Claims
- 1. 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.
- 2. A tungsten bridge device as claimed in claim 1 further comprising an additional insulating layer between said substrate and said bridge.
- 3. A tungsten bridge device as claimed in claim 1 wherein said insulating material of said first layer of said bridge is silicon.
- 4. A tungsten bridge device as claimed in claim 2 wherein said lands comprise aluminum.
- 5. A tungsten bridge device as claimed in claim 4 wherein said substrate comprises silicon.
- 6. A tungsten bridge device as claimed in claim 5 wherein said first layer of said bridge comprises silicon.
- 7. 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.
- 8. 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.
- 9. A tungsten bridge device as claimed in claim 8 wherein said first layer is from about 1 to about 3 micrometers in thickness.
- 10. A tungsten bridge device as claimed in claim 4 wherein said substrate comprises sapphire.
- 11. 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.
- 12. A method in accordance with claim 11 wherein said step of depositing a layer of tungsten comprises chemical vapor deposition.
- 13. A method in accordance with claim 12 wherein said step of defining a bridge shape comprises integrated circuit processing.
- 14. 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.
- 15. A method in accordance with claim 11 wherein said first material is silicon.
- 16. A method in accordance with claim 15 wherein said substrate is sapphire.
Government Interests
The present invention relates generally to bridges for igniting explosive materials, and more particularly to a tungsten bridge which may be used as a low-energy igniter for explosive devices. The Goverment has rights in this invention pursuant to Contract No. DE-AC04-76DP00789, between the U.S. Department of Energy and AT&T Technologies, Inc.
US Referenced Citations (10)
Non-Patent Literature Citations (2)
Entry |
R. Blewer et al., "Thick Tungsten Films In Multilayer Conductor Systems: Properties and Deposition Technique", 1984 Proceedings, First International IEEE VLSI Multilevel Interconnection Conference, New Orleans, LA, Jun. 21-22, 1984, pp. 153-158. |
R. Smith et al., "Design of Solid-State Film-Bridge Detonators with Heat Transfer Calculations for Film-Bridge and Hot-Wire Electro-Explosive Devices", NWC TP 6448, Sep. 1983, pp. 1-97. |