Dynamic Warpage Characterization and Reflow Soldering Defects of BGA Packages

High temperature reflow dynamic warpage deformation of BGA packages with various sizes and preconditioning is analyzed using Shadow Moire and Laser reflection techniques to characterize their warpage behavior. A controlled-gap experiment to simulate the separation between solder balls and their underlying solder pastes on substrates caused by package warping was developed to determine the gap effect on reflow defects such as head-in-pillow (HiP) and non-wet open (NWO).