传感器芯片系统研究与应用

基于微纳制造、微电子等技术的传感器芯片系统具有体积小、质量轻、功耗低、易于批量化生产、成本低、易于集成化等优点,是传感技术领域的一个重要研究方向.近年来相关的研究主要包括微纳传感器芯片、微传感器阵列、多传感器集成芯片系统、传感器与电路集成芯片系统、微流控芯片系统、无线网络传感器节点芯片系统等.文中分别以糖化血红蛋白免疫传感器、催化燃烧气体传感器和电场传感器为例,简要介绍若干典型的生物量、化学量和物理量微传感器系统及其应用.     

SARS病毒的微流控芯片实验室系统检测

采用自行设计的RT-PCR试剂盒。在自制的由聚合酶链反应(PCR)——毛管电泳(CE)芯片、芯片热循环仪和激光诱导荧光芯片分析仪组成的微流控芯片系统上，对SARS病毒(重症急性呼吸综合症)和18例SARS患者咽拭子样品连行了分析和检测，实现了聚合酶链反应和电泳检测的微流控芯片在线分析。微流控芯片系统具有高检潮灵敏度、高分辨率、高检出率等优点，试剂消耗少和检测时间短，可能成为SARS早期检测的一种新的手段。     

集成电路芯片引脚外观自动检测系统的研究

基于集成电路芯片引脚外观检测的需要,开发了自动检测系统.介绍了系统的组成、硬件结构、软件流程.该系统由芯片自动输送线、芯片拾取吸臂、机器视觉系统、良品与不良品分选臂、良品补给装置等组成,由工控机通过PLC控制技术,实现芯片上料、输送、外观检测、分选、卸料等的全自动化.该系统可检测芯片引脚在空间的11个尺寸参数,具有检测精度高、产品更换快速、操作简便等优点,适用于QFP封装集成电路芯片引脚外观的自动检测,可显著提高生产效率及产品质量.     

微流控芯片PCR循环温控系统

介绍了一种适用于微流控芯片PCR扩增的新型循环加热系统,包括系统可控电源电路设计、控制方案确定及控制算法实验.实验表明该系统消耗试剂量小,温度控制准确、稳定,适用于微流控芯片PCR扩增实验.     

基于BioMEMS技术的DNA芯片研究

近年来基于微电子机械系统 (MEMS)技术研究和开发的一个新领域就是BioMEMS ,特别是对生物芯片和生物化学微分析系统的研究。文中叙述了基于BioMEMS技术的DNA芯片研究 ,介绍了几种不同结构的DNA芯片 ,以及DNA PCR扩增器芯片、DNA CE毛细管电泳芯片、微流动控制器件和实验室芯片 (LabonaChip)等。还报告了作者们成功采用MEMS技术 ,研制成集成化微结构型PCR DNA扩增芯片 ,芯片上包括有加热器、温度传感器、2 μL容积的反应池以及输入输出通道 ;能实现快速扩增 ,最快加热速度为 15℃ s ,降温速度为 10℃ s。研制成Si—玻璃 ,玻璃—玻璃和玻璃—PDMS三种结构的毛细管电泳芯片 ,沟道宽 2 0 0 μm ,深 2 0 0 μm。研制成一种表面等离子体谐振 (SPR)生化分析系统 ,其入射光扫描角范围从 40°到 70° ,分辨率 0 .1%度 ,可测折射率范围 1.0 4～ 1.47。     

将数学形态学应用于检测芯片机器视觉的研究

研制检测集成电路芯片的机器视觉系统,采用数学形态学方法对芯片图像进行滤波平滑处理,用于改善芯片图像的质量。结果表明:将数学形态学应用于检测芯片的机器视觉系统,提高了系统的检测速度和检测的准确性,满足了检测流水线对机器视觉系统检测实时性的要求。     

基于PLC控制技术的高压整流桥芯片测试分选机

高压整流桥芯片测试分选机是对整流桥芯片进行如VF、IR和TRR等性能参数的测试,并按照要求,对测试过的芯片进行分档,采用PLC作为高压整流桥芯片分选机的控制设备能够实现高速、准确的测试与精确无误的分选,论文介绍了高压整流桥芯片测试分选机的组成及工艺流程,并对PLC控制系统及程序设计方法进行了详细描述。高压整流桥芯片测试分选机广泛应用于半导体行业。     

基于计算机视觉技术的BGA芯片精准焊接定位的研究

针对BGA芯片的特点,本文介绍一种基于计算机视觉技术的单摄像头双目成像焊接定位系统,本文介绍了单CCD视觉系统的构成及原理,并采用经典算子和利用灰色系统理论对BGA芯片图像进行处理。实验结果证明灰色系统理论是一种有效的、具有可调功能的边缘检测新算法,能够较为准确地检测出有用的边缘信息,具有一定的抗噪声能力,进而有效的提高BGA芯片定位精度。     

RS-485总线在多节点远距离通信系统中的应用

介绍RS-485接口SN65HVD3082E芯片的结构、性能特点，及以该芯片为主的通信系统的构成，包括它们的硬件电路和软件设计方法；说明了该系统的优点及应用领域。     

微流控芯片的研制及其相关仪器的集成化研究

本文报道了微流控芯片的制作方法、芯片的材料选择以及研究过程中的一些实验方法,侧重介绍芯片毛细管电泳分离与检测的基本原理和应用研究的进展情况,总结了近年来作者的研究成果和最新研制成功的微流控芯片仪器.     

Relationship between cutting conditions and chips morphology during milling of aluminium Al-2050

In the aeronautical field, some parts are forged and consequently some fibers orientation occurs. However, the thin walls are hard to get with forging method. Consequently, some machining operations are done to get a thin wall and reduce the weight of part. However, because of the size of part of the volume of chips can be significant. The ratio between the final weight of part and the final weight of chips is approximately 80 %. To improve the economical and the environmental sustainability, a method consists of recycling directly the chip after machining operations. However, studies show a great impact of different points on chip recyclability like chip thickness, chip roughness, or chip density. Consequently, control of the chip morphology is a first point in ensuring a good recyclability. This article concerns the relationship between the cutting conditions, the cutting tool geometries, the lubricant conditions, and the chips morphology. This analysis is decomposed on several points: chip length, chip morphology, chip thickness, and the chip formation. The observations show also a strong influence of cutting conditions on chip morphology where an increase of cutting conditions reduces drastically the chip size. Concerning the chip formation, because the chip is produced during milling where the uncut chip thickness varies, the chip microstructure is then affected.     

深孔钻削切屑形态的研究

通过试验研究了φ14 mm的YT15刀片BTA钻、涂层刀片BTA钻和陶瓷刀片BTA钻在不同切削参数的切屑形态和切屑容屑系数λ(λ为单位体积金属的切屑所具有的容积)对排屑的影响,试验表明,切屑容屑系数越小排屑越好,而且C形切屑的切屑容屑系数最小,对排屑最有利。     

45钢深孔枪钻切削试验与切屑形态分析

切屑形态对枪钻深孔加工中孔成型精度影响极大,钻尖切屑易堵塞在V型排屑槽中或缠绕在钻头上,合理的断屑和排屑是保证加工顺利进行的前提。选用硬质合金枪钻对45钢进行深孔加工试验,采用单因素试验法研究切削速度和进给量对切屑形态的影响规律。试验表明:切削速度较低时,主要为带状切屑;切削速度较高时,主要为单元切屑;当切削速度保持不变时,随着进给量的增大,切屑的主要形状从长带状向单元切屑逐渐转变;当进给量保持不变时,随着切削速度的增大,切屑尺寸从大变小再变大。     

An experimental study on three dimensional heat transfer characteristics of simulated electronic chips

Naphthalene sublimation technique is employed to investigate three dimensional heat transfer characteristics of the simulated electronic chips. Experiments are performed for a single chip and chip arrays. In case of a single chip, local heat transfer coefficients on four surfaces of the chip are measured for various gap sizes and air velocities. Dramatic change of local heat transfer is seen on each surface of the chip, and gap size between chip and base plate is found to affect heat transfer significantly. In case of chip arrays, heat transfer characteristics from two-dimensional array of rectangular modules and three-dimensional array of hexahedral modules are investigated. Chip location, gap between chip and base plate and streamwise chip without gap. Fully developed behavior is found from the third row, but it slightly depends on flow conditions. Local and average heat transfer coefficients of three-dimensional modules are a little bit greater than those of two-dimensional modules. The differences in magnitude decrease as the longitudinal chip spacing decreases.     

错齿BTA深孔钻削切屑变形断裂影响因素研究

利用错齿BTA深孔钻削切屑弯曲变形规律,对导致错齿BTA内排屑深孔钻切屑断裂的影响因素进行了分析,通过试验研究了错齿BTA深孔钻削切屑的变形断裂随刀齿钻削半径、钻削工艺参数、断屑台尺寸的变化规律。研究结果表明,刀齿钻削半径对切屑厚度影响很大,随钻削半径的增大,各刀齿切屑厚度增大,切屑厚度最大值点均位于刀齿切屑大径边缘且中心齿、中间齿、外齿的切屑厚度最大值依次减小;与转速相比,进给量对切屑厚度和切屑应变增量的影响更大,随进给量增大,切屑厚度增大,切屑应变增量增大;随断屑台宽度减小、高度增大,切屑应变增量增大,断屑条件改善。     

On the attritious wear of abrasive grains

The overcut fly milling operation that closely simulates fine grinding has been used extensively to study the performance of several grain types at moderate and low wheel speeds. Results indicate that the wear of abrasive grains for a particular grain-work-piece combination is a function of chip thickness, chip length and wheel speed. For a constant chip length, the wear rate increases exponentially with increasing chip thickness. There is, however, an optimum value of chip length which gives minimum wear at any particular chip thickness.     

AN INVESTIGATION OF 3-D CURLED CHIP IN MACHINING-PART 2: SIMULATION AND VALIDATION USING FE TECHNIQUES

This paper presents a finite element modeling approach for the 3-D curled chip. Four different chip types, with varying complexities are modeled using this approach. The complexities include chip twist, serrations on the inner radius of the chip, thickness variation along the length of the chip, etc. The chip is treated as a 3-D elastic beam and the neutral axis of the chip is modeled as a 3-D spiral with instantaneously varying center and curl radius. Bending and shear stresses generated in the chip show very distinct patterns. Comparisons made between the mechanics-based and finite element models show good correlation in the magnitude and location of the failure stresses. The 3-D chip breaking pattern was also observed using high-speed filming techniques, and comparisons made between the FE model and experimental results show good correlation.     

Adiabatic shear in chip formation with negative rake angle

The mechanics of chip formation in grinding is investigated based on thermo-elastic-plastic finite element simulations of orthogonal cutting with a large negative rake abrasive-grits. The modeling is coupled with temperature and strain-rate-dependent flow stress characteristics of a work material SK-5 (0.93%C carbon steel). The shape of chip calculated is affected by the cutting speed and the undeformed chip thickness. In high-speed cutting, serrated chip formation caused by adiabatic shear, which is usually observed experimentally under the cutting conditions of grinding region, is obtained analytically without any consideration of crack propagation. Temperature and flow stress calculated in the primary shear zone vary periodically according to the segmentation of serrated chip. Then changes in temperature, flow stress, strain rate and strain at a material point fixed to and moving with chip is monitored in order to investigate the chip formation process. This clarifies the cutting mechanisms of different types of chip formation with negative rake.     

Machining with tool–chip contact on the tool secondary rake face—Part II: analysis and discussion

The forces, chip thickness, and natural tool–chip contact length in machining with a double-rake-angled tool are predicted in Part II of the present study. It is revealed that in comparison with a single-rake-angled tool, a double-rake-angled tool increases the forces, especially the thrust force. However, the increase in chip thickness and tool–chip contact length is not significant under the input conditions specified in the present study. The effect of seven input variables of the proposed model is quantitatively investigated. The predicted variations of forces, chip thickness, and natural tool–chip contact length are in good agreement with theoretical and experimental results obtained by other researchers. The interrelationships among the resultant force, the chip thickness, and the natural tool–chip contact length are established, which provides a new and promising method to estimate the tool–chip contact length by employing the resultant force. It is demonstrated that the model can also be extended to study the problem of machining with a groove-type chip breaker tool.     

热超声倒装键合界面的运动传递过程

采用改进的激光多普勒振动测量系统,获得小直径激光斑,解决了大量数据采集和分析、同步触发等技术问题,实时精密测量热超声倒装键合过程中工具和芯片的运动.通过分析运动曲线,发现"速度分离"是表征键合过程状态改变的重要临界现象;发现在"速度分离"前工具/芯片粘着在一起运动,之后它们间是"粘滑"交替的过程;在"速度分离"后的运动过程中,工具能量一部分通过芯片传递到键合界面,形成键合强度;另一部分消耗在芯片/工具间的摩擦上,磨损芯片和工具,损害键合界面结构和强度.根据研究结果提出了新的超声加载过程思路,以期减小磨损,提高键合强度.