基于MEMS工艺的柔性基底磁通门传感器关键技术研究

发布时间：2018-03-18 06:52

本文选题：磁通门　切入点：MEMS　出处：《西北工业大学》2016年博士论文　论文类型：学位论文

【摘要】：磁通门传感器因其在温度稳定性、精度、分辨率和灵敏度方面的优势,以及结构简单、可测量静态和低频磁场的特性,使其成为综合性能最好的矢量磁场传感器。柔性基底材料具有良好的弯曲延展性、生物兼容性和轻质廉价等特性,使其拥有巨大的应用前景。随着MEMS(微机电系统)工艺的发展,以及柔性基底材料研究和柔性器件应用领域的不断扩大,结合磁通门和柔性基底的优势,研究基于MEMS工艺的柔性基底磁通门传感器,能进一步扩展磁通门在非平面表面磁场检测、在线电流测量、生物医学检测、可穿戴传感器以及柔性电子等领域的应用。然而MEMS工艺和柔性化给磁通门也带来了许多新的挑战和问题,MEMS工艺与微电子工艺兼容,磁通门和处理电路可以集成到一块芯片上,这就需要一种总体设计方法来优化系统性能;相比立体结构,平面结构磁通门不用实现上下层线圈互连,降低了工艺难度,但其线圈激励效率较差、功耗较高,需要研究如何优化线圈和铁芯拓扑结构;基于MEMS工艺的磁通门采用薄膜铁芯,其软磁性能较传统磁通门采用的带材铁芯有大幅下降,并且随着体积的减小噪声显著增大,研究薄膜铁芯软磁性能提升十分必要;在应用领域,结合磁通门和柔性基底的优点,研究基于磁通门原理的柔性基底电流传感器,有望提高目前电流传感器在线测试能力和测量精度。针对以上提到的这些挑战和问题,本文在理论分析的基础上,针对磁通门传感器铁芯线圈拓扑结构和铁芯软磁性能这两个方面对传感器性能进行优化,采用MEMS工艺制备了柔性基底磁通门,并应用其进行了磁场和电流检测。本文的主要工作及创新性研究成果如下:1、提出了一种基于MEMS工艺的柔性基底磁通门制备方法,并应用制备得到的柔性基底磁通门进行了电流在线测量。基于MEMS工艺,结合磁通门高精度、高稳定性等优势,以及柔性基底可弯曲延展的特性,制备了一种具有柔性基底的磁通门电流传感器,并利用其进行了电流在线测量。制备得到的这种柔性基底磁通门电流传感器既具有磁通门传感器精度高的特点,又具备洛可夫斯基线圈(空心感应线圈)方便在线测量的优势。2、提出了一种电压激励磁通门SPICE模型,并利用此模型对磁通门的铁芯结构参数、线圈结构参数、铁芯磁参数和激励电压参数进行优化。磁通门SPICE模型的建立可以将磁通门传感器和处理电路进行联合仿真,进而可以对整个系统进行整体优化,而现有的磁通门SPICE模型都是电流激励的,与实际情况有一定差距。本文使用反正切函数描述铁芯磁滞回线,用电压来激励磁通门,将磁通门建模归结为变系数非齐次常微分方程组求解问题,最后用SPICE实现了该模型的求解。此模型能在已知激励电压、线圈匝数、铁芯尺寸、铁芯磁滞回线数据和外磁场的基础上,方便快速地得到磁通门的输入输出特性。3、提出了一种基于MEMS工艺的磁通门用不同粘附层薄膜铁芯材料制备方法。基于MEMS工艺的磁通门采用软磁材料薄膜作为铁芯,然而薄膜铁芯较传统磁通门使用的带材铁芯在软磁性能方面有大幅下降,并且随着铁芯体积的减小噪声显著增大。本文在理论分析磁通门铁芯需要的软磁性能的基础上,通过溅射工艺研究了四种不同粘附层基底对Ni81Fe19薄膜铁芯软磁性能的影响,同时研究了不同电镀工艺条件下NiFe合金薄膜的软磁性能,以及不同应力条件对铁芯软磁性能的影响。研究结果指出在常用粘附层金属材料中钽最适合作为Ni81Fe19薄膜铁芯的粘附层基底;电镀NiFe合金的最佳电镀条件;以及不同方向应力对铁芯软磁性能的影响。4、提出了一种基于退磁场理论的平面结构磁通门低功耗方法,并根据此方法对平面结构磁通门进行了结构优化和仿真验证。平面结构磁通门具有结构和制备简单的优点,但因其激励效率较差、激励线圈电阻较大导致的功耗偏大问题有待进一步研究。本文在分析平面结构磁通门理论的基础上,给出了利用退磁场理论降低传感器功耗的办法,并在此方法基础上设计了几种平面结构磁通门,最后对它们进行了磁场仿真验证,仿真结果为进一步器件制备提供了理论支持。本文的研究结合国家自然科学基金课题“微型磁通门的低功耗技术研究(No.60874101)”和教育部高等学校博士学科点专项科研基金课题“基于多孔软磁薄膜的微型磁通门低功耗技术研究(No.20126102110031)”进行,对基于MEMS工艺的磁通门传感器总体设计优化、降低功耗、薄膜铁芯制备、非平面磁场测量、电流测量等有重要意义,研究成果可应用于电流检测、非平面磁场测量、柔性电子、生物医学、可穿戴传感器、小型机器人控制、无损探伤、磁标记检测、飞机导航等诸多领域。
[Abstract]:Fluxgate sensor because of its accuracy in temperature stability, sensitivity and resolution of the advantages and characteristics of simple structure, can measure static and low-frequency magnetic field, the magnetic field vector sensor. The best comprehensive performance of flexible base material has good bending ductility, biological compatibility and light, cheap and other characteristics, it has great prospect. With MEMS (microelectromechanical systems) technology development, and constantly expand the research on flexible substrate and flexible device applications, combined with the flux gate and a flexible substrate, the flexible substrate research of fluxgate sensor based on MEMS technology, to further expand the fluxgate magnetic field in non planar surface detection, online the current measurement, biomedical detection, wearable sensors and application of flexible electronics and other fields. However, the process of MEMS and the flexibility to bring a lot of new fluxgate The challenges and problems, compatible with MEMS technology and microelectronics technology, fluxgate sensor and processing circuit can be integrated into a chip, which requires an overall design method to optimize the system performance; compared with three-dimensional structure, plane structure withfluxgates realized without interconnecting coil, reduces the difficulty of the process, but the coil excitation efficiency is poor, high power consumption, need to study how to optimize the topology of the coil and the iron core; fluxgate MEMS process using thin film based on the iron core, iron core of the soft magnetic strip can be compared with the traditional fluxgate with a sharp decline, and with decreasing noise volume increased significantly, enhance the soft magnetic properties of thin film core is necessary; in the application domain, combined with the advantages of fluxgate and flexible substrate, the flexible substrate of current sensor based on the principle of fluxgate sensor, is expected to improve the current online testing capability and measurement precision . according to these challenges and problems mentioned above, this paper on the basis of theoretical analysis, aiming to optimize the sensor performance of fluxgate sensor coil topology and core soft magnetic properties of these two aspects, the fluxgate flexible substrate were fabricated by MEMS process, and the application of magnetic field and current detection. The work and achievements are summarized as follows: 1, this paper proposes a flexible substrate flux gate preparation method based on MEMS technology, and the application of fluxgate flexible substrate prepared by current on-line measurement. MEMS technology based on the combination of fluxgate high precision, high stability and other advantages, and the characteristics of flexible substrate flexible extension, a flexible substrate current fluxgate sensor was prepared, and then analyzes the current on-line measurement. The flexible substrate fluxgate current sensor was prepared by both Has the characteristics of fluxgate sensor with high precision, but also have the Roco J J Ki coil (hollow coil) convenient online measurement of the advantages of.2, puts forward a SPICE model of fluxgate excitation voltage, and using this model the core structural parameters of fluxgate, coil structure parameters, magnetic parameters and excitation voltage of magnetic flux parameters were optimized. SPICE model can be combined with the simulation of fluxgate sensor and processing circuit, which can optimize the whole system, and the existing SPICE model of fluxgate is current excitation, there is a certain gap between the actual situation. This paper use the arctangent function to describe the core hysteresis loop, voltage to excitation flux gate, will fluxgate modeling due to non-homogeneous ordinary differential equations to solve the problem of variable coefficient, the solution of the model is realized by SPICE. This model can be known excitation voltage, line The number of turns, core size, based on the hysteresis curve of the core data and the external magnetic field, fast and convenient to get the.3 input and output characteristics of fluxgate, presents a different adhesion film core materials preparation method of fluxgate based on MEMS technology. The flux gate MEMS process with soft magnetic film as the core based on however, compared with the traditional film strip core core fluxgate used in soft magnetic properties have declined sharply, and with the decrease of the volume of the core of the noise increased significantly. This paper analysis the soft magnetic properties of fluxgate core needed in theory, through the sputtering process on the four different substrate adhesion layer on Ni81Fe19 film soft magnetic core the influence also studied the soft magnetic properties of NiFe alloy films with different plating conditions, and the effect of different stress conditions on the core of soft magnetic properties. The results pointed out in The commonly used adhesive layer of tantalum in metal materials as the most suitable adhesion layer Ni81Fe19 films core; optimum plating conditions of NiFe alloy electroplating; and different direction of stress effect on core soft magnetic properties of.4, proposes a method of planar structure consumption fluxgate low power demagnetizing field based on the theory, and according to the method of plane the structure of the fluxgate are optimized and simulated. The plane structure of fluxgate structure and has the advantages of simple preparation, but because of its poor incentive incentive efficiency, power consumption due to the large coil resistance is big problems to be further studied. Based on the analysis of the plane structure withfluxgates theory, gives a way to reduce the power consumption of the sensor the demagnetizing field theory, and based on this method we designed several plane structure of fluxgate, they were at the end of the magnetic field simulation, the simulation results for further device system Prepare and provide theoretical support. The research of low power of National Natural Science Fund Project "micro fluxgate based on (No.60874101) and the specialized research fund for the doctoral program of higher education project" micro fluxgate low power technology of porous soft magnetic thin film based on the (No.20126102110031) ", to reduce power consumption optimization overall, the design of fluxgate sensor based on MEMS technology, the core of film preparation, non planar magnetic field measurement, current measurement has important significance. The research results can be applied to current detection, non planar magnetic field measurement, flexible electronics, biomedicine, wearable sensors, robot control, nondestructive testing, magnetic marker detection, aircraft navigation etc. in many fields.

【学位授予单位】：西北工业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TP212

【相似文献】