在现有工艺条件基础上进行工艺流片。详细介绍了工艺流程及工艺过程中用到的重点和难点工艺，最后提出一种有效的封装结构对传感器进行真空封装。
研制出MEMS谐振压力传感器初样器件，所得传感芯片尺寸为8.3mm×4.7mm×300
，为后续的谐振式传感器研究奠定了基础。
关键词：MEMS传感器，谐振式压力传感器，电磁谐振梁
ABSTRACT
MEMS (Microelectromechanical System) is a multidiscipline technology based on microelectronics technology. MEMS are integrated devices or systems composed of microsensors, microactuators, signal processing IC, controlling IC, communication interface IC and/or battery. The microsensors based on MEMS technology have the advantages of miniaturization, integration and high accuracy.
The resonant pressure sensor measures the applied pressure by
detecting resonant frequency changes of its resonant beam. Comparing with other pressure sensor, resonant pressure sensors based on MEMS are characterized by small size, high accuracy, excellent stability and convenient interfacing with digital electronics, showing wide applications prospects. Electrostatic, optical thermal and
electromagnetic excitations are common way used in the resonant sensors. Electromagnetic excitation has been selected for the developed sensor since it has the advantage of high stability. The paper presents the design, analysis, modeling and fabrication of the MEMS resonant sensor. The construction of two sensing units is presented, one unit for absolute pressure and another for the atmosphere. Every sensing unit is constructed with the diaphragm on which the resonant beam (or the resonator) is fabricated by three-dimensional semiconductor process technology. The sensor has low stress, high stability and good repeatability because the resonator is sculpted from the diaphragm directly and made from single crystal silicon which has excellent elastic characteristics.
Here the simplified model of the sensing unit is analysed and simulated by theory computing and FEA (finite element analysis). The resonant characteristics and pressure sensitivity of the sensor has been calculated for the design and fabrication of the sensor.
A model of positive feedback self-oscillation system is established based on the theory of equiamplitude and stable self-oscillation. Due to its stability we use electro-magnetic excitation and electro-magnetic detection to excitate the resonators and detect the output signals by the H type conductors fabricated on the resonators.
The fabrication process of the sensor is focused in this paper. The key process is the fabrication of the resonators. Two kinds of
fabrication processes are designed based on the available conditions. Finally an effective vacuum packaging technology is developed.
The sensor chip in the size of 8.3mm×4.7mm×300
is fabricated
successfully, and it will be used for the further research.
Keyword:
MEMS sensor, Resonant pressure sensor, Electro-magnetic resonator
基于MEMS加速度计的数字倾角测量仪的设计(PDF) 《电子设计工程》[ISSN:1674-6236/CN:61-1477/TN] 期数:
2009年08期 页码: 71-72 栏目:
主题论文：自控与仪器仪表 出版日期: 2009-08-05 Title:
Design of digital dipmeter based on MEMS accelerometer 作者:
段晓敏; 李杰; 刘文怡; 沙承贤
中北大学电子科学与技术系，电子测试技术国防重点实验室，山西太原030051 Author(s):
DUAN Xiao-min; LI Jie; LIU Wen-yi; SHA Cheng-xian
National Key Laboratory for Electronic Measurement Technology，Department of Electronic Science and Technology，North University of China，Taiyuan030051，China 关键词:
MEMS加速度计; 倾角测量仪; 单片机; 误差补偿 Keywords:
MEMS（Micro Electro Mechanical System）accelerometer; dipmeter; MCU; error compensation 分类号: TP212.9 DOI: -
文献标识码: A 摘要:
设计由MEMS加速度计与SoC型单片机C8051F040组合而成的一种新型数字倾角测量仪，通过对MEMS加速度计的输出信号进行调理和A/D采集，并且在获得数字信号后进行温度补偿，解算出倾角值并通过LCD1602显示。该倾角测量仪具有体积小、重量轻、精度高的特性，可广泛应用于建筑、机械、道路、桥梁和地质勘探等重力参考系下测量倾角的场合。 Abstract:
A new type digital dipmeter combined with the MEMS accelerometer and the SoC-type C8051F040MCU is de-signed.By conditioning and A/D acquisition for MEMS accelerometer output signal,it compensates the temperature after obtaining digital signal,calculates inclination value and uses LCD1602display.The dipmeter features small size,light weight,high precision,it can be widely used in building,machinery,roads,bridges and geological exploration and so on,such as gravity reference system to measure the inclination. 参考文献/References
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为进一步提高MEMS陀螺仪的品质因数及其稳定性,研究了MEMS陀螺仪器件级真空封装的高真空获取技术和真空保持技术。以Z轴MEMS陀螺仪动力学方程为基础,分析了MEMS陀螺仪的误差信号与品质因数之间的关系,并采用稀薄气体动力学分析具有高品质因数陀螺仪的空气阻尼。对早期真空封装陀螺仪品质因数的变化曲线进行了分析,得出了腔体内残余气体是品质因数下降的主要原因。采用程序升温脱附质谱分析法(TPD-MS)分析陶瓷管壳和金属盖板的放气特性,并选用了合适的吸气剂。最后,改进了器件级真空封装流程。测试结果表明,采用改进的器件级真空封装的陀螺仪品质因数最高可达162 660,约为早期真空封装陀螺仪品质因数的14倍,且在一年内的变化＜0.05%。
标 签 MEMS陀螺仪 真空封装 真空保持度 吸气剂 MEMS gyroscope vacuum packaging vacuum maintenance getter
Abstract
The high vacuum acquisition and vacuum maintenance of device-level vacuum packaging for MEMS gyroscopes are studied to increase their quality factors and stability. The relationship between error signals and quality factors is analyzed based on the dynamics equations of Z-axis MEMS gyroscopes and the air damping of gyroscopes with high quality factors is analyzed using rarefied gas dynamics theory.The changes of quality factor of an early vacuum packaged
gyroscope are analyzed,and the result shows that residual gasses in vacuum cavity result in the decreasing of vacuum level.A temperature programmed desorption-mass spectrometry (TPD-MS) is used to measure the contents of the evolution gases for the ceramic packages and the lids.According to the contents of trapped gases,the reasonable getter is chosen to absorb the gases and to keep the vacuum level of the cavity.Finally,the device-level vacuum packaging process is improved.The test results show that the quality factor of the gyroscope packaged with a new device-level vacuum packaging process is about 162 660,which is about 14 times those of previous vacuum packaged MEMS gyroscopes,and the change of quality factor is less than 0.05% within one year. 参考文献
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【2】 采用惯性MEMS开发高精度导航系统
【3】 作者：ADI公司iSensor产品业务拓展经理 来源:电子设计应用2009年第5期 【4】 【5】 【6】 摘要：惯性导航系统是一种不依赖于外部信息、也不向外部辐射能量的自主式导航系统。
其工作环境不仅包括空中、地面，还有水下。该系统通过测量载体在惯性参考系的加速度，将它对时间进行积分，且把它变换到导航坐标系中，就能够得到在导航坐标系中的速度、偏航角和位置等信息。本文介绍了采用惯性MEMS开发的具有成本效益的高精度导航系统。
关键词：惯性；导航系统；MEMS
惯性导航系统不仅可以工作在空中、地面，还可以工作在水下。该系统结合多个轴上的直线和旋转运动信息，产生准确的位置、速度和方向输出信号。系统复杂度与系统数据处理融合所有输入并实现相关制导，这取决于系统机体动力学、其他传感器的可用性或域特定数据。而设计及实现这样的一种惯性导航的复杂度与所使用的传感器种类，特别是器件的集成度和校准的准确性密切相关。
导航方案的选择
惯性导航的可能方案很多，从简单的传感器到最高端的环形激光陀螺仪，都在人们的使用范围之内。对大多数情况，环形激光陀螺仪的成本令人难以承受。
精确导航要求更高，多年来，精确导航的首选方案是使用环形激光或光纤陀螺仪技术开发的高精度惯性测量单元(IMU)。其性能指标表现不错，但它们在成本(达数千美元)、功耗和尺寸方面给系统带来沉重的预算负担。
幸运的是，几年前发展成熟的微机电系统(MEMS)陀螺仪使人们开始重新审视导航系统的设计方法。使用MEMS陀螺仪的主要好处是，它可以把成本降低一个数量级，并可减小尺寸和降低功耗。对设计者来说，面临的挑战是如何重新分配系统性能预算，如何通过设计而不是完全依靠核心IMU来提供附加性能。一些成功的设计者发现，成本优势也为许多新应用的开创提供了机会。
现在，MEMS陀螺仪与加速计相结合不仅成为汽车安全系统的基本单元，而且已被公认