US3836994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thyristor overvoltage protective element
Assignee: General Electric Co
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Filing: 1973-07-05
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Granted: 1974-09-17
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Expires: 1993-07-05
Abstract
Abstract A PNPN semiconductor element comprises an improved doubletriggering device wherein two concentric electrode-less auxiliary regions are provided in one end layer, the two regions being so constructed and arranged that the outboard one has an underpass effect and the other one does not.
Inventors
- 👤 D Piccone
- 👤 I Somos
- 👤 Intyre J Mc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:53
CPC Classifications
H; H02; H02M; H02M1/00; H02M1/32; H03; H03K; H03K17/00; H03K17/08; H03K17/081; H03K17/08108; H10; H10D; H10D99/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
186 words
An overvoltage triggered PNPN semiconductor element comprising: a. a semiconductor body having four layers arranged in succession with contiguous layers being of different conductivity types, whereby rectifying junctions are formed between contiguous layers of the body; b. a main current-carrying contact; c. means for connecting said contact to a predetermined end layer of said body; d. said predetermined end layer comprising a central main region joined to said contact, a first auxiliary region disposed adjacent to the lateral border of said main region, and a second auxiliary region disposed outboard with respect to said first auxiliary region, all of said regions being contiguous with the intermediate layer of said body that adjoins said predetermined end layer; e. a ring of electroconductive material spaced apart from said contact and connected to said first auxiliary region; f. said second auxiliary region being characterized by a lateral resistance appreciably higher than the resistance between said ring and said contact; and g. said semiconductor body being so constructed and arranged that, when connected in a circuit which is subjected to an overvoltage condition, leakage current triggers a peripheral area thereof.
Claim 2
Dependent Claim
186 words
An overvoltage triggered PNPN semiconductor element comprising: a. a semiconductor body having four layers arranged in succession with contiguous layers being of different conductivity types, whereby rectifying junctions are formed between contiguous layers of the body; b. a main current-carrying contact; c. means for connecting said contact to a predetermined end layer of said body; d. said predetermined end layer comprising a central main region joined to said contact, a first auxiliary region disposed adjacent to the lateral border of said main region, and a second auxiliary region disposed outboard with respect to said first auxiliary region, all of said regions being contiguous with the intermediate layer of said body that adjoins said predetermined end layer; e. a ring of electroconductive material spaced apart from said contact and connected to said first auxiliary region; f. said second auxiliary region being characterized by a lateral resistance appreciably higher than the resistance between said ring and said contact; and g. said semiconductor body being so constructed and arranged that, when connected in a circuit which is subjected to an overvoltage condition, leakage current triggers a peripheral area thereof.
Claim 3
Dependent Claim
67 words
The element of claim 1 in which said auxiliary regions are so constructed and arranged that, upon triggering of the element in response to said overvoltage condition, the path that initially conducts main current will include said first auxiliary region, and at least a portion of the initial main current will act as a peremptory trigger signal for a broad area of said body subtending said contact.
Claim 4
Dependent Claim
35 words
The element of claim 1 in which an annular island of electroconductive material is connected to the perimeter of said second auxiliary region, said island being spaced apart from said ring and being concentric therewith.
Claim 5
Dependent Claim
25 words
The element of claim 1 in which said first auxiliary region is separated from said main region by a gap in said predetermined end layer.
Claim 6
Dependent Claim
33 words
The element of claim 4 in which a portion of said intermediate layer of said body is exposed between said first auxiliary region and said main region and said ring is connected thereto.
Claim 7
Dependent Claim
167 words
An improved PNPN semiconductor element comprising a plurality of layers of semiconductor material arranged in succession between first and second metal contacts, with contiguous layers being of different conductivity types so that rectifying junctions are formed therebetween, a first one of the opposite end layers of semiconductor material including a central main region joined to said first contact and an annular auxiliary region disposed laterally adjacent thereto, said auxiliary region being located outside said main region and having superimposed thereon a ring of electroconductive material spaced apart from said first contact, said element being so constructed and arranged that, upon applying across said first and second contacts a forward bias voltage of sufficiently high value to cause a voltage breakover of said element, breakover action begins in a peripheral area thereof, wherein the improvement comprises: an additional annular auxiliary region of said first end layer circumscribing the first-mentioned auxiliary region and having a lateral resistance appreciably higher than the resistance between said ring and said first contact.
Claim 8
Dependent Claim
167 words
An improved PNPN semiconductor element comprising a plurality of layers of semiconductor material arranged in succession between first and second metal contacts, with contiguous layers being of different conductivity types so that rectifying junctions are formed therebetween, a first one of the opposite end layers of semiconductor material including a central main region joined to said first contact and an annular auxiliary region disposed laterally adjacent thereto, said auxiliary region being located outside said main region and having superimposed thereon a ring of electroconductive material spaced apart from said first contact, said element being so constructed and arranged that, upon applying across said first and second contacts a forward bias voltage of sufficiently high value to cause a voltage breakover of said element, breakover action begins in a peripheral area thereof, wherein the improvement comprises: an additional annular auxiliary region of said first end layer circumscribing the first-mentioned auxiliary region and having a lateral resistance appreciably higher than the resistance between said ring and said first contact.
Claim 9
Dependent Claim
19 words
The element of claim 6 wherein said additional auxiliary region has sufficient lateral resistance to provide an underpass effect.
References Cited (Backward Citations)
US3440501A
Cited
US3622845A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |