MEMS永磁薄膜磁场的设计与仿真

The Design and Simulation of MEMS Permanent Magnetic Field

由于在MEMS隧道磁阻微机械陀螺中需要一个较高磁场变化率的磁场,其检测模块主要是利用磁场的变化率对位移信息进行敏感,需要利用磁场的变化敏感质量块的位移,所以设计一个具有较高磁场变化率的磁场是十分有必要的。通过仿真分析,设计了一个MEMS隧道磁阻陀螺中应用的磁场,尺寸规格为500μm×500μm×20μm,材料为钕铁硼,相对磁导率为1.18,表面剩磁为1.3T,充磁方向垂直于截面。在此设计规格下,永磁体选用面内方向作为检测方向,磁场的变化率最大可达到0.2 Oe/nm,并且在其他方向上磁场保持一定程度上的匀强,不对检测方向上的磁场产生干扰。

Because of the need of a high magnetic field change rate in the MEMS tunneling magnetoresistance micro machined gyroscope,the detection module is mainly used to change the frequency of the displacement sensitivity of the information and need to use the change of the magnetic field sensitive mass block displacement.Therefore,it is necessary to design a magnetic field with high magnetic field rate.Through the simulation analysis,the design and application of a MEMS gyro magnetic field have been set up in tunnel magnetoresistance,dimensions 500μm×500μm×20μm,materials for NdFeB,relative permeability 1.18,surface remanence 1.3T,magnetization direction perpendicular to the cross section.Under the design specifications,the permanent magnet with in-plane direction as the direction of magnetic field detection,maximum change rate can reach 0.2 Oe/nm,and the magnetic field to keep a certain degree of uniform in the other direction,not on the direction of magnetic field interference detection.