作者：施江焕¹, 马丹跃², 吴琼³, 吴梓坚³, 黄腓力¹, 陈杭武¹, 吕沛¹

作者单位：1. 宁波市计量测试研究院（宁波新材料检验检测中心），浙江 宁波 315040;
2. 北京航空航天大学大科学装置研究院，北京 100191;
3. 中国计量大学材料与化学学院，浙江 杭州 310018

关键词：表面磁场分布;薄膜阵列;磁场变化率

摘要：

基于隧道磁电阻效应的微机械陀螺中，磁场的产生和分布是决定器件性能的重要因素。该文以NdFeB永磁薄膜为磁场源，利用基于有限元法的Comsol Multiphysics软件对NdFeB永磁薄膜表面磁场进行系统分析，研究不同薄膜厚度下的薄膜表面磁场分布的均匀性及隧道磁阻敏感轴方向磁场分量的变化率。研究发现，随着薄膜厚度的增加，薄膜表面磁场和磁场变化率也在变大，薄膜厚度为20 µm时，薄膜所产生的磁场变化率可达0.43 mT/µm。考虑到薄膜阵列化可以有效抑制薄膜过厚所导致的薄膜与基底附着力变弱的问题，该文通过改变设计参数，研究NdFeB永磁厚膜一维阵列的表面磁场分布。发现阵列单元的厚度和宽度增加时，阵列的磁场强度和磁场变化率也会变大，而间距增加会导致薄膜阵列的表面磁场和磁场变化率降低。

Surface magnetic field distribution simulation of permanent magnet thin film in micromechanical gyro
SHI Jianghuan¹, MA Danyue², WU Qiong³, WU Zijian³, HUANG Feili¹, CHEN Hangwu¹, Lü Pei¹
1. Ningbo Institute of Measurement and Testing (Ningbo Inspection and Testing Center for New Materials), Ningbo 315040, China;
2. Research Institute of Large Scientific Facility, Beihang University, Beijing 100191, China;
3. College of Materials and Chemistry, China Jiliang University, Hangzhou 310018, China
Abstract: In the micromachined gyroscope based on the tunneling magnetoresistance effect, the generation and distribution of magnetic field is an important factor to determine the performance of the device. In this paper, NdFeB permanent magnet film is used as the magnetic field source, and the surface magnetic field of NdFeB permanent magnet film is systematically analyzed by Comsol Multiphysics software based on finite element method. The uniformity of the magnetic field distribution on the surface of the film under different film thicknesses and the change rate of the magnetic field component in the direction of the tunnel reluctance sensitive axis are studied. It is found that with the increase of film thickness, the surface magnetic field and magnetic field change rate of the film also increase. When the film thickness is 20 μm, the magnetic field change rate generated by the film can reach 0.43 mT/μm. Considering that the film array can effectively suppress the weakening of the adhesion between the film and the substrate caused by the excessive thickness of the film, the surface magnetic field distribution of the one-dimensional array of NdFeB permanent magnet thick film is studied by changing the design parameters. It is found that when the thickness and width of the array unit increase, the magnetic field intensity and magnetic field change rate of the array will also increase, while the increase of the spacing will lead to the decrease of the surface magnetic field and magnetic field change rate of the film array.
Keywords: surface magnetic field distribution;thin film array;magnetic field change rate
2024, 50(4):16-23  收稿日期: 2023-06-07;收到修改稿日期: 2023-07-21
基金项目: 浙江省市场监督管理局科技计划项目（ZC2023060）
作者简介: 施江焕(1984-),男,浙江温岭市人,高级工程师,硕士,主要从事磁性材料检测方面的研究工作。
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