电子封装无铅化现状

近年来铅污染广泛地受到了人们的重视。2003年2月13日欧盟颁布WEEE/RoHS法案,在世界范围内引发了一场电子封装的无铅化革命。综述了电子封装技术的现状以及我国如何面对无铅化的问题。     

Mechanical reliability in electronic packaging

The dramatic increase in the number of devices and functionality of the latest ultra large scale integration designs have resulted in increasing chip size. Concurrently, to achieve higher circuit board component densities, package dimensions have been shrinking. These two competing trends are leading to ever more rigorous requirements on the mechanical characteristics of the packaging technology. The dominant issue in component level reliability is delamination and cracks initiated at the interface between dissimilar materials. In board level reliability, solder joint reliability is a primary issue. This paper describes the methodology of prediction and the explanation for interfacial delamination, cracks at the top of the interfaces and the edge of corner, and also solder joint reliability. This paper furthermore presents the role of the chip backside contamination affecting interfacial delamination, the surface characterizations and an explanation of the interface chemistry, and the strength of solders with a variety of plating materials for Sn–Ag-based lead free solders.     

Photonics challenge to electronic packaging

Photonics packaging is a challenge to electronic packaging for two important reasons. The first and most obvious is that light must have access to the device. There must be a window, port or optical fiber interface. The other and more serious problem is that most devices require a highly controlled atmosphere. And if having to accommodate both electrons and photons were not enough, innovators have added mechanical motion to optical devices. Micro-opto-electro-mechanical systems (MOEMS) bring photonics, electronics, optics, physics and mechanical engineering together on one semiconductor device. This appears to be the ultimate convergence of technology domains and can also include biology and chemistry     

在工业领域电子信息工程应用的探析

本文围绕着工业领域中电子信息工程的应用这一主题展开了讨论,首先分析了工业领域中电子信息工程的应用,随后提出了推动工业领域中电子信息工程应用发展的措施.随着科学技术的发展,社会各行业领域都开始应用电子信息工程,工业领域也不例外.     

Material issues in electronic interconnects and packaging

Electronic packages consist of metallic, polymeric, and sometimes ceramic materials as integral entities. Individual physical and mechanical properties of these constituents, and their influence on each other's behavior, affect the overall reliability of the electronic packages. The most common failures in electronic interconnects arise from thermomechanical fatigue of the solder joints. Mismatches in coefficient of thermal expansion (CTE) that exist between these constituent materials are the main cause of such failures. Several approaches such as alloying and composite methodology are being explored to improve the reliability of the solder, which is metallic in nature, by improving its mechanical attributes. Other avenues such as matching the CTE of the constitutent materials are also being considered. In addition, the metallization of the electrical components and electrically non-conducting polymeric/ceramic layer to make it solderable has also been a source of concern regarding the joint reliability. Another concern relates to the high CTE of polymeric boards. This can cause significant CTE mismatch problems if silicon chips are directly mounted on them. Some of our significant findings in these respects are presented.     

Materials for high-density electronic packaging and interconnections in the higher packaging levels

This paper concentrates on the materials requirements anticipated for future packaging strategies of electronic components beyond the 1st level package. This includes Wafer Scale Integration (Level 0), hybrid assembly of bare chips in multichip modules (Level 1.5), printed wiring board (PWB) assembly, including surface mount (Level 2), and higher levels (connectors, mother boards, and cables). Furthermore, high-performance digital VLSI logic packaging only is addressed, to the exclusion of memory, analog, and power circuitry (except power supplies).     

电子信息工程在建筑工程中的应用

作为一门综合性较强的学科,电子信息工程在21世纪得到了良好的发展和广泛的应用,这使得其已经成为独立的产业。当然,对于某些领域来说,电子信息工程是一种先进的、有效的手段,这就包括建筑领域。将电子信息工程有效地应用于建筑工程之中,能够优化建筑工程项目管理,提高其有效性,为高质量、低成本、高效率地建成建筑工程创造条件。基于此,文章将立足于电子信息工程,通过概述电子信息技术,分析电子信息技术在建筑工程项目管理之中的应用情况,希望对于更好地建设建筑工程有所帮助。     

新世纪电子器件封装技术展望

扼要分析了电子器件封装技术迅速发展的成因，预测了电子封装新技术的发展方向，深入阐述了引脚布置方式的突破，BGA技术的发展，BGA和倒装芯片结合的优势，CSP产业化的关键，在晶圆片上进行CSP封装的新工艺，以及倒装芯片和CSP封装的综合比校。     

控制工程在机械电子工程中的应用

随着科技的进步,我国机械电子工程不断发展,逐渐应用在工业生产的各个领域,有效地推进了经济的发展。控制工程是科技发展过程中一个重要的产物,它的出现提高了工业设备的自动化程度,将控制工程运用在机械电子工程上,不仅有利于推动机电一体化的进步,更提高了机械电子工程的可操作性、可控制性,促进了机械电子工程的工作效率。文章将对控制工程在机械电子工程上的应用做简单的研究,提出几点参考性建议,以期促进机械电子工程的进一步发展。     

简述电子工程自动化控制中的智能技术

近年来,随着我国社会主义市场经济飞速发展,人们生活质量和生活水平不断提高,对电子工程自动化控制提出了更高的要求,而智能技术作为其中的重要组成部分,在其中发挥了十分重要的作用。本文针对电子工程自动化控制中的智能技术发展的现状以及存在的问题,提出几点有效的措施和建议,从而实现电力企业又好又快发展。     

Influence of pad shape on self-alignment in electronic packaging

Anisotropic self-alignment of the noncircular pads is investigated to reduce the misalignment in electronic packaging, and the effects of the direction and length ratio of the noncircular pads are analyzed. The restoring forces of circular and noncircular pads are calculated numerically using the surface evolver and are compared with the experimental data. The restoring force in the minor-axis direction of the noncircular pad becomes largest followed by the circular pad and the major-axis direction of the noncircular pad. Directionality increases with the length ratio, which implies that more accurate alignment can be achieved in the specific direction.     

浅谈自动化技术在电子信息工程设计中的应用

伴随着我国全面进入到信息化时代当中,使得自动化技术越发的成熟,并已经十分广泛的应用到了各个领域当中.因此,为了推动社会的现代化进程,就需要各个行业的工作人员,提升自动化技术的掌握程度,并在电子信息工程设计过程中,实现更加深入的研究.本文就基于当下自动化技术,在电子信息工程设计中的应用,进行详细的阐述与分析,以此为相关领...     

试论计算机技术在电子商务中的作用

电子商务是市场发展、时代发展的必然趋势,它是一种新型的交易渠道,与人们的生活节奏相符.所谓电子商务,就是指在互联网技术、计算机技术的支持下,在全球范围内,利用网络手段完成等价交换、产品信息交换的一种贸易方式.随着计算机技术的飞速进步与发展,计算机网络技术在电子商务中发挥了重要作用,为人们网上支付、网上购物提供了有利条件.然而在电子商务的发展过程中,人们还需意识到其中潜在的安全隐患问题,及时发现安全隐患,并采取措施解决问题,有利于提高电子商务发展的安全性.     

电子封装用环氧树脂基复合材料的优化

研究了593固化剂不同用量加入电子封装用环氧树脂E-51中的效果,以及在E-51,Al2O3复合材料中硅烷偶联剂不同用量的效果,结果显示:593固化剂与环氧树脂质量比为1:4时,复合材料的致密度高,气孔少,成型效果好;当硅烷偶联剂KH-560质量分数为8%时,复合材料的热导率达到0.75 W/(m·K).     

Trends and issues in Pb-free soldering for electronic packaging

A variety of Pb-free solder alloys have been proposed for use as interconnects for electronic packaging including Sn?Ag, Sn?Cu, Sn?Ag?Cu, Sn?Ag?Bi, and Sn?Sb, among others. This paper presents a review of the behavior of promising Pb-free solder alloys as related to their microstructure. Recommendations of optimal alloy composition as a function of performance requirements are given. For surface mount applications, eutectic Sn?Ag?Cu is recommended as the optimal alloy. For flip chip interconnects, the eutectic Sn-Cu alloy has the best performance. The materials and process trends of Pb-free packaging are summarized with optimal conditions identified.     

Damage based fatigue criterion for solders in electronic packaging

A fatigue failure criterion based on physical damage mechanism is proposed for solders. A solder structure is defined as fatigued when the portion of its failed grains reaches a critical percolation threshold, since under such state the failed grains may form large cluster of cracks, leading to the structure's mechanical instability as well as electrical degradation. Mechanically the inception of such state corresponds to a turning point of load carry capability in a simple fixed-strain tension-tension test of a solder structure. Experimental data for both lead-rich solders such as 96.5Pb-3.5Sn solders and lead-free solders such as 96.5Sn-3.5Ag showed consistency with the proposed criterion. Experimental data also show that by adoption of this failure criterion a better prediction of mechanical fatigue for a lead rich solder can be achieved. The criterion is derived from a science based fatigue theory, therefore the criterion should be applicable to anisotropic as well as isotropic structures regardless of solder structure sizes, which is useful to the development and design of small-scale (micron scale or smaller) solder joints for current electronic packaging.     

电子安装技术的最新动向和展望

概述了电子安装技术的最新动向和将来展望。     

The emergence of the technician engineer in electrical and electronic engineering

For many years Britain's electrical and electronic engineering industry had been perplexed over the ``technician problem': what acceptable title might be found for those senior engineering personnel to whom the generic term Technician was unacceptable, because of their training, experience and functions as engineers. This article surveys the current situation and traces the events leading to the setting up, in 1965, of the Institution of Electrical and Electronics Technician Engineers (IEETE), to meet the professional needs of the technician engineer. His distinct status is now firmly established: a responsible engineer in his own right, he has an identity, qualification and career of his own.