Patent US4226899A successfully refreshed from Google Patents.
US4226899A
Expired / Lapsed
US
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Method for fabricating controlled TCR thin film resistors
Assignee: BAE Systems National Security Solutions Inc
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Filing: 1978-08-21
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Granted: 1980-10-07
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Expires: 1998-08-21
Abstract
Abstract High stability thin film resistors are made from an alloy comprising selected portions of nickel, chromium, and gold selected in a ratio to provide the desired temperature coefficient of resistance (TCR). The resistors are made by co-depositing gold with the nickel chromium alloy by a flash evaporation process. The evaporation process is carried out by feeding a nickel chromium wire, having a gold wire extending therealong to provide the desired composition, onto a heated tungsten strip within a vacuum system with substrates disposed in a position to obtain uniform deposition of the evaporated material thereon.
Inventors
- 👤 Ronald A. Thiel
- 👤 Edward H. Maurer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:43
CPC Classifications
H; H01; H01C; H01C17/00; H01C17/06; H01C17/075; H01C17/10; H01C17/08; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49099
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
64 words
A method of fabricating thin film resistors comprising the steps of: selecting a dielectric substrate, and co-deposit preselected percentages of gold, nickel and chromium on said substrate forming a resistive film of not more than 5,000 angstroms in thickness of an alloy consisting of gold, nickel and chromium wherein the percentage of gold is no greater than the combined percentage of nickel and chromium.
Claim 2
Independent Claim
64 words
A method of fabricating thin film resistors comprising the steps of: selecting a dielectric substrate, and co-deposit preselected percentages of gold, nickel and chromium on said substrate forming a resistive film of not more than 5,000 angstroms in thickness of an alloy consisting of gold, nickel and chromium wherein the percentage of gold is no greater than the combined percentage of nickel and chromium.
Claim 3
Dependent Claim
29 words
The method of claim 1, including the step of adjusting the rate of deposition of the gold to obtain a zero TCR in parts per million per degree centrigrade.
Claim 4
Dependent Claim
19 words
The method of claim 1, wherein said step of co-depositing is carried out by flash evaporation in a vacuum.
Claim 5
Dependent Claim
19 words
The method of claim 3, including the step of feeding a composite wire onto a resistance heated tungsten strip.
Claim 6
Dependent Claim
39 words
The method of claim 4, wherein said composite wire is formed by selecting a nickel chromium wire of a desired ratio, selecting a gold wire of a predetermined diameter, and winding said gold wire about said nickel chromium wire.
Claim 7
Dependent Claim
22 words
The method of claim 5, wherein said nickel chromium wire is selected to have a ratio of 40% nickel to 60% chrome.
Claim 8
Dependent Claim
47 words
The method of claim 4, including the steps of forming said composite wire by selecting and adjusting a nickel chromium core wire to a desired nickel to chrome ratio, and applying gold along the length of said wire in a predetermined amount to obtain the desired alloy.
Claim 9
Dependent Claim
26 words
The method of claim 7, including the step of adjusting the ratio of nickel to chrome in said core wire by plating chrome onto said wire.
Claim 10
Dependent Claim
16 words
The method of claim 7, wherein said gold is applied to said core wire by plating.
Claim 11
Dependent Claim
20 words
The method of claim 7 wherein said gold is applied to said core wire by winding onto said core wire.
Claim 12
Dependent Claim
36 words
The method of claim 1, comprising the step of selecting and adjusting the percentage of gold in said alloy for thereby producing a resistive film having a selected predictable TCR between approximately -40 and +65 ppm/°C.
Claim 13
Dependent Claim
24 words
The method of claim 1 including the step of adjusting the TCR of the film by adjusting the percent of gold in the alloy.
Claim 14
Dependent Claim
24 words
The method of claim 1, including the step of adjusting the TCR of the film by adjusting the temperature of the substrate during deposition.
References Cited (Backward Citations)
US3578420A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-10-07 | 1984-04-07 | 1984-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-07 | 1988-04-07 | 1988-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-07 | 1992-04-07 | 1992-10-07 | $7700.00 | Window Closed / Lapsed |