Methods to improve burst uniformity and efficiency in exploding foil initiators

Patent metadata

Field	Value
Publication number	US-11209249-B2
Application number	US-201816639974-A
Country	US
Kind code	B2
Filing date	Aug 17, 2018
Priority date	Aug 21, 2017
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

Exploding foil initiator apparatus, system, and method that improve the current density in the bridge region by modifying the shape and dimensions of the bridge and related components. The exploding foil initiator reduces burn-back by making areas of the bridge thicker except directly under the flyer. The exploding foil initiator boards are built so the flyer is not connected to the rest of the top cover-lay. This avoids losing energy due to the flyer having to tear away from the solid cover-lay.

First claim

The invention claimed is:

1. An exploding foil initiator apparatus, comprising:
a bridge, said bridge having a first side, a second side, a bridge width, a bridge shape, and bridge dimensions;
a first extension of said bridge adjacent said first side that has a first extension width wherein said bridge width and said first extension width are the same;
a second extension of said bridge adjacent said second side that has a second extension width wherein said bridge width and said second extension width are the same;
a first upper electrical conductor portion connected to said first extension of said bridge that has a first electrical conductor width wherein said first electrical conductor width is greater than said bridge width;
a second upper electrical conductor portion connected to said second extension of said bridge that has a second electrical conductor width wherein said second electrical conductor width is greater than said bridge width;
an insulator under said bridge, under said first extension of said bridge on said first side, under said second extension of said bridge on said second side; under said first upper electrical conductor portion connected to said first extension of said bridge, and under said second upper electrical conductor portion;
a lower conductor under said insulator;
a jumper connecting said first upper electrical conductor portion, said second upper electrical conductor portion, said insulator, and said lower conductor;
a flyer on said bridge;
a current path in said bridge; and
a fireset connected to said first extension of said bridge and said second extension of said bridge that produces an applied current pulse;
wherein said fireset produces said applied current pulse that produces a current density having a peak of applied current in said current path in said bridge; and
wherein said bridge shape, said bridge dimensions, and said current path are such that said peak of applied current occurs in said bridge.

2. The exploding foil initiator apparatus of claim 1
wherein said bridge shape and said bridge dimensions are such that when said peak of applied current occurs in said current path in said bridge and said flyer leaves said bridge said flyer remains intact.

3. The exploding foil initiator apparatus of claim 2
wherein said bridge has a melt temperature and
wherein said bridge shape and said bridge dimensions are chosen to stay below said melt temperature when said fireset produces said applied current pulse in said bridge.

4. The exploding foil initiator apparatus of claim 1
wherein said lower conductor under said insulator is patterned to produce uniform current density in said bridge.

5. A method of making an exploding foil initiator, comprising the steps of:
providing a bridge having a first side, a second side, a bridge width, a bridge shape, and bridge dimensions;
providing a first extension of said bridge adjacent said first side that has a first extension width wherein said bridge width and said first extension width are the same;
providing a second extension of said bridge adjacent said second side that has a second extension width wherein said bridge width and said second extension width are the same;
providing a first upper electrical conductor portion connected to said first extension of said bridge that has a first electrical conductor width wherein said first electrical conductor width is greater than said bridge width;
providing a second upper electrical conductor portion connected to said second extension of said bridge that has a second electrical conductor width wherein said second electrical conductor width is greater than said bridge width;
providing an insulator under said bridge, under said first extension of said bridge on said first side, under said second extension of said bridge on said second side; under said first upper electrical conductor portion connected to said first extension of said bridge, and under said second upper electrical conductor portion;
providing a lower conductor under said insulator;
providing a jumper connecting said first upper electrical conductor portion, said second upper electrical conductor portion, said insulator, and said lower conductor;
positioning a flyer on said bridge;
providing a current path in said bridge; and
connecting a fireset to said first extension of said bridge and said second extension of said bridge that produces an applied current pulse;
wherein said fireset produces said applied current pulse that produces a current density having a peak of applied current in said current path in said bridge; and
wherein said bridge shape, said bridge dimensions, and said current path are such that said peak of applied current occurs in said bridge.

6. The method of making an exploding foil initiator of claim 5
wherein said bridge has a melt temperature and
wherein said bridge shape and bridge dimensions are chosen to stay below said melt temperature when said fireset produces a current density having a peak of applied current in said current path in said bridge.

7. The method of making an exploding foil initiator of claim 5 wherein said shape and said dimensions of said bridge are such that they allow said flyer to be intact when said flyer leaves said bridge.

8. The method of making an exploding foil initiator of claim 5 wherein said lower conductor under said insulator is patterned to produce uniform current density in said bridge.

9. An exploding foil initiator apparatus, comprising:
a bridge, said bridge having a first side, a second side, a bridge width, a bridge thickness, a bridge shape, and bridge dimensions;
a first extension of said bridge adjacent said first side that has a first extension width, wherein said bridge width and said first extension width are the same and has a first extension thickness wherein said first extension thickness is greater than said bridge thickness;
a second extension of said bridge adjacent said first side that has a second extension width, wherein said bridge width and said second extension width are the same and has a second extension thickness wherein said second extension thickness is greater than said bridge thickness;
a first upper electrical conductor portion connected to said first extension of said bridge that has a first electrical conductor width wherein said first electrical conductor width is greater than said bridge width;
a second upper electrical conductor portion connected to said second extension of said bridge that has a second electrical conductor width wherein said second electrical conductor width is greater than said bridge width;
an insulator under said bridge, under said first extension of said bridge on said first side, under said second extension of said bridge on said second side; under said first upper electrical conductor portion connected to said first extension of said bridge, and under said second upper electrical conductor portion;
a lower conductor under said insulator;
a jumper that connects said first upper electrical conductor portion, said second upper electrical conductor portion, said insulator, and said lower conductor;
an upper electrical lead connected to said first upper electrical conductor portion;
a lower electrical lead connected to said lower ground electrical conductor;
a current path in said bridge;
a flyer on said bridge; and
a fireset connected to said upper electrical lead and to said lower electrical lead that produces a current density having a peak of applied current in said current path in said bridge,
wherein said bridge shape, said bridge dimensions, and said current path are such that said peak of applied current occurs in said bridge.

10. The exploding f

Assignees

• L Livermore Nat Security Llc

Inventors

• Rhodes Mark
• May Chadd M

Classifications

• F42C19/12

  electric · CPC title

• F42B3/127

  the case having burst direction defining elements · CPC title

• F42B3/124 Primary

  characterised by the configuration or material of the bridge (F42B3/13 takes precedence) · CPC title

• F42B3/121

  Initiators with incorporated integrated circuit · CPC title

• F42B3/11

  characterised by the material used, e.g. for initiator case or electric leads (F42B3/107 takes precedence) · CPC title