Abstract
Due to the development of technology and the users demand, electronic packaging has been evolved from the traditional single chip package to a multi-chip package, i.e., three-dimensional integrated circuit package. The main advantages of three-dimensional integrated circuit package are small size and lower signal delay, thus it has been broadly used in mobile electronic device. Mobile electronic devices are prone to be dropped because of the portable characteristic. During drop impact, the temperature inside the packages is higher than ambient temperature especially for three-dimensional package. The reacher focused on the drop reliability considering glass transition temperature effect. Nowadays board level drop test is widely used for estimating the reliability of packaging subject to impact. A simulation with Input-G method was adopted to analyze the dynamic behavior of packaging. To analyze the effect of glass transition temperature, a simplified finite element model was constructed and subjected to a temperature loading from 25℃ to 90℃ for thermal stress analysis. The result showed that the reliability of structure with underfill might be worse than that without underfill when the temperature loading is higher than the glass transition temperature, meanwhile the CTE of underfill is too large. To Investigate temperature effect on the failure mode of solder joints during drop impact, the study perform an implicit-to-explicit sequential solution by LS-DYNA 3D and validated with experiment from literature. Finite element model without underfill was established based on real 3D IC integration package to predict the drop life through life prediction model and cumulative damage theory. To investigate the effect on thermal stress analysis and the behavior of drop impact while ambient temperature exceeding glass transition temperature.