US 11,927,431 B1
Firing switch for compact capacitive discharge unit
James D. Lucas, Chanhassen, MN (US); and Eric M. McDonough, Minneapolis, MN (US)
Assigned to Northrop Grumman Systems Corporation, Falls Church, VA (US)
Filed by Northrop Grumman Systems Corporation, Falls Church, VA (US)
Filed on Dec. 10, 2019, as Appl. No. 16/602,843.
Claims priority of provisional application 62/917,491, filed on Dec. 11, 2018.
Int. Cl. F42B 3/12 (2006.01); F42C 11/04 (2006.01); F42D 1/05 (2006.01); H01L 23/498 (2006.01); H05K 1/18 (2006.01)
CPC F42B 3/124 (2013.01) [F42C 11/04 (2013.01); F42D 1/05 (2013.01); H01L 23/49811 (2013.01); H05K 1/181 (2013.01); F42B 3/121 (2013.01); H05K 2201/10015 (2013.01); H05K 2201/10166 (2013.01); H05K 2201/10522 (2013.01); H05K 2201/10628 (2013.01); H05K 2201/10757 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A capacitive discharge unit (CDU) for detonating an explosive in response to a control signal, the CDU comprising:
an exploding foil initiator (EFI); a trigger circuit;
a firing capacitor; and
an insulated-gate bipolar transistor (IGBT) firing switch, the IGBT firing switch including:
a die encased in a package, the die having an IGBT chip; and
a gate pin, a collector pin, and an emitter pin, the collector pin and emitter pin each including one or more individual pins having a first end portion electrically connected to the die and an opposite end portion extending outward from the package, and the collector pin having a first end electrically connected to one or more substrate layers of the die and an opposite end extending outward from the package, wherein the gate pin is positioned adjacent to, at most, one of the collector pin and the emitter pin, and wherein the collector and emitter pins are positioned on opposing sides of the package; and
a board for mechanically and electrically supporting the trigger circuit, the EFI, the firing capacitor, and the IGBT firing switch, the CDU having an axial length defined by an ordered arrangement along a CDU axis of two or more of the EFI, the firing capacitor, and the IGBT firing switch, wherein the trigger circuit is offset from the CDU axis such that the trigger circuit does not contribute to the axial length;
wherein an axial length of the IGBT firing switch is not more than 35% of the axial length of the CDU.