基于Halcon的IC测试探针表面质量的机器视觉检测系统

IC测试是集成电路生产中的重要工序,探针表面诸如划痕、凹坑等缺陷对性能测试结果影响大.文章研究了IC探针表面质量的机器视觉检测方法,讨论了灰度变换、均值滤波、区域连通、图像分割等缺陷图像处理和形状识别方法,建立了相应的探针表面质量检测系统,并基于机器视觉软件Halcon开发了探针表面质量检测系统软件.实验表明:开发的检测系统可对直径0.3~0.6 mm的IC测试探针表面质量进行快速检测评估,且系统的稳定性好、检测精度高,能有效缩短检测时间和减少检测成本.     

Behavior of Ni-Al particles in argon: Helium plasma jets

To better understand the plasma spray coating process, an experimental study of the interaction between a subsonic thermal plasma jet and injected nickel- aluminum particles was performed. The velocity, temperature, and composition of the argon/helium gas flow field was mapped using an enthalpy probe/mass spectrometer system. The sprayed particle flow field was examined by simultaneously measuring the size, velocity, and temperature of individual particles. Particle and gas temperatures were compared at the nominal substrate stand- off distance and axially along the median particle trajectory. Temperature and velocity differences between the particle and the gas surrounding it are shown to vary substantially depending on the trajectory of the particles. On the median trajectory, the average particle is transferring heat and momentum back to the plasma by the time it reaches the substrate. Because the exchange of heat and momentum is highly dependent on the particle residence time in the core of the plasma, the condition of particles at the substrate can be optimized by controlling the particle trajectory through the plasma.     

用Kelvin探头技术研究铝合金的大气腐蚀

选择航空工业广泛使用的铝、铝合金及其涂层的试样，利用自行研制的Kelvin探头大气腐蚀测定仪、扫描电镜等设备，研究了纯铝试样随温、湿度变化，其表面电位的变化规律，测定了铝合金及涂层试样大气曝晒试验和周浸试验前后的表面电位、形貌,对铝、铝合金以及涂层的腐蚀规律进行了初步的探讨.结果表明，纯铝试样表面无可见液膜时，腐蚀电位随相对湿度增加逐渐下降；表面有可见液膜时，随着液层蒸发逐渐减薄，电位逐渐正移.铝合金裸材在北京大气环境下电位变化较小，且各个位置的电位基本相同.带涂层的试样优先在缺陷处发生腐蚀，并不断向周围扩展，涂层的剥离面积不断增大.涂层的铝合金，划痕处在腐蚀发生的初期腐蚀电位向负方向变化很快，但是随着时间的延长，腐蚀电位变化的速率减慢，并有向正方向移动的趋势.      

Design of a six-axis high precision machine tool and its application in machining aspherical optical mirrors

The paper presents the design of a six-axis machining system and its application in fabricating large off-axis aspherical mirrors with sub-aperture lapping techniques. The new system is based on computer-controlled optical surfacing (CCOS), which combines the faculties of grinding, polishing, and on-machine profile measuring, has the features of conventional loose abrasive machining with the characteristics of a tool having multiple degrees of freedom moving in planar model. And a novel dual touch-trigger probe profiler is designed, which is composed of a probe, model METRO-MT60 made by HEIDENHAIN Co., is integrated into the system for measuring the shape accuracy of the tested aspherical surface, another probe modeled METRO-MT12 is designed as a calibrating device for minimizing the cosine error caused by assembly inaccuracy. The new CNC machining system with two kinds of moving coordinate systems, dual tool activities and on-machine measuring is presently developed based on the new concept. The general material removal function during machining is analyzed on the basis of the Preston hypothesis. Further, an alignment test of the measuring profiler is carried out using a leveling rule as a specimen. The accuracy of the optical surfaces measured by the dual probe profiler is found to be within 1 μm PV after removing cosine error and error compensating, achieves to the resolving power of the profiler is about 0.2–0.5 μm, so the developed system can be applied to the shape accuracy measuring of aspheric fabrication with micro precision during fine grinding process according to the calibrating results. Finally, the manufacturing experiments are carried out by virtue of an off-axis oblate ellipsoid mirror with rectangular aperture as 770 mm×210 mm and centered 127 mm. The accuracy of the aspherical mirror improved from the initial form error of 17.648 μm rms to the final one of 0.728 μm rms after grinding for 200 h.     

The characteristics of a low-power-consumption plasma jet and ceramic coatings

The effects of the composition of plasma gases (Ar-N₂, Ar-H₂), arc current, and voltage on the temperature and velocity of a low-power (5 kW) plasma torch in the arc field free region has been investigated using an enthalpy probe. Coatings of Al₂O₃-13TiO₂ were deposited under different conditions. The results show that in the Ar-N₂ plasma, the enthalpy, temperature, and velocity change little with arc current and voltage when regulating the nitrogen proportion in the plasma gas. The hardness of the resulting coatings is 800 to 900 kg/mm² HV.300. For Ar-H₂ plasma, however, increases in the H₂ content in the mixture of the gases remarkably enhanced the velocity and heat transfer ability of the plasma jet, with the result that the coatings showed high hardness up to 1200 HV.     

基于几何推理的坐标测量机测头选择及可达性分析

本文提出一种零件信息表示的模式—ＩＦＯＮＧ。ＩＦＯＮＧ可以满足智能检测规划系统的需要。利用ＩＦＯＮＧ提供的表面与其邻接表面的关系和特征描述等信息，给出建立用于测头选择及可达性分析的知识库的策略及方法。这种方法简单而有效，使得以基于知识的专家系统进行测头选择具有简单、高效和实用的特点。     

可调向靠背式测速探头测向方法的实验验证及标定系数研究

为解决流场中速度、方向的测量问题，自行设计了一种新型的可调向靠背式测速探头，本文介绍了此测速探头的测向方法，通过实验验证了此方法的可行性，并对标定系数曲线进行了测试。     

电磁波层析成像反演射线路径的探讨

在电磁波 CT 测试中,发射、接收探头间的电磁波射线发射点、接收点位置决定反演后成果数据记录点的位置。为了确定电磁波仪发射、接收探头记录点位置,对探头分别进行钢管屏蔽实验,实验表明电磁波仪工作时电磁波能量主要集中在两探头的馈电点及天线末端间近似于平行四边形的区域内,不宜直接地简化为一条直线,将平行四边形区域简化为4条线段进行电磁波层析成像反演计算更符合实际情况。在此基础上,提出对电磁波 CT 数据采取4条射线路径单独反演后,再将4个结果按综合平均的方法进行处理。将此种处理方法应用于武汉地铁岩溶勘察数据处理中,并与目前基于1条射线的反演处理方法进行对比、验证。对比剖面反演数据结果表明,在采用同一反演软件条件下4条射线路径综合反演法精度优于1条射线反演法。     

Atom probe tomography and transmission electron microscopy characterisation of precipitation in an Al-Cu-Li-Mg-Ag alloy

State-of-the art atom probe tomography (APT) combined with transmission electron microscopy (TEM) were used to investigate the microstructure at different stages of the ageing process of an alloy of composition (at%) Al-1.68%Cu-4.62%Li-0.33%Mg-0.1%Ag. These alloys were shown to exhibit a complex microstructure of T₁ plates and several metastable phases, including θ′ and S. We will highlight the early stages of clustering, precipitate interactions and possible solute segregation at the matrix/precipitate interfaces and detail the chemical composition of the different phases.     

Ultrasonic force microscopy: detection and imaging of ultra-thin molecular domains

The analysis of the formation of ultra-thin organic films is a very important issue. In fact, it is known that the properties of organic light emitting diodes and field effect transistors are strongly affected by the early growth stages. For instance, in the case of sexithiophene, the presence of domains made of molecules with the backbone parallel to the substrate surface has been indirectly evidenced by photoluminescence spectroscopy and confocal microscopy. On the contrary, conventional scanning force microscopy both in contact and intermittent contact modes have failed to detect such domains. In this paper, we show that Ultrasonic Force Microscopy (UFM), sensitive to nanomechanical properties, allows one to directly identify the structure of sub-monolayer thick films. Sexithiophene flat domains have been imaged for the first time with nanometer scale spatial resolution. A comparison with lateral force and intermittent contact modes has been carried out in order to explain the origins of the UFM contrast and its advantages. In particular, it indicates that UFM is highly suitable for investigations where high sensitivity to material properties, low specimen damage and high spatial resolution are required.