US3998980A
Expired / Lapsed
US
⏱️ 0.0 years remaining
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 18:26
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.
References Cited (Backward Citations)
US3200010A
Cited
US3386165A
Cited
US3370262A
Cited
US3308528A
Cited
US3453727A
Cited
US3457637A
Cited
US3607386A
Cited
US3560410A
Cited
US3699650A
Cited
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 |