金刚石膜MEMS及其应用

由于金刚石膜优异的力学、电学、热学及化学性质,使其成为MEMS中的微型传感器和微型结构的重要的首选材料。利用金刚石膜作为MEMS材料和各种微型机械的技术正在引起极大的兴趣。本文主要综述了金刚石MEMS器件的技术和应用。     

MEMS传感器现状及应用

MEMS传感器种类繁多,发展迅猛,应用广泛。首先,简单介绍了MEMS传感器的分类和典型应用。其次,对MEMS压力传感器、加速度计和陀螺仪三种最典型的MEMS传感器进行了详细阐述,包括类别、技术现状和性能指标、最新研究进展、产品,及应用情况。介绍MEMS压力传感器时,给出了国内外采用新型材料制作用于极端环境下压力传感器的研究情况。最后,从新材料、加工和组装技术方面对MEMS传感器的发展趋势进行了展望。     

Integrating microelectromechanical systems with integrated circuits

From the very beginning, integration of microelectromechanical systems (MEMS) with integrated circuits (ICs) was a major attraction of silicon micromachining technology. Significant progress toward integrating MEMS with ICs technologies has been made over the last four decades. Many products have been introduced and the benefits of such integration have been demonstrated. One of the most attractive developments, during the period of time called the Optical Bubble, was the vertical MEMS-IC integration, pioneered by Transparent Networks. It enabled a short path to merging VLSI electronics with MEMS. This approach can be easily applied to capacitive sensors, such as pressure, acceleration, gyro, and vacuum sensors, as well as to a broad range of other products.     

Rapid Manufacturing of Intelligent Mold With Embedded Microsensors

The objectives of this research are to integrate the laser-powered direct metallic rapid tooling (RT) system and the microelectromechanical-system (MEMS)-based microtemperature sensors, and to develop the intelligent direct metallic RT mold with embedded MEMS-based microsensors. Since the quantity demand for complicated mold of high-class products is increasing, the development of RT technology is also growing correspondingly fast. With the continuing improvement of semiconductor fabrication and MEMS techniques, it allows us to fabricate much smaller sensors. The MEMS-based microtemperature sensors have been successfully fabricated by MEMS technology. The sensors have been shown to have temperature effect, and were able to obtain accurate temperature measurement after calibration with real temperature coefficient of resistance (TCR) ranging from -0.294 to -0.366%/degC. This microsensor-embedded approach is proposed in order to rapidly measure global and local temperature and pressure distribution inside the RT's core and cavity during the injection, hold, and cooling process. This research's approach with MEMS-based microtemperature sensors has demonstrated the feasibility and the advancement of another milestone in automated injection molding     

Multi-layer microstructure fabrication by combining bulk silicon micromachining and UV-LIGA technology

A novel method for fabrication of multi-layer microstructures of microelectro-mechanical system (MEMS) devices is described. This technique, which combines bulk silicon micromachining technique and UV-LIGA technique can overcome some shape limitations of single technique on complex microstructures. To demonstrate this combination, the SU-8 microstructure fabricated in the etched silicon grooves is presented. In this fabrication process, a SU-8 removal method by fuming sulfuric acid was introduced and a novel type of plastics PETG was tried in microhot embossing process. The proposed fabrication process can be applied to fabricating a high-aspect-ratio microstructure for a large displacement actuator and precision sensors. Moreover, this combined process enables the fabrication of more complex structures, which cannot be fabricated by bulk micromachining or UV-LIGA alone.     

The HARPSS process for fabrication of precision MEMS inertial sensors

The high aspect-ratio combined poly- and single-crystal silicon micromachining technology (HARPSS) and its application to fabrication of precision MEMS inertial sensors are presented. HARPSS is a single wafer, all silicon, front-side release process which is capable of producing 10–100's of microns thick, electrically isolated, 3-D poly- and single-crystalline silicon microstructures with various size air-gaps ranging from sub-micron to tens of microns. High aspect-ratio (>50:1) polysilicon structures are created by refilling 100's of microns deep trenches with polysilicon deposited over a sacrificial oxide layer. This technology provides features required for precision micromachined inertial sensors. The all-silicon feature of this technology improves long term stability and temperature sensitivity while fabrication of large area, vertical electrodes with sub-micron gap spacing will increase the sensitivity by orders of magnitude.     

The GaAs exclusion zone

Thanks to SiGe, silicon continues to threaten GaAs in the amplifier business. New products incrementally encroach on what used to be the GaAs exclusion zone. The SiGe market* is now worth around US$270m pa and will likely grow to US$720m by 2006, but this is conditional on many factors.     

MEMS reliability: Where are we now?

This paper reviews the significant successes in MEMS products from a reliability perspective. MEMS reliability is challenging and can be device and process dependent, but exercising the proper reliability techniques very early in product development has yielded success for many manufacturers. The reliability concerns of various devices are discussed including ink jet printhead, inertial sensors, pressure sensors, micro-mirror arrays, and the emerging applications of RF switches and resonators. Metal contacting RF switches are susceptible to hydrocarbon contamination which can increase the contact resistance over cycle count. Packaging techniques are described in the context of the whole reliability program.     

MEMS磁场传感器的研究进展

磁场检测在工农业生产和人们日常生活中非常普遍。随着微电子机械（MEMS）的发展，用MEMS技术研制磁场传感器正获得越来越多的研究。基于MEMS磁场传感器的原理，对各类磁场传感器做了简要介绍，评述了各种MEMS磁场传感器的加工工艺及工作原理，并对MEMS磁场传感器的发展进行了展望。     

MEMS惯性传感器可靠性试验方法研究

MEMS惯性传感器在军事与商业应用中的一个主要问题便是可靠性试验方法尚未标准化,因而目前绝大多数MEMS惯性传感器器件的可靠性试验依据的是傲电子的试验标准。但是,这些标准对于这类器件的适用性却受到许多机构的质疑,国外关于该问题的研究也已起步。汇总了MEMS惯性传感器器件的结构和工作原理等信息,重点总结了该类器件的典型环境失效机理,并将典型的环境载荷情况与失效机理进行了对比分析：从现有的微电子可靠性试验标准中选取了针对不同环境失效机理的试验方法。并对其适用性问题进行了讨论。     

面向Micro-IMU的MEMS三维可折叠系统的设计与研制

提出了一种面向微惯性测量单元(Micro-IMU)应用的微电子机械系统(MEMS)三维可折叠结构,其主要组成部分包括绝缘层上硅(SOI)基底、聚酰亚胺柔性链、金属线以及MEMS多环陀螺仪。文章基于有限元仿真技术,分析了可折叠结构及器件的可行性。基于SOI一体化MEMS技术,将核心传感器的制作工艺与折叠结构工艺相结合,在结构中搭载单轴圆盘多环谐振微陀螺,利用柔性铰链实现结构的三维折叠以及各个传感器之间的电互连,实现单轴惯性传感器的集成,制备出体积为1cm3、质量为250mg的搭载多环谐振微陀螺的三维可折叠系统。     

Deformation analysis in microstructures and micro-devices

The mechanical behaviors of microstructures and micro-devices have drawn the attention from researchers on materials and mechanics in recent years. To understand the rule of these behaviors, the deformation measurement techniques with micro/nanometer sensitivity and spatial resolution are required. In this paper, a micro-marker identification method is developed to measure microstructure deformation. The micro-markers were directly produced on the top surface of microstructures by taking advantage of ion milling of focused ion beam (FIB) system. Based on the analysis of marker images captured by electronic microscope with specific correlation software, the deformation information in microstructures can be easily obtained. The principle of the technique is introduced in detail in the paper. An example experiment was executed to measure the displacement and strain distribution in a MEMS device. Obtained results show that the technique can be well applied to the deformation measurement of the micro/nano-electro-mechanical-systems (MEMS/NEMS).     

Application of MEMS technology in automotive sensors and actuators

Sensors and actuators are the critical system components that collect and act on information in the analog environment and link it to the world of digital electronics. The functional groups of sensors, software, controller hardware, and actuators from the backbone of present and future automotive systems. Unit volumes for sensors and actuators in the automotive industry are measured in millions per year and at a unit cost of a few dollars. The design of sensors and actuators has increasingly made use of microelectromechanical systems (MEMS) technology. This technology is well suited to producing a class of micromachined sensors and actuators that combines signal processing and communications on a single silicon chip or contained within the same package. This paper contains a discussion of the issues in producing MEMS sensors and actuators from the concept selection stage to the manufacturing platform. Examples of commercial and emerging automotive sensors and actuators are given, which illustrate the various aspects of device development. Future trends in MEMS technology as applied to automotive components are also discussed     

基于薄膜结构的MEMS技术研究

报导了基于低应力自支撑SiNx薄膜结构的MEMS部分研究结果,包括从薄膜生长工艺、内应力和薄膜微观结构控制、薄膜的物性分析、镂空自支撑薄膜结构的工艺制作、自支撑薄膜结构动力学的有限元模拟、到最后镂空自支撑薄膜结构在MEMS系统中的应用所做的部分研究工作。     

TV advertising highlights energy wastage in UK industry

A new advertising campaign, called ‘Lifeblood’, highlights the fact that British small business is wasting as much as 30% of its energy consumption. With small and medium enterprises (SMEs) facing an annual energy bill of £3.5 billion (US$6 billion), this amounts to a total loss of £1.1bn ($1.9bn), or £7000 ($12 000) on average per business.     

埋入式无线MEMS 应变片系数的标定

本文研究了一种埋入式MEMS（微电子机械系统）无线应变片性能的实验标定方法，通过引入一个当量应变片，遵照标准应变片的标定规定，本文设计了实用有效的实际标定步骤，分别对标准应变片和MEMS试样进行完全相同的拉伸实验，从而得到埋入MEMS应变片的应变片系数（灵敏度）为13，同时获得在实验试样的制作条件下，测量应变与实际应变之比为2。     

Reliability of vacuum packaged MEMS gyroscopes

The greatest challenge for the successful commercialization of MEMS (micro-electro-mechanical system) technology is proving its reliability. Of concern in particular are the reliability and long-term stability of wafer level vacuum packaged MEMS gyroscope sensors subjected to cyclic mechanical stresses at high frequencies. In this study, we carried out several reliability tests and investigated the failure mechanisms of the anodically bonded vacuum gyroscope sensors designed for commercial electronic products. Particularly we studied mechanical reliability issues such as fatigue, shock, and vibration. It was found that successful vacuum packaging could be achieved through the optimization of the bonding process by reducing leakage and the deposition of titanium coating for reducing out-gassing inside the cavity. The effects of the pre-baking process are also described in this study. The current design of the gyroscope structure is found to be safe from fatigue failure for the 1000 h of operation test. The MEMS gyroscope sensor survives the drop and vibration qualification tests for electronic products without any damage, indicating the robustness of the sensor. The reliability test results presented in this study demonstrate that the MEMS gyroscope sensor is very close to commercialization.     

A review: crystalline silicon membranes over sealed cavities for pressure sensors by using silicon migration technology

A silicon pressure sensor is one of the very first MEMS components appearing in the microsystem area.The market for the MEMS pressure sensor is rapidly growing due to consumer electronic applications in recent years.Requirements of the pressure sensors with low cost,low power consumption and high accuracy drive one to develop a novel technology.This paper first overviews the historical development of the absolute pressure sensor briefly.It then reviews the state of the art technology for fabricating crystalline silicon membranes over sealed cavities by using the silicon migration technology in detail.By using only one lithographic step,the membranes defined in lateral and vertical dimensions can be realized by the technology.Finally,applications of MEMS through using the silicon migration technology are summarized.     

三维微结构制作现状与进展

随着微机电系统(MEMS)的深入研究和快速发展,三维微细加工技术对于微机电的开发和生产具有非常重要的意义.详细介绍了现阶段三维微结构各种制作方法和工艺技术,分析了其原理和特点,比较了各种方法的优劣;讨论了三维微结构开发现状及有待解决的关键技术,综述了利用电子束曝光技术进行三维微结构制作的应用现状并指出了其发展前景.     

SiP与PoP

文章介绍了SiP与PoP的特点、市场、产品和设计工具。手机、数码相机等便携式数字电子产品是推动SiP、PiP和PoP的主动力。2010年SiP产品市场预计将达100亿美元;2009年PoP、PiP产品市场出货量预计将达21亿块。PoP比PiP更先进,PoP封装中底部为逻辑器件(如基带处理器、应用处理器、多媒体处理器),顶部为存储器。两种器件一般采用FBGA封装,焊球凸起(点)直径300μm,焊球节距0.65mm。