倒装片封装基板焊接问题 White Paper: Virtex-II and Virtex-II Pro Families R WP208 (v1.1) January 14, 2004 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 co……