US4976200A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tungsten bridge for the low energy ignition of explosive and energetic materials
Assignee: National Technology and Engineering Solutions of Sandia LLC
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Filing: 1988-12-30
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Granted: 1990-12-11
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Expires: 2008-12-30
Abstract
Abstract A tungsten bridge device for the low energy ignition of explosive and energetic materials is disclosed. The device is fabricated on a silicon-on-sapphire substrate which has an insulating bridge element defined therein using standard integrated circuit fabrication techniques. Then, a thin layer of tungsten is selectively deposited on the silicon bridge layer using chemical vapor deposition techniques. Finally, conductive lands are deposited on each end of the tungsten bridge layer to form the device. It has been found that this device exhibits substantially shorter ignition times than standard metal bridges and foil igniting devices. In addition, substantially less energy is required to cause ignition of the tungsten bridge device of the present invention than is required for common metal bridges and foil devices used for the same purpose.
Inventors
- 👤 David A. Benson
- 👤 Robert W. Bickes, Jr.
- 👤 Robert S. Blewer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:36
CPC Classifications
F; F42; F42B; F42B3/00; F42B3/10; F42B3/195; F42B3/198; F42B3/12; F42B3/13
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
102 words
A tungsten bridge device for the low energy ignition of explosive and energetic materials, said device comprising: a substrate; an electrical bridge on the surface of and substantially electrically insulated from the substrate, said bridge consisting of: a first bridge-shaped layer of an insulating material in contact with said substrate, said material intrinsically conducting when heated, and a second layer of tungsten selectively deposited only over said entire first layer; a pair of conductive lands located over said tungsten layer, said lands being spaced from each other; and a pair of electrical conductors, one conductor being connected to each of said lands.
Claim 2
Dependent Claim
102 words
A tungsten bridge device for the low energy ignition of explosive and energetic materials, said device comprising: a substrate; an electrical bridge on the surface of and substantially electrically insulated from the substrate, said bridge consisting of: a first bridge-shaped layer of an insulating material in contact with said substrate, said material intrinsically conducting when heated, and a second layer of tungsten selectively deposited only over said entire first layer; a pair of conductive lands located over said tungsten layer, said lands being spaced from each other; and a pair of electrical conductors, one conductor being connected to each of said lands.
Claim 3
Dependent Claim
21 words
A tungsten bridge device as claimed in claim 1 further comprising an additional insulating layer between said substrate and said bridge.
Claim 4
Dependent Claim
22 words
A tungsten bridge device as claimed in claim 1 wherein said insulating material of said first layer of said bridge is silicon.
Claim 5
Dependent Claim
14 words
A tungsten bridge device as claimed in claim 2 wherein said lands comprise aluminum.
Claim 6
Dependent Claim
14 words
A tungsten bridge device as claimed in claim 4 wherein said substrate comprises silicon.
Claim 7
Dependent Claim
18 words
A tungsten bridge device as claimed in claim 5 wherein said first layer of said bridge comprises silicon.
Claim 8
Dependent Claim
26 words
A tungsten bridge device as claimed in claim 3 wherein said tungsten layer is a thickness sufficient to produce a resistance of less than 10 ohms.
Claim 9
Dependent Claim
23 words
A tungsten bridge device as claimed in claim 3 wherein said tungsten layer is from about 0.1 to about 0.5 micrometers in thickness.
Claim 10
Dependent Claim
23 words
A tungsten bridge device as claimed in claim 8 wherein said first layer is from about 1 to about 3 micrometers in thickness.
Claim 11
Dependent Claim
14 words
A tungsten bridge device as claimed in claim 4 wherein said substrate comprises sapphire.
Claim 12
Independent Claim
75 words
A method of manufacturing metal film bridge devices for the ignition of explosive and energetic materials comprising the steps of: defining a bridge shape from a first material on an insulating substrate, said first material being an insulator that intrinsically conducts when heated; selectively depositing a layer of tungsten over the entire bridge shape; and depositing a pair of conductive lands over the tungsten layer such that said lands are spaced apart one from another.
Claim 13
Independent Claim
75 words
A method of manufacturing metal film bridge devices for the ignition of explosive and energetic materials comprising the steps of: defining a bridge shape from a first material on an insulating substrate, said first material being an insulator that intrinsically conducts when heated; selectively depositing a layer of tungsten over the entire bridge shape; and depositing a pair of conductive lands over the tungsten layer such that said lands are spaced apart one from another.
Claim 14
Dependent Claim
20 words
A method in accordance with claim 11 wherein said step of depositing a layer of tungsten comprises chemical vapor deposition.
Claim 15
Dependent Claim
19 words
A method in accordance with claim 12 wherein said step of defining a bridge shape comprises integrated circuit processing.
Claim 16
Dependent Claim
27 words
A method in accordance with claim 13 further comprising the step of depositing an oxide layer on the surface of the insulating substrate before said defining step.
Claim 17
Dependent Claim
13 words
A method in accordance with claim 11 wherein said first material is silicon.
Claim 18
Dependent Claim
12 words
A method in accordance with claim 15 wherein said substrate is sapphire.
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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) | 1993-12-10 | 1994-06-11 | 1994-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-10 | 1998-06-11 | 1998-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-10 | 2002-06-11 | 2002-12-11 | $7700.00 | Window Closed / Lapsed |