3D Integration Technologies for Miniaturized Tire Pressure Monitor System(TPMS)

摘要

3D integration of micro electromechanical systems (MEMS) together with integrated circuits (ICs) brings in severalrnspecific requirements. For instance, 3D integration of the different modules that make up a Tire Pressure MonitorrnSystem (TPMS) is a real technological challenge. A TPMS typically consists of a MEMS device, an applicationrnspecific integrated circuit (ASIC), a power supply, a radio and an antenna. As part of the European project e-rnCUBES, a miniaturized TMPS demonstrator is being fabricated in which the MEMS, ASIC and radio devices are 3Drnintegrated into a heterogeneous system. Au stud bump bonding (Au SBB), SnAg micro bumps and Cu/Sn solid liquidrninterdiffusion soldering (SLID) are used for electrical and mechanical interconnection between the individualrnlayers. W filled through silicon vias (TSV) are applied through the transceiver chip whereas two different types ofrnTSVs are demonstrated for the cap wafer of the MEMS device. The maturity of the applied technologies spans fromrnbrand new to well established, but combining these into a single 3D integrated device is nevertheless a significantrnlogistical and technological challenge. As a follow-up to previous publications, this paper will focus mainly on therntechnological studies performed for the Au SBB, the SLID connections and the TSVs for the MEMS cap wafer.rnVisual, electrical and mechanical characterization will be presented, including reliability studies. Some results fromrnthe final miniaturized TPMS demonstrator will also be presented.