单片机控制电路板在线测试系统设计

本文设计了一套电路板的在线测试系统.该系统由一个缓冲箱、一个电源负载箱、一系列针床和相配套的软件组成.该系统可登录输入标准电路板在正常工作时的动、静态特性参数;登录后进行检测;最后经分析处理,给出电路板的动、静态特性.由此可在生产线上直接判别电路板的质量好坏.与传统在线测试技术相比,这套技术具有模拟外部条件而进行动态(程序工作)参数检测的功能,目前在国内处于领先地位.     

电动汽车能量管理单元电路板自动测试系统

针对电动汽车能量管理单元其电路板测试繁杂的问题,研究设计一种自动测试系统。采用Frescale MC9S12系列MCU作为主控芯片,通过CAN总线实现上位机、下位机、被测板之间的数据传输。系统实现了对能量管理单元4种板件及整机的6类不同测试。上位机软件可对测试项目进行高度灵活地配置,实时显示测试结果,保存至数据库,并生成Word报表。经前期测试,对于同一种板件的全功能测试可在1 min内完成,单个通道的绝对误差可小于0.05 V,并且其故障检出率可达到100%。     

在线测试技术的发展与展望

在线测试技术的发展与展望□胡诞康在线测试技术是近年来迅速发展的新颖测试技术，它可以在印刷电路板上直接测量电参数（如电流）和元器件参数。采用在线测试技术配合以计算机和必要的接口可以组成自动测试系统（ＡＴＥ）。随着电子工业和科学技术的发展，印刷电路板（Ｐ...     

基于电荷耦合器的在线实时检测仪的研制

本文阐述了在线实时检测仪在研制中选用的线阵电荷耦合器件CCD的特点、主要技术指标 ,光源的选择与照度的匹配 ,对光束准直系统、二值化处理的线阵CCD驱动板、主电路板系统的设计 ,最后给出了实验测试结果。     

红外焦平面阵列相对光谱响应测试系统

由电子41所研制的红外焦平面阵列相对光谱响应测试系统采用单光路标准替代法进行测量，系统组成灵活并可扩展，配合自行研制的图形发生器，偏置，时钟驱动、数据采集子系统，可以满足不同被测器件的需要。     

多功能电力参数测试仪

介绍了一种基于89C52单片机电力参数测试系统的组成和检测原理。系统利用双保持器解决了电压电流的同步测量。利用倍频锁相环路防止了被测信号的失真。同时解决了无法进行在线测试的难题，使得低压供电系统对电力的分配与调度更加合理，更加快捷。     

固态功率器件测试技术研究

深入探究和分析固态微波功率器件测试中的影响因素及注意事项,并给出解决问题的措施;采用负载牵引技术及TRL校准技术实现测试系统的阻抗匹配和测试夹具的校准,搭建测试平台,对某款Si C功率晶体管进行测试,测试结果满足技术指标要求,证明测试系统可以有效提取被测器件的真实参数。     

基于SOPC技术的电路板通用测试插槽设计

为实现用一个测试插槽检测多个不同的印刷电路板(PCB),提出了利用可编程器件(PLD)的在线重配置功能,运用可编程片上系统(SOPC)技术研发通用测试插槽的设计思想,完成了通用插槽的硬件设计和软件设计,包括:现场可编程门阵列(FPGA)中的独立接口模块设计、通用接口控制模块设计、系统层软件设计和应用层软件设计.实际应用结果表明:基于SOPC技术的通用插槽的研制有利于故障检测方法的实施,方便了电路板的自动测试,减小了测试设备的体积,增强了测试系统的通用性和可扩展性.     

基于在线可编程逻辑器件MACH4的高精度频率测量仪设计

本文应用多周期间接测频原理 ,介绍了一种基于系统在线可编程 (ISP -InSystemProgrammability)逻辑器件MACH4为依托的高精度频率测量仪的设计方法。给出了测频仪的原理框图 ,分析了多周期间接测频算法的原理 ,并以测频仪在某型导弹地面测试设备的计量检定的应用为例 ,对测频仪的误差进行了讨论 ,给出了减小误差的方法     

更正

目前大话务量准确率的测试方法通常有两种：一种是采取直接模拟拨测的方式．即将测试装置和被测交换机并联成测试环路。并由测试仪模拟呼叫和接收进行测试：另一种是采用系统在线监测的方式，即将测试装置串联在话路中．通过长期记录所有用户话单准确信息进行测试。本文推荐直接模拟拨测方式。一是该方式更符合计量应针对被检主体的要求：二是该方式简单易行。检测周期短。     

A Portable Noncontact Heartbeat and Respiration Monitoring System Using 5-GHz Radar

A portable noncontact heartbeat and respiration monitoring system operating in 5-GHz band is reported in this letter. Compared with the previously reported system operating at Ka-band, this system has been simplified to include only two PCB antennas, a palm-size PCB radio module, a data acquisition module, and a laptop. The system, powered by the laptop battery through USB connection, is compact, low-cost, and convenient for field test. A detection accuracy of better than 80% has been achieved at a distance of 2.8 m and at a low transmitted power of 20 muW. The system can be used for various applications in biology, medicine, and security.     

板级封装焊点的振动冲击加速失效方法研究

设计了一种针对板级微电子封装微焊点的振动冲击加速失效试验。对线路板施加定频正弦振动载荷,测量线路板应变值以标定PCB板级载荷水平,采用高速数据采集系统记录了振动载荷作用下的微焊点失效动态过程。结果表明：通过调节振动条件,采用板级振动试验可以获得近似板级跌落冲击试验的峰值形变,其峰值载荷作用频次高于跌落冲击试验;失效数据监测结果显示焊点在振动冲击试验中表现为疲劳失效特征。本加速失效试验在保持焊点失效特征的同时提高了试验效率,可作为跌落冲击条件下微焊点板级可靠性评估的备选试验方案。     

机载电子设备中印制板边界条件的识别

在机载电子设备机箱中，印制板通过插座和锁紧机构固定在机箱内。印制板与机箱的这种连接方法，给它的边界条件的确定带来了极大的困难。根据机载电子设备中印制板有限元动力学模型与模态试验的固有频率之差，建立了印制板边界参数识别的优化模型，并采用信赖域法中的Levenberg-Marquardt法，求解上述优化问题。验证试验结果表明，提供的印制板边界条件识别方法是有效的，识别的印制板边界参数完全可以用于印制板的动力学分析与设计。     

Advanced characterization of mechanical properties of multilayer ceramic capacitors

Characterization of the mechanical properties of small components is a significant issue. For the multilayer ceramic capacitor (MLCC), direct loading by conventional facilities is not suitable because of its small size. To date, the standard method used to determine MLCC’s mechanical properties is board flex test; i.e., mounting the capacitor onto a printed circuit board (PCB) and applying bending to the entire system. Failure is defined as cracking or capacitance loss of the MLCC when the mounted PCB is subjected to a specified deflection, and the measurements are usually performed after the test. In this case, characterization of the mechanical properties of MLCCs is qualitative. The purpose of the present study was to quantitatively characterize the mechanical properties of MLCCs. Specifically, the acoustic emission was used to detect cracking of MLCCs during the board flex test. To confirm cracking-induced acoustic emission, telemicroscope was used to perform the in situ observation of cracking. Finite element analyses were also performed to analyze the stress field resulting from the test to compare with the observed cracking path. In addition, nanoindentation was used to explore the mechanical properties of the constituents of MLCCs in the nanoscale. Our work not only allows identification and understanding of the fracture origin, but also provides guidelines in the material design.     

VXIbus模块仪器在电路印制板故障诊断系统中的应用

本文介绍了一个由VXIbus模块仪器组建的用于电路印制板故障诊断的自动测试系统,具体的讨论了组建中的主控计算机和接口控制器的选择及被测单元与自动测试设备之间通用接口设计等问题。在文章的最后,给出了测试软件设计实例。实际应用表明,VXIbus模块仪器的应用,为电路印制板故障诊断系统提供了优良的测试性能,使系统的实用行、通用性、灵活性及自动化程度得到了明显的提高。     

Zwitterionic Nanocages Overcome the Efficacy Loss of Biologic Drugs

For biotherapeutics that require multiple administrations to fully cure diseases, the induction of undesirable immune response is one common cause for the failure of their treatment. Covalent binding of hydrophilic polymers to proteins is commonly employed to mitigate potential immune responses. However, while this technique is proved to partially reduce the antibodies (Abs) reactive to proteins, it may induce Abs toward their associated polymers and thus result in the loss of efficacy. Zwitterionic poly(carboxybetaine) (PCB) is recently shown to improve the immunologic properties of proteins without inducing any antipolymer Abs against itself. However, it is unclear if the improved immunologic profiles can translate to better clinical outcomes since improved immunogenicity cannot directly reflect amelioration in efficacy. Here, a PCB nanocage (PCB NC) is developed, which can physically encase proteins while keeping their structure intact. PCB NC encapsulation of uricase, a highly immunogenic enzyme, is demonstrated to eradicate all the immune responses. To bridge the gap between immunogenicity and efficacy studies, the therapeutic performance of PCB NC uricase is evaluated and compared with its PEGylated counterpart in a clinical‐mimicking gouty rat model to determine any loss of efficacy evoked after five administrations.     

边界扫描技术在板级可测性设计中的应用

硬件系统的规模越来越大，复杂程度越来越高，对其进行测试也越来越困难，边界扫描技术很好地解决了传统测试的不足。阐述了JTAG技术的基本原理，从设计方法、优化策略及实现技术等方面，对基于JTAG的PCB可测性设计进行了研究，给出了具体的实现方法，并实现了自动测试系统中数据采集电路板的可测性设计。结果证明该方法有效缩短了测试时间，降低了维修测试费用，具有较大的实用价值。     

PCB钻孔自动光电检测精确配准关键算法

为了实现快速印制电路板（PCB）钻孔自动检测,提出了一种PCB待测板和标准板快速自动配置算法。介绍了PCB钻孔自动光学检测系统的基本结构。采用粗匹配和精匹配两步进行配准的方法,通过边缘提取和Hough变换得到待测板4个角点坐标,利用角点坐标和标准板角点的关系进行粗配准,并找到待测板的定位孔;然后利用待测板定位孔圆心和标准板定位孔圆心的关系进行精确配准。实验证明,该算法计算速度和精度完全能够满足实际要求。     

Simulation-based performance analysis and optimization of electronics assembly equipment

Due to the high degree of automation in modern printed circuit board (PCB) assembly, production planning and scheduling in this industry relies heavily on the accuracy of the underlying models of the automated machinery. In this paper, the derivation of such mathematical models is exemplified for one of the most wide-spread machine types (the so-called chip shooter). Moreover, a simulation system for practical use in the electronics assembly is presented which incorporates various types of assembly machines. It serves as a tactical production planning aid as well as a test field for the analysis of the kinematic processes of PCB assembly machines. Such simulation, tailored to the specifics of a production environment, gives reliable estimates of the achievable production volume. Considerable deviations between the performance figures provided by the machine supplier and the actual result can thus be explained, and potential assembly system configurations be compared by drawing on reliable measures. Since the equipment is modelled at a level which takes precise account of its specific kinematics, a detailed analysis of the operations of the individual machine can also be performed revealing potential bottlenecks in its design. These insights are used to optimize machine design and control. Methods based on graph theory as well as on modern numerical search algorithms have been developed for the latter purpose. They lead to considerable performance improvements.     

A systems approach to photolithography process optimization in an electronics manufacturing environment

There are many complex problems in the optimization of an electronics manufacturing environment, and it is the view of the authors that these problems should not be solved and optimized in isolation, but analysed in the framework of a system. A systems approach offers an overall approach for solving problems, and optimizing the whole of the system as well as discrete subsystems. The research introduced in this paper integrates several techniques, namely: Integrated computer aided manufacturing DEFinition (IDEF), and experimental design and response surface methods for the analysis, control and optimization of electronic manufacturing processes. Electronics manufacturing includes three major processes; Printed Circuit Board (PCB) manufacturing, semiconductor device manufacturing and electronics assembly. This paper describes a novel generic systematic methodology that has been used to create a model to optimize the photolithography process in PCB manufacture. For this, photolithography has been considered as a whole system made up of several sub-systems. This is shown in the process map for PCBs that focuses on photolithography and its subprocesses. A model of the manufacturing process is then given with the results of this being validated using an industrial study. Optimized settings for processing equipment are given resulting in an increase in process yield within industry.