Patent US4647900A successfully refreshed from Google Patents.
US4647900A
Expired / Lapsed
US
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High power thick film resistor
Assignee: Lockheed Martin Corp
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Filing: 1985-08-16
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Granted: 1987-03-03
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Expires: 2005-08-16
Abstract
Abstract A high power thick film resistor having improved power handling capability is obtained with a resistor having two overlying thick film layers wherein the first thick film layer has a relatively low resistivity and the second thick film layer has a relatively high resistivity.
Inventors
- 👤 Robert L. Schelhorn
- 👤 Colleen A. Matier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:42
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/18; H01C7/003
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
91 words
A thick film resistor capable of handling high power comprising: an electrically insulative, heat conductive substrate having a surface; a pair of spaced apart terminals attached to the surface; and a resistor body consisting of two continuous thick film layers, a first layer in contact with said substrate having a first resistance and extending between and being in electrical contact with said terminals and a second layer having a second resistance which is substantially greater than said first resistance overlying and being contiguous and in electrical contact with said first layer.
Claim 2
Dependent Claim
91 words
A thick film resistor capable of handling high power comprising: an electrically insulative, heat conductive substrate having a surface; a pair of spaced apart terminals attached to the surface; and a resistor body consisting of two continuous thick film layers, a first layer in contact with said substrate having a first resistance and extending between and being in electrical contact with said terminals and a second layer having a second resistance which is substantially greater than said first resistance overlying and being contiguous and in electrical contact with said first layer.
Claim 3
Dependent Claim
27 words
The thick film resistor according to claim 1 wherein the resistance of the second layer is approximately ten times greater than the resistance of the first layer.
Claim 4
Dependent Claim
17 words
The thick film resistor according to claim 1 having a hermetic dielectric layer overlying the resistor body.
Claim 5
Dependent Claim
47 words
The thick film resistor according to claim 1 wherein the first and second thick film layers are comprised of resistor materials consisting of the same components in different proportions sufficient to impart said first resistance to said first layer and said second resistance to said second layer.
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) | 1990-03-02 | 1990-09-01 | 1991-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-02 | 1994-09-01 | 1995-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-02 | 1998-09-01 | 1999-03-03 | $7700.00 | Window Closed / Lapsed |