Fabrication of electrostatic MEMS microactuator based on X-ray lithography with Pb-based X-ray mask and dry-film-transfer-to-PCB process

Lithographie Galvanoformung Abformung (LIGA) is a promising approach for fabrication of high aspect ratio 3D microactuator for dual-stage slider in hard disk drive. However, this approach involves practically challenging X-ray lithography and structural transfer processes. In this work, electrostatic MEMS actuator is developed based on a LIGA approach with cost-effective X-ray lithography and dry-film-transfer-to-PCB process. X-ray lithography is performed with X-ray mask based on lift-off sputtered Pb film on mylar substrate and photoresist application using casting-polishing method. High quality and high aspect ratio SU8 microstructures with inverted microactuator pattern have been achieved with the interdigit spacing of ~5 μm, vertical sidewall and a high aspect ratio of 29 by X-ray lithography using the low-cost Pb based X-ray mask. A new dry-film-transfer-to-PCB is employed by using low-cost dry film photoresist to transfer electroplated nickel from surface-treated chromium-coated glass substrate to printed circuit board (PCB) substrate. The dry film is subsequently released everywhere except anchor contacts of the electrostatic actuator structure. The fabricated actuator exhibits good actuation performance with high displacement at moderate operating voltage and suitably high resonance frequency. Therefore, the proposed fabrication process is a promising alternative to realize low-cost MEMS microactuator for industrial applications.     

基于MEMS的微泵研究进展

主要介绍了基于MEMS的微泵 10年来的研究成果和研究现状。微泵是微电子机械系统(MEMS)中重要的执行器件 ,在系统中占有很重要的地位。微泵可以分为有阀泵和无阀泵两大类 ,一般来说 ,有阀泵的制造工艺和应用技术比较成熟 ,但存在加工尺寸限制和使用寿命的问题 ;无阀泵的原理新颖 ,结构相对简单 ,更适合微型化发展 ,是目前研究的热点。     

Large-stroke MEMS deformable mirrors for adaptive optics

Surface-micromachined deformable mirrors that exhibit greater than 10 /spl mu/m of stroke are presented. The segmented arrays described here consist of 61 and 85 hexagonal, piston/tip/tilt mirrors (three actuators each) with diameters of 500 and 430 /spl mu/m, respectively, and fill a 4 mm circular aperture. Devices were packaged in 208 and 256 pin-grid arrays and driven by a compact control board designed for turn-key operation. After metallization and packaging mirror bow is /spl sim/680 nm (/spl lambda//1), but a heat-treatment procedure is proposed for controlling mirror curvature to better than /spl lambda//10. An optical test bed was used to demonstrate basic beam splitting and open-loop aberration correction, the results of which are also presented.     

基于MEMS技术的载体催化甲烷检测元件制作方法

在分析载体催化甲烷检测原理的基础上,提出采用先进的微机电系统(Microelectro Mechanical System,MEMS)技术对传统载体催化甲烷检测元件的制作方法进行改进,给出了具体的元件制作流程,并对元件的性能进行了测试。测试结果表明,基于MEMS技术的载体催化甲烷检测元件较传统载体催化甲烷检测元件在功耗、抗中毒、一致性等方面有明显改善。     

MEMS器件贴片工艺研究

贴片工艺是MEMS封装中的关键工艺。根据残余应力理论,应用有限元方法和试验技术研究了贴片胶杨氏模量和热膨胀系数对贴片应力和芯片翘曲的影响。结果表明:杨氏模量和热膨胀系数是影响贴片应力和芯片翘曲的重要因数。杨氏模量越大,贴片后产生的应力越大,引起芯片的翘曲越大,但杨氏模量大到一定数值后,应力不会再增大,反而对应力具有一定的隔离作用;热膨胀系数越大,贴片后产生的应力越小,引起芯片的翘曲越小,反之,引起芯片的翘曲越大。在满足粘接强度和工艺条件下,选用软胶有利于减小应力和芯片翘曲。     

基于MEMS微加速度计的振动测试仪

采用16位单片机MSP430、微加速度计ADXL203及射频收发芯片nRF2401设计制作了一种微型振动测试仪。采用ADXL203检测振动,输出与加速度大小成比例关系的电压信号经滤波、放大、A/D转换等处理后转换为单片机能识别的数字信号,信号经处理器处理后,通过nRF2401发送至PC机显示,并以加速度曲线的形式显示。重点研究了低功耗的轻巧敏感元件ADXL203的振动信号的检测和调理、中断方式下的A/D采样以及nRF2401的射频通信,并通过振动测试试验验证了设计的正确性,该方案适用于低功耗、微型化、网络化的振动测试。     

基于MEMS的生物微传感技术

微电子机械系统(MEMS)技术为生物微传感器和生物芯片的研制以及实现小型化、便携式、低成本,高灵敏度的生化片上系统提供了有力的技术支持。综述了基于MEMS的生物微传感技术,介绍了生物微传感器和生物芯片的原理、结构、分类及应用,并探讨了其发展和应用前景。     

高量程MEMS加速度计封装工艺研究

对一种先进的双悬臂梁高量程MEMS加速度计的单芯片封装工艺进行了失效机理分析。手工粘贴芯片盖板可靠性不高,加速度计失效是由于胶粘剂(粘贴胶或灌封胶 )从芯片盖板和芯片的间隙流淌进入悬臂梁的过载保护间隙,阻碍了悬臂梁的摆动。高量程加速度计采用单芯片封装方法时,存在芯片正面和背面保护的可靠性问题,更好的封装方法是采用圆片级封装。黑胶不适宜用作加速度计的贴片胶,至少使用聚酰亚胺膜作背面保护时如此。     

基于MEMS技术的气体传感器

综述了目前国内外主要MEMS气体传感器的原理,包括谐振式微悬臂梁型、声表面波型、阻抗变化型、声光法、气体光谱、催化燃烧式和高场非对称波形离子迁移谱(FAIMS)检测法。对各种传感器的特点进行了比较。     

High speed LANs based on fiber optics

Fiber technology has come to be the preferred solution in telephony applications and now it appears to be attractive for use in local network applications. In this paper same basic issues related to the impact of fibers on local networks are discussed. In particular, emerging LAN system trends along with the most cost effective solution for use in local network applications are reviewed. Some aspects of the Fiber Distributed Data Interface (FDDI) standard are introduced and main problems related to the voice and digital data integration are also discussed.     

Fabrication of micro-trench structures with high aspect ratio based on DRIE process for MEMS device applications

The micro-trench structures with high aspect ratio based on the single crystal silicon substrate are fabricated via the deep reactive ion etching (DRIE) process at different etching patterns. The relationship between the micro-trench structures and the DRIE etching patterns is investigated by simulating and processing. The micro-trench structures are obtained to meet the requirements of some MEMS devices for special applications. The profile roughness and micro-trench structures are observed by the atomic force-microscope and the field emission scanning electron microscopy. The verticality (V) of micro-trench structures is average 0.19 in the oxygen environment. The micro-trench structures exhibit better verticality, less roughness and better stability than that of no oxygen. The scalloping effects gradually decreased and the profile becomes more and more polished.     

基于低成本MEMS器件的捷联航姿系统设计

针对军事和工程领域对低成本、微小型航姿系统的迫切需求,介绍了自行设计的基于低成本MEMS器件的航姿系统,深入研究了构建该系统的关键技术。针对MIMU的性能特点及核心处理器的运算速度,给出了磁传感器的补偿算法,采用了基于等效旋转矢量的姿态解算方法,并应用了降阶卡尔曼滤波器。通过移植μC/OS-Ⅱ实时操作系统,增强了系统的实时性。实验结果表明,所设计的航姿系统实时性好,精度可达要求,具有广阔的应用前景。     

Research of trackball based on MEMS gyro

为解决精密球体在研磨过程中的研磨轨迹无法测量等问题,将MEMS陀螺仪测量角速度技术应用到球体研磨轨迹的测量中,研究并实现了一种基于MEMS三轴陀螺仪和STM32微控制器的轨迹测量系统.介绍了ITG3200三轴陀螺仪的特点、原理以及轨迹测量系统方案设计;分析了温度影响陀螺仪零偏的机理,基于最小二乘法原理,建立了零偏补偿模型,有效地提高零偏稳定性,满足了工程需要.进行轨迹测量系统的双自转研磨实验,结果表明:双自转研磨方式研磨均匀性较好.     

基于MEMS加速度传感器的无手鼠标

设计一种无手鼠标,使手部残疾或脊髓损伤的患者能够通过无手操作的方式使用计算机。系统以 MSP430F5529为控制芯片,控制放置在头部的 MEMS 加速度传感器测量头部倾角,并将倾角转换为光标位移量来控制光标的移动;利用声控模块和继电器模块设计声控开关,来实现鼠标按键的点击功能;利用 nRF2401无线模块实现鼠标系统与计算机的无线通信。该倾斜鼠标可以使用户通过倾斜头部来控制光标的移动,通过向吹气开关吹气实现鼠标按键的点击功能。该倾斜鼠标可以辅助手部残疾或脊髓损伤的患者通过无手操作的方式有效地控制光标移动,为其使用计算机提供了一种途径。     

Fabrication methods based on wet etching process for the realization of silicon MEMS structures with new shapes

In this paper, fabrication methods are developed in order to realize the silicon microelectromechanical systems components with new shapes in {100} Si wafers. Fabrication process utilizes wet etching with a single step of photolithography. The silicon etching is carried out in complementary metal oxide semiconductor process compatible pure and surfactant Triton-X-100 [C₁₄H₂₂O(C₂H₄O] _n , n = 9–10) added tetramethylammonium hydroxide (TMAH) solutions. The fabricated structures are divided in two categories: fixed and freestanding. The fixed structures are realized in single oxidized silicon wafers, while freestanding are formed in silicon nitride-based silicon on insulator (SOI) wafers. The SOI wafers are prepared by bonding the oxidized and the nitride deposited wafers, followed by thinning and chemical mechanical polishing processes. The etching results such as {100} and {110}Si etch rates, undercutting at rounded concave and sharp convex corners and etched surface morphologies are measured in both pure and Triton added TMAH solutions. Different concentrations of TMAH are used to optimize the etching conditions for desired etched profiles.     

基于MEMS加速度计的输入系统的研究

该文章介绍了一种新的电脑无线输入系统,使用MEMS微加速度计作为系统的敏感元器件.该输入系统包括发射端和接收端两个子系统.文章分别从工作原理、软硬件设计等方面介绍了该输入系统,包括所使用的微加速度计、微处理器和传输模块,并给出了输入系统的第一代实际PCB原型.并且在二维的基础上扩展了微加速度计在三维的应用,设计了一个新的三维模型,并进行了试验的验证.     

基于MEMS传感器的虚拟现实参观系统

提出了一种基于MEMS传感器、LM3S1138嵌入式处理器和Vega仿真平台的虚拟现实参观系统,介绍了系统主机端和手柄模块的系统结构。通过坐标变换的方法将传感器测量值转换成手柄在球坐标系中的状态,并计算出动作指令发送给主机端以改变虚拟场景中的视角。在Vega虚拟场景中对比了理论指令边界和实测指令边界,说明该系统可以达到预期设计目标。     

基于MEMS技术的微型磁性开关阵列

为了在二维微驱动系统中实时检出磁性移动块的存在位置 ,提出并试制了一种基于MEMS工艺的微型磁性开关阵列 ,它作为一种位置传感器通过扫描查询方式工作。对该传感器的工作原理、制做工艺做了详细的描述 ,并给出了一些实验结果。