Impact of packaging design on reliability of large die Cu/low-κ (BD) interconnect

This paper presents the study on the effect of low k stacked layer, chip pad design structures, and shift pad design TM of a large die size Cu/low kappa (BDtrade) chip for improving assembly and reliability performance on organic buildup substrate FCBGA (FlipChip ball grid array). Bump shear characterization has been performed on the integrity of different stacked layer and pad structure, supported by bump shear modeling analysis. Initial reliability testing was performed on assembled package to identify the best choice of design and finally implemented on the reliability test vehicle for verification. In addition, a potential chip crack problem due to excessive warpage in FCBGA with large die assembly is examined and a simple failure criterion is proposed.