基于SOI衬底的一种新型磁敏晶体管研究

设计了一种基于SOI衬底且由新型磁敏晶体管组成的磁敏测量电路。理论分析了n^＋-π-n^＋晶体管基区长度大于载流子有效扩散长度Leff时的磁灵敏度。该磁敏晶体管可应用于磁场的测量,实验结果表明在磁场B=0．1T时,这种新型结构给出高的磁灵敏度即△Ic/Ic≈20%,并且有很好的电控制特性。该磁敏晶体管的槽形复合区采用MEMS技术制造。     

MEMS高量程加速度传感器压膜阻尼效果分析

为实现一种高量程加速度传感器的近临界阻尼设计以提高其输出性能,采用有限元方法分别研究了阻尼带隙宽度、阻尼介质特性及温度等对器件冲击性能的影响。结果表明:器件冲击响应是受迫振动与悬梁固有振动叠加;随着阻尼带隙变宽,悬梁固有振动渐突显,峰值电压增加;阻尼介质粘滞系数越大,其峰值电压越低;介质温度对器件输出特性影响不大。在常温空气介质中,过载保护曲面平移距离为0.5μm时,阻尼比为0.24,近临界阻尼,输出电压高达77.9mV。     

终端式MEMS微波功率传感器的结构模拟

在工艺流程以及材料选择的基础上,用Coventorware和HFSS对间接加热终端式MEMS微波功率传感器进行了模拟与设计。模拟结果包括共面波导(CPW)与终端电阻上的温度分布,以及热电堆的接近对CPW性能的影响。确定了热偶对数为50,热电堆与CPW之间的距离为50μm,并选择了GaAs和Au作为热电偶的两臂,TaN作终端电阻。     

微机电光学电流传感器的设计

提出了一种检测50Hz交流电的微机电光学电流传感器。通过电磁学、微机电与光学方法说明了传感器的敏感原理与光学转换原理,结合工艺条件给出了器件的设计要求,并利用matlab软件模拟分析了传感器的仿真测试结果。计算表明,器件可以测试1~7.2kA的交流电,大电流下的灵敏度可达到0.01dB/A以上。     

Design and optimization of an integrated MEMS gas chamber with high transmissivity

Non-Dispersive InfraRed (NDIR) gas sensor is widely used for gas detection in collieries and the gas chemical industry, etc. The performance of the NDIR gas sensor depends on the volume, optical length and transmittance of the gas chamber. However, the existing gas sensor products have problems of large volume, high cost and incapable of integration, which need to develop towards the miniaturized sensor. This paper first presents the theoretical background of the NDIR gas sensor and the novel structure of a fully integrated infrared gas sensor and its micro-machined gas chamber structure. Then, the light structure and the gas flow of the gas chamber are optimized on Tracepro software and Ansys workbench, respectively, and the technological process for preparing the Micro-Electro-Mechanical System (MEMS) gas chamber is designed. Finally, we produce a gas chamber with a small volume and good transmissivity, which would be the most important part of producing the miniaturized NDIR gas sensor.     

微笔直写成型聚酰亚胺图形工艺研究

选用均苯四甲酸二酐(PMDA)、4,4′-二氨基二苯醚(ODA)为单体,通过低温缩聚反应制备了PMDA-ODA型聚酰胺酸溶液,通过调节其黏度特性使之适合于微笔直写沉积工艺.采用微笔直写沉积PAA溶液和热亚胺化处理两步法制作出PI图形,并通过Au/PI微桥阵列结构实例显示了该工艺在MEMS聚合物牺牲层或结构层制造领域的应用潜力.     

求解力电耦合方程的控制弧长法

静电作用下的柔性薄板是微电机械的核心部件,其控制方程是变形控制方程和静电平衡方程构成的一组非线性耦合方程.本文在分别给出求解这两组方程数值方法的基础上,把控制弧长法进行了合理的推广,变直接加载电压为由构型控制的电压加载方式.结果表明这种方法不仅能够克服收敛性难的问题,而且能够得到致动板吸入失稳后的构形.算例还表明用本方法计算的吸入临界值要比用解析模型得到的临界值更接近实验值.     

Flexible Liquid Crystal Polymer Technologies from Microwave to Terahertz Frequencies

With the emergence of fifth-generation (5G) cellular networks, millimeter-wave (mmW) and terahertz (THz) frequencies have attracted ever-growing interest for advanced wireless applications. The traditional printed circuit board materials have become uncompetitive at such high frequencies due to their high dielectric loss and large water absorption rates. As a promising high-frequency alternative, liquid crystal polymers (LCPs) have been widely investigated for use in circuit devices, chip integration, and module packaging over the last decade due to their low loss tangent up to 1.8 THz and good hermeticity. The previous review articles have summarized the chemical properties of LCP films, flexible LCP antennas, and LCP-based antenna-in-package and system-in-package technologies for 5G applications, although these articles did not discuss synthetic LCP technologies. In addition to wireless applications, the attractive mechanical, chemical, and thermal properties of LCP films enable interesting applications in micro-electro-mechanical systems (MEMS), biomedical electronics, and microfluidics, which have not been summarized to date. Here, a comprehensive review of flexible LCP technologies covering electric circuits, antennas, integration and packaging technologies, front-end modules, MEMS, biomedical devices, and microfluidics from microwave to THz frequencies is presented for the first time, which gives a broad introduction for those outside or just entering the field and provides perspective and breadth for those who are well established in the field.     

新型微通道散热器设计仿真

在传统的硅基微通道散热器原理基础上,通过采用高热导率的散热板,以及特殊的变截面微通道阵列,实现微型散热器工作流体的整体稳定流动和短程均匀散热工作模式.采用ANSYS通用有限元分析软件,给出了典型换热单元在参考流速1 m/s,温度283 K初始状态下的流速场和温度场,散热器可输运5×107 W/m2的热通量,总热阻低至0.0106℃/W.仿真结果初步验证了设计构想的合理性,散热器有望拥有良好工作特性.     

自组装技术在MEMS中的应用

起源于生物化学领域的自组装技术正被广泛地应用到了化学、材料、生物、电子、机械等不同的学科中。在MEMS和NEMS中,自组装作为一种新型的“自下而上”的微(纳)结构制备和装配技术而得到积极的关注,并显示出良好的应用前景。在阐述自组装技术发展的基础上,介绍了该技术在MEMS中的典型应用,讨论一些待解决的关键问题,最后展望了自组装技术的发展趋势。