Drop analysis of 3D SiP with Through Silicon Via

Mechanical impact or shock resulted from inevitably transport or usage of electronic equipment, may cause great stress and strain in the electronic package, even lead to the failure of electronic equipment, so it's of great significance to explore the mechanical behavior of electronic packaging under drop/impact. In all kinds of package, 3D System in Package with Through Silicon Via has become a hot research field. Many researches have been done on the drop analysis of solder ball on the PCB substrate, but few vibration and drop analysis on the Micro-bump of Through Silicon Via related to the practical fabrication process and size has been proposed. In this paper, a finite element dynamic model of the structure is established by using HyperMesh and LS-DYNA for a typical TSV package structure. We discussed the influence of different drop directions on the dynamic response of the structure, the effect of the strain rate property of solder balls, the effect of underfill in the solder ball layer and TSV layer, and the reliability of TSV in different numbers of solder balls. The results show that the stress of solder balls is the largest under the direction of the chip-down, the strain rate effect of solder balls can't be neglected under the impact load, the underfill can effectively reduce the maximum impact stress of solder balls and TSV, and increasing the number of solder balls can reduce the maximum stress, but not too much. The results of this study can provide the basis for improving the reliability of TSV package.