Reliability Characterization of Ni-based Microinsert Interconnections for Flip Chip Die on Wafer Attachment and Their Evaluation in Multichip SIMCARD Prototype

Face to face interconnection is an important technology for the assembly of heterogeneously integrated systems; it permits the integration of technologies from disparate backgrounds and allows separate technology optimization prior to assembly. This paper reports work on the optimization of micro-insert technology, which allows the electrical connection between the two systems. SimCard Prototypes have been developed and evaluated in usual and moisture conditions.Thermal cycling of test structures between -40°C and + 85°C has been performed at wafer level and results indicate that the average resistance of the daisy chain observed between the two devices does not change. However, electrical yield of the structures under damping tests @85°C and 85% of humidity decrease significantly as a consequence of the glue degradation. However further damping tests have been realized on the final packaged cards without any deterioration of the prototype.