多晶硅纳米薄膜压阻式压力传感器

多晶硅纳米薄膜具有优越的应变灵敏特性和稳定的温度特性.为了使这种良好的压阻特性得到实际应用,文中给出了多晶硅纳米薄膜压阻式压力传感器的设计方法.根据多晶硅纳米薄膜压阻特性和硅杯腐蚀技术条件确定弹性膜片结构,并采用有限元分析方法对弹性膜片尺寸以及应变电阻分布进行了优化.依据优化设计结果试制了压力传感器芯片.实验表明该传感器工艺简单、高温特性好、灵敏度高.     

固态压阻式压力传感器的计算机辅助分析与设计 二

五、传感器系统综合性能指标的 容差分析、容差设计及综合优化 压力传感器的基本特性参数如灵敏度、线性度、量程和零点误差以及零点温度漂移、灵敏度温度漂移、极限断裂应力和固有频率等,都不同程度地取决于材料类型、晶向、力学结构、几何尺寸、杂质浓度、容差控制等与压阻效应、力学结构和制作工艺有关的内容。如表1所示。灵敏度取决于晶向选择、力学结构类型、几何尺寸、电阻在膜片上的位置及杂质浓度等。非线性来自压阻效应的非线性及力学结构的应力非线性。为减小压阻效应的非线性的影响,力敏电阻所     

多晶硅纳米薄膜牺牲层压力敏感结构设计

为使多晶硅纳米薄膜良好的压阻特性在MEMS(微机电系统)压阻传感器中得到有效应用,在设计牺牲层结构压力传感器芯片中探索性地采用了多晶硅纳米薄膜作为应变电阻,并给出这种传感器的设计方法。分析了牺牲层结构弹性膜片的应力分布对传感器灵敏度的影响,优化设计了量程为0~0.2 MPa多晶硅纳米膜压力传感器芯片的结构参数。有限元法仿真结果表明:在保证传感器灵敏度大于50 mV/(MPa.V)的前提下,零点温漂系数可小于1×10-3FS/℃;灵敏度温漂(无电路补偿)可小于1×10-3FS/℃.为高灵敏、低温漂、低成本的高温压力传感器集成化发展提供了一条可行途径。     

硅基力敏传感器及其工业应用（上）

一 硅基力敏传感器的现状 硅基力敏传感器是指以硅（单晶或多晶）材料为基础，利用MEMS工艺，其特性参数受外力或应力变化而明显变化的敏感元件制成的传感器。这里的力包括重力、拉力、压力、力矩、压强等物理量。力敏传感器包括力、压力、差压、液位传感器等。     

低热零点漂移的高温绝压压力传感器

传统的高温绝压压力传感器一般采用硅和玻璃进行阳极键合来制备绝压腔。由于高温环境下硅片和硼硅玻璃的热膨胀系数不匹配，从而产生较高的热零点漂移。文中提出了一种低热零点漂移的压力传感器设计方案，由硅-玻璃-硅的三层结构代替普通的双层阳极键合结构，并给出了热力学仿真模型。分析表明：改变传感器硅与玻璃的结构比例，实现应力匹配可以有效减小热应力。对芯片进行了高温实验测试，发现传感器的热零点漂移变化率减小了50%。     

耐高温压阻式压力传感器研究与进展

传统的硅扩散压阻式压力传感器用重掺杂4个P型硅应变电阻构成惠斯顿电桥的力敏检测模式，采用PN结隔离，高温压阻式压力传感器取消了PlN结隔离，与半导体集成电路平面工艺兼容，符合传感器的发展方向。根据力敏材料的分类，分别介绍了多晶硅中高温压力传感器、SiC高温压力传感器和单晶硅SOI（silicon on insulator）高温压力传感器的基本工作原理和国内外的发展现状，重点论述了BESOI（bonding and etch-backSOI）、SMARTCUT和SIMOX（separation by implanted oxygen）技术的SOI晶片加工工艺。以及由此晶片微机械加工成的芯片封装的高温微型压力传感器部分特性，对此领域的发展作了展望。     

新型宽温区压力传感器技术

为研制新型耐高温和耐低温压力传感器,提出了一种基于SOS(蓝宝石上硅)技术制造的压力传感器.所述硅-蓝宝石压力传感器采用先封装再刻制应变电阻的新工艺,制成的应变电阻和补偿用热电阻精度高、质量好,且在整个工艺流程中不使用化学药品,对环境无污染.制成的硅-蓝宝石压力传感器,可以测量在-55～+400 ℃宽温区范围内的流体压力,并可以同时测量温度.给出了该传感器的试验数据,得到了比较满意的结果.     

高温压力传感器温度特性的芯片内补偿技术

本文在分析、测试多晶硅高温压力传感器温度特性的基础上 ,提出了一种新的改善传感器温度特性的措施。通过在压力传感器芯片上集成低阻值的多晶硅电阻网络与温度传感器 ,不仅可以很好的补偿传感器的零点温漂 ,也可以借助传感器信号处理单元 ,方便地实现对灵敏度温度系数的补偿。经补偿 ,传感器的零点温漂达到 1× 10 -4/℃ ,灵敏度温漂小于 -2× 10 -4/℃。实验表明 :该方法的补偿温区宽 ,通用性强 ,是高温压力传感器十分有效的温度补偿方法     

基于硅硅键合技术的高精度压力传感器的研究

硅压阻压力传感器核心部件一般是由单晶硅和玻璃组成的微结构,由于单晶硅和玻璃的材料特性存在差异,在制造过程中会引入封装应力对传感器的性能产生不利影响。采用硅硅键合技术制造压力传感器核心部件的微结构,以同质材料替代异质材料实现器件的封装,可有效减少封装应力,提升压力传感器的性能。文中通过结合硅压阻压力敏感芯片的制造工艺和硅硅键合工艺,实现了敏感芯片与硅衬底间的硅硅键合,键合强度达到体硅强度。研制的差压型压力敏感芯片装配成传感器的零点温度漂移下降60%,静压误差下降约1个数量级。     

广普型压阻式传感器测量仪的研制

CYX100型压力传感器是采用硅横向电压应变技术制作的力敏器件,四个力敏电阻组成惠斯顿全桥,具有80年代先进水平。利用该传感器为探头组成测量仪,可用于各种非腐蚀性气体和液体压力的检测,在化工、水文、生物医学工程、土壤湿度等国民经济各个领域中有着极其广泛的应用。该测量仪的特点是体积小、重量轻、性能可靠、价廉物美、携带方便,可作为一种广普式测量工具。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.