晶圆级导通电阻测试精度的改进方法

针对晶圆级导通电阻测试误差过高,满足不了低压金属氧化物半导体场效应晶体管(MOSFET)毫欧级导通电阻的测试精度要求,给产品晶圆测试规范的制定及品质监控带来困扰的问题,提出了晶圆级导通电阻测试精度的改进方法。基于开尔文法电阻测试理论,具体分析了晶圆级导通电阻测试原理,且得出其测试精度不高的根本原因是减薄背金后粗糙不平的硅片背面与测试机的承片台的非充分接触而引入了毫欧级接触电阻。提出3种相应改进测试精度的方法,单相邻芯片辅助的测试方法、双相邻芯片辅助的测试方法和正面漏极测试窗的测试方法。经过验证,3种方法均能将毫欧级导通电阻测试误差控制到小于10%,实现低压MOSFET晶圆级导通电阻参数的有效监测。     

PTC热敏元件启动器的选择

PTC元件是正温度系数的热敏电阻,在常温状态下是导通的.在电路中,PTC启动器与启动绕组串联,当接通电源时,有很大的电流流过PTC元件,PTC元件发热,而其阻值在短时内急剧增高到高阻态,此时电流很小,近似"断"状态,相当于将启动绕组在短时内从电路中断开(只有十几毫安电流通过PTC元件),压缩机顺利启动.更换已损坏的PTC启动器时,应选择同阻值的PTC启动器.如果不知原阻值可根据压缩机功率大小选配:165W左右的压缩机可用阻值为18Ω的PTC启动器;145W左右的压缩机可用阻值为22Ω的PTC启动器;120W左右的压缩机可用阻值为33Ω的PTC启动器.     

一种判别短路的有效方法——在线检测

在仪器仪表、电器设备和建筑物电气安装上,经常会遇到因接线错误、元器件损坏等引起的短路问题。一般的处理方法是分段把接头、元器件拆掉,或用好的元器件置换被怀疑损坏的元器件,不断缩小短路范围来达到检查短路的目的。这样既费工费力,检测效率又低,尤其在高层建筑的电气安装上,更显得如此。我们在实践中发现,线路长度距短路点越远,其线路阻值越大,一般在0～2Ω之间。由于数字万用表2 0 0Ω电阻档或动圈式万用表DΩ低电阻档的分辨率可达0 .0 1Ω～0 .1Ω,且只需判别线路阻值大小,故对测量精度要求不高,为此,可用上述电阻档测量在线短路电…     

提升精细线路蚀刻良率的方法探讨

针对以减成法制作的印制电路板（PCB）在精细线路中存在部分区域良率较差的情况，通过分析电镀铜厚、干膜显影、蚀刻线的均匀性对良率的影响，找出蚀刻后线宽分布与测试板的电镀铜厚度、显影后干膜宽度及蚀刻均匀性之间的关系。根据实测结果，对非均匀的线宽曝光补偿值进行修订优化。通过实验，在20μm铜厚下将25/25μm线路的局部开路/短路良率从40.91%提升到95.45%，整板的开路/短路良率从88.26%提升到93.94%。优化后较大提升了整板的线宽一致性。     

有线广播线路故障速查法

县广播站到公社站的广播信号线路,一般都比较长,线路的维护工作量也很大。广播信号线路最常见的故障是短路(混线),查找方法通常是采用测量线路的直流电阻,再根据每公里导钱的电阻值来估算短路点的位置。表1是20℃时单根镀锌铁线每公里直流电阻值R_(20),     

电阻温度換算尺的設計和应用

检查长途线路是否正常的方法之一,是随时量测线路电阻,而将测试结果换算为20℃时的阻值,再与已知的20℃时的标准值比较,从而判断有无障碍。但是每次换算需要一定的时间,历时愈久,线障的时间也愈长。为了准确、迅速地发现线障,提高线路暢通率,我们采用了一种“电阻温度换算尺”来代替繁复的     

飞机电源配电线路故障在翼测试系统的设计研究

飞机电源系统的配电线路安全直接影响着飞机上电气设备的工作安全。飞机供电线路阻值以及故障保护时间是重要性能参数,反映了线路的导电性和可靠性。基于LabVIEW开发的飞机电源配电线路故障在翼测试系统实现了配电线路、跳开关和连接件等多种线路连接元素的总等效阻值测试,诊断回路导通性故障;并通过人机交互界面按需设置模拟飞机线路过载或短路故障,测试线路故障保护时间和I~2t保护曲线,获取跳开关性能状态。该测试系统在不影响飞机原有线路构型情况下模拟线路故障并实现在翼测试,可快速诊断线路导通性及保护器件性能状态,具备多通道拓展功能,对飞机电源系统故障诊断研究具有参考价值。     

一种基于仲裁器的键合前硅通孔测试方法

硅通孔(TSV)故障严重降低了三维集成电路的良率和可靠性。为了在制造流程中尽早精确地排除TSV故障,提出了一种基于仲裁器的键合前TSV测试方法。由于高电平信号通过故障TSV的延迟时间小于无故障TSV,比较被测TSV与无故障TSV的延迟时间,即可判断被测TSV是否存在故障,比较结果由仲裁器给出。依次将被测TSV的延迟时间与不同的延迟时间相比,可对其延迟进行区间定位,实现TSV故障分级。实验结果表明,该方案能够检测出开路电阻大于281 Ω的电阻开路故障、泄漏电阻小于223 MΩ的泄漏故障,有效解决了两种TSV故障共存的检测问题。与现有同类方法相比,该方法提高了测试精度,增加了可检测故障范围,并且可以进行故障分级。     

传输线参数测试方法研究

传统的传输线参数测试方法是终端开路、短路测试。对于高压输电线路,终端直接短路时,短路电流较大,对电力设备有损害。本文提出了在线路正常运行时利用全球定位系统（GPS）提供的时间为基准,对传输线两端的电压、电流进行同步采样和测量。根据牛顿—拉夫逊法对传输线方程进行迭代计算可以得到传输线参数。通过Matlab仿真计算验证了该方法是有效的。     

Build-up印制板和MCM基板电测技术

1 前言Build up 板和 MCM 基板中一般都含有大量的网络,而每个网络的测试端点都在板的两个表面。通过测线网中有无开路和线网间有无短路,我们可以预测线路板的质量好坏。同时可为质量控制提供重要的反馈信息。电测试必须保证所有线路完好无损,然而,高密度 Buildup 板和 MCM 基板给电测试过程提出了挑战,这     

具有四个输出并基于微处理器的双定时器

基于Freescale半导体公司MCC908QY型8位闪存微型计算机的图1所示电路，可提供一个低成本通用双定时器．该定时器可代替单触发电路。您可以通过修改汇编语言软件来满足特定应用要求。该电路采用微处理器IC1的内部12．8MHz时钟振荡器。内部时钟除以4即获得3．2MHz时钟频率，此频率进一步除以定时器预定比例64即获得50kHz时钟。将定时器模数计数器除以50000．可获得可产生1次／秒实时中断与主定时间隔的1Hz时基。     

消色散四棱镜扩束器

本文介绍了消色散四棱镜扩束器的特征、原理、设计考虑、存在问题和解决方法。给出了测量结果和激光实验结果。     

The four jobs of strategy implementation

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The four components of a procedure

Background. As they guide people in performing a task, procedures are the heart of most manuals. It is, therefore, somewhat surprising that the theoretical and empirical knowledge of their nature has remained somewhat elusive. This paper describes a theoretical framework for procedures, summarized as the four components model, which is grounded in systems theory and rhetoric. Aim. The study addresses two research questions: (1) What are procedures made of? and (2) Which design guidelines for procedures can be abstracted from theory and research? Results. The model distinguishes between: goals, prerequisite states, unwanted states (warnings and problem-solving information), and actions and reactions. For each component pertinent research findings are summarized and lead to the formulation of design guidelines. Occasionally these guidelines are compared with existing procedures from a sample of 104 manuals to see how well theory and practice agree. Conclusion. The model offers a manageable and expandable framework for creating user support that is based on scientific research. It can be used for a systematic analysis of procedures and for their (re)design.     

Master the four seasons of management

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Gated turn-on of four layer switch

The n-p-n-p switch (silicon controlled rectifier--SCR) reacts to a gate electrode signal by first going into the high conductivity state in the neighborhood of the gate. Following this initial event the ON state spreads laterally, the "gate" current to the regions which turn on later being supplied by those regions already ON. The current density in the gate region just prior to turn-on is of the order of 1 amp/cm². The rate of spread or of contraction of the operative area is crudely computed. Hysteresis between increasing and decreasing current characteristics is explained.     

四粒子W态的概率隐形传态

提出利用两个二粒子非最大纠缠态作为量子信道传送任意四粒子W纠缠态的方案。发送者只需做一次正交完备基测量, 然后通过经典信道将测量结果告知接收者,接受者通过引入辅助粒子F,并在适当的么正变换后做Von Neumann测量, 接着引入辅助粒子B3B4,并对手中拥有的粒子进行再一次的幺正变换,就能以一定的概率完成四粒子纠缠态的隐形传输。整个隐形传态过程中,发送者只需一次正交完备基测量,且当量子信道为最大纠缠态时,此方案可实现完全传输。     

Comparative study of four adaptive frequency trackers

We study and compare four algorithms for adaptive retrieval of slowly time-varying multiple cisoids in noise: the adaptive notch filter, the multiple frequency tracker, the adaptive estimation scheme, and the hyperstable adaptive line enhancer. The local behavior of the algorithms in a neighborhood of their equilibrium state [assuming high signal-to-noise ratio (SNR) and large data sample] for a two-cisoid signal is treated in a similar way to the linear filter approximation technique used for a single-cisoid case. The validity of the results is confirmed by computer simulations     

多束激光的合成和传输

描述多束激光的合成和传输系统的结构及特性,给出系统光束合成混合度和传输效率的测量结果。