Patent US4079403A successfully refreshed from Google Patents.
US4079403A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thyristor device with self-protection against breakover turn-on failure
Assignee: Electric Power Research Institute
•
Filing: 1976-11-01
•
Granted: 1978-03-14
•
Expires: 1996-11-01
Abstract
Abstract Self-protection against breakover turn-on failure is achieved for a thyristor by providing for adjustment of the curvature of the planar junction termination in the gate region. In addition, breakdown of the outer edge of the device at the junctions is maintained at a relatively higher breakdown voltage by the techniques of beveling, floating field rings or by etching around the cathode emitter region.
Inventors
- 👤 Victor A. K. Temple
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:07
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/124; H10D62/125; H10D18/00; H10D18/211; H10D62/102; H10D62/103; H10D62/104; H10D62/17; H10D62/192; H10D62/206; H10D62/105; H10D62/106
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
124 words
A thyristor device having a cathode anode, a first base with a gate and a second base and with self-protection against breakover turn-on failure comprising: a semiconductive substrate of one conductivity type with a planar surface and forming said second base; a region of opposite conductivity type, forming said first base, and inset through said surface into said region of said one conductivity type forming a PN junction said region of opposite conductivity type having a gate area and a cathode emitter area, at least a portion of said PN junction extending to said surface near said gate area with a radius of curvature to provide a lower breakdown voltage in the region near said gate area relative to the remainder of said device.
Claim 2
Dependent Claim
124 words
A thyristor device having a cathode anode, a first base with a gate and a second base and with self-protection against breakover turn-on failure comprising: a semiconductive substrate of one conductivity type with a planar surface and forming said second base; a region of opposite conductivity type, forming said first base, and inset through said surface into said region of said one conductivity type forming a PN junction said region of opposite conductivity type having a gate area and a cathode emitter area, at least a portion of said PN junction extending to said surface near said gate area with a radius of curvature to provide a lower breakdown voltage in the region near said gate area relative to the remainder of said device.
Claim 3
Dependent Claim
32 words
A device as in claim 1 where said PN junction extends to the edge of said substrate and including means for maximizing the breakdown voltage of said PN junction at said edge.
Claim 4
Dependent Claim
13 words
A device as in claim 2 where said means include a bevelled substrate.
Claim 5
Dependent Claim
20 words
A device as in claim 2 where said means include a floating field ring junction around said cathode emitter area.
Claim 6
Dependent Claim
18 words
A device as in claim 2 where said means include an etched periphery around said cathode emitter area.
Claim 7
Dependent Claim
37 words
A device as in claim 1 in which the breakdown voltage of said gate area is adjusted upward by the use of a floating limiting ring located in said substrate adjacent said PN junction at said surface.
Claim 8
Dependent Claim
28 words
A device as in claim 1 in which the breakdown voltage of said gate area is adjusted upward by an etch of controlled depth in said gate area.
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) | 1981-03-13 | 1981-09-12 | 1982-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-13 | 1985-09-12 | 1986-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-13 | 1989-09-12 | 1990-03-14 | $7700.00 | Window Closed / Lapsed |