Abstract
ABSTRACT Due to the complicated geometry and material properties of the assembly, the warpage of FC-PBGA (Flip Chip Plastic Ball Grid Array) after solder reflow process has been studied. Accounting for the plastic, creep and temperature-dependent material behaviors of underfill, a detailed three-dimensional finite element model is established and performed by ANSYS program. To verify the computed results, the experiments for warpage measurement are also conducted. Good agreement between the computed results and experimental data shows the merits of the analysis model. By this model, the effects of substrate and chip dimensions on the warpage of FC-PBGA are also presented. Finally, the necessity of cooling time as suggested by JEDEC (Test Method A113-A) after solder reflow is also evaluated. Those would be of help for design engineer to reduce the warpage of FC-PBGA.