SMT焊点半经验随机振动疲劳寿命累积模型

研究了SMT焊点在随机振动条件下引起的振动疲劳情况,给出了SMT焊点半经验随机振动疲劳寿命累计模型,并通过对某SMT电路板进行随机振动疲劳测试,验证了模型的正确性.     

印制线路板设计和加工规范

本文阐述通信产品用印制板的分类,材料选择,技术发展方向,设计和加工技术规范,可供印制电路设计师、工艺师使用。     

表面安装器件及其国内外发展状况

表面安装器件是当前世界上正在普及推广应用的新型电子器件。其主要特点是体积小、重量轻、能实现工业自动化组装，使用中可靠性高、高频特性好等。本文介绍了ＳＭＤ的历史背景和基本概念，论述了国内外ＳＭＤ的发展状况，并就发展我国的ＳＭＤ产业提出了几点建议。     

Strategic maintenance-management in Nigerian industries

A developing society needs to adapt to change and foster creativity. In the pursuit of continual improvement (e.g., reducing fossil-fuel consumption and waste, better service performance, greater availability and improved reliability), implementing wise maintenance-schedules is essential for contemporary organisations. Several studies of a wide range of Nigerian industries indicate that indigenous low availability and low productivity are endemic. The resulting closure of some of these industries has triggered off a realisation of the strategic challenges in maintenance management. In addition, the increasingly-competitive business environment in Nigeria has raised the strategic importance of maintenance functions, especially in organisations with significant investments in physical assets. Five strategic aspects of maintenance management have been identified, namely: maintenance methodology; support processes; organisation and work structuring; comparable culture; and general management policy. Three factors that permeate these dimensions are wise leadership, excellent communications and an understanding of the human factors involved.     

SMT片式元件焊点质量信息提取仿真光源建立

为检测SMT片式元件焊点的质量，减少研究过程中制作实际光源的成本，方便观察各个角度下的焊点形态，研究了仿真光源检测办法。通过建立SMT片式元件焊点模型，比较确定条件下仿真光源和实际光源的效果，确定最佳光照模型。通过改变仿真光源的位置，确定最佳仿真光源的光照位置，从而确定最佳实际光源光照位置。该研究通过Surface Evolver软件建立各种SMT片式元件焊点模型，并通过OPENGL编程完成SMT片式元件焊点模型的转化和光源的仿真过程，该研究对SMT片式元件焊点的检测研究起到优化光源位置结构的作用，对SMT片式元件焊点后期检测提供了坚实基础。     

An exPerimental study of effect of solder joint geometry on thermal cycle life in SMT

The geometry of solder joint in SMT is one of the important factors which determine the solder joint reliability. In this study, a type of solder joint specimen has been designed and is subjected to thermal cycling to failure between -55℃ to 125℃ with a 36 ℃/min heating and cooling rate and 10 min temperature holding times. The solder joint geometry is castellated and controlled with different solder fillet shape and stand off height. A statistical analysis of the scattered thermal cycle lives of solder joints by two parameter Weibull's probability density function has been carried out in this paper. The experimental results show that the more reliable solder.joint geometry has flat or slight convex solder fillet with a stand off height larger than 0.1 mm. The results may be the recommended guideline to design optimal solder joint geometry.     

超线程技术初探

介绍了超线程技术的基本概念，设计思想、特点及其发展，讨论了超线程的技术的实现。     

现代电子封装技术

根据国际电子封装的发展，论述了电子封装的地位和作用，回顾了电子封装的发展简史，提出现代电子封装的概念，并就发展我国电子封装发表几点建议。     

材料模式选择对SMT焊点寿命分析的影响

通过对SnPb钎料在弹塑性与蠕变，弹性与黏塑性两种材料模式下受热循环作用产生应力应变的有限元仿真。讨论了材料模式对SMT焊点寿命分析的影响。     

Automatic method for searching integral distinguishers of ARX block ciphers

Firstly,based on three subsets division property propagation technique,the propagation function of the K-set and L-set of ARX block ciphers was constructed respectively.All vectors in L-set affected the propagation of K-set when propagate through xored round key operation.With SAT/SMT solver,round reduced integral propagation functions of ARX block ciphers could be established.Finally,by exhausting all possible input integral characteristics with proper data complexity,round reduced integral distinguishers of ARX block ciphers could be found.The proposed method can be used for searching integral distinguishers of ARX block ciphers including SIMON-like family block ciphers,HIGHT,SPECK family block ciphers and LEA effectively.