纳米光波导表面粗糙度与散射损耗的分析与测试

针对目前纳米光波导传输中散射损耗严重的问题,详细分析了表面粗糙度与波导宽度对散射损耗的影响,给出了清晰的对应关系图。设计并采用MEMS工艺制备出纳米光波导结构,在此基础上对波导结构进行了表面粗糙度的测试,进一步提出采用高温热处理方法使波导表面粗糙度降低了3 nm左右。实验发现:高温热处理后的光波导结构其散射损耗降低到3.343 dB/cm。     

基于机器视觉的表面粗糙度检测系统设计

针对光切法显微镜测量的实验装置,开发了一种基于机器视觉的表面粗糙度检测系统.介绍了系统的硬件构成和软件设计原理,运用图像处理技术从光切显微图像中提取出表面轮廓信号计算粗糙度评定参数.该检测系统能够实现工件表面粗糙度的智能、快速、多参数测量,通过测量实验与样本标准件的数值进行对比,验证了该检测系统能达到满意的精度.     

基于相容关系的粗糙模糊集的扩展

对Pawlak的粗糙集模型进行了扩展，提出了基于相容关系的粗糙模糊集模型。分别用相容核和相容关系构造了邻域算子m（x）和r（x），来代替粗糙集中的等价类[x]，从而形成了两种基于相容关系的粗糙模糊集模型。并对这两种模型刻画观察对象的粗糙度ρR（A）和关于参数α，β的粗糙度ρA^α.β分别做了比较，证明了基于m（x）的ρR（A）和ρA^α.β都小于基于r（x）的。     

血凝分析仪凝血过程参数检测系统设计

基于C8051F040单片机的血凝分析仪凝血过程参数检测系统的设计,实现对凝血过程血液凝固时间和吸光率两参数的检测,为血凝仪系统中部分医学指标的获取提供了有效的方法.阐述全自动血凝仪的总体方案设计,重点研究了凝血过程参数检测系统中散射光和透射光检测部分的硬件及软件设计.实现了凝血过程中散射、透射光强信号的采集与传送,并基于Matlab软件平台,对采集到的数据进行计算和分析,给出了散射、透射光的数据处理算法.实验结果表明该检测系统具有检测数据准确,测量精度高、系统稳定性好等优点,所获检测参数具有一定医用价值.     

金属粉尘浓度检测技术研究

针对称重法无法实现金属粉尘浓度的实时、在线检测问题,分析了光散射法和电荷感应法应用于金属粉尘浓度检测技术的基本原理,设计了基于光散射法和基于电荷感应法的金属粉尘浓度信号采集及处理电路。实验结果表明:在检测初期,光散射法和电荷感应法检测误差均较小;但在长时间连续检测后,光散射法检测误差增大且检测值均偏高,而电荷感应法检测精度仍较高。     

一种新的简缩极化SAR图像H/α特征空间

现有简缩极化(Compact Polarimetry)SAR图像H/α经验特征空间存在两个问题:一是没有考虑简缩极化模式下的散射熵普遍高于全极化模式;二是在散射机制重叠区域,简缩极化H/α空间的分类能力较弱,尤其是多次散射。针对以上问题首先定量分析了DCP模式简缩极化SAR的散射角与全极化SAR数据散射角之间的关系,且在对7组不同传感器的SAR数据分析的基础上,提出了散射熵的替代参数ED,基于Monte Carlo模拟实验得到了H/α分解的各参数(熵H、平均散射角α和替代参数ED)分解的稳态条件;然后通过统计各散射机制在ED/α分布的密度空间,提出了一种新的简缩极化SAR图像ED/α特征空间。实验结果表明:替代参数ED与全极化熵具有良好相关性,而且ED/α特征空间提高了散射机制分类的精度。     

表面粗糙度光学测量方法研究进展

表面粗糙度对工件的性能有很大的影响,由于机械、电子及光学工业的飞速发展,对精密机械加工表面的质量及结构小型化的要求日益提高,使得表面粗糙度测量显现出越来越重要的地位。采用光学方法测量表面粗糙度具有非接触、无损伤、测量精度高等优点。介绍了用光散射法、像散法、散斑法、光干涉法、光学触针法测量表面粗糙度的原理及研究进展,讨论了上述方法各自的优缺点,对表面粗糙度测量的发展方向进行了预测。     

光散射烟雾报警器应用综述

分析光散射探测原理,对国内外主要光散射烟雾报警器产品特性进行总结,指出激光散射烟雾传感技术优势及应用,对光散射的检测技术发展方向进行讨论。     

光切法在动态表面粗糙度检测中的应用

应用光切显微镜、CCD摄像机、虚拟仪器和图像处理技术开发了表面粗糙度动态检测系统,利用光切法获得运动表面形貌,再使用图像处理技术提取轮廓特征计算评定参数。通过与触针式仪器进行测量对比实验,论证了检测系统能达到较高的精度。应用检测系统进行了动态检测实验,分析了样本表面的振动和运动速度对检测系统的影响。实验证明,在被测表面的振动幅度小于景深的前提下,该图像检测系统能够应用于动态检测表面粗糙度,适用的速度范围可达到:0￣2000rpm(3.14m/s)。     

工件表面粗糙度计算机预报平台设计

构建了基于工控机的工件表面粗糙度预报硬件平台,完成了自动检测和预报软件的分析与设计,核心部分采用神经网络进行建模,提出利用神经网络进行高速铣削表面粗糙度预报的方法,给出了具体的网络实现过程,应用灵敏度剪枝算法克服了网络隐层难以确定的问题,仿真结果表明该方法的有效性,对高速加工切削参数的选择和表面质量控制具有指导意义。     

Automatic optical inspection system for IC molding surface

Success or failure of an IC product hinges on the quality of molding process which protects chips from the harm done by external force and moisture. Defects such as cracks, dilapidations or voids may be embedding on the molding surface while a chip was being molded. Human inspection often neglects a very tiny crack or a low-contrast void. Hence an automatic optical inspection system for the integrated circuit (IC) molding surface cannot be over emphasized. The proposed system is composed of a charged coupled device, a coaxial light, a back light and a motion control unit. Based on the characteristics of statistical textures of the molding surface, a series of digital image processing is carried out, including normalization, shrinking, segmenting and Fourier based image restoration and defect identification. Training of the parameter associated with defect inspection algorithm is also discussed. Results of the experiment suggest that the inspection system works effectively with high accuracy rate of 94.2 %, contributing to the inspection quality of IC molding surface.     

Femtosecond laser-induced silicon surface morphology in water confinement

This article investigates the use of femtosecond laser induced surface morphology on silicon wafer surface in water confinement. Unlike irradiation of silicon surfaces in the air, there are no laser induced periodic structures, but irregular roughness is formed when the silicon wafer is ablated under water. The unique discovery of a smoothly processed silicon surface in water confinement under certain laser parameter combinations may help improve laser direct micromachining surface quality in industrial applications.     

Wafer‐scale monolithic hybrid integration of Si‐based IC and III–V epi‐layers—A mass manufacturable approach for active matrix micro‐LED micro‐displays

Hybridization of silicon integrated circuits (ICs) with compound semiconductor device arrays are crucial for making functional hybrid chips, which are found to have enormous applications in many areas. Although widely used in manufacturing hybrid chips, the flip‐chip technology suffers from several limitations that are difficult to overcome, especially when the demand is raised to make functional hybrid chips with higher device array density without sacrificing the chip footprint. To address those issues, Beida Jade Bird Display Limited has developed its unique wafer‐level monolithic hybrid integration technology and demonstrated its advantages in making large‐scale hybrid integration of functional device arrays on Si IC wafers. Active matrix micro‐light‐emitting diode micro‐displays with a resolution of 5000+ pixel per inch were successfully fabricated using Beida Jade Bird Display Limited's monolithic hybrid integration technology. The general fabrication method is described, and the result is presented in this paper. The fabricated monochromatic micro‐light‐emitting diode micro‐displays exhibit improved device performance than do other micro‐display technologies and have great potentials in applications such as portable projectors and near‐to‐eye projection for augmented reality. More importantly, the wafer‐scale monolithic hybrid integration technology offers a clear path for low‐cost mass production of hybrid optoelectronic IC chips.     

A new intelligent SOFM-based sampling plan for advanced process control

Sample measurement inspecting for a process parameter is a necessity in semiconductor manufacturing because of the prohibitive amount of time involved in 100% inspection while maintaining sensitivity to all types of defects and abnormality. In current industrial practice, sample measurement locations are chosen approximately evenly across the wafer, in order to have all regions of the wafer equally well represented, but they are not adequate if process-related defective chips are distributed with spatial pattern within the wafer.In this paper, we propose the methodology for generating effective measurement sampling plan for process parameter by applying the Self-Organizing Feature Map (SOFM) network, unsupervised learning neural network, to wafer bin map data within a certain time period. The sampling plan specifies which chips within the wafer need to be inspected, and how many chips within the wafer need to be inspected for a good sensitivity of 100% wafer coverage and defect detection. We finally illustrate the effectiveness of our proposed sampling plan using actual semiconductor fab data.     

基于高斯滤波和信息熵原理的Ra评定研究

提出了一种表面粗糙度R_a测量不确定度的计算方法。该方法依据高斯滤波的基本原理计算检验结果,并根据信息熵与不确定度的关系计算检验结果的不确定度。实验结果表明,根据R_a的测量结果及其不确定度和ISO14253-1给出的判定原则,可以定量地判定产品是否合格,从而减少产品的误收和误废。最后,对利用高斯滤波法和最小二乘法计算的检验结果及其不确定度进行对比,认为在考虑检验结果不确定因素的基础上,高斯滤波法更适合表面粗糙度参数的评定。     

Flexible integration of MEMS and IC for low-cost production of wireless sensor nodes

In this paper, we proposed a flexible process for size-free MEMS and IC integration with high efficiency for MEMS ubiquitous applications in wireless sensor network. In this approach, MEMS and IC can be fabricated individually by different wafers. MEMS and IC known-good-dies (KGD) are temporarily bonded onto carrier wafer with rapid and high-accurate self-alignment by using fine pattern of hydrophobic surface assembled monolayer and capillary force of H₂O; and then KGD are de-bonded from carrier wafer and transferred to target wafer by wafer level permanent bonding with plasma surface activation to reduce bonding temperature and load force. By applying above 2-step process, size of both wafer and chip could be flexible selected. Besides, CMOS processed wafer or silicon interposer can be used as the target wafer. This approach offers us excellent process flexibilities for low-cost production of wireless sensor nodes.     

晶圆表面缺陷在线检测研究

针对准确与实时检测晶圆表面缺陷的需求,提出了一种基于主成分分析(Principal Component Analysis, PCA)和贝叶斯概率模型(Bayesian Probability Model, BPM)的在线检测算法。首先,改进双边滤波方法以消除晶圆表面图像中的噪声和突出晶圆表面的模式特征。然后,提取晶圆表面缺陷的Hu不变矩、方向梯度直方图(Histogram of Oriented Gradients, HOG)和尺度不变特征变换特征(Scale Invariant Feature Transform, SIFT)。接着,采用PCA方法对特征进行降维。最后,在离线建模阶段构建各种缺陷模式的BPMs;在在线检测阶段采用胜者全取(Winner-take-all, WTA)法判断缺陷的模式和构建新缺陷模式的BPMs。提出算法在WM-811K晶圆数据库中得到了87.2%的检测准确率。单副图像的平均检测时间为40.5ms。实验结果表明,提出算法具有较高的检测准确性与实时性,可以实际应用到集成电路制造产线的晶圆表面缺陷在线检测中。     

Diffractive optical coupling element for surface plasmon resonance sensors

Design, technological features, and performance of polymeric diffractive optical coupling elements (DOCEs), developed for surface plasmon resonance (SPR) sensors are reported. The concept is based on input and output coupling of collimated and perpendicularly incident light beams to exchangeable SPR sensor chips. In the SPR sensor chips, one DOCE couples the input light beam to a (bio-)chemical sensor surface and another DOCE images the output light beam onto a detector array. The manufacturing technique is based on an injection moulding process similarly to the manufacturing process of compact discs allowing precision manufacturing and reproduction of the grating topography of the DOCEs. The DOCE-based SPR sensor chip is specifically suitable for miniaturisation and large scale production, while maintaining high optical quality and performance.     

Automatic testing of MMIC wafers

Microwave probes are used extensively for linear and nonlinear characterization of microwave devices on wafer and are commercially available for use at frequencies up to 65 GHz. An on-wafer noise measurement test system, for discrete devices, is now commercially available and on-wafer power measurement techniques are emerging slowly. These probes are also getting more recognition for the testing of packaged chips, packages, and modules. More accurate calibration techniques and their on-wafer validation are being developed. Automatic testing of MMIC wafers, using an integrated test system, is a key requirement for the development of low-cost IC production.     

Influence of tool fabrication process on characteristics of hot embossed polymer microfluidic chips for electrospray

Fabrication techniques for mass manufacture of disposable polymer microfluidic chips are important for electrospray application used in mass spectrometry. Hot embossing offers advantages over traditional MEMS fabrication techniques and is the focus of this research. The aim of the paper is to evaluate hot embossed open channel polymer chips using two different hot embossing tools. One tool was fabricated in nickel using the electroforming process, and the other in high carbon bright steel by laser machining technique using a pulsed Nd:YAG laser that is normally used for conventional applications. Process parameters are determined and measurement of dimensions and surface roughness of tools and chips are presented. Depending on the fabrication method, each tool exhibits its own characteristic profile feature and surface roughness. Polystyrene and polycarbonate substrates embossed with the electroformed tool exhibited lowest surface roughness of 48 nm compared to 450 nm for the laser machined tool. The embossed microfluidic chips were tested for fluid flow and electrospray and showed good performance.