Flip chip has been one of the mainstream technologies in microelectronic packaging, and quality inspection for flip chip has gained more and more attention. Solder bump missing, a typical defect in flip chip, is studied in this paper. The vibration equation of flip chip is deduced based on the vibration model. The influence of defects on the vibration response was described, and the principle of defects inspection for flip chip using modal analysis is presented. The influence of solder bumping missing on the variation of the natural frequencies of flip chip used in the experiments is calculated. Then, the shifting of the natural frequencies of the reference flip chip and flip chips containing defect are simulated and measured in the experiments. The results validates the analytic models, indicating that solder bump missing of the flip chip can be detected using modal analysis. Therefore, the inspection technique can be used to detect defects for flip chip.
ZENG Miao LIAO Guanglan ZHANG Xuekun LIU Junchao SHI Tielin.
Defects Detection for Flip Chip Using Modal Analysis[J]. Journal of Vibration and Shock, 2013, 32(6): 24-28