Resolving Deformation Field Near Corners and Interfaces by Phase Shifting Moiré Interferometry

Although it is challenging to resolve deformation fields near corners or interfaces for layered structures, it is essential for a measurement technique to deal with of stress/strain concentrations, strain gradients, failure initiation and growth, local microstructure evolutions, etc. In this study, an innovative phase shifting technique is proposed, coupled with an image processing software, to investigate several interesting problems in electronic packaging. A power plastic IC package and a flip-chip package are selected to demonstrate the powerfulness of the system. A nanoscale deformation field is obtained for both the corner area and the underfilled containing flip-chip solder balls.