Patent US3998980A successfully refreshed from Google Patents.
US3998980A
Expired / Lapsed
US
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Fabrication of thick film resistors
Assignee: HP Inc
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Filing: 1974-05-30
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Granted: 1976-12-21
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Expires: 1994-05-30
Abstract
Abstract A glass material is deposited upon a ceramic substrate and then fired at an elevated temperature in air. Screen printed resistor elements formed on the glass material are fired, lapped, and annealed.
Inventors
- 👤 Alan C. Antes
- 👤 James R. Drehle
- 👤 Blair H. Harrison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:21
CPC Classifications
H; H01; H01C; H01C17/00; H01C17/06; H01C17/065; H05; H05K; H05K1/00; H05K1/02; H05K1/09; H05K1/092; H05K1/16; H05K1/167; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49099
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
60 words
A process for fabricating a thick film resistor upon an element, said process comprising the steps of: depositing a crystallizable dielectric layer upon the element; firing the crystallizable dielectric layer at an elevated temperature; depositing a layer of cermet resistive material upon the crystallizable dielectric layer; and firing the cermet resistive material at an elevated temperature in a neutral atmosphere.
Claim 2
Dependent Claim
60 words
A process for fabricating a thick film resistor upon an element, said process comprising the steps of: depositing a crystallizable dielectric layer upon the element; firing the crystallizable dielectric layer at an elevated temperature; depositing a layer of cermet resistive material upon the crystallizable dielectric layer; and firing the cermet resistive material at an elevated temperature in a neutral atmosphere.
Claim 3
Dependent Claim
21 words
A process as in claim 1 wherein the cermet resistive material is fired at an elevated temperature in an oxidizing atmosphere.
Claim 4
Dependent Claim
33 words
A process as in claim 2 wherein the crystallizable dielectric layer is fired at a temperature within the range of 850° to 1100° C. and for a time period greater than ten minutes.
Claim 5
Dependent Claim
33 words
A process as in claim 1 wherein the crystallizable dielectric layer is fired at a temperature within the range of 850° to 1100° C. and for a time period greater than ten minutes.
Claim 6
Dependent Claim
25 words
A process as in claim 1 wherein the element is a ceramic substrate and the crystallizable dielectric layer is deposited upon a face surface thereof.
Claim 7
Dependent Claim
17 words
A process as in claim 1 further comprising the step of lapping the fired cermet resistive material.
Claim 8
Dependent Claim
23 words
A process as in claim 6 further comprising the step of annealing the cermet resistive material to impede the formation of microcracks therein.
Claim 9
Dependent Claim
13 words
A process as in claim 1 wherein said crystallizable dielectric layer is glass.
Claim 10
Dependent Claim
13 words
A process as in claim 2 wherein said crystallizable dielectric layer is glass.
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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) | 1979-12-21 | 1980-06-21 | 1980-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-12-21 | 1984-06-21 | 1984-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-12-21 | 1988-06-21 | 1988-12-21 | $7700.00 | Window Closed / Lapsed |