Applications of XPS and TOF-SIMS in the investigation of PCB package delamination

In this study, die to printed circuit board (PCB) interfacial failure was investigated. Instead of using conventional Scanning Electron Microscope - Energy Dispersive X-ray Spectroscopy (SEM-EDX) and Fourier Transform Infrared Spectroscopy (FTIR) for bulk material analysis, advanced surface analysis techniques such as X-ray Photoelectron Spectroscopy (XPS) and Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) were employed to analyze the delamination between die and PCB. High percentage of siloxane bond was revealed at the failure interface using XPS. TOF-SIMS was used to further validate that the siloxane bond belongs to Polydimethylsiloxane (PDMS) from blue tape. Combining both XPS and TOF-SIMS analysis techniques, it was shown that the die to PCB delamination was attributed to PDMS contamination.