Failure localization in IC packages using time domain reflectometry: technique limitations and possible improvements

Our case study has shown the efficiency of isolating failing sites (shorts, opens) in IC packages using TDR and especially sequential comparative TDR analysis, which allowed to overcome some of TDR hardware limitations and to identify the different regions of the DUT. Currently, it's possible to increase the bandwidth of the main standard TDR sources available on the market up to 70 GHz, but the main limitation is due to TDR probes which best bandwidth only reaches 20 GHz. Anyway, TDR technique has already proved to definitively take up its own place in the non-destructive failure analysis flow of FA labs beside SCAT and x-ray ones for most of common IC packages used in semiconductors industry.