Three-dimensional Magnetic Field / Triaxial Acceleration / Pressure Sensor Integration Research

This paper presents the basic structure of a three-dimensional magnetic field/three-axis acceleration/pressure integrated multifunctional sensor based on micro-electromechanical systems(MEMS)technology.The three-dimensional magnetic field sensor consists of five Hall sensors and magnetic field concentrator.Based on Hall effect and the principle of magnetic field conHall magnetic field sensorcentrator,this sensor can achieve the measurement of three-dimensional magnetic field(B_x,B_y and B_z).The three-axis acceleration sensor consists of elastic element and piezoresistors.The elastic element consists of four L-shaped double beams,two masses and middle double beam.Twelve piezoresistors are distributed in the root of L-shaped double beams and middle double beam.Twelve piezoresistors constitute three Wheatstone bridge structures,respectively.Based on piezoresistive effect,this sensor can achieve the measurement of three-axis acceleration(a_x,a_y and a_z).The pressure sensor consists of a square silicon film and four piezoresistors in the edge of silicon film.Based on piezoresistive effect of diffusion silicon,this sensor can achieve the measurement of pressure(P).This paper builds a simulation model of three-dimensional magnetic field sensor using TCAD-Atlas software and builds simulation models of magnetic field concentrator,three-axis acceleration sensor and pressure sensor using ANSYS Workbench software.The paper studies the simulation of characteristics of sensors and presents the design plan of sensors.This paper designs the layout of integrated sensor using L-Edit software.Based on MEMS technology,the integrated sensor chip is fabricated.The nonmagnetized package is achieved by using the inner lead bonding technology and nonmagnetized package materials.At room temperature,the characteristics of the packaged integrated sensor chip are tested.When the supply voltage is 5.0V,the magnetic sensitivities of three-dimensional magnetic field sensor along x-direction,y-direction and z-direction are 15.2mV/T,15.5mV/T and 301.5mV/T,respectively.The sensitivities of three-axis acceleration sensor along x-axis,y-axis and z-axis are164.025?V/g,49.208?V/g and 37.392?V/g,respectively.The sensitivity of pressure sensor is 0.104mV/kPa...