Patent US4794367A successfully refreshed from Google Patents.
US4794367A
Expired / Lapsed
US
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Circuit arrangement
Assignee: Marconi Electronic Devices Ltd
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Filing: 1986-12-18
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Granted: 1988-12-27
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Expires: 2006-12-18
Abstract
Abstract In a thin film circuit, high values of resistance/surface area can be attained by forming the resistive material as a mesh rather than a solid block. The advantages of this are that it gives a high resistance value in a small area and allows laser trimming, both without adversely affecting resistor characteristics such as stability.
Inventors
- 👤 James Ashe
- 👤 Nicholas Chandler
- 👤 Andrew J. Crofts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:09
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/22; H01C17/00; H01C17/22; H01C17/23; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
117 words
A circuit arrangement including an electrically insulating substrate having a top surface supporting a layer of an electrically resistive material in which said layer is provided with a plurality of closed apertures distributed over its surface, each closed aperture being a recess extending through the thickness of said electrically resistive material and being wholly bounded by the resistive material and extending to said top surface, said resistive material defining a first plurality of electrically parallel paths extending between two terminations and a second plurality of electrically parallel paths which form a plurality of cross linkages between the first plurality of paths, such that said plurality of closed apertures are disposed upon said substrate as a two-dimensional array.
Claim 2
Dependent Claim
117 words
A circuit arrangement including an electrically insulating substrate having a top surface supporting a layer of an electrically resistive material in which said layer is provided with a plurality of closed apertures distributed over its surface, each closed aperture being a recess extending through the thickness of said electrically resistive material and being wholly bounded by the resistive material and extending to said top surface, said resistive material defining a first plurality of electrically parallel paths extending between two terminations and a second plurality of electrically parallel paths which form a plurality of cross linkages between the first plurality of paths, such that said plurality of closed apertures are disposed upon said substrate as a two-dimensional array.
Claim 3
Dependent Claim
21 words
An arrangement as claimed in claim 1 and wherein said apertures are distributed over the entire area of said resistive material.
Claim 4
Dependent Claim
31 words
An arrangement as claimed in claim 1 and wherein said apertures are arranged in a regular way such that the first and second plurality of paths together constitute a regular lattice.
Claim 5
Dependent Claim
15 words
An arrangement as claimed in claim 1, and wherein each of said apertures is rectangular.
Claim 6
Dependent Claim
17 words
An arrangement as claimed in claim 1 and wherein the substrate is an electrically insulating dielectric ceramic.
Claim 7
Dependent Claim
13 words
An arrangement as claimed in claim 5 and wherein the substrate is alumina.
Claim 8
Dependent Claim
14 words
An arrangement as claimed in claim 1 and wherein the resistive material is nichrome.
Claim 9
Independent Claim
140 words
A method of forming a circuit arrangement in which a resistive element has a predetermined value including the steps of forming upon an insulating substrate having a top surface and a layer of resistive material having therein a plurality of closed apertures distributed over the surface of the substrate and extending to said top surface, the apertures being arranged so that the resistive material between them forms a network having a first and second plurality of electrical paths, the first plurality of current paths being electrically parallel and a second set of current paths being in parallel to one another and forming a plurality of cross-linkages between the first set of current paths; and breaking at least one path of the resistive material between adjacent apertures so as to increase the resistance of the resistive element to its predetermined value.
Claim 10
Independent Claim
140 words
A method of forming a circuit arrangement in which a resistive element has a predetermined value including the steps of forming upon an insulating substrate having a top surface and a layer of resistive material having therein a plurality of closed apertures distributed over the surface of the substrate and extending to said top surface, the apertures being arranged so that the resistive material between them forms a network having a first and second plurality of electrical paths, the first plurality of current paths being electrically parallel and a second set of current paths being in parallel to one another and forming a plurality of cross-linkages between the first set of current paths; and breaking at least one path of the resistive material between adjacent apertures so as to increase the resistance of the resistive element to its predetermined value.
Claim 11
Dependent Claim
78 words
A method of forming a circuit arrangement as claimed in claim 8 and wherein the step of forming upon an insulating substrate a layer of resistive material having therein a plurality of closed apertures distributed over the surface of the substrate includes the steps of; forming a continuous layer of resistive material upon an insulating substrate, and forming a plurality of closed apertures in said layer of resistive material by selective removal of areas of said resistive material.
Claim 12
Dependent Claim
26 words
A method of forming a circuit arrangement as claimed in claim 8 and wherein the resistive material between the apertures is formed as a regular lattice.
Claim 13
Dependent Claim
20 words
A method as claimed in claim 8 and wherein the link or links is broken by means of a laser.
Claim 14
Dependent Claim
31 words
A method as claimed in claim 8, and wherein each closed aperture is formed by means of an ion milling technique which selectively removes part of the layer of resistive material.
References Cited (Backward Citations)
GB696207A
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GB1566151A
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US4294648A
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GB2132030A
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US4486738A
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GB2131625A
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GB2154373A
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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) | 1991-12-27 | 1992-06-27 | 1992-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-27 | 1996-06-27 | 1996-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-27 | 2000-06-27 | 2000-12-27 | $7700.00 | Window Closed / Lapsed |