MEMS虚拟组装设计的建模研究

虚拟组装是基于部件库的MEMS设计系统的重要组成部分,虚拟组装研究的重点在于建立组装模型,以表达部件之间的组装关系和进行组装顺序的规划.本文结合MEMS的层次性特点,提出了增强关联图的组装模型,并在组装关系纵横分类基础上,提出增强关联图的简化算法,最终采用拆卸法完成组装顺序的规划.     

MEMS虚拟组装设计的建模研究

虚拟组装是基于部件库的MEMS设计系统的重要组成部分,虚拟组装研究的重点在于建立组装模型,以表达部件之间的组装关系和进行组装顺序的规划。本文结合MEMS的层次性特点,提出了增强关联图的组装模型,并在组装关系纵横分类基础上,提出增强关联图的简化算法,最终采用拆卸法完成组装顺序的规划。     

面向掩模精化的表面微加工MEMS器件几何建模

MEMS器件设计流程中,为优化MEMS器件,常常需要对MEMS掩模进行精化设计.为了在MEMS精化设计中同步更新MEMS掩模与几何模型,提出一种面向掩模精化的表面微加工MEMS器件几何建模方法.该方法主要通过建立MEMS器件几何模型和工艺模型之间的依赖关系图,通过变动依赖关系,求出掩模精化所影响的几何元素,而后在几何模型中仅仅更新所影响的几何元素;对于所对应的几何模型存在拓扑突变等情况,该方法采用参数限定或局部几何模拟进行更新.实例分析表明,提出的几何建模方法能快速有效地响应掩模精化,从而有效地促进MEMS器件设计.     

基于部件库的MEMS设计方法

针对当前MEMS设计工具中机械性能评测不充分的问题 ,提出了基于部件库的MEMS设计方法 ;介绍了部件及部件库的概念和基于部件库的MEMS设计环境的总体结构及关键技术。完成了各关键技术的攻关 ,并建立了一个原形系统。     

基于部件库的 MEMS 设计方法

针对当前MEMS设计工具中机械性能评测不充分的问题,提出了基于部件库的MEMS设计方法;介绍了部件及部件库的概念和基于部件库的MEMS设计环境的总体结构及关键技术.完成了各关键技术的攻关,并建立了一个原形系统.     

基于部件库的 MEMS 设计方法

针对当前MEMS设计工具中机械性能评测不充分的问题,提出了基于部件库的MEMS设计方法;介绍了部件及部件库的概念和基于部件库的MEMS设计环境的总体结构及关键技术.完成了各关键技术的攻关,并建立了一个原形系统.     

基才部件库的MEMS设计方法

针对当前MEMS设计工具中机械性能评测不充分的问题，提出了基于部件库的MEMS设计方法；介绍了部件及部件库的概念和基于部件库的MEMS设计环境的总体结构及关键技术。完成了各关键技术的攻关，并建立了一个原形系统。     

MEMS系统级设计与基于多端口组件网络的建模方法

MEMS的系统级设计对保证其整体综合性能和合理开发MEMS产品至关重要。针对MEMS的多能量域耦合、多信号混合的特点以及能量非保守等特殊要求 ,提出了基于多端口组件网络的MEMS系统级建模方法———采用多端口组件表示MEMS的功能结构部件 ,组件与组件通过端口联成网络表示整个系统 ;用统一规范化的微分代数方程表征并用硬件描述语言表述多端口组件。针对梁等具体的MEMS功能结构部件 ,采用宏建模方法确定其行为方程 ,从而得到有特定物理意义的、可供重用的组件模型。最后 ,给出了微加速度计的基于多端口组件网络方法的系统级设计示例     

MEMS系统级设计与基于多端口组件网络的建模方法

MEMS的系统级设计对保证其整体综合性能和合理开发MEMS产品至关重要.针对MEMS的多能量域耦合、多信号混合的特点以及能量非保守等特殊要求,提出了基于多端口组件网络的MEMS系统级建模方法--采用多端口组件表示MEMS的功能结构部件,组件与组件通过端口联成网络表示整个系统;用统一规范化的微分代数方程表征并用硬件描述语言表述多端口组件.针对梁等具体的MEMS功能结构部件,采用宏建模方法确定其行为方程,从而得到有特定物理意义的、可供重用的组件模型.最后,给出了微加速度计的基于多端口组件网络方法的系统级设计示例.     

MEMS系统级设计与基于多端口组件网络的建模方法

MEMS的系统级设计对保证其整体综合性能和合理开发MEMS产品至关重要。针对MEMS的多能量域耦合、多信号混合的特点以及能量非保守等特殊要求，提出了基于多端口组件网络的MEMS系统级建模方法——采用多端口组件表示MEMS的功能结构部件，组件与组件通过端口联成网络表示整个系统；用统一规范化的微分代数方程表征并用硬件描述语言表述多端口组件。针对梁等具体的MEMS功能结构部件，采用宏建模方法确定其行为方程，从而得到有特定物理意义的、可供重用的组件模型。最后，给出了微加速度计的基于多端口组件网络方法的系统级设计示例。     

Yield analysis of optical MEMS assembly Process using a Monte Carlo Simulation technique

We developed a statistical Monte Carlo technique for the performance estimation of optical microelectromechanical systems (MEMS) components taking into account the randomness nature of its assembly. The developed technique is applied on the 2/spl times/2 moving mirror optical MEMS switch as a typical example to study its performance under realistic passive-alignment conditions. The obtained results enable us to evaluate the assembly process capability and to analyze the performance sensitivity to different fabrication parameters. This enables us to establish a design for manufacturability technique for the optical MEMS components.     

Rare-earth-enabled universal solders for microelectromechanical systems and optical packaging

In packaging of microelectromechanical systems (MEMS), optical, and electronic devices, there is a need to directly bond a wide variety of inorganic materials, such as oxides, nitrides, and semiconductors. Such applications involve hermetic-sealing components, three-dimensional MEMS assembly components as well as active semiconductor or optical components, dielectric layers, diffusion barriers, waveguides, and heat sinks. These materials are known to be very difficult to wet and bond with low melting-point solders. New Sn-Ag- or Au-Sn-based universal solders doped with a small amount of rare-earth (RE) elements have been developed, which now allow direct and powerful bonding onto the surfaces of various MEMS, optical, or electronic device materials. The microstructure, interface properties, and mechanical behavior of the bonds as well as the potential packaging applications of these new solder materials for MEMS and optical fiber devices are described. Various packaging-related structural, thermal, or electrical issues in MEMS are also discussed.     

MEMS光开关及其与光纤组装方式的研究

光开关是一种在光路中应用极其广泛的光无源器件,可用于扫描、投影、通讯等多种不同的领域,其中用于全光通讯中连接光纤之间的光开关日渐成为人们关注的焦点.高性能、低成本、又能大量生产的MEMS光开关很好地满足了全光网络对器件的要求.本文对这种MEMS光纤光开关的类型、特点以及研究现状进行了介绍,并给出了MEMS光开关与输入输出光纤的组装与自组装以及主要方式.     

MEMS器件中的微体缺陷检测研究

为实现对硅基材料和MEMS器件内微体缺陷的无损、高效和准确检测，在研究广义洛仑兹-米氏散射理论的基础上，针对硅基材料和MEMS器件的物理特点，对球形缺陷与红外激光相互作用在非垂直方向散射光强分布特点进行了研究和计算机仿真，提出利用红外激光背散射分布分析对硅基材料和MEMS器件内部缺陷进行检测的方法，并通过实验验证了该方法的有效性。     

Modal Properties of Long-Wavelength Tunable MEMS-VCSELs With Curved Mirrors: Comparison of Experiment and Modeling

The effective interplay of simulation and experimental results for analysis and optimization of microelectromechanical system (MEMS)-tunable vertical-cavity surface-emitting lasers (VCSELs) operating at wavelength around 1.55 mum is presented. The VCSEL combines a MEMS with concave Al-GaAs-GaAs mirror membrane and an InP-based active cavity with tunnel junction aperture in a hybrid two-chip assembly. Using electrothermal MEMS actuation the included air-gap can be expanded and the cavity resonance can be tuned to longer wavelengths. The experimental results are compared with the theoretical results provided by VELM (VCSEL ELectroMagnetic), the efficient code based on the coupled mode model and adapted for the first time to handle curved-mirror geometries. The vectorial code is found to be able to fully reproduce the experimental results, such as device tuning range, modal frequency splitting, threshold gains and modal selectivity.     

Optimizing the performance of a surface mount placement machine

Process planning is an important and integral part of effectively operating a printed circuit board (PCB) assembly system. A PCB assembly system generally consists of different types of placement machines, testing equipment, and material handling equipment. This research develops a new solution approach to determine the component placement sequence and feeder arrangement for a turret style surface mount-placement machine often used in PCB assembly systems. This solution approach can be integrated into a process planning system to reduce assembly time and improve productivity. The algorithm consists of a construction procedure that uses a set of rules to generate an initial component placement sequence and feeder arrangement along with an improvement procedure to improve the initial solution. An industrial case study conducted at Ericsson, Inc., using a Fuji CP4-3 machine and actual PCB data, is presented to demonstrate the performance of the proposed solution approach. The solutions obtained using the proposed solution approach are compared to those obtained using state of the art PCB assembly process optimization software. For all PCBs in the case study, the proposed solution approach yielded lower placement times than the commercial software, thus generating additional valuable production capacity. This research is applicable for both researchers and practitioners in printed circuit board assembly systems     

RF MEMS switch integrated on printed circuit board with metallic membrane first sequence and transferring

This letter reports, for the first time, on RF MEMS switches integrated on flexible printed circuit boards (i.e., FR-4) using transfer technology. The devices were first processed on Si-substrate using a modified MEMS sequence and subsequently transferred onto an FR-4 substrate by thermal compressive bonding, mechanical grinding, and wet removal of silicon. The switches were demonstrated with flat metal membrane (top electrode), precisely controlled gap between the membrane and bottom electrode, low insertion loss (/spl les/ 0.15 dB at 20 GHz), and high isolation (/spl sim/ 21 dB at 20 GHz). This technology shows the potential to monolithically integrate RF MEMS components with other RF devices on organic substrate for RF system implementation.     

软件无线电中RF-MEMS元件

本文分析了软件无线电系统中的MEMS(Micro-Electric-Machine-Systems)解决方案、及其可应用于软件无线电系统中的MEMS器件,主要有对称锥形弯曲缝隙微带天线、用于G波段的微尺度宽频天线、微机械自适应帖片天线、高Q值、双频段MEMS开关、薄膜体声波谐振器、腔结构微机械谐振器、分布式MEMS传输线微机械滤波器等典型的MEMS器件,这些器件克服了普通射频器件体积大,功耗高等缺点,有望在软件无线电系统中得到应用。最后,对MEMS器件在软件无线电系统中的应用做了展望。     

Packaging influences on the reliability of MEMS resonators

In this paper, the effect of assembly processes on the reliability of MEMS resonators is investigated. The common functions of MEMS resonators in the current technology are described as well as the most common designs. Virtual prototyping of a resonator during several assembly steps is used to estimate their influence. Experiments are executed in order to verify the simulation results. These experiments are also used to find yet unknown failure modes.