Characterization of PCB expansion using moire interferometry and the impact of expansion variability on the life of solder joints

摘要

Area-array packages such as the Ball-Grid-Array (BGA), Chip-Scale-Package (CSP), and the Direct-Chip-Attach (DCA) are becoming increasingly common at the present time. The major industry roadmaps such as the SIA roadmap indicate a critical rolefor these packages in future applications with large I/O counts. For instance, the SIA roadmap predicts that by the year 2012, complex, high-density area array packages with over 5000 I/Os will be needed.