US3842495A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control of rate of change of resistance as a function of temperature in manufacture of resistance elements
Assignee: GTI Corp
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Filing: 1973-01-24
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Granted: 1974-10-22
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Expires: 1993-01-24
Abstract
Abstract The method of improving the properties of a film type electrical resistance element having a characteristic rate of change of resistance as a function of temperature change, within a selected temperature range, the steps that include A. HEATING SAID ELEMENT WHILE EXPOSED TO A GASEOUS MEDIUM CONTAINING NITROGEN IN SUFFICIENT CONCENTRATION TO REDUCE SAID RATE, AND B. THEREAFTER IMPINGING LASER RADIATION ON THE RESISTANCE ELEMENT TO CONTROLLABLY ALTER THE RESISTANCE LEVEL THEREOF, AT TEMPERATURES WITHIN SAID SELECTED TEMPERATURE RANGE.
Inventors
- 👤 K Bennett
- 👤 J Crownover
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:51
CPC Classifications
H; H01; H01C; H01C17/00; H01C17/22; H01C17/26; H01C17/265; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49085; Y10T29/49099
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
95 words
THE METHOD OF IMPROVING THE TEMPERATURE STABILITY OF AN ELECTRICAL RESISTANCE ELEMENT IN FILM FORM AND WHICH HAS BEEN FIRED AT RELATIVELY HIGH TEMPERATURE IN AIR, THE ELEMENT SELECTED FROM THE GROUP CONSISTING OF NOBLE METALS AND OXIDES THEREOF, THAT INCLUDES: A. HEATING SAID ELEMENT AT RELATIVELY HIGH TEMPERATURE BETWEEN ABOUT 650*C AND 750*C AND WHILE THE ELEMENT IS EXPOSED TO A GASEOUS ENVIRONMENT CONTAINING NITROGEN IN GREATER PERCENTAGE THAN FOUND IN AIR, AND B. CONTINUING SAID HEATING FOR A TIME INTERVAL CHARACTERIZED IN THAT THE RATE OF CHANGE OF RESISTANCE OF THE ELEMENT AS
Claim 2
Independent Claim
95 words
THE METHOD OF IMPROVING THE TEMPERATURE STABILITY OF AN ELECTRICAL RESISTANCE ELEMENT IN FILM FORM AND WHICH HAS BEEN FIRED AT RELATIVELY HIGH TEMPERATURE IN AIR, THE ELEMENT SELECTED FROM THE GROUP CONSISTING OF NOBLE METALS AND OXIDES THEREOF, THAT INCLUDES: A. HEATING SAID ELEMENT AT RELATIVELY HIGH TEMPERATURE BETWEEN ABOUT 650*C AND 750*C AND WHILE THE ELEMENT IS EXPOSED TO A GASEOUS ENVIRONMENT CONTAINING NITROGEN IN GREATER PERCENTAGE THAN FOUND IN AIR, AND B. CONTINUING SAID HEATING FOR A TIME INTERVAL CHARACTERIZED IN THAT THE RATE OF CHANGE OF RESISTANCE OF THE ELEMENT AS
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein said metals include ruthenium, palladium and silver.
Claim 4
Dependent Claim
25 words
The method of claim 1 wherein said gas is at a temperature of about 700*C and in contact with the resistor element during said interval.
Claim 5
Dependent Claim
14 words
The method of claim 1 wherein said time interval is less than 1 minute.
Claim 6
Dependent Claim
16 words
The method of claim 3 wherein said time interval is between about 20 and 40 seconds.
Claim 7
Dependent Claim
14 words
The method of claim 1 wherein the resistance element film is in glassy state.
Claim 8
Dependent Claim
14 words
The method of claim 5 wherein the resistance element film is in glassy state.
Claim 9
Dependent Claim
35 words
The method of claim 7 wherein the percentage of nitrogen, by weight, in the gaseous mixture is selected to produce a parts per million change in resistance per *C change in temperature of about 10.
Claim 10
Dependent Claim
34 words
The method of claim 1 including the step of directing a laser beam to impinge on said element and thereby effect a change in the electrical resistance of said element to a desired value.
Claim 11
Dependent Claim
22 words
The method of claim 9 wherein the laser beam exhibits a wave length of at least about one thousandth of a millimeter.
Claim 12
Dependent Claim
27 words
The method of claim 9 including the step of effecting relative movement of the beam and element to impinge the beam on different portions of the element.
Claim 13
Independent Claim
100 words
The method of improving the properties of a film type electrical resistance element having a characteristic rate of change of resistance as a function of temperature change, within a selected temperature range between about 0*C to 100*C, the element selected from the group consisting of metals and metal oxides, the steps that include a. heating said element while exposed to a gaseous medium containing nitrogen in greater percentage than found in air to reduce said rate, and b. thereafter impinging laser radiation on the resistance element to controllably alter the resistance level thereof, at temperature within said selected temperature range.
Claim 14
Independent Claim
100 words
The method of improving the properties of a film type electrical resistance element having a characteristic rate of change of resistance as a function of temperature change, within a selected temperature range between about 0*C to 100*C, the element selected from the group consisting of metals and metal oxides, the steps that include a. heating said element while exposed to a gaseous medium containing nitrogen in greater percentage than found in air to reduce said rate, and b. thereafter impinging laser radiation on the resistance element to controllably alter the resistance level thereof, at temperature within said selected temperature range.
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) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |