Board-level Reliability Design

摘要

Detailed solder joint fatigue models with life prediction capability are established for three types of CSPs. Modified Darveaux's approach is applied with unique correlation constants for TFBGA, QFN and WL-CSP package families. The correlation between modeling and thermal cycling test is good. The relative fatigue life predictions are consistent with typical experimental observations. Generally, for enhanced solder joint reliability of CSPs, it is recommended to choose smaller die size, thinner die, higher solder joint standoff, bigger solder pad opening size and thinner boards. Fatigue modeling can be applied for design analysis of solder joint reliability to save cost, time and manpower in performing the DOE studies by thermal cycling tests. This is especially useful for new package development. Fatigue modeling also can be integrated with electrical simulation and thermal analysis for a complete board-level reliability design solution.