US4293838A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Resistance material, resistor and method of making the same
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1979-01-29
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Granted: 1981-10-06
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Expires: 1999-01-29
Abstract
Abstract A vitreous enamel resistor material comprising a mixture of a vitreous glass frit, an insulating material containing an oxide of zirconium, and a conductive phase of fine particles of tin oxide. The insulating material is selected from the group consisting of zirconia (ZrO 2 ), calcium zirconate (CaZrO 2 ), barium zirconate (BaZrO 3 ) and strontium zirconate (SrZrO 3 ), and the conductive phase may also contain an additive such as tantalum oxide. An electrical resistor is made from the resistor material by applying the material to a substrate and firing the coated substrate to a temperature at which the glass softens. Upon cooling, the substrate has on the surface thereof a film of glass and insulating material having the particles of the conductive phase embedded therein and dispersed therethroughout. The resistor material provides a resistor having relatively high resistivity as well as rugged physical characteristics.
Inventors
- 👤 Richard L. Wahlers
- 👤 Vernon E. Osborne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:41
CPC Classifications
H; H01; H01C; H01C17/00; H01C17/06; H01C17/065; H01C17/06506; H01C17/06513; H01C17/06533; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49099
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
76 words
An electrical resistor of relatively high resistivity and rugged physical characteristics comprising an insulating substrate and a layer of resistor material on a surface of the substrate, the resistor material including a conductive phase of particles of tin oxide embedded in and dispersed throughout a glass which includes an insulating material containing an oxide of zirconium, the glass and insulating material being present in an amount up to about 70% by volume of the resistor material.
Claim 2
Dependent Claim
76 words
An electrical resistor of relatively high resistivity and rugged physical characteristics comprising an insulating substrate and a layer of resistor material on a surface of the substrate, the resistor material including a conductive phase of particles of tin oxide embedded in and dispersed throughout a glass which includes an insulating material containing an oxide of zirconium, the glass and insulating material being present in an amount up to about 70% by volume of the resistor material.
Claim 3
Dependent Claim
28 words
An electrical resistor in accordance with claim 1 in which the insulating material is selected from the group consisting of zirconia, calcium zirconate, barium zirconate, and strontium zirconate.
Claim 4
Dependent Claim
18 words
An electrical resistor in accordance with claim 2 in which the conductive phase includes particles of tantalum oxide.
Claim 5
Dependent Claim
18 words
An electrical resistor in accordance with claim 2 in which the glass is an alkaline earth borosilicate glass.
Claim 6
Dependent Claim
33 words
An electrical resistor in accordance with claim 1, 2, 3, or 4 in which the insulating material is present in an amount of up to about 15% by volume of the resistor material.
Claim 7
Dependent Claim
34 words
An electrical resistor in accordance with claim 1, 2, 3, or 4 in which the conductive phase is present in an amount of not greater than about 50% by volume of the resistor material.
Claim 8
Dependent Claim
53 words
An electrical resistor in accordance with claim 1, 2, 3 or 4 in which the glass and insulating material are present in the amount of about 50% by volume of the resistor material, and the insulating material is present in an amount of up to about 15% by volume of the resistor material.
Claim 9
Independent Claim
79 words
A method of making an electrical resistor of relatively high resistivity and rugged physical characteristics comprising the steps of mixing together a glass frit, an insulating material containing an oxide of zirconium, and a conductive phase of fine particles of tin oxide, the glass frit and insulating material being present in an amount up to about 70% by volume of the mixture cooling the coated substrate to form a resistor having a glass matrix with conductive particles dispersed therein.
Claim 10
Independent Claim
79 words
A method of making an electrical resistor of relatively high resistivity and rugged physical characteristics comprising the steps of mixing together a glass frit, an insulating material containing an oxide of zirconium, and a conductive phase of fine particles of tin oxide, the glass frit and insulating material being present in an amount up to about 70% by volume of the mixture cooling the coated substrate to form a resistor having a glass matrix with conductive particles dispersed therein.
Claim 11
Dependent Claim
27 words
The method in accordance with claim 8 in which the insulating material is selected from the group consisting of zirconia, calcium zirconate, barium zirconate, and strontium zirconate.
Claim 12
Dependent Claim
17 words
The method in accordance with claim 9 in which the conductive phase includes particles of tantalum oxide.
Claim 13
Dependent Claim
19 words
The method in accordance with claim 10 in which the glass frit is of an alkaline earth borosilicate glass.
Claim 14
Dependent Claim
34 words
The method in accordance with claim 11 in which the mixture is fired in a nitrogen atmosphere to a peak temperature of between 950° C. and 1025° C. over approximately a 30 minute cycle.
Claim 15
Dependent Claim
31 words
The method in accordance with claim 8, 9, 10 or 11 in which the insulating material is present in an amount of up to about 15% by volume of the mixture.
Claim 16
Dependent Claim
32 words
The method in accordance with claim 8, 9, 10 or 11 in which the conductive phase is present in an amount of not greater than about 50% by volume of the mixture.
Claim 17
Dependent Claim
51 words
The method in accordance with claim 8, 9, 10 or 11 in which the glass frit and insulating material are present in the amount of about 50% by volume of the mixture, and the insulating material is present in an amount of up to about 15% by volume of the mixture.
Claim 18
Dependent Claim
115 words
An electrical resistor of relatively high resistivity and rugged physical characteristics of the vitreous glaze type made by mixing together a glass frit, an insulating material containing an oxide of zirconium, and a conductive phase of fine particles of tin oxide, the glass frit and insulating material being preseint in an amount up to about 70% by volume of the mixture applying the mixture to a surface of an insulating substrate and firing same in a substantially inert atmosphere to the softening temperature of the glass frit but below the temperature at which the tin oxide melts, and cooling the coated substrate to form a resistor having a glass matrix with conductive particles dispersed therein.
Claim 19
Dependent Claim
115 words
An electrical resistor of relatively high resistivity and rugged physical characteristics of the vitreous glaze type made by mixing together a glass frit, an insulating material containing an oxide of zirconium, and a conductive phase of fine particles of tin oxide, the glass frit and insulating material being preseint in an amount up to about 70% by volume of the mixture applying the mixture to a surface of an insulating substrate and firing same in a substantially inert atmosphere to the softening temperature of the glass frit but below the temperature at which the tin oxide melts, and cooling the coated substrate to form a resistor having a glass matrix with conductive particles dispersed therein.
Claim 20
Dependent Claim
29 words
An electrical resistor made in accordance with claim 16 in which the insulating material is selected from the group consisting of zirconia, calcium zirconate, barium zirconate, and strontium zirconate.
Claim 21
Dependent Claim
19 words
An electrical resistor made in accordance with claim 17 in which the conductive phase includes particles of tantalum oxide.
Claim 22
Dependent Claim
21 words
An electrical resistor made in accordance with claim 18 in which the glass frit is of an alkaline earth borosilicate glass.
Claim 23
Dependent Claim
36 words
An electrical resistor made in accordance with claim 19 in which the mixture is fired in a nitrogen atmosphere to a peak temperature of between 950° C. and 1025° C. over approximately a 30 minute cycle.
Claim 24
Dependent Claim
33 words
An electrical resistor made in accordance with claim 16, 17, 18, or 19 in which the insulating material is present in an amount of up to about 15% by volume of the mixture.
Claim 25
Dependent Claim
34 words
An electrical resistor made in accordance with claim 16, 17, 18, or 19 in which the conductive phase is present in an amount of not greater than about 60% by volume of the mixture.
Claim 26
Dependent Claim
53 words
An electrical resistor made in accordance with claim 16, 17, 18, or 19 in which the glass frit and insulating material are present in the amount of about 50% by volume of the mixture, and the insulating material is present in an amount of up to about 15% by volume of the mixture.
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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) | 1984-10-05 | 1985-04-06 | 1985-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-05 | 1989-04-06 | 1989-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-05 | 1993-04-06 | 1993-10-06 | $7700.00 | Window Closed / Lapsed |