Tracks: 2018FLEX Full Conference, IC/Hybrid Integration, Integration, Our Funded R&D Projects
A flexible fan-out wafer level packaging (FOWLP) process for heterogeneous integration of high performance dies in a flexible and biocompatible elastomeric package (FlexTrateTM) was used to assemble >600 dies with co-planarity and tilt <1µm, average die-shift of 3.28 µm with σ < 2.23 µm, and die rotation of average of <100 milli-degree with σ < 70 milli-degree. We have also engineered a novel corrugated topography of a stress buffer layer for metal interconnects on FlexTrateTM to mitigate the buckling phenomenon of metal films deposited on elastomeric substrates. Corrugated interconnects were then tested for their mechanical bending reliability, and have shown less than 0.4% change in resistance after bending at 1mm radius for 1000 cycles.