Development of MEMS Pressure Sensor with High Proof Pressure for Adjustable Ranges

The various application conditions of MEMS pressure sensors require achieving a wide range of specific parameters. The ability to save pressure sensor by repeated proof pressure is one of the important requirements. The research presents a new microassembly design for the piezoresistive pressure sensor chip for adjustable differential pressure ranges up to 10...60 kPa. The microassembly design contains stops on both sides of the chip to increase the proof pressure to Pproof = 1.5 MPa. Additionally, the microassembly also allows for significant improvement of mechanical decoupling of chip from packing and all existing mechanical connections. The research demonstrates the efficiency of using of thermocycling and barocycling for pressure sensor. In results, more than 120 samples of developed pressure sensor have sensitivity S = 0.61 ± 0.15 mV/V/kPa and low error for nonlinearity 2KNL < 0.20%/FS, mechanical hysteresis H < 0.10%/FS and mechanical repeatability R < 0.05%/FS, as well as for the effect of overload pressure dUPproof < 0.30%/FS and all-round compression with pressure of 16 MPa dUcomp < 0.15%/FS. The significant advantage of the microassembly design for removing the residual mechanical stresses (RMS) is also summarized in the achievement of relatively low uncompensated error for long-term stability during 1 year for the zero signal dU0 stab < 0.15 %/FS and sensitivity dU0 stab < 0.20/FS.