Capacitive Pressure Sensor With Integrated Signal-Conversion Circuit for High-Temperature Applications

Abstract

In this paper, a capacitive pressure sensor for high-temperature application is proposed. This sensor includes three parts: a capacitive pressure-sensitive chip fabricated from green tapes using lamination technology, a C-V conversion circuit fabricated using high-temperature-resistant electronic components and a PCB board, and a thermal-insulation shell fabricated from a high-temperature-resistant alloy and aerogel. Due to the aerogel, which is a thermal-insulation material, being filled between the circuit board and the rear-end shell, when the air intake temperature reaches 350℃, the temperature transmitted to the C-V conversion circuit board can be kept below 60℃; this ensures normal operation of the C-V converter circuit. The developed sensor can record pressure values from room temperature to 350 ℃. According to the pressure-voltage curves at different temperatures obtained from tests, the sensor's sensitivity is 38 mV/bar, and its repeatability error is less than 1.948%. The results show that the proposed sensor has a high operating temperature and is more reliable and linear than existing sensors. INDEX TERMS Capacitive pressure sensor, ceramic sensitive chip, Thermal insulation, high temperature environment application

Femtosecond Laser Processing Assisted SiC High-Temperature Pressure Sensor Fabrication and Performance Test

“…Capacitive pressure sensors have high resolution and low thermal sensitivity drift [ 11 , 12 ] and can also be miniaturized at low cost. For example, Chen Li reported a split-type pressure sensor based on differential capability with a working temperature range of 25–400 °C and a sensitivity of 9.27 mV/kPa [ 13 , 14 ]. However, capacitive pressure sensors can be affected by parasitic capacitance creating difficulties ensuring measurement accuracy in complex environments.…”