Patent US3774085A successfully refreshed from Google Patents.
US3774085A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thyristor with means for internal breakthrough
Assignee: Individual
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Filing: 1972-08-17
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Granted: 1973-11-20
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Expires: 1992-08-17
Abstract
Abstract A thyristor including an emitter, a p-base and an n-base wherein a gate electrode is positioned on a free surface of the p-base and an emitter electrode is positioned on the emitter, with the area dimension encompassed by the electrodes being smaller than that of the thyristor. The n-base is provided with an area below the gate electrode and within the area encompassed by the electrodes that is characterized by a resistivity about 10 to 40 percent lower than the resistivity of areas outside the electrode encompassed area. By having the area of the n-base below the electrodes of lower resistivity, the breakover voltage of this area is reached prior to that of the outer or border areas of the thyristor. When a voltage exceeding the breakover voltage is applied to the thyristor, the n-base area below the electrodes triggers first and border break-through of high current loads is avoided. In embodiments wherein short-circuit rings are utilized, expansion of the triggering process is not prevented. High di/dt values are possible during a breakover triggering process.
Inventors
- 👤 K Platzoeder
- 👤 P Voss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:02
CPC Classifications
H; H10; H10D; H10D18/00; H10D18/211
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
96 words
A thyristor comprising a semiconductor member having at least four zones with adjacent zones being of opposite conductivity types, a first zone being an emitter, a second zone being a first base and a third zone being a second base, and including a gate electrode in contact with said first base and an emitter electrode in contact with said emitter, said second base having a first portion located beneath said electrodes, said first portion of said second base having a resistivity 10 to 40 percent below the resistivity of the remaining portion of said second base.
Claim 2
Dependent Claim
96 words
A thyristor comprising a semiconductor member having at least four zones with adjacent zones being of opposite conductivity types, a first zone being an emitter, a second zone being a first base and a third zone being a second base, and including a gate electrode in contact with said first base and an emitter electrode in contact with said emitter, said second base having a first portion located beneath said electrodes, said first portion of said second base having a resistivity 10 to 40 percent below the resistivity of the remaining portion of said second base.
Claim 3
Dependent Claim
29 words
A thyristor as defined in claim 1 wherein said first portion of the second base has a resistivity less than the resistivity of any region of said remaining portion.
Claim 4
Dependent Claim
30 words
A thyristor as defined in claim 2 wherein the resistivity of said first portion is 10 to 40 percent lower than the resistivity of any region of said remaining portion.
Claim 5
Dependent Claim
33 words
A thyristor as defined in claim 1 wherein said first portion of the second base is located beneath the gate electrode and beneath a part of the emitter electrode adjacent said gate electrode.
Claim 6
Dependent Claim
119 words
A thyristor comprising a monolithic semiconductor device with a plurality of zones of alternate conductivity types, a first zone being an emitter, a second zone being a first base, and a third zone being a second base, said emitter being positioned on select areas of said first base leaving other areas thereof free, a gate electrode of a dimension smaller than said semiconductor device in contact with a free area of said first base and an emitter electrode spaced from said gate electrode and in contact with said emitter, said second base having a first portion beneath at least said gate electrode with a resistivity 10 to 40 percent below the resistivity of remaining portion of said second base.
Claim 7
Dependent Claim
119 words
A thyristor comprising a monolithic semiconductor device with a plurality of zones of alternate conductivity types, a first zone being an emitter, a second zone being a first base, and a third zone being a second base, said emitter being positioned on select areas of said first base leaving other areas thereof free, a gate electrode of a dimension smaller than said semiconductor device in contact with a free area of said first base and an emitter electrode spaced from said gate electrode and in contact with said emitter, said second base having a first portion beneath at least said gate electrode with a resistivity 10 to 40 percent below the resistivity of remaining portion of said second base.
Claim 8
Dependent Claim
27 words
A thyristor as defined in claim 5 wherein the resistivity of said first portion of the second base is below the lowest resistivity of said remaining portion.
Claim 9
Dependent Claim
35 words
A thyristor as defined in claim 5 wherein said first portion of the second base is located beneath the gate electrode and within the area encompassed by at least a porion of the emitter electrode.
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) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |