Research On Production And Characteristics Of SOI Monolithic Integrated Angle Sensor

In order to solve the problems of contact wear,small range,complex structure and high environmental requirements of angle sensor in vehicle streeing assit applications,in this paper the SOI monolithic integrated angle sensor is designed and manufactured based on micro-electromechanical systems(MEMS)technology,the sensor consists of x and y direction of the magnetic sensing unit,the mobile outside permanent magnet provide the sensor with magnetic field.When the permanent magnet rotates around the sensor in a plane with a fixed radius,the angle ? between the vector direction of the magnetic field generated by the permanent magnet and the direction of sensor's magnetic sensitivity is deflected.Therefore,the magnetic field components felt by the magnetic sensing unit show a sinusoidal and cosine trend change respectively,resulting in a sinusoidal and cosine trend change of the output voltage value in the corresponding direction of the sensor.By analyzing the output voltage value in the two directions of the sensor,the measurement of the rotation angle ? in the rotation process of the permanent magnet can be realized.Through theoretical analysis,the sensor can realize non-contact angle measurement.In order to improve the performance of the angle sensor,the magnetic field generated by the permanent magnet is amplified by a polymagnetic structure.On this basis,the finite element analysis software ANSYS-Workbench and the semiconductor device simulation software TCAD-Atlas are used to build the corresponding simulation models and characteristics of the sensor's magnetic sensing unit and CMFS respectively.At the same time,the software L-Edit is used to construct the layout of the sensor chip,the fabrication and packaging of the chip are completed based on MEMS technology.At room temperature,the self-built sensor characteristic test system is used to test and analyze the magnetic field collection ability of the CMFS,then the basic electrical characteristics,magnetic sensitivity characteristics and rotation characteristics of the magnetic sensing unit are tested and analyzed.The experimental results show that in the range of-80 mT?80 mT magnetic field,the magnetic field can be amplified 3.5 times by CMFS.When the applied voltage is 5.0 V,the base injection current is 8.0 mA and loading resistance is 1.6 k?,the magnetic sensitivity of the two directions of the magnetic sensing unit in angle sensor is 266 mV/T and 219 mV/T,respectively.The sensor can realize non-contact angle measurement,which lays a foundation for the further research of angle sensor.