Area-Array Electronics Models and Survivability Under 50,000G Shock Loads
Authors: Pradeep Lall, Kewal Patel, Ryan Lowe, Mark Strickland, Dave Geist, Randall Montgomery, and Jim Blanche Company: Auburn University and NASA Marshall Space Flight Center Date Published: 10/14/2012
Abstract: Electronics in aerospace applications may be subjected to very high g-loads during normal operation. A novel micro-coil array interconnect has been studied for increased reliability during extended duration aerospace missions in presence of high-g loads. Ceramic area-array components have been populated with micro-coil interconnects. The micro-coil spring (MCS) is fabricated using a beryllium copper wire post plated with 100 µin of Sn63Pb37, 50 mils in height with a diameter of 20 mils. Board assemblies have been subjected to high g-loads in the 0°, horizontal orientation. The board assemblies are daisy chained. Damage initiation and progression in interconnects has been measured using in-situ monitoring with high speed data-acquisition systems. Transient deformation of the board assemblies has been measured using high-speed cameras with digital image correlation. Multiple board assemblies have been subjected to shock tests till failure. Peak shock pulse magnitude ranges from 1,500g typical of JEDEC standard, to very high g-levels of 50,000g. The MCS interconnects are daisy chained and failures are measured using electrical continuity. A finite element model using explicit global to local models has been used to study interconnect reliability under shock loads. Models have been correlated with experimental data. The reliability performance of micro-coil interconnects has been compared to column interconnects. Results have shown that the micro-coil spring array has a higher reliability than the ceramic column grid array (CCGA). Failure modes have been determined.