Dynamic bending test and simulation of PBGA packages

Solder joints, which serve as mechanical, thermal and electrical interconnections between the electronic packages and the printed circuit board (PCB), are the most vulnerable part in a portable product when the product is subjected to mechanical loading. Therefore, a comprehensive study of mechanics behavior of solder joints is indispensable for understanding the reliability of portable electronic products. JEDEC standards have recommended the procedure and conditions for the board level drop test of portable electronic products. However, it is expensive and time-consuming to run the tests. Also, subsequent analysis is complicated to model the JEDEC drop test. Thus, manufacturers and researchers are trying to develop simpler and cheaper test methods. The use of bend tests instead of drop tests to study the drop impact reliability of PCB assemblies might be one of the solutions. In this paper, reliability of solder joints using 4-point dynamic bending test for the assessment of board level electronic package has been carried out. Finite element model of 4-point dynamic bending test was established and analyzed. The modeling results were validated by the experiment results, which indicates that the numerical simulation methodology developed in this study can be used to extract the details of stress and strain of the critical solder joints under drop/impact loading.