High Accuracy MEMS Pressure Sensor Based on Quartz Crystal Resonator

This paper reports a high accuracy oil-filled MEMS absolute pressure sensor based on quartz crystal double-ended tuning fork (DETF) resonator, which is suitable for application in ocean, petroleum, meteorological, aerospace and spacecraft field, etc. The pressure sensing unit is mainly composed of DETF resonator, diaphragm and back cavity structure. These pieces are all fabricated by quartz crystal using MEMS process, and are bonded together as ‘sandwich’ structure to form the absolute pressure sensing unit using glass frit under low temperature and vacuum condition. This process could effectively eliminate the thermal stress effect and form the reference vacuum cavity. The isolated packaged pressure sensor is composed of corrugated stainless steel diaphragm, silicone oil, pressure sensing unit and ceramic base package. The experimental results show that the accuracy is up to ±0.033% FS in the pressure range 0~300 kPa over the temperature range −20 °C~+45 °C