Abstract
A novel glass wafer level chip scaled packaging (WLCSP) structure is proposed herein to resolve the challenge faced by the packaging house to modify their mass-production packaging equipments from an 8″ wafer process to a 12″ one due to the increasing demand of the semiconductor manufacturers 12″ wafer process. The finite element method and parametric analysis are applied to obtain a robust design parameter for the proposed glass WLCSP structure. This novel packaging structure comprises a chip that is first diced from the 12″ wafer and is attached to 8″ glass. Then the conventional 8" WLCSP process can be accomplished on this 8″ glass. After the validation of the solder joint stand-off height, a finite element model is conducted to elucidate the reliability issues of the proposed glass WLCSP. Afterward, a parametric analysis is conducted by integrating the fractional factorial orthogonal array with the reliable solder fatigue prediction finite element models, in order to identify the strength of the main factors. Furthermore, to estimate the impact of the process uncertainty on the proposed novel glass WLCSP structure, the noise factors are further adapted in the parametric analysis. The simulation results show that the robust design parameters could enhance the reliability of the proposed glass WLCSP structure by about 3.5 times, compared to the original design parameters.