BOARD MOUNTED RELIABILITY CHARACTERISTICS OF FLIP-CHIP PBGA

摘要

Following its initial use in pagers and two way radios in the early 1990s, overmolded wire-bond based plastic ball grid array (PBGA) packages have proliferated into a variety of applications. These applications include those with severe environments such as automotive and outdoor telecommunications products. In most cases, BGA exhibits diminished board mounted reliability during thermal cycling when compared to the more compliant peripherally leaded packages. Therefore, many solder joint reliability investigations have been performed to characterize PBGA performance. More recently, PBGAs employing flip-chip (FC) die to package interconnect have been deployed by several companies. For reliability and cost reasons, the current generation of FC PBGA packages are generally limited to computing and telecomm applications. This paper will investigate the board-level reliability characteristics of flip-chip based PBGAs with body sizes ranging from 14X22 to 33 mm square. Data taken at 0 to 100? with two dwell times as well as -40 to 125℃ will be presented and compared to that of ceramic BGA. The relevant factors affecting board mounted reliability of FC PBGA as well as a unique solder joint failure mode that was observed will be discussed. The data shows that the FC PBGA configurations tested are suitable for all but the most severe applications. Performance of FC PBGAs with heat sinks will also be addressed.