Characterization of flip chip interconnect failure modes using high frequency acoustic micro imaging with correlative analysis

New acoustic micro techniques have been developed for the analysis of flip chip solder interconnects. Previous techniques were only appropriate to generally evaluate the chip to bump interface. The new methods involve using acoustic micro imaging to analyze the solder joint through the entire thickness of the solder ball at the solder/substrate interface and analyzing the interface between the silicon and the bond pad. We have found laminar cracks under the bond pad and in the surrounding glassivation layers on the silicon die in some samples. This paper will include a description of the analysis methods, the acoustic signatures of defects in flip chip interconnects and supporting correlative analyses