US4110780A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor power component
Assignee: BBC Brown Boveri AG Switzerland
•
Filing: 1976-04-08
•
Granted: 1978-08-29
•
Expires: 1996-04-08
Abstract
Abstract A semiconductor power element comprising two successive opposed polarity planar pn junctions, said element being positively tapered on its lateral surface in the regions of both pn junctions to form an average angle of both tapers of between 30° and 60°.
Inventors
- 👤 Jozef Cornu
- 👤 Erich Weisshaar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:21
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/102; H10D62/103; H10D62/104
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
139 words
A semiconductor power element comprising two successive opposed polarity planar pn junctions, the element being positively tapered on its lateral surface in the regions of both pn junctions to form an average angle of both tapers of between 30° and 60°, the pn junctions appearing on the lateral surface of the semiconductor element outside of the tapers wherein the doping of the zone between the two pn junctions is lower than 3.5 × 10 13 cm -3 and its thickness is equal to the thickness of the space charge region found in it at maximal voltage-blocking plus at least two minority carrier diffusion lengths and wherein the circumferential groove formed by the two tapers forms angles of inclination with respect to the pn junctions between 40° and 45° with the bottom of the groove being longer than 40 μm.
Claim 2
Dependent Claim
139 words
A semiconductor power element comprising two successive opposed polarity planar pn junctions, the element being positively tapered on its lateral surface in the regions of both pn junctions to form an average angle of both tapers of between 30° and 60°, the pn junctions appearing on the lateral surface of the semiconductor element outside of the tapers wherein the doping of the zone between the two pn junctions is lower than 3.5 × 10 13 cm -3 and its thickness is equal to the thickness of the space charge region found in it at maximal voltage-blocking plus at least two minority carrier diffusion lengths and wherein the circumferential groove formed by the two tapers forms angles of inclination with respect to the pn junctions between 40° and 45° with the bottom of the groove being longer than 40 μm.
Claim 3
Dependent Claim
17 words
A semiconductor power element as in claim 1 wherein the average angle is between 40° and 45°.
Claim 4
Dependent Claim
30 words
A semiconductor power element as in claim 1 wherein the circumferential groove formed by the two tapers is symmetric in shape and location with respect to the two pn junctions.
Claim 5
Dependent Claim
61 words
A semiconductor power element as in claim 1 wherein the straight lines intersecting the central axis of the element and fitted to the tapers by the method of least squares intersect a straight line parallel to the central axis and tangent to the bottom of the curve in two points which are separated by a distance of at least 40 μm.
Claim 6
Dependent Claim
21 words
A semiconductor power element as in claim 1 wherein the circumferential groove resulting from the two tapers is produced by sandblasting.
Claim 7
Dependent Claim
18 words
A semiconductor power element as in claim 1 capable of receiving blocking voltages in excess of 3.5 kv.
References Cited (Backward Citations)
DE1211336B
Cited
GB1031043A
Cited
US3491272A
Cited
US3437886A
Cited
US3611554A
Cited
US3943547A
Cited
US3984858A
Cited
US3987479A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-08-28 | 1982-02-27 | 1982-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-28 | 1986-02-27 | 1986-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-28 | 1990-02-27 | 1990-08-29 | $7700.00 | Window Closed / Lapsed |