Finite element analysis of micro-scale CSP solder joint in 3D packaging under random vibration

In this study three-dimensional finite analysis models of 3D micro-scale chip scale package (CSP) solder joints were set up. The stress-strain distribution of micro-scale CSP solder joints was obtained by finite element analysis under the condition of random vibration load. The influence of different solder, pad diameter and solder joint volume on the stress-strain of micro-scale CSP solder joint was analyzed. The results show that the maximum equivalent stress of SAC387 is the largest in SAC305, SAC387, 63Sn37Pb and 62Sn36Pb2Ag four kinds of solder joint materials under random vibration condition. When the maximum diameter of the joint is reduced from 0.105mm to 0.085mm, the stress and strain in the micro-scale CSP solder joint show an increasing trend. When the diameter of the pad is reduced from 0.09mm to 0.06mm, the stress and strain in the micro-scale solder joint show an increasing trend.