Applicability of Existing Reliability Models: Focus on Finite Element Modeling of Various BGA Package Designs and Materials

摘要

The work presented here is one of the key elements of an integrated methodology for predicting reliability inpackaging systems (IMPRPK) developed by Arizona State University (ASU) and Intel. IMPRPK approach is basedon a probabilistic methodology, focusing on three major tasks: (1) Finite Element analysis (FEM) to predict loadingconditions, (2) Characterization of BGA solder joints to identify failure mechanisms and obtain statistical data, and(3) development of a probabilistic methodology to achieve an integrated reliability solution. The focus of this paperis on FEM (task 1), evaluating the effect of package design/form-factor and solder materials on the extent ofdeformation (e.g., inelastic stress/strain and strain energy density) experienced by BGA solder joints. Global andLocal FEM results for two different package designs (Flip-chip and wire-bonded FLI) and two different BGA soldermaterials (lead-free SAC405 and lead-rich eutectic Sn37Pb) are discussed. The FEM results and the applicability ofthe existing reliability models (e.g., energy-based model) to the complex microelectronics packaging systems arevalidated through independent comparison with the accelerated thermal cycled (ATC) test data.