Low-temperature drift and high-accuracy MEMS pressure sensor with inverted package structure

For the application requirements in the temperature range of -40 to 150℃, A pressure sensor with high accuracy and low-temperature drift has been developed by using MEMS (MEMS, Micro-Electro-Mechanical System) technology and SOI (Silicon-On-Insulator) substrate. The silica isolation of SOI is utilized to address the electrical failure of the force-sensitive chip at elevated temperatures. The ion implantation process was optimized to reduce output drift and accuracy drift of the chip with temperature. The back bottom pressure-bearing flushed package structure is designed, and the glass sintering process is used to reduce the lumen effect and improve the frequency response and anti-interference capability of the sensor. The test results show that the sensor has an accuracy error of ±0.2% of Full Scale (FS) over the temperature range of -40 to 150°C. The sensor displays the thermal sensitivity drift of -0.07% FS and the thermal zero drift of +0.006% FS.