Combination of Modern Test Methods for Thermo-mechanical Deformation Analysis in Flip-Chip-Assemblies

The reliability of flip-chip-interconnects is primarily affected by the thermo-mechanical deformation of the solder ball or bump, which is a consequence of the well-known CTE-mismatch problem. The common approach to determine the stresses and strains for reliability predictions in the critical interconnections is the use of finite elements simulations of the assembly. Simulation results should be verified by experiments in order to prevent systematic errors. A combination of tests and FE-simulations can help to reduce the simulation errors and to verify the computed results. The objective of this work is to apply modern test methods for thermo-mechanical investigations on CSP- and flip-chip-assemblies and to evaluate these quantitatively and qualitatively. Applied test methods were electronic-speckle-pattern-interferometry (ESPI) and a test chip which exhibits specifically designed thin film structures on the chip surface of the flip-chip assembly