventors
- 👤 Michael W. Cresswell
- 👤 John S. Roberts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:26
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/50; H10D62/53; H10D62/10; H10D62/13; H10D62/141; H10D62/148; H10D62/17; H10D62/192; H10D62/206; H10D62/60; H10P; H10P34/00; H10P34/40
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
97 words
A thrystor comprising: semiconductor body having disposed therein a cathode-base region with an impurity concentration at the working point below 5 × 10 15 per cm 3 and having a gating portion and a conducting portion, said gating portion adjoining a major surface of the semiconductor body and having been irradiated with a radiation source to decrease gate sensitivity of the thyristor, and said conducting portion adjoining a cathode-emitter region and having been nonirradiated with said radiation source by masking said conducting portion against irradiation by said radiation source to maintain forward voltage drop of the device.
Claim 2
Dependent Claim
97 words
A thrystor comprising: semiconductor body having disposed therein a cathode-base region with an impurity concentration at the working point below 5 × 10 15 per cm 3 and having a gating portion and a conducting portion, said gating portion adjoining a major surface of the semiconductor body and having been irradiated with a radiation source to decrease gate sensitivity of the thyristor, and said conducting portion adjoining a cathode-emitter region and having been nonirradiated with said radiation source by masking said conducting portion against irradiation by said radiation source to maintain forward voltage drop of the device.
Claim 3
Dependent Claim
36 words
A thyristor as set forth in claim 1 wherein: the gating portion is irradiated with electron radiation to an intensity greater than 1 Mev and a dosage greater than 1 × 10 13 electrons/cm 2 .
Claim 4
Dependent Claim
26 words
A thyristor as set forth in claim 1 wherein: the impurity concentration at the working point is below 1 × 10 15 per cm 3 .
Claim 5
Dependent Claim
35 words
A thyristor as set forth in claim 1 wherein: said cathode-base region includes shunts through cathode-emitter regions to said major surface of said semiconductor body to control the V BO and dV/dt of the thyristor.
Claim 6
Dependent Claim
26 words
A thyristor as set forth in claim 2 wherein: the impurity concentration at the working point is below 1 × 10 15 per cm 3 .
Claim 7
Dependent Claim
35 words
A thyristor as set forth in claim 2 wherein: said cathode-base region includes shunts through cathode-emitter regions to said major surface of said semiconductor body to control the V BO and dV/dt of the thyristor.
References Cited (Backward Citations)
US3246172A
Cited
US3390020A
Cited
US3470036A
Cited
US3442722A
Cited
US3532910A
Cited
US3881964A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-11-02 | 1980-05-03 | 1980-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-02 | 1984-05-03 | 1984-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-02 | 1988-05-03 | 1988-11-02 | $7700.00 | Window Closed / Lapsed |