A study of warpage of electronic package and effect of reflow

Warpage is a concern in the microelectronics industry. The accurate estimation of package warpage is the important factors to improve the package reliability. The purpose of this study is to select the best analytical model for prediction of warpage of microelectronic packages. This study compares the warpage prediction from corrected Suhir's theory and classical laminate theory. The warpage prediction was performed based on both analytical models and compared with the experimental and finite element analysis (FEA) result. Package warpage is highly dependent on underfill material property. Secondary purpose of this study is to investigate die substrate assembly warpage behavior after cure and reflow temperature exposure due to the underfill material property change. The result indicates that Laminate theory provides the better prediction of warpage when underfill layer thickness is comparable with die and substrate layer thickness. Also it is shown that package warpage changes with change in stress free temperature.