Generation of component level fault models for MEMS

Component level (nodal) simulations have been proposed to both implement closed loop simulation of complete microsystems to support the migration to shorter design cycles and implement fault models of micromechanical components. Within such a simulation environment, library cells in the form of behavioural models are used for the basic components of microelectromechanical (MEM) transducers, such as beams, plates, comb-drives and membranes. This paper presents both methodologies to generate the model parameters required for the implementation of accurate component fault models and simulation results from representative defective structures in a MEMS product.     

Generation of Electrically Induced Stimuli for MEMS Self-Test

A major task for the implementation of Built-In-Self-Test (BIST) strategies for MEMS is the generation of the test stimuli. These devices can work in different energy domains and are thus designed to sense signals which are generally not electrical. In this work, we describe, for different types of MEMS, how the required non-electrical test stimuli can be induced on-chip by means of electrical signals. This provides the basis for adding BIST strategies for MEMS parts embedded in the coming generation of integrated systems. The on-chip test signal generation is illustrated for the case of MEMS transducers which exploit such physical principles as time-varying electrostatic capacitance, piezo-resistivity effect and Seebeck effect. These principles are used in devices such as accelerometers, infrared imagers, pressure sensors or tactile sensors. For implementation, we have used two major MEMS technologies including CMOS-compatible bulk micromachining and surface micromachining. We illustrate the ability to generate on-chip test stimuli and to implement a self-test strategy for the case of a complete application. This corresponds to an infrared imager that can be used in multiple applications such as overheating detection, night vision, and earth tracking for satellite positioning. The imager consists of an array of thermal pixels that sense an infrared radiation. Each pixel is implemented as a suspended membrane that contains several thermopiles along the different support arms. The on-chip test signal generation proposed requires only slight modifications and allows a production test of the imager with a standard test equipment, without the need of special infrared sources and the associated optical equipment. The test function can also be activated off-line in the field for validation and maintenance purposes.     

On-Chip Pseudorandom MEMS Testing

This paper presents a Built-In-Self-Test (BIST) implementation of pseudo-random testing for MEMS. The technique is based on Impulse Response (IR) evaluation using pseudo-random Maximum–Length Sequences (MLS). The MLS approach is capable of providing vastly superior dynamic range in comparison to the straightforward technique using an impulse excitation and is thus an optimal solution for measurements in noisy environments and for low-power test signals. The use of a pseudo-random sequence makes the practical on-chip implementation very efficient in terms of the extra hardware required for on-chip testing. We will demonstrate the use of this technique for an on-chip fast and accurate broadband determination of MEMS behaviour, in particular for the characterisation of cantilever MEMS structures, determining their mechanical and thermal behaviour using just electrical tests.Libor Rufer has received Engineering and PhD degrees from the Czech Technical University, Prague, Czech Republic. Until 1993 he was with the Faculty of Electrical Engineering of the Czech Technical University, Prague and since 1994, he is Associate Professor at the Joseph Fourier University, Grenoble, France. In 1998, he joined the Microsystems research team of the TIMA Laboratory. Currently he is a member of the Reliable Mixed-signal Systems Group of the same Laboratory. His expertise and research interests pertain MEMS-based sensors and actuators, electro-acoustic and electro-mechanical transducers, their modelling, applications, associated measurement techniques, and analogue and mixed-signal system test.Salvador Mir has an Industrial Engineering (Electrical, 1987) degree from the Polytechnic University of Catalonia, Barcelona, Spain, and M.Sc. (1989) and Ph.D. (1993) degrees in Computer Science from the University of Manchester, UK. He is a researcher of Centre National de la Recherche Scientifique, France, and he is leading the RMS (Reliable Mixed-signal Systems) Group at TIMA Laboratory in Grenoble, France. He is the author of many research papers and editor of two books on silicon microsystems. His research interests include analogue, mixed-signal, RF and microsystem design and test, and applications of Artificial Intelligence to Computer-Aided Design.Emmanuel Simeu received Electrical Engineering degree, DEA and Ph.D. in Automatic Control from National Polytechnic Institute of Grenoble in 1987, 1988 and 1992, respectively. He is Associate Professor of Automatic Control and Electrical engineering in Joseph Fourier University of Grenoble. He is also a researcher in the RMS Group at TIMA Laboratory. His research interests include system modelling, reliability of integrated systems, online testing of analogue, digital and mixed signal systems.Christian Domingues was born in Lyon, France, in 1978. He received a Master degree in Microelectronics from the Institut National Polytechnique de Grenoble, France, in 2001. He is currently pursuing a Ph.D. degree at TIMA Laboratory in Grenoble, France. His research interests include mixed-signal integrated circuit design, and micromachined sensors and actuators.     

Pseudorandom BIST for test and characterization of linear and nonlinear MEMS

In this paper we study the use of the pseudorandom (PR) technique for test and characterization of linear and nonlinear devices, in particular for micro electro mechanical systems (MEMS). The PR test technique leads to a digital built-in-self-test (BIST) technique that is accurate in the presence of parametric variations, noise tolerant, and has high-quality test metrics. We will describe the use of the PR test technique for testing linear and nonlinear MEMS, where impulse response samples of the device under test are considered to verify its functionality. Next, we illustrate and evaluate the application of this technique for linear and nonlinear MEMS characterization.     

Self-tuning fault diagnosis of MEMS

Multiple-model adaptive estimation techniques have been previously successfully applied to fault diagnosis of microsystems. Their diagnosis performance highly depends on the accuracy of modeling techniques used in representing faults. This paper presents the application of a self-tuning forgetting factor technique in the modeling of faults in MEMS and its effects on diagnosis performance compared with the application of Kalman filters and fixed gain estimation techniques. The self-tuning-based modeling used in the diagnosis algorithm was experimentally implemented. It demonstrated superior results compared to Kalman filter and fixed gain estimation techniques by accelerating the diagnosis process.     

微机电安全密码锁的设计技术

微机电安全密码锁是一类用于确保“要害系统”安全性的装置 ,也可称为微锁、微型组合锁、微型密码鉴别器或微型使用控制开关。本文重点介绍了微机电安全密码锁的基本功能单元 :即鉴别器机构、驱动器与能量耦合器 ,结合工作原理的分析 ,探讨了装置总体设计中应考虑的关键问题     

硅基梳齿式MEMS器件及封装的失效调查

对典型硅基梳齿式MEMS器件进行失效调查和分析,验证其主要失效模式,分析其失效机理.利用电子扫描显微镜(SEM),X射线透视系统、扫描声学显微镜(SAM),X射线能谱成份分析(EDX)、金相切片分析、封装气体分析及电性能测试等分析技术,发现在工艺制造中的机械失效是造成此类器件失效的主要原因.另外,此类器件的封装失效主要表现为气密性失效和装配工艺失效.     

焊料键合实现MEMS真空封装的模拟

结合典型的焊料键合MEMS真空封装工艺,应用真空物理的相关理论,建立了封装腔体的真空度与气体吸附和解吸、气体的渗透、材料的蒸气压、气体通过小孔的流动等的数学模型,确定了其数值模拟的算法．通过实验初步验证了模拟结果的准确性,分析了毛细孔尺寸对腔体和烘箱真空度的影响,实现了MEMS器件真空封装工艺的参数化建模与模拟和仿真优化设计．     

微机电系统基于端口的多领域建模和仿真

微机电系统是典型的多领域复杂系统,需要一种能够将复杂组件和子系统紧密集成跨领域的通用建模和仿真方法.介绍了微机电系统设计和仿真的现状,给出了基于端口的多领域建模概念,分析了其建模基础和基于VHDL-AMS、键合图和线图的实现方法,并给出了组件层次仿真的实现方法.分析表明,基于端口的建模实现了多领域物理现象的统一描述,并通过界面与实现的分离,实现了自上而下的层次化建模,可用一种仿真语言和仿真器实现整个MEMS系统的建模与仿真.     

MEMS技术对火控系统的影响

结合火控系统的发展趋势 ,说明了MEMS技术在火控系统中的应用 ,分析了MEMS技术在机械结构、系统性能以及体系结构等方面对火控系统的影响     

Study, comparison and application of different VHDL-based fault injection techniques for the experimental validation of a fault-tolerant system

In this work different VHDL-based fault injection techniques (simulator commands, saboteurs and mutants) have been compared and applied in the validation of a fault-tolerant system. Some extensions and implementation designs of these techniques have been introduced. As a complement of these injection techniques, a wide set of fault models (including several non-usual models) have been implemented. We have injected both transient and permanent faults on the system model, using two different workloads, with the help of a fault injection tool that we have developed. We have studied the pathology of the propagated errors, measured their latencies, and calculated both detection and recovery coverages. Results show that coverages for transient faults can be obtained quite accurately with any of the three techniques. This enables the use of different abstraction level models for the same system. We have also verified significant differences in implementation and simulation cost between the studied injection techniques.     

一种用于微拉伸系统的MEMS弹簧设计与制作

针对微拉伸测试系统支撑梁因塑性变形带来的误差,采用UV-LIGA技术制备出S型支撑弹簧来代替刚性梁,这样即可测量大变形薄膜的力学性能.实验结果表明,用UV-LIGA工艺制备的Ni金属S形弹簧具有良好的均匀性,在较大的变形范围内有很好的线弹性.     

射频微机电系统技术现状

较全面地介绍了 RF MEMS 器件、由 RF 器件构成的组件及应用系统,并给出了一些新的典型示例。通过比较 RF MEMS 器件与传统微波器件在性能、尺寸等各方面的差别,可以了解 RF MEMS 技术在相控阵雷达上运用的优势。     

MEMS传感器开创汽车主动安全系统的新时代

本文试图让从事汽车电子系统设计的工程经理以及工程师概要了解MEMS传感器在汽车安全系统设计创新中的应用,全球主要MEMS传感器系统制造商和半导体公司,从而了解产业发展的现状和趋势。     

基于湿法刻蚀的MEMS压印模版制作

介绍了一种基于玻璃湿法刻蚀低成本的MEMS压印模版制作工艺,工艺中以单层光刻胶作为刻蚀掩模,重点研究了改善刻蚀图形几何轮廓和提高表面质量的方法。在对钻蚀形成机理进行分析的基础上,通过对比偶联剂不同涂敷方式及不同蒸镀时间对刻蚀结果的影响,优化了硅烷偶联剂的涂敷工艺,使钻蚀率降低到0.6,图形几何形状得到改善。分析了刻蚀生成物的溶解度,采用HCl作为刻蚀液添加剂对刻蚀产生的难溶物进行分解,提高了表面质量。对刻蚀表面缺陷的形成原因进行了分析,采用厚胶层工艺消除了表面缺陷。利用该工艺制作了图形特征尺寸为100μm的MEMS压印模版,并进行了初步压印实验,得到了很高的复型精度。     

碳纳米管在MEMS微电极中的应用研究

采用丝网印刷技术,将配制好的碳纳米管浆料涂敷到金属衬底上,形成碳纳米管薄膜,用四探针仪及表面轮廓仪分别测量了薄膜的方块电阻和表面粗糙度。结果表明,将碳纳米管球磨1 h,以质量比10%~12%与有机溶剂混合配制成浆料,丝网印刷后在真空烘箱内加热至100℃,干燥1 h,最后350℃烧结40 min,所获得的碳纳米管薄膜具有较好的导电性和较平整的表面。根据测量结果,优化了工艺参数,并结合微细加工技术获得了碳纳米管MEMS微电极。     

Electromagnetic modelling of conductor-backed CPW based RF MEMS capacitive shunt switch

This article will detail the creation of an electromagnetic model of an RF MEMS capacitive shunt switch using the conductor-backed CPW configuration. Full-wave S-parameter analysis has been carried out to extract the S-parameter of the switches for different variants. The modelling also covers the effect of the tapering of the RF signal line as well as the permittivity variation on the switch parameters. Further, the ground metallisation effect because of the CB-CPW configuration on the switch parameters has been modelled and compared with the standard topology. A scalable lumped circuit model for the proposed topology has been generated which can be easily incorporated in the circuit simulator. The topology demonstrated can achieve frequency downscaling without increasing the size and complexity of the circuit. Comparison of modelled and full wave simulated results shows good agreement.     

MEMS封装技术的发展及应用

封装技术在微电子机械系统(MEMS)器件中的地位和作用越来越重要。本文归纳与总结了MEMS封装的特点和发展趋势,重点对MEMS封装技术的应用进行了分析,最后给出一些有益的想法和看法。     

毛细作用驱动的MEMS流体自组装模拟仿真

介绍了毛细作用驱动的MEMS流体微器件自组装技术的研究和发展概况,并对组装中的自对准过程进行了模拟仿真。通过仿真模拟,证明即使在器件与衬底组装区域形状大小不同时,仍可能实现自对准。这说明自组装对组装器件和衬底粘合层的形状尺寸匹配精度的要求不苛刻。同一个衬底粘合层的版图将可能适用于具有不同尺寸粘合层的器件进行安装,反之拥有同样粘合层的器件则可能安装到不同的衬底中。这些结论有助于未来更合理地设计自组装系统。     

毛细作用驱动的MEMS流休自组装模拟仿真

介绍了毛细作用驱动的MEMS流体微器件自组装技术的研究和发展概况，并对组装中的自对准过程进行了模拟仿真。通过仿真模拟，证明即使在器件与衬底组装区域形状大小不同时，仍可能实现自对准。这说明自组装对组装器件和衬底粘合层的形状尺寸匹配精度的要求不苛刻。同一个衬底粘合层的版图将可能适用于具有不同尺寸粘合层的器件进行安装，反之拥有同样粘合层的器件则可能安装到不同的衬底中。这些结论有助于未来更合理地设计自组装系统。