Delamination Failure Analysis on FCBGA Package with Heat Spreader

With continuous increase in computing demand in almost all semiconductor field, Flip-chip ball grid array (FCBGA) packages are widely used. Most of failure analysis on FCBGA were focused on the thermal performance and reliability of thermal interface materials (TIM) in FCBGA package. In this study, we focused on the delamination failure of the FCBGA package with heat spreader after high temperature operating life (HTOL) test. Combined X-ray photoelectron spectroscopy (XPS) and Time-of-flight secondary ion mass spectrometry (TOFSIMS) technique has been found to be an effective method for surface contamination analysis on FCBGA packages. The results revealed that there is indeed a thin siloxane related contamination on top surface of the failed heat spreader, causing the delamination failure after HTOL test. In addition, it is suggested that this failure may be reworkable by applying Ar/O2 plasma cleaning. Further verification is in progress.