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设计了一种可用于器件级真空封装的三明治电容式MEMS加速度传感器.该传感器被设计为四层硅结构,其中上下两层为固定电极,中间两层为硅-硅直接键合的双面梁-质量块结构的可动电极.利用自停止腐蚀工艺在中间质量块键合层上腐蚀出2个深入腔内的V型抽气槽,使得MEMS器件在后续的封装中能够实现内部真空.为防止V型抽气槽在划片中被水或硅渣堵塞,采用双面划片工艺.划片后,器件的总尺寸为6.8mm ×5.6mm ×1.72 mm,其中,敏感质量块尺寸为3.2mm×3.2mm ×0.86mm,检测电容间隙2.1 μm.对器件级真空封装后的MEMS加速度传感器进行了初步测试,结果表明:制作的传感器的谐振频率为861 Hz,品质因数Q为76,灵敏度为1.53 V/gn,C-V特性正常,氦气细漏<1×10-9 atm-cm3/s,粗漏无气泡. 相似文献
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《传感器与微系统》2019,(9)
提出了基于模糊控制的微机电系统(MEMS)陀螺驱动闭环设计的方法,介绍该方法在MEMS陀螺驱动模态的应用,并在现场可编程门阵列(FPGA)平台上实现。模糊控制属于智能控制的一种,具有很强的鲁棒性、稳定性和非线性系统的控制能力。主要在于基于模糊控制的MEMS陀螺数字驱动闭环的方法,将陀螺驱动信号在FPGA的内部处理。由坐标旋转数字计算机(CORDIC)算法产生驱动及解调正弦波信号,驱动模态位移信号经过解调和低通滤波后,再由模糊控制对幅值进行恒定控制。实验结果表明:该设计方法能够使MEMS陀螺仪稳定工作在谐振状态下,幅值基本保持恒定,数字驱动闭环的响应信号幅值抖动精度可达到51×10~(-6)。 相似文献
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基于面内振动模态工作的圆盘陀螺在利用压电方式驱动和检测时,需要在圆盘振动体侧壁上加工压电换能器,很难由MEMS工艺实现.为实现压电圆盘陀螺的小型化,设计制作了一种直接由压电材料作为振动体,基于厚度剪切振动模态工作的新型压电圆盘微陀螺.厚度剪切振动模态使得陀螺可以通过在压电基片上下表面制作金属电极的MEMS工艺进行加工.通过对加工出的陀螺器件进行阻抗分析发现加工出的陀螺具有良好的对称性,基于阻抗分析得到的品质因数通过有限元分析可知,陀螺可实现高灵敏度、低非线性度、大量程、低角速度耦合误差等性能. 相似文献
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频率裂解和品质因数是制约MEMS陀螺准确度的关键因素。本文以嵌套环式MEMS陀螺为研究对象,以降低频率裂解与提高品质因数为目的,开展频率裂解与品质因数仿真研究。针对频率裂解问题,提出一种转轴偏心修调方法,建立ANSYS模态分析仿真模型,解析转轴偏心参数对模态振型的影响机制,明确频率裂解变化规律;针对品质因数问题,聚焦空气阻尼及热弹性阻尼损耗的影响机理,明确低压强、多谐振环数、薄谐振环、小锚点会有效提高陀螺品质因数。此外,对比仿真与Zener理论模型,说明仿真模型有效性。以上研究有效揭示嵌套环式MEMS陀螺频率裂解和品质因数的变化规律,为MEMS陀螺准确度的提高提供研究基础。 相似文献
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提出一种基于近似模型的MEMS系统级优化方法,给出具体实现流程,并结合一个y轴微机械陀螺进行优化。该方法解决了如何得到近似优化目标函数表达式的关键问题。所得的y轴微机械陀螺优化参数,使得陀螺驱动模态谐振频率fx和检测模态谐振频率fz分别为3 074 Hz和2 998 Hz,两者之间相差7 6 Hz,较好的实现了模态匹配,且都在3 000 Hz的设计要求附近,约束条件也得到了满足。该优化方法为在MEMS设计中快速获得系统级优化方案提供较好参考。 相似文献
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在分析了微机械陀螺机械耦合误差产生原因的基础上,提出了一种解耦梁方案,可以从结构上消除振动式微机械陀螺敏感模态对驱动模态的耦合影响;基于该解耦梁方案设计了一种新型的Z轴微机械陀螺结构.分析表明,该陀螺结构消除了敏感模态对驱动模态的耦合影响,实现了解耦设计的目的. 相似文献
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Sung-Hoon Choa 《Microsystem Technologies》2005,11(11):1187-1196
In this study, the dominant reliability issues of MEMS packaging that include vacuum maintenance and packaging induced stress, are discussed, and design considerations to improve the reliability are presented. The MEMS vibratory gyroscope sensor is fabricated with anodically bonded wafer level vacuum packaging followed by die-bonding and wire-bonding processes. The epoxy-molding compound (EMC) is applied to encapsulate the gyroscope sensor. Several methods to improve reliability of the vacuum packaging are suggested based on extensive work. The two major failure mechanisms of anodic vacuum packaging, namely leakage and outgassing are investigated. Leakage is effectively reduced by optimization of the bonding process. Outgassing inside the cavity can be minimized by application of Ti coating. Packaging induced stress is mainly caused by thermal expansion mismatch among the materials used to fabricate the package. During anodic bonding, thermo-mechanical stress is generated to the bonded wafer, which increases with temperature. The EMC encapsulation also produces package-induced stress. In order to increase robustness of the structure against deformation, a crab-leg type spring is replaced with a semi-folded spring. The results show that the frequency shift is greatly reduced after applying the semi-folded spring. 相似文献
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本文介绍了一种基于多通道检测的光纤陀螺系统测试方案,给出了系统的硬件环境设计思想及测控软件的实现技术和方法,可实现光纤陀螺及其相关光电器件的综合检测,以提高光纤陀螺的测试效率,为光纤陀螺工程化服务。 相似文献
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一种微惯性测量单元标定补偿方法 总被引:2,自引:0,他引:2
在介绍微惯性测量单元组成与结构的基础上,根据MEMS惯性器件的输出特性,建立了微惯性测量单元中加速度计和陀螺仪的数学标定模型,提出并推导了一种适用于微惯性测量单元的标定方法,该方法可以得到微惯性测量单元中惯性传感器的零位、标度因数、安装误差系数及g值敏感项等33个参数;然后,具体介绍了通过加速度计重力场静态翻滚试验和陀螺仪恒角速率试验对MIMU中参数标定的方法和步骤,并对实验室自研的MIMU进行了标定;最后利用得到的标定参数对测试结果进行了误差分析与补偿;实验结果表明,该方法使MIMU的测量精度提高了1~2个数量级,能够满足姿态解算及导航计算的精度要求。 相似文献
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Jianbing Xie Qiang Shen Yongcun Hao Honglong Chang Weizheng Yuan 《Microsystem Technologies》2015,21(3):625-630
This paper presents the design, fabrication and characterization of a low-noise Z-axis micromachined gyroscope. A triple-mass scheme is adopted to obtain a decoupled mode and matched vibration structure. The gyroscope was fabricated based on a 30-μm silicon on insulator wafer. A DRIE, lag-effect-based, dicing-free process was used to easily and rapidly create the gyroscope devices without requiring normal dicing. The fabricated gyroscopes were vacuum packaged (pressure of approximately 2,000 Pa) and tested. The measured power spectral density of the noises is as low as 17.5 μV/√Hz, and the resolution of the fabricated gyroscope is 7.1 × 10–4°/s/√Hz (2.52°/h/√Hz). 相似文献
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Zhiyin Gan Dexiu Huang Xuefang Wang Dong Lin Sheng Liu 《Sensors and actuators. A, Physical》2009,149(1):159-164
Quite a few MEMS devices such as accelerators, gyroscopes, infrared sensors need to work in vacuum environment to enhance their performance. The traditional vacuum packaging methods use getters to increase vacuum maintaining lifetime. However, the getter's characteristics of high temperature activation, powder pollution, large package size limit its use in MEMS vacuum packaging. This study analyzes the factors that influence the vacuum level, and derived a relationship between the balanced vacuum level, the effective leak rate, and vacuum maintaining lifetime. A novel vacuum package design with vacuum buffer cavity was proposed, the vacuum maintaining lifetime could be increased at least 20 times as compared to the ordinary package with the same volume. Reliability experiments were conducted so as to verify that the new package design can achieve reliable vacuum packaging without getters to meet the requirements of device applications for vacuum with about 0.1 Pa in pressure level. This unique package design also provided a complementary way to work with getters to enhance the vacuum package performance and reliability of hermeticity. 相似文献