Chip Board Package Interaction Reliability for Large Size FCBGA Package

An overview of the major reliability physics of failure for advanced 2.5D/3D/3.5D packages was conducted. Systematic study was performed to assess chip board package interaction reliability of a large size FCBGA package that enables complex heterogeneous integrations. Mechanical test vehicle with multi-level daisy chain structures was designed to accelerate and detect the failures due to the interaction between chip board and package. The stresses in this study include the thermal cycling, monolithic bending, mechanical shock/vibration and biased HAST. The time to failures is analyzed and Weibull based statistical models are used to characterize different failure modes. Finally, finite element analysis (FEA) was performed to guide physical analysis of potential failure locations. Cross-sections are performed to check the integrity of interconnects in high stress zones. These interconnects include the traces/vias in PCB, substrate, BGA joints and C4 bumps, etc. Comprehensive FA was performed to isolate the location of the failures based on the in-situ monitoring. Median time to testing failures was predicted and compared with the modeling data.