Analysis of a micro pressure-sensor employing SiC-AlN-SiC structure

In this research paper, we design a touch mode capacitive micro pressure-sensor with circular stepped-cavity and SiC-AlN-SiC material structure, which can be more precisely measured pressure in a high-temperature environment. Using the finite element analysis method (based on ANSYS software), we found that the sensitivity of the sensor reached 3.5 pF/MPa, up almost one-third from traditional single-cavity structure in the long linear working range as 0.9-1.4 MPa. Moreover, the research to thermal behaviours of the sensor is shown that high temperature has affected the diaphragm deformation and the von Mises stress of the sensor due to thermal buckling. But the thermal deformation did not change the intrinsic characteristics of this sensor. Consequently, the sensor packaging with high-temperature ceramic material is endured the higher temperature to be applied in a harsh environment.