Design Guidance for the Mechanical Reliability of Low-K Flip Chip BGA Package

Flip Chip Ball Grid Array (FCBGA) package has been introduced in recent years to address the needs in the microelectronic packaging industry for increasing performance and I/O density, which offers a cost effective solution with smaller form factor. Furthermore, Cu interconnects with low-k dielectric material were also introduced to reduce power consumption and further enhance device performance. Due to the nature of low-k dielectric material characteristics, it is more sensitive while a package with low-k material subjected to thermal loading stress. This work conducted analyses on various FCBGA package design parameters using 3-D finite element method (FEM) and provided design suggestions while selecting the packaging materials. To demonstrate the appropriateness of the finite element models, the modeling results were also calibrated with experimental package warpage measurements. Based on modeling data it was revealed that certain set of packaging materials would further enhance overall package reliability performance. Basic package design guidelines will be presented upon the findings of this study, which products designers could benefit from the superior power consumption and devices performance offered from the integration of Cu interconnect and low-k dielectric.