Patent US3711428A successfully refreshed from Google Patents.
US3711428A
Expired / Lapsed
US
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Electrical resistor paste containing a small amount of charcoal
Assignee: International Business Machines Corp
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Filing: 1971-02-01
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Granted: 1973-01-16
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Expires: 1991-02-01
Abstract
Abstract A resistor paste composition contains a small amount of powdered activated charcoal. The composition is applied to a ceramic substrate by screen printing, fired at an elevated temperature, and cooled to room temperature to form an electrical resistor element.
Inventors
- 👤 T Aycock
- 👤 J Wright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:59
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/003; H01B; H01B1/00; H01B1/14; H01C17/00; H01C17/06; H01C17/065; H01C17/06506; H01C17/06573; H01C17/0658; H01C17/06586
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
12 words
The paste of claim 1 wherein said solid portion includes dopant ions.
Claim 2
Dependent Claim
27 words
The paste of claim 1 wherein said charcoal is present in an amount of about 0.4 to 2.0 percent by weight of the total weight of paste.
Claim 3
Dependent Claim
16 words
The paste of claim 3 wherein said charcoal is a pharmaceutical grade highly refined wood charcoal.
Claim 4
Dependent Claim
12 words
The paste of claim 1 wherein said vehicle includes a wetting agent.
Claim 5
Dependent Claim
12 words
The paste of claim 1 wherein said solid portion includes colloidal silica.
Claim 6
Dependent Claim
35 words
The resistor composition of claim 1 wherein said powdered conductive material is lithium doped paladium oxide said powdered glass insulating material is a borosilicate glass, and said vehicle compises a volatile solvent and ethyl cellulose.
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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) | 1976-01-16 | 1976-07-17 | 1977-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-16 | 1980-07-17 | 1981-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-16 | 1984-07-17 | 1985-01-16 | $7700.00 | Window Closed / Lapsed |