US4498071A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High resistance film resistor
Assignee: Vishay Dale Electronics LLC
•
Filing: 1982-09-30
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Granted: 1985-02-05
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Expires: 2002-09-30
Abstract
Abstract An electrical resistor and method of making the same is disclosed wherein a ceramic substrate is coated with a relatively rough dielectric film which is subsequently coated with a thin metal film such as nichrome.
Inventors
- 👤 Charles T. Plough, Jr.
- 👤 Ralph D. Hight
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:02
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/006; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49099
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
131 words
A high resistance film resistor comprising: a ceramic substrate having a supporting surface; a dielectric film coated on said supporting surface of said substrate, said dielectric film having a rough surface facing away from said substrate and being substantially rougher than said supporting surface of said substrate, said dielectric film being substantially nitride material; a thin metal film forming a resistance element coated on said rough surface of said dielectric film, said dielectric film providing a barrier against diffusion of impurities from said substrate into said resistance element and providing electrical stability to said resistance element, whereby the sheet resistance of said resistance element is of a value a plurality of times greater than the sheet resistance obtained by placing said thin film directly on said supporting surface of said substrate.
Claim 2
Dependent Claim
131 words
A high resistance film resistor comprising: a ceramic substrate having a supporting surface; a dielectric film coated on said supporting surface of said substrate, said dielectric film having a rough surface facing away from said substrate and being substantially rougher than said supporting surface of said substrate, said dielectric film being substantially nitride material; a thin metal film forming a resistance element coated on said rough surface of said dielectric film, said dielectric film providing a barrier against diffusion of impurities from said substrate into said resistance element and providing electrical stability to said resistance element, whereby the sheet resistance of said resistance element is of a value a plurality of times greater than the sheet resistance obtained by placing said thin film directly on said supporting surface of said substrate.
Claim 3
Dependent Claim
14 words
The device of claim 1 wherein said metal film is comprised primarily of nichrome.
Claim 4
Dependent Claim
12 words
The device of claim 1 wherein said dielectric material is silicon nitride.
Claim 5
Dependent Claim
12 words
The device of claim 2 wherein said dielectric material is silicon nitride.
Claim 6
Dependent Claim
10 words
The device of claim 1 wherein said substrate is alumina.
Claim 7
Dependent Claim
12 words
The device of claim 1 wherein said dielectric material is aluminum nitride.
Claim 8
Dependent Claim
37 words
A resistor according to claim 1 wherein said resistance element has a sheet resistance of approximately 1500 ohms per square and exhibits resistance shifts of no more than 1.5% after 2000 hours of use at 150° C.
Claim 9
Dependent Claim
37 words
A resistor according to claim 7 wherein said resistance element has a sheet resistance of approximately 5000 ohms per square and exhibits resistance shifts of no more than 1.5% after 2000 hours of use at 150° C.
Claim 10
Dependent Claim
19 words
A resistor according to claim 8 wherein said resistance element has a temperature coefficient of resistance below 100 ppm/°C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-05 | 1988-08-06 | 1989-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-05 | 1992-08-06 | 1993-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-05 | 1996-08-06 | 1997-02-05 | $7700.00 | Window Closed / Lapsed |