Highly Integrated EFI Chip Assembly for Reliable Use after Multi- andPyro-Shock Events

ABSTRACT: The Tanner EFI chip assembly, mass fabricated in batches of 1800 devices on a 4-in PC-board substrate, was tested at LANL with recorded slapper velocity exceeding 4000 meters/sec. The high-fill factor is coupled with a PC-board process that allows protruding header pins to be soldered into plated blind vias eliminating wire bonds completely. This contact architecture provides a robust electromechanical connection able to withstand high G-force exposure. The EFI chip is manufactured using a MEMS process that is intimately coupled with industry standard PCB manufacturing.This MEMS process enables a lithographically defined barrel which can survive high G environments due to its 100 micro-gram mass.The Tanner EFI chip assembly is fully customizable during fabrication allowing for the adjustment of important design parameters to vary output performance, including: slapper density/speed, height of barrel stand-off, and foil consistency/resistance. In the proposed Phase I, Tanner will develop and demonstrate structural simulations designed to portray the improved shock survivability of this highly integrated monolithic EFI chip design, and to fabricate and test preliminary high-G robust EFI device.; BENEFIT: Improvements in the fundamental EFI chip assembly mechanism can be reliably optimized in a highly stressing G-force environment. High-G characterization of the PCB manufacturing process will enable better understand of high-G shock survivability and failure modes of accompanying EFI fireset PCB substrates, and ancillary electronics.The FR4 PC-board substrate, being less dense than typical EFI substrates, provides a mass with significantly lower susceptibility to shear-stress concentration. With the two header pins partially embedded into the EFI chip assembly, the mechanically strength of the Tanner design is much greater. Most importantly, our design avoids any wire-bonding that is fragile and unable to reliably transport fast-rise time high current to efficiently activate an exploding foil.