WAFER-LEVEL CHIP SCALE FLEXIBLE WIRELESS MICROSYSTEM FABRICATION

Abstract

The paper demonstrates a low-cost flexible wireless microsystem fabrication technology combining the previously developed bumpless RFSOP scheme [1,2] with a special surface cleaning process to assemble a CMOS chip with an organic substrate (SU-8/PDMS) by Au-Au thermocompressive bonds (<200 degrees C). About -15dB return loss and -0.8dB insertion loss @ 40GHz interconnecting structure and above 6MPa bonding strength make the technology practical for flexible wireless microsystem integration. Besides, taking advantage of chemical inertia of Au, a wafer-level sacrificial release process is performed for the low-cost fabrication.