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

Chen Li,Mangu Jia,Pengyu Jia,Yanan Xue,Boshan Sun,Jijun Xiong

doi:10.1109/access.2020.3027951

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°C, the temperature transmitted to the C–V conversion circuit board can be kept below 60°C; this ensures normal operation of the C–V converter circuit. The developed sensor can record pressure values from room temperature to 350 °C. 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.

Highlights

With advancements in scientific research, aerospace, and other fields, high-temperature pressure sensors are being widely used in various applications [1]–[8], especially those that involve oil wells, ships, water conservancy and hydropower, aerospace, and military satellites. Sensors used in such applications must be able to withstand high temperatures and provide accurate measurements, which is critical for normal operation of other subsystems
In 2018, Tan et al [9] studied an infinite passive high-temperature pressure sensor based on HTCC (High Temperature Co-fired Ceramics)technology
A thermal insulation material, being filled between the circuit board and the rear-end shell, when the air intake temperature reaches 350◦C, the temperature transmitted to the C–V conversion circuit board can be kept below 60◦C

Summary

Introduction

With advancements in scientific research, aerospace, and other fields, high-temperature pressure sensors are being widely used in various applications [1]–[8], especially those that involve oil wells, ships, water conservancy and hydropower, aerospace, and military satellites. INDEX TERMS Capacitive pressure sensor, ceramic sensitive chip, thermal insulation, high temperature environment application. C. Li et al.: Capacitive Pressure Sensor With Integrated Signal-Conversion Circuit for High-Temperature Applications pressures of 0–2 kPa, and has a sensitivity of 21 mV/MPa. due to limitations in terms of its material properties, this sensor can function only at low temperatures.

Results

Conclusion