LED芯片封装在线非接触检测系统

根据p-n结的光生伏特效应,采用交变光源照射待测LED芯片,在封装的短路支架上激励出光生短路电流;通过对该微弱电流信号的测量,判断引脚式封装的LED芯片在压焊工艺中/后的功能状态及焊线质量,实现LED芯片的非接触检测。构建了以单片机为控制核心的测试系统,采取了提高系统检测准确性和检测效率的措施,实现了系统控制、数据处理分析等功能。实验结果表明,该系统能正确检测红光、黄光及绿光LED芯片,系统检测效率高,单个LED芯片的检测时间仅为10ms,适用于实际LED生产时引脚式封装工艺过程中的在线检测。     

一种LED芯片在线非接触检测系统

本文介绍了一种发光二极管(LED)芯片非接触在线检测系统。阐述了检测系统工作原理及检测系统构成。系统采用C8051F020单片机进行控制,利用LED p-n结的光生伏特效应,通过对光生伏特效应中产生的光生短路电流的测量,实现对LED芯片质量及芯片与引线支架电气连接状态的检测。通过对常用LED芯片测量的实验结果表明,该系统能快速有效的对封装过程中的LED芯片状态进行非接触检测。     

LED芯片封装缺陷检测方法研究

引脚式LED芯片封装工艺中封装缺陷不可避免.基于p-n结的光生伏特效应和电子隧穿效应,分析了一种封装缺陷对LED支架回路光电流的影响.利用电磁感应定律对LED支架回路光电流进行非接触检测,得到LED芯片功能状态及芯片电极与引线支架问的电气连接情况,并对检测精度的影响因素进行分析.实验表明,该方法具有高检测信噪比,能够实现对封装过程LED芯片功能状态及封装缺陷的检测.计算结果与实验结果较好吻合.     

水果分级机器人关键技术的研究和发展

水果分级技术能够保证水果的质量，提高消费者的满意度，增强水果产业的竞争力和利润水平。本文介绍了水果自动分级机器人的研究现状，主要包括光学检测(机器视觉、高光谱／多光谱、红外线、X射线等)、冲击检测与介电特性检测等水果品质的无损检测技术和自动分级装置，并展望了其今后的发展趋势。     

CBGA阵列的组装技术

随着计算机技术和IT技术的发展,对电路元器件的封装提出了更好的要求。期中SMT技术得到了广泛的应用,SMT封装对在高密度、高引出端数和高性能方面要求的提高,发展了陶瓷焊球阵列（CBGA）技术,本文重点介绍了陶瓷焊球（CBGA）的工艺以及封装技巧和返修方法。     

当前SMT环境中的热门先进技术

只要关注一下如今在各地举办的形形色色的专业会议的主题,我们就不难了解电子产品中采用了哪些最新技术。CSP (芯片尺寸封装_)、0201无源元件、无铅焊接、MCM(多芯片组件)、AXI(自动X射线检测)和选择性焊接可以说是近来许多公司在PCB上实践和积极评价的热门先进技术。而随着这些新技术的实施,也带来了一些新的挑战。比如说,如何处理在CSP和0201组装中常见的超小开孔(250um)问题,就是焊膏印刷以前从未有过的基本物理问题。     

轻松实现DAS向SAN移植

与CPU一样,内存的制造工艺同样对其性能高低具有决定意义,而在内存制造工艺流程上的最后一步也是最关键的一步就是内存的封装技术。 封装技术其实就是一种将集成电路打包的技术。这种打包对于芯片来说是必须的,也是至关重要的。因为芯片必须与外界隔离,以防止空气中的杂质对芯片电路的腐蚀而造成电学性能下降。另一方面,封装后的芯片也更便于安装和运输。 芯片的封装技术种类是多种多样,诸如DIP、PQFP、TSOP、TSSOP、PGA、BGA、QFP等。目     

环境老化对底部填充胶性能的影响

焊球可靠性是电子封装过程中重点关注的问题之一,底部填充胶被引入电子封装领域用来匹配基板和芯片之间的热膨胀系数,从而保护焊球,提高焊球的可靠性,但是底部填充胶的引入也会出现老化过程中一些由材料本体变化造成的可靠性问题.该文主要研究了几种老化处理对底部填充胶热机械性能和黏接性能的影响.对于胶水的热机械性能,经过水热老化处理...     

液晶显示屏背光源模组表面缺陷自动光学检测系统设计

详细介绍了自动光学检测技术在液晶显示屏背光源模组表面缺陷在线检测中的应用,分析并比较了背光源模组缺陷自动光学在线检测中的成像技术、检测系统的组成、结构原理与设计方法,阐述了检测结果为不良品的返修方法。给出了背光源模组表面缺陷常见缺陷的种类和缺陷分类判断准则,把种类繁多的背光源模组表面缺陷分为画面缺陷、外观缺陷与异常缺陷;根据背光源模组缺陷形成的原因、种类,设计了背光源模组缺陷点灯检测和非点灯检测两种自动光学检测方案,所设计的自动光学检测方案对背光源模组组装产业开发缺陷检测系统具有有益的参考价值。     

光传感器中劣化绝缘子非接触式检测技术研究

传统的检测技术在检测光传感器中的劣化绝缘子时,检测范围小,成本高,且工作人员必须要直接接触传感器。为了解决上述问题,提出了一种新的光传感器中劣化绝缘子检测技术。利用驱动控制电机、LD光源、调节电路、光学传感头和电源设定检测通道,通过光纤自动判断绝缘子串的空间分布特性,将分析数据与数据库中的标准数据进行对比,得到检测结果。为验证所提检测技术的工作效果,与传统技术进行实验对比,结果表明,运用所提技术对劣化绝缘子进行检测时,检测成本远低于传统方法,说明该技术能够实现非接触式检测,检测范围广,成本低,对于保障电网安全运行有重要的意义。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。