Development Of SiC-LC Resonant Wireless High Temperature Pressure Sensor

High temperature pressure sensor has broad application requirements in aerospace,aviation,national defense construction,energy development and other fields.Silicon material performance is greatly affected in the higher than 200?performance,can not meet the requirements of high temperature applications.At present,high temperature sensor will lead to power supply,signal circuit temperature rise because of metal wire.The wireless sensor based on LC resonance can realize non-contact measurement,which can realize the physical isolation of the electrical connection,the conditioning circuit and the high temperature heat source.Based on this,this paper presents a SiC-LC resonant wireless high temperature pressure sensor to solve these problems,the main research work is as follows:(1)According to the principle of LC resonance measurement,two kinds of sensitive components are designed.Silvaco software is used to analyze the bulk capacitance of two schemes.It is considered that the scheme 2 is easy to be detected and the preparation process is less difficult.Therefore,the built-in structure scheme of inductance is adopted.The size of the inductive structure is designed.The parameters of force-electric-thermal multi-physics are simulated by COMSOL,and the parameters such as the thickness of the sensitive film and the height of the capacitor cavity are simulated and optimized.Finally,the size parameters of the sensitive structure are determined.(2)The preparation of high temperature inductance was studied,and gold,platinum,nickel single layer inductance and gold-nickel-gold,gold-platinum multi-layered inductances were fabricated and compared with their high temperature performance.Discuss the possibility of anode bonding applications on SiC and BF33.The process of preparation of sensitive chip was determined.The preparation of bonding wafer was carried out by MEMS process such as photolithography,metal deposition,ICP etching,electroplating,stripping and anode bonding.By thinning and dicing the sensitive chip size is 11mm×11mm×0.65mm.(3)The sensitive chip was screened and the influence of the coupling distance on the signal intensity was investigated experimentally.Equipped with a pressure test platform,the five sensitive chips measured at room temperature.The sensitivity at room temperature are greater than 94.8 Hz/Pa.The sensor is packaged and equipped with high temperature pressure calibration platform for its high temperature performance.The maximum test temperature was 450 ?,the nonlinearity was 1.41%,the retardation was 0.57%,the repeatability was 2.55%,and the relative uncertainty was 3.66%.