Dynamic Bending Experiment And Numerical Study Of Board Level Electronics Package

Solder joints of mobile electronic products between PCB and microelectronic packages tend to fail during mechanical impact or shock. Therefore, it is critical important to predict mechanical behavior of solder joints for reliability design of electronic products.4-point dynamic bending tests of board level electronics packages were carried out in order to investigate the reliability of solder joints. A high speed camera and the digital image correlation method were used to measure the deflection of the PCB board. A finite element model to simulate the test was built up and was validated by the test data. A parameter study was subsequently implemented.The results show that stress of solder joints and deformation of PCB increases with drop/impact height. When the height reaches 163mm, the increase of stress goes slowness. At certain value of PCB stiffness the peeling stress reaches its peak, and then it decreases with the increase of stiffness. The package installation angel has significant effect on the peeling stress of the solder joints, which suggests that installation angel should be maked small as far as possible in design.The results presented in this paper provide engineers the evolution process of strain and deformation in PCB and stress in solder joints, which are helpful to understand failure mode of solder joints and to do better drop/impact reliability design of mobile electronic products.