Bond failures on hybrid-WSI substrates

Modern hybrid wafer scale integration (HWSI) devices increasingly employ flip-chip bonding. Thermal cycling tests do not model the true operating conditions of HWSI devices, as the differences in operating temperatures of chips and substrate are neglected. These temperature differences resemble the most important thermal bond failure mechanism. An approach to the modeling of true operating conditions is presented, and its impact on the reliability of flip-chip bonds in silicon-on-silicon assemblies is assessed.