US3652907A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin film power fet
Assignee: Westinghouse Electric Corp
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Filing: 1970-05-05
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Granted: 1972-03-28
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Expires: 1990-05-05
Abstract
Abstract This disclosure is concerned with a thin film, power field effect transistor having a power dissipation capability of 80 watts/cm.2. The transistor has a thin film interdigitated source and drain used in conjunction with a thick film source and drain leads. The thick film source and drain leads essentially eliminates negative feedback resulting from a voltage drop in the source and drain.
Inventors
- 👤 Derrick J Page
- 👤 Thomas P Brody
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:42
CPC Classifications
H; H10; H10D; H10D99/00; H10D48/00; H10D48/30; H10D48/32; H10D48/36
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
185 words
A thin film power field effect transistor comprising: an electrically and thermally conductive substrate, a layer of an electrically insulating, thermally conducting material on at least the top surface of the substrate, a metal source electrode, a metal drain electrode, said source and drain disposed on said layer of electrically insulating, thermally conducting material, said source and drain being spaced apart from each other and having an interdigitated relationship relative to each other, said source and drain electrode each consisting of a thick film metal electrical lead portion and a thin film metal electrical contact portion, said contact portion of said source and said drain each being disposed over and completely covering said lead portion said source and drain leads have a thickness of from 0.1 to 5 mils and the source and drain contacts have a thickness of from 200 A to 1,000 A, and, a thin film of a semiconductor material in contact with said source and drain electrodes and in contact with said layer of electrically insulating and thermal conducting material at least in the space between said source and drain electrodes.
Claim 2
Dependent Claim
185 words
A thin film power field effect transistor comprising: an electrically and thermally conductive substrate, a layer of an electrically insulating, thermally conducting material on at least the top surface of the substrate, a metal source electrode, a metal drain electrode, said source and drain disposed on said layer of electrically insulating, thermally conducting material, said source and drain being spaced apart from each other and having an interdigitated relationship relative to each other, said source and drain electrode each consisting of a thick film metal electrical lead portion and a thin film metal electrical contact portion, said contact portion of said source and said drain each being disposed over and completely covering said lead portion said source and drain leads have a thickness of from 0.1 to 5 mils and the source and drain contacts have a thickness of from 200 A to 1,000 A, and, a thin film of a semiconductor material in contact with said source and drain electrodes and in contact with said layer of electrically insulating and thermal conducting material at least in the space between said source and drain electrodes.
Claim 3
Dependent Claim
23 words
The transistor of claim 1 in which the substrate is aluminum and the layer of electrically insulating, thermally conductive material is aluminum oxide.
Claim 4
Dependent Claim
20 words
The transistor of claim 1 in which the layer of semiconductor material is disposed over the source and drain electrode.
Claim 5
Dependent Claim
46 words
A thin film power field effect transistor of claim 1 in which input current and output current is electrically shunted around electrical resistance of thin film source and drain contacts by employing thick film source and drain leads under the thin film source and drain contacts.
Claim 6
Dependent Claim
161 words
A thin film power field effect transistor comprising: an electrically and thermally conductive substrate, a layer of an electrically insulating, thermally conducting material on at least the top surface of the substrate, a thin film of a semiconductor material disposed on said layer of electrically insulating, thermally conductive material, a metal source electrode, a metal drain electrode, said source and drain being disposed on said layer of semiconductor material, said source and drain being spaced apart from each other and having an interdigitated relationship relative to each other, said source and drain electrode each consisting of a thick film metal electrical lead portion and a thin film metal electrical contact portion, and said contact portion of said source and said drain each being disposed over and completely covering said lead portion said source and drain leads have a thickness of from 0.1 to 5 mils and the source and drain contacts have a thickness of from 200 A to 2,000 A.
Claim 7
Dependent Claim
161 words
A thin film power field effect transistor comprising: an electrically and thermally conductive substrate, a layer of an electrically insulating, thermally conducting material on at least the top surface of the substrate, a thin film of a semiconductor material disposed on said layer of electrically insulating, thermally conductive material, a metal source electrode, a metal drain electrode, said source and drain being disposed on said layer of semiconductor material, said source and drain being spaced apart from each other and having an interdigitated relationship relative to each other, said source and drain electrode each consisting of a thick film metal electrical lead portion and a thin film metal electrical contact portion, and said contact portion of said source and said drain each being disposed over and completely covering said lead portion said source and drain leads have a thickness of from 0.1 to 5 mils and the source and drain contacts have a thickness of from 200 A to 2,000 A.
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) | 1975-03-28 | 1975-09-27 | 1976-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-28 | 1979-09-27 | 1980-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-28 | 1983-09-27 | 1984-03-28 | $7700.00 | Window Closed / Lapsed |