Difficulties in the design of high temperature pressure sensors
Pressure sensors are currently the most widely used type of sensor. The traditional pressure sensor is based on a mechanical structure type device, utilizing the piezoelectric effect, the elastic body
The deformation is converted to the corresponding pressure. With the development of semiconductor technology and MEMS technology, the pressure sensor performance has been greatly improved, not only small size, light weight, and power
It consumes less, and has higher accuracy, stability and reliability, which greatly expands its application market. High temperature pressure sensor is mainly used to solve various gases in high temperature environment
The measurement of liquid pressure is widely used in boilers, pipelines, pressures in high-temperature reaction vessels, downhole pressures, pressures in various engine chambers, and high-temperature oil level.
Testing, pressure measurements in oil wells and other areas. In these fields, the sensors are all working in high temperature environment, making the amplifier's amplification circuit work very easy to lose
Effectiveness, this is also the difficulty of high temperature pressure sensor design. The best solution is to separate the sensor device from the amplifier circuit. The sensor device is implemented by MEMS technology.
Now, signal excitation and signal processing are done by computers.
Now, there are many high-temperature pressure sensors that mainly include semiconductor sensors such as SOS, SOI, SiO2, and Poly2Si, as well as high temperature and pressure sensors for sputtering alloy thin films.
Temperature fiber pressure sensor and high temperature capacitive pressure sensor. Compared with traditional piezoresistive pressure sensors, semiconductor capacitive pressure sensors have high sensitivity and temperature
The advantages of good stability, low power consumption, etc., and it is only sensitive to pressure, insensitive to stress, so capacitive pressure sensors are widely used in many fields. Here is a brief introduction
Capacitive high temperature pressure sensor manufacturing process.
The sensing element of the silicon capacitive pressure sensor is a semiconductor film, which is mainly made of single crystal silicon and polysilicon. A typical capacitive sensor structure consists of upper and lower electrodes
, insulator and substrate. When the film is subjected to pressure, it deforms, causing the distance between the upper and lower electrodes to change immediately, causing the capacitance to change.
. However, the change in capacitance has a nonlinear relationship with the distance between the upper and lower electrodes. Therefore, use a compensation circuit to compensate for it. Due to the high temperature conditions affect the compensation circuit
Therefore, the compensation circuit should be avoided to work under high temperature environment. The best solution is to separate the sensor device from the amplifier circuit and obtain the measured environment through model identification.
With the development of electronic circuit devices, the anti-high-temperature performance of Xi'an SHELOK Air Pressure Sensor/Transmitter pressure sensors will become better in the future, which requires the joint efforts of scientific and technological workers