US4397915A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical resistor material, resistor made therefrom and method of making the same
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1981-09-03
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Granted: 1983-08-09
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Expires: 2001-09-03
Abstract
Abstract A vitreous enamel resistor material comprising a mixture of a vitreous glass frit and fine particles of tin oxide (SnO 2 ). An electrical resistor is made from the resistor material by applying the material to a substrate and firing the coated substrate to a temperature between about 850° C. and 1150° C. at which the glass melts. Upon cooling, the substrate has on the surface thereof, a film of the glass having the particles of the tin oxide embedded therein and dispersed therethroughout. The resistor material provides a resistor having a resistivity within a wide range and a low temperature coefficient of resistance.
Inventors
- 👤 Richard L. Wahlers
- 👤 Kenneth M. Merz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:59
CPC Classifications
H; H01; H01C; H01C17/00; H01C17/06; H01C17/065; H01C17/06506; H01C17/06513; H01C17/06533
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
94 words
A vitreous enamel resistor material adapted to be applied to and fired on a substrate to form an electrical resistor with a controlled temperature coefficient of resistance within ±2000 ppm/°C. consisting essentially of a mixture of tin oxide particles and a glass frit, said glass frit having a softening point below the melting point of the tin oxide particles, said mixture being fired in a inert atmosphere to a temperature between approximately 850° C. and 1150° C., the glass frit being present in the amount of 30% to 80% by volume of the mixture.
Claim 2
Dependent Claim
94 words
A vitreous enamel resistor material adapted to be applied to and fired on a substrate to form an electrical resistor with a controlled temperature coefficient of resistance within ±2000 ppm/°C. consisting essentially of a mixture of tin oxide particles and a glass frit, said glass frit having a softening point below the melting point of the tin oxide particles, said mixture being fired in a inert atmosphere to a temperature between approximately 850° C. and 1150° C., the glass frit being present in the amount of 30% to 80% by volume of the mixture.
Claim 3
Dependent Claim
31 words
A vitreous enamel resistor material in accordance with claim 1 in which the tin oxide particles are present in the resistor material in the amount of 40% to 70% by volume.
Claim 4
Dependent Claim
30 words
A vitreous enamel resistor material in accordance with claim 1 in which the glass frit and tin oxide particles are present in respective amounts between 40% to 60% by volume.
Claim 5
Dependent Claim
31 words
A vitreous enamel resistor material in accordance with claim 1 in which the tin oxide particles are heat treated prior to said tin oxide particles being mixed with said glass frit.
Claim 6
Dependent Claim
36 words
A vitreous enamel resistor material in accordance with claim 4 in which the tin oxide is heat treated in a furnace having a nitrogen atmosphere and a peak temperature of 1100° C. for about one hour.
Claim 7
Dependent Claim
44 words
A vitreous enamel resistor material in accordance with claim 4 in which the tin oxide is heat treated by heating in an atmosphere of forming gas at about 525° C. for about 10 minutes and then allowed to cool in the forming gas atmosphere.
Claim 8
Dependent Claim
20 words
A vitreous enamel resistor material in accordance with claim 1 in which the glass frit is a borosilicate glass frit.
Claim 9
Dependent Claim
22 words
A vitreous enamel resistor material in accordance with claim 7 in which the glass frit is an alkaline earth borosilicate glass frit.
Claim 10
Dependent Claim
60 words
An electrical resistor characterized by providing a relatively low temperature coefficient of resistance within ±2000 ppm/°C. comprising a ceramic substrate and a layer of a resistor material on a surface of said substrate, said resistor material consisting essentially of tin oxide particles dispersed throughout a glass, the tin oxide being present in the amount of 20% to 70% by volume.
Claim 11
Dependent Claim
60 words
An electrical resistor characterized by providing a relatively low temperature coefficient of resistance within ±2000 ppm/°C. comprising a ceramic substrate and a layer of a resistor material on a surface of said substrate, said resistor material consisting essentially of tin oxide particles dispersed throughout a glass, the tin oxide being present in the amount of 20% to 70% by volume.
Claim 12
Dependent Claim
29 words
An electrical resistor in accordance with claim 9 in which the tin oxide particles are present in the resistor material in the amount of 40% to 70% by volume.
Claim 13
Dependent Claim
25 words
An electrical resistor in accordance with claim 9 in which the tin oxide particles are present in the amount of 40% to 60% by volume.
Claim 14
Dependent Claim
28 words
An electrical resistor in accordance with claim 9 in which the tin oxide particles are of tin oxide which has been heat treated subsequent to its initial formation.
Claim 15
Dependent Claim
16 words
An electrical resistor in accordance with claim 9 in which the glass is a borosilicate glass.
Claim 16
Dependent Claim
18 words
An electrical resistor in accordance with claim 13 in which the glass is an alkaline earth borosilicate glass.
Claim 17
Independent Claim
129 words
A method of making electrical resistors providing selected resistivities within a wide range and with controlled temperature coefficients of resistance within ±2000 ppm/°C. comprising the steps of mixing together in selected amounts a glass frit and conductive particles consisting essentially of tin oxide, the glass frit being present in the amount of 30% to 80% by volume, applying said mixture to a surface of a substrate, firing said coated substrate in an inert atmosphere to a selected temperature between approximately 850° C. and 1150° C. at which the glass softens but below the point at which the tin oxide melts, and cooling the coated substrate to form a layer of glass bonded to the substrate and having conductive particles of tin oxide embedded in and dispersed throughout the glass.
Claim 18
Independent Claim
129 words
A method of making electrical resistors providing selected resistivities within a wide range and with controlled temperature coefficients of resistance within ±2000 ppm/°C. comprising the steps of mixing together in selected amounts a glass frit and conductive particles consisting essentially of tin oxide, the glass frit being present in the amount of 30% to 80% by volume, applying said mixture to a surface of a substrate, firing said coated substrate in an inert atmosphere to a selected temperature between approximately 850° C. and 1150° C. at which the glass softens but below the point at which the tin oxide melts, and cooling the coated substrate to form a layer of glass bonded to the substrate and having conductive particles of tin oxide embedded in and dispersed throughout the glass.
Claim 19
Dependent Claim
39 words
The method in accordance with claim 15 in which the tin oxide is present in the amount of 40% to 70% by volume and the coated substrate is fired to a temperature between approximately 850° C. and 1100° C.
Claim 20
Dependent Claim
39 words
The method in accordance with claim 15 in which the tin oxide is present in the amount of 40% to 60% by volume and the coated substrate is fired to a temperature between approximately 850° C. and 1100° C.
Claim 21
Dependent Claim
40 words
The method in accordance with claim 15 in which the glass frit and tin oxide are mixed with a vehicle suitable for applying the mixture to the substrate, and after the mixture is applied to the substrate it is dried.
Claim 22
Dependent Claim
26 words
The method in accordance with claim 18 in which prior to firing the coated substrate it is heated to burn off the vehicle in the mixture.
Claim 23
Dependent Claim
24 words
The method in accordance with claim 19 in which the coated substrate is heated to 350° C. in air to burn off the vehicle.
Claim 24
Dependent Claim
26 words
The method in accordance with claim 19 in which the coated substrate is heated to 350° C. in a nitrogen atmosphere to burn off the vehicle.
Claim 25
Dependent Claim
24 words
The method in accordance with claim 19 in which the coated substrate is heated to 400° C. in air to burn off the vehicle.
Claim 26
Dependent Claim
25 words
The method in accordance with claim 15 in which prior to mixing the tin oxide with the glass frit the tin oxide is heat treated.
Claim 27
Dependent Claim
33 words
The method in accordance with claim 23 in which the tin oxide is heat treated in a furnace having a nitrogen atmosphere and a peak temperature of 1100° C. for about one hour.
Claim 28
Dependent Claim
41 words
The method in accordance with claim 23 in which the tin oxide is heat treated by heating in an atmosphere of forming gas at about 525° C. for about 10 minutes and then allowed to cool in the forming gas atmosphere.
Claim 29
Dependent Claim
120 words
An electrical resistor of the vitreous enamel type providing a temperature coefficient of resistance within ±2000 ppm/°C. made by mixing together in selected amounts a glass frit and conductive particles consisting essentially of tin oxide, the glass frit being present in the amount of 30% to 80% by volume, applying said mixture to a surface of a substrate, firing said coated substrate in an inert atmosphere to a temperature between approximately 850° C. and 1150° C. at which the glass softens and below the point at which the tin oxide melts, and cooling the coated substrate to form a layer of glass bonded to the substrate and having conductive particles of tin oxide embedded in and dispersed throughout the glass.
Claim 30
Dependent Claim
120 words
An electrical resistor of the vitreous enamel type providing a temperature coefficient of resistance within ±2000 ppm/°C. made by mixing together in selected amounts a glass frit and conductive particles consisting essentially of tin oxide, the glass frit being present in the amount of 30% to 80% by volume, applying said mixture to a surface of a substrate, firing said coated substrate in an inert atmosphere to a temperature between approximately 850° C. and 1150° C. at which the glass softens and below the point at which the tin oxide melts, and cooling the coated substrate to form a layer of glass bonded to the substrate and having conductive particles of tin oxide embedded in and dispersed throughout the glass.
Claim 31
Dependent Claim
40 words
An electrical resistor in accordance with claim 26 in which the tin oxide is present in the amount of 40% to 70% by volume and the coated substrate is fired to a temperature between approximately 850° C. and 1100° C.
Claim 32
Dependent Claim
40 words
An electrical resistor in accordance with claim 26 in which the tin oxide is present in the amount of 40% to 60% by volume and the coated substrate is fired to a temperature between approximately 850° C. and 1100° C.
Claim 33
Dependent Claim
44 words
An electrical resistor made in accordance with claim 26 in which prior to applying said mixture the glass frit and tin oxide are mixed with a vehicle suitable for applying the mixture to the substrate, and after the mixture is applied it is dried.
Claim 34
Dependent Claim
28 words
An electrical resistor made in accordance with claim 29 in which prior to firing the coated substrate it is heated to burn off the vehicle in the mixture.
Claim 35
Dependent Claim
26 words
An electrical resistor made in accordance with claim 30 in which the coated substrate is heated to 350° C. in air to burn off the vehicle.
Claim 36
Dependent Claim
28 words
An electrical resistor made in accordance with claim 30 in which the coated substrate is heated to 350° C. in a nitrogen atmosphere to burn off the vehicle.
Claim 37
Dependent Claim
26 words
An electrical resistor made in accordance with claim 30 in which the coated substrate is heated to 400° C. in air to burn off the vehicle.
Claim 38
Dependent Claim
27 words
An electrical resistor made in accordance with claim 26 in which prior to mixing the tin oxide with the glass frit the tin oxide is heat treated.
Claim 39
Dependent Claim
35 words
An electrical resistor made in accordance with claim 34 in which the tin oxide is heat treated in a furnace having a nitrogen atmosphere and a peak temperature of 1100° C. for about one hour.
Claim 40
Dependent Claim
41 words
An electrical resistor made in accordance with claim 34 in which the tin oxide is heat treated in an atmosphere of forming gas at about 525° C. for about 10 minutes and then allowed to cool in the forming gas atmosphere.
Claim 41
Dependent Claim
66 words
An electrical resistor characterized by providing a relatively low temperature coefficient of resistance and a resistivity between approximately 2.75 K and 7.16 meg ohms/square comprising a ceramic substrate and a layer of resistor material on a surface of said substrate, said resistor material consisting essentially of tin oxide particles dispersed throughout a glass, the glass being present in the amount of 30% to 80% by volume.
Claim 42
Dependent Claim
66 words
An electrical resistor characterized by providing a relatively low temperature coefficient of resistance and a resistivity between approximately 2.75 K and 7.16 meg ohms/square comprising a ceramic substrate and a layer of resistor material on a surface of said substrate, said resistor material consisting essentially of tin oxide particles dispersed throughout a glass, the glass being present in the amount of 30% to 80% by volume.
Claim 43
Dependent Claim
29 words
An electrical resistor in accordance with claim 37 in which the tin oxide particles are present in the resistor material in the amount of 20% to 70% by volume.
Claim 44
Dependent Claim
25 words
An electrical resistor in accordance with claim 38 in which the tin oxide particles are present in the amount of 40% to 60% by volume.
Claim 45
Dependent Claim
29 words
An electrical resistor in accordance with claim 38 in which the tin oxide particles are heat treated prior to said tin oxide particles being mixed with said glass frit.
Claim 46
Dependent Claim
16 words
An electrical resistor in accordance with claim 38 in which the glass is a borosilicate glass.
Claim 47
Dependent Claim
18 words
An electrical resistor in accordance with claim 41 in which the glass is an alkaline earth borosilicate 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) | 1986-08-08 | 1987-02-07 | 1987-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-08 | 1991-02-07 | 1991-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-08 | 1995-02-07 | 1995-08-09 | $7700.00 | Window Closed / Lapsed |