Numerical Analysis of 3D CSP MEMS under Thermal Cycle-Impact Coupled Multiphysics Loads

In this article, reliability analysis of 3D CSP micro-electro mechanical system (MEMS) and IC under thermal cycle-impact coupled multiphysics loads was investigated. COMSOL Multiphysics, a finite element software, was used to analyze our device's mechanical behavior under a-55 °C/125 °C thermal cycling and 1500 G at 1 ms with half-sine pulse impact coupled load. In detail, MEMS chip was bonded on a silicon interposer by solder balls and an application specific integrated circuit (ASIC). Thermal stress of single solder joint, whole device, and the simulation of device reliability under different magnitudes and forms of mechanical shock were carried out, respectively. Combining the effects of impact and thermal stress loads, we hope to find out the failure modes of interconnect structures for future design including solder joints and whole device. The stress distribution and deformation of the overall device will be carried out for layout optimization of interconnect structures.