MEMS电容式加速度计敏感结构研究
发布时间：2019-05-12 03:16
【摘要】：电容式加速度计因具备结构设计简单、性能好、精度高、功耗低、易制作等优点而被普遍研究。本论文设计了一种基于硅-玻璃阳极键合加工工艺的电容式双轴加速度计和一种Z轴加速度计。论文相关工作分为五部分展开:首先,在第一部分中简要介绍了MEMS相关方面的基础知识以及当前MEMS加速度计在国内外的研究现状。第二部分阐述了加速度计的相关工作原理和数学模型的建立,根据牛顿第二力学可以将加速度计简化为敏感质量-阻尼-弹簧构成的系统。通过对此系统的分析得出了加速度计的一些技术指标如机械灵敏度等。其次对各类加速度计的原理进行阐述,并且对比分析了电容式加速度计的两种不同的检测方式:变间距式和变面积式。变间距式检测方式可获得高灵敏度、高性能等优点,在实际结构设计中使用较多。根据各种类型结构的优缺点确定最终选用电容变间距式加速度计作为文章主要研究结构。其次,在文章第三部分给出了本论文设计的两种电容式加速度计的具体结构和参数。主要包括梁结构的分析、整体结构的设计以及交叉耦合性能的理论分析。之后使用商用软件ANSYS对设计结构进行理论仿真和验证:通过力学分析得到了加速度计在工作范围内是线性的,及其在不同轴向上的机械灵敏度S_x=0.0845μm/g、S_y=0.1382μm/g和S_z=0.262μm/g。通过结构强度分析论证了所设计的结构具有良好的抗冲击性能。在大冲击(1000g)之下,结构的最大应力337.18MPa、457.34MPa和349.26Mpa出现在支撑梁和敏感质量的连接点上,其值均在硅材料极限应力1.3GPa的范围之内。最后通过模态分析得到了结构的前四阶的工作频率,结构前两阶为工作模态,和其他模态相比,工作模态的频率很小,因此能够消除其他方向上的运动对检测方向上的影响。之后依照设计的加速度计的结构结合常用的MEMS加工技术,设计了相对应的工艺流程并且详述了具体工艺步骤、工艺中需要注意的问题以及相关步骤中涉及的工艺参数,最终加工制得加速度计样品,通过对比样品的显微照片及电镜扫描结果和理论参数对比验证结构合理性。文章最后部分设计了电容式加速度计相对应的电路,对电路各部分的原理及设计进行了阐述以及对加工制备的加速度计样品进行简单测试。
[Abstract]:Capacitive accelerometer has been widely studied because of its simple structure design, good performance, high precision, low power consumption, easy to fabricate and so on. In this paper, a capacitive biaxial accelerometer and a Z-axis accelerometer based on silicon-glass anode bonding process are designed. The related work of this paper is divided into five parts: firstly, in the first part, the basic knowledge of MEMS and the current research status of MEMS accelerometer at home and abroad are briefly introduced. In the second part, the working principle and mathematical model of accelerometer are described. According to Newton's second mechanics, the accelerometer can be simplified to a system composed of sensitive mass, damping and spring. Through the analysis of this system, some technical indexes of accelerometer, such as mechanical sensitivity and so on, are obtained. Secondly, the principle of all kinds of accelerometers is described, and two different detection methods of capacitive accelerometers are compared and analyzed: variable spacing type and variable area type. The variable distance detection method can obtain the advantages of high sensitivity and high performance, and is widely used in practical structural design. According to the advantages and disadvantages of various types of structures, the capacitance variable distance accelerometer is selected as the main research structure in this paper. Secondly, in the third part of the paper, the concrete structure and parameters of two kinds of capacitive accelerometers designed in this paper are given. It mainly includes the analysis of the beam structure, the design of the whole structure and the theoretical analysis of the cross-coupling performance. Then the commercial software ANSYS is used to simulate and verify the design structure: through mechanical analysis, it is found that the accelerometer is linear in the working range and its mechanical sensitivity S 鈮，
本文编号：2475061
[Abstract]:Capacitive accelerometer has been widely studied because of its simple structure design, good performance, high precision, low power consumption, easy to fabricate and so on. In this paper, a capacitive biaxial accelerometer and a Z-axis accelerometer based on silicon-glass anode bonding process are designed. The related work of this paper is divided into five parts: firstly, in the first part, the basic knowledge of MEMS and the current research status of MEMS accelerometer at home and abroad are briefly introduced. In the second part, the working principle and mathematical model of accelerometer are described. According to Newton's second mechanics, the accelerometer can be simplified to a system composed of sensitive mass, damping and spring. Through the analysis of this system, some technical indexes of accelerometer, such as mechanical sensitivity and so on, are obtained. Secondly, the principle of all kinds of accelerometers is described, and two different detection methods of capacitive accelerometers are compared and analyzed: variable spacing type and variable area type. The variable distance detection method can obtain the advantages of high sensitivity and high performance, and is widely used in practical structural design. According to the advantages and disadvantages of various types of structures, the capacitance variable distance accelerometer is selected as the main research structure in this paper. Secondly, in the third part of the paper, the concrete structure and parameters of two kinds of capacitive accelerometers designed in this paper are given. It mainly includes the analysis of the beam structure, the design of the whole structure and the theoretical analysis of the cross-coupling performance. Then the commercial software ANSYS is used to simulate and verify the design structure: through mechanical analysis, it is found that the accelerometer is linear in the working range and its mechanical sensitivity S 鈮，
本文编号：2475061
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