"Flip-Chip Package Substrate Solder Issue"

By Abhay Maheshwari and Austin Lesea

Alpha particle emission in close proximity to the device circuitry is minimized by following Xilinx low alpha solder requirements on package substrate
pads. One flip-chip packaging vendor’s failure to comply with these requirements has resulted in contamination by high alpha solder causing possible
soft errors due to flipped device configuration bits. This white paper provides an overview on soldering material, describes the specific soldering problem,
and offers some solutions.

January 14, 2004