Quantitative Investigation of the Chemical Shrinkage Stress in Flip Chip using a 3D Moire Interferometry System

摘要

Thermo-mechanical reliability is a key issue of IC packaging. In this paper, the chemical shrinkage stress caused by the underfill curing is quantitatively investigated: DSC test result provides the basis for the determination of temperature profile for the curing of underfill. The 3D deformation of the flip chip during the underfill curing process is measured with 3D Moire interferometry system. Also a simple theoretical model is set up for this problem, DMA test provide the necessary parameters for this model. The experimental and theoretical results agree well with each other, both results show that the chemical shrinkage stress is fairly small when compared with the thermal residual stress, so this part of residual stress can be neglected in the commonly used finite element analysis (FEA) model.