一种抗大过载微型加速度计研究

讨论了一种抗大过载 (15 0 0 0 0 g)的微型加速度计 ,主要内容包括 :阐述加速度计的工作原理 ;设计一种新型十字梁的器件结构 ,并对这种结构进行抗大过载的冲击实验 ,以验证这种新型的结构对于大过载冲击的可靠性 ;进而利用ANSYS对器件进行模态分析 ,找出结构上应变最大的位置 ,并对结构尺寸进行优化 ;提供一种可能的电路版图说明 ,并对加速度计的灵敏性进行理论分析 ;最后提供一种可行的加工工艺方法     

一种抗大过载微型加速度计研究

讨论了一种抗大过载(150000g)的微型加速度计,主要内容包括:阐述加速度计的工作原理; 设计一种新型十字梁的器件结构,并对这种结构进行抗大过载的冲击实验,以验证这种新型的结构对于大过载冲击的可靠性; 进而利用ANSYS对器件进行模态分析, 找出结构上应变最大的位置, 并对结构尺寸进行优化; 提供一种可能的电路版图说明,并对加速度计的灵敏性进行理论分析; 最后提供一种可行的加工工艺方法.     

一种谐振式微加速度计的设计

提出一种基于谐振原理、电容检测的微型加速度计。通过外加加速度使质量块经杠杆将力放大施加到谐振器上,改变谐振梁上的轴向应力,从而改变谐振梁的振动频率。研究表明这种加速度计的测量范围达66 g。同时采用有限元法进行了仿真模拟,结果显示传感器灵敏度约18 Hz/g,工作模态固有频率为625.981 kHz。     

一种高g电容加速度计的设计

本文分析了电容式加速度传感器的工作原理,在此基础上设计了一种大量程加速度计,通过MATLAB进行系统仿真和ANSYS仿真验证,结果显示本设计可以很好的实现要求:量程70g,线性度小于2%,并有较好的稳定性。     

PWM数字微型加速度计摆片温度应力研究

针对微加速度计摆片废品率高的问题,从摆片的加工工艺,分析了PWM数字微加速度计温度应力对摆片刚度的影响;发现当摆片工作在不同状态,在某些加工温差段,摆片的刚度出现奇异值,摆片变形已不再满足小变形条件,导致摆片无法正常工作。本文亦提出了改善措施。     

MEMS微加速度计在振动环境下的可靠性研究

由于微加速度计的可靠性成为其产品商业化过程中的一个重要问题,而冲击断裂是导致其性能失效的主要原因。主要研究了压阻式微加速度计在振动环境下的可靠性问题。设计了微加速度计在振动环境下的可靠性试验并通过ANSYS进行仿真。经过分析得出微加速度计在振动环境下的主要失效模式,并进行了相应的失效机理分析。通过可靠性实验进行了验证,对微加速度计在振动环境下的可靠性进行评估,并描绘了其可靠度与失效概率曲线。     

一种基于VCO量化的MEMS加速度计接口电路

采用0.18 μm CMOS工艺,设计了一种基于VCO量化的电容式MEMS加速度计接口电路。电路基于VCO实现量化,可直接输出数字信号,克服了传统模拟力反馈的非线性问题,且不需要ADC或额外的比较器电路,大大降低了电路的复杂性。仿真结果表明,该接口电路系统噪声基底为18 μg·Hz-1/2,最大非线性误差为0.57%,电路功耗为6.7 mW,输入带宽和检测范围分别为2.5 kHz和±1.0 g。该接口电路达到较好的性能。     

耐高冲击过载电容式微加速度计设计

针对近年来常规弹药制导化改造对经历高动态环境的加速度传感器的迫切需求,该文设计了一种抗高过载、低量程的微机电系统(MEMS)电容式加速度传感器。该加速度传感器使用4组折叠梁组对可动结构进行支撑,并带动其在敏感方向移动,同时敏感结构采用差分式电容检测结构和叉齿止档限位结构方案,降低了结构受冲击时的区域应力,提高了输出信号增益及传感器灵敏度。理论计算和有限元分析结果表明,传感器轴向灵敏度为0.22 pF/g(g=9.8 m/s²),可承受轴向幅值为3×10⁴g、脉宽约8 ms的加速度冲击。     

MEMS隧道加速度计的系统分析与设计

主要论述了一种新型体硅工艺MEMS隧道加速度计的系统分析与设计，对加速度计敏感头与伺服反馈电路组成的系统进行系统建模，其中包含了结构的模型和反馈控制电路的模型。以系统模型作为基础，分析了器件工作所必须的条件，对器件的结构参数和反馈控制电路的参数进行了设计，并给出了系统的静态与动态输出。另外，本文提出了参数敏感度因子的概念及其计算方法，利用这种方法可以对每一个参数计算其对应的敏感因子，从而为参数容差设计提供了依据。     

一种新型体硅谐振加速度计

设计了一种谐振加速度计.这种加速度计包括两个双端固定音叉、一个质量块、四套放大惯性力的杠杆系统以及激励和敏感梳.利用梳状电极每个音叉被静电激励和敏感.利用MEMS体硅工艺研制了这种新型加速度计,测试的灵敏度为27.3Hz/g,分辨率为167.8μg.     

一种压阻式单片集成MEMS三轴加速度传感器

An integrated MEMS accelerometer has been designed and fabricated.The device,which is based on the piezoresistive effect,accomplishes the detection of three components of acceleration by using piezoresistors to compose three Wheatstone bridges that are sensitive to the only given orientation.The fabrication of the accelerometer is described,and the theory behind its operation developed.Experimental results on sensitivity,crossaxis-coupling degree,and linearity are presented.The sensitivity of X,Y and Z were 5.49 mV/g,5.12 mV/g and 4.82 mV/g,respectively;the nonlinearity of X,Y and Z were 0.01%,0.04% and 0.01%,respectively;the crossaxis-coupling factor of X axis to Y axis and Z axis are 0.119% and 2.26%;the cross-axis-coupling factor of Y axis to X axis and Z axis are 0.157%and 4.12%;the cross-axis-coupling factor of Z axis to X axis and Y axis are 0.511% and 0.938%.The measured performance indexes attain accurate vector-detection in practical applications, and even at a navigation level.In conclusion,the accelerometer is a highly integrated sensor.     

基于MEMS的压阻式超声传感器的设计与测试

A kind of piezoresistive ultrasonic sensor based on MEMS is proposed,which is composed of a membrane and two side beams.A simplified mathematical model has been established to analyze the mechanical properties of the sensor.On the basis of the theoretical analysis,the structural size and layout location of the piezoresistors are determined by simulation analysis.The boron-implanted piezoresistors located on membrane and side beams form a Wheatstone bridge to detect acoustic signal.The membrane-beam microstructure is fabricated integrally by MEMS manufacturing technology.Finally,this paper presents the experimental characterization of the ultrasonic sensor,validating the theoretical model used and the simulated model.The sensitivity reaches -116.2 dB(0 dB reference = 1 V/μbar,31 kHz),resonant frequency is 39.6 kHz,direction angle is 55°.     

MEMS压阻式三轴加速度传感器的双路循环电桥检测法

A cycle bridge detection method, which uses a piezoresistive triaxial accelerometer, has been described innovatively. This method just uses eight resistors to form a cycle detection bridge, which can detect the signal of the three directions for real time. It breaks the law of the ordinary independent Wheatstone bridge detection method, which uses at least 12 resistors and each four resistors connected as a Wheatstone bridge to detect the output signal from a specific direction. In order to verify the feasibility of this method, the modeling and simulating of the sensor structure have been conducted by ANSYS, then the dual cycle bridge detection method and independent Wheatstone bridge detection method are compared, the result shows that the former method can improve the sensitivity of the sensor effectively. The sensitivity of the x, y-axis used in the former method is two times that of the sensor used in the latter method, and the sensitivity of the z-axis is four times. At the same time, it can also reduce the cross-axis coupling degree of the sensor used in the dual cycle bridge detection method. In addition, a signal amplifier circuit and adder circuit have been provided, Finally, the test result of the ＂eight-beams/mass＂ triaxial accelerometer, which is based on the dual cycle bridge detection method and the related circuits, have been provided. The results of the test and the theoretical analysis are consistent, on the whole.     

一种微机械压阻式加速度传感器及其设计优化

给出了一种新型的微梁直拉直压的微机械压阻式加速度传感器的工作原理。该设计能同时提高传感器的灵敏度和自由振动频率。基于分析模型,本文还给出了传感器的结构优化和各种量程的设计规则。采用SOI硅片和深反应离子刻蚀(DRIE)工艺给出了传感器的制造和测试结果。     

一种微机械压阻式加速度传感器及其设计优化

给出了一种新型的微梁直拉直压的微机械压阻式加速度传感器的工作原理。该设计能同时提高传感器的灵敏度和自由振动频率。基于分析模型 ,本文还给出了传感器的结构优化和各种量程的设计规则。采用SOI硅片和深反应离子刻蚀 (DRIE)工艺给出了传感器的制造和测试结果     

Characteristics of a novel biaxial capacitive MEMS accelerometer

A novel MEMS accelerometer with grid strip capacitors is developed.The mechanical and electrical noise can be reduced greatly for the novel structure design.ANSOFT-Maxwell software was used to analyze the fringing electric field of the grid strip structure and its effects on the designed accelerometer.The effects of the width,thickness and overlapping width of the grid strip on the sensing capacitance are analyzed by using the ANSOFT-Maxwell software.The results show that the parameters have little effect on the characteristics of the presented accelerometer.The designed accelerometer was fabricated based on deep RIE and silicon-glass bonding processes.The preliminary tested sensitivities are 0.53 pF/g and 0.49 pF/g in the x and y axis directions,respectively.A resonator with grid strip structure was also fabricated whose tested quality factor is 514 in air,which proves that the grid strip structure can reduce mechanical noise.     

新型双向电容式MEMS加速度计特性分析

文章研究了一新型的栅形条电容MEMS加速度计,通过新型结构设计降低了传感器的机械噪声和电子噪声。用软件ANSOFT-Maxwell对栅形条电容的宽度、厚度及叠加宽度对检测电容的影响进行了分析。用深度离子刻蚀工艺和硅-玻璃键合工艺制作了传感器,初步测试结果表明其在X和Y方向的灵敏度分别为0.53pF/g 、0.49pF/g。制作的栅形条谐振子在大气下的品质因子达到514,说明栅形条结构可大大降低机械噪声。     

新型硅基MEMS集成光波导加速度传感器

本文设计了一种新型硅基ＭＥＭＳ集成光强调制型光波导加速度传感器，在同一 集成了分束器、悬臂梁、质量块、光波导、光探测器等元件，解决了光纤传感器向微型化发展时遇到的装配困难及长期稳定性差等问题，讨论了利用现有工艺在硅基片上实现ＭＥＭＳ集成光波导加速度传感器的可行性。     

叠加电桥检测的加速度传感器的设计

This paper describes the design,simulation,processing and test result of a high sensitivity accelerometer based on the piezoresistive effect which uses an overlay bridge detection method.The structure of this accelerometer is supersymmetric "mass-beams".This accelerometer has 8 beams,where two varistors are put in the two ends.Four varistors compose a Wheatstone bridge and the output voltages of the 4 Wheatstone bridges have been superimposed as the final output voltage.The sensitivity of the accelerometer can be improved effectively by these clever methods. A simplified mathematical model has been created to analyze the mechanical properties of the sensor,then the finite element modeling and simulation have been used to verify the feasibility of the accelerometer.The results show that the sensitivity of the accelerometer is 1.1381 m V/g,which is about four times larger than that of the single bridge accelerometers and series bridge sensor.The bandwidth is 0-1000 Hz which is equal to that of the single bridge accelerometers and the series bridge sensor.The comparison reveals that the new overlay detection bridge method can improve the sensitivity of the sensor in the same bandwidth.Meanwhile,this method provides an effective method to improve the sensitivity of piezoresistive sensors.