在无铅环境中的热风整平

当电子工业走向无铅焊接的时候,热风焊料整平仍然是继续可焊性保护的优选方法。     

提高焊膏印刷质量的工艺改进

焊膏印刷作为SMT工艺的第一步，其质量好坏对SMT工艺有着重要影响。文章通过对焊膏成分、特性的分析，讨论了印刷中各种工艺参数的正确选择；对焊膏印刷中容易出现的质量问题进行了详细分析，指出了产生问题的原因，提出了改进措施。     

Intermetallic compounds formed at the interface between liquid indium and copper substrates

The interfacial reactions between liquid In and Cu substrates at temperatures ranging from 175°C to 400°C are investigated for the applications in bonding recycled sputtering targets to their backing plates. Experimental results show that a scallop-shaped Cu₁₆In₉ intermetallic compound is found at the Cu/In interface after solder reactions at temperatures above 300°C. A double-layer structure of intermetallic compounds containing scallop-shaped Cu₁₁In₉ and continuous CuIn is observed after the Cu/In interfacial reaction at temperatures below 300°C. The growth of all these intermetallic compounds follows the parabolic law, which implies that the growth is diffusion-controlled. The activation energies for the growth of Cu₁₆In₉, Cu₁₁In₉, and CuIn intermetallic compounds calculated from the Arrhenius plot of growth reaction constants are 59.5, 16.9, and 23.5 kJ/mole, respectively.     

厚膜混合集成电路常见工艺缺陷及其消除方法

除设计和材料外，工艺和操作对厚膜混合集成电路的质量和性能也有较大的影响。分析了厚膜混合集成电路生产过程中一些常见的工艺缺陷，如线条变形、起泡、阻值不稳、元件受损、锡珠等的产生原因，并提出了相应的消除方法。     

Low temperature bonding of LD31 aluminum alloys by electric brush plating Ni and Cu coatings

0Introduction Amongavarietyofbondingtechnologies,vacuum brazinghasbeenwidelyadoptedasareliablemethodfor joiningaluminumcomponents[1],whereintheAl Sialloys systemisrecognizedasthemostpopularfillermetals[2,3]. Althoughasoundjointcanbeachievedforcertainalumi…     

WZ型系列真空铝钎焊炉的研制

简要介绍了WZ型系列真空铝钎焊炉型号，规格等技术参数，并以WZLQH－30型真空铝钎焊炉为例介绍了真空铝钎焊炉的结构及其特点，总结了真空铝钎焊炉设计研究及调试过程中的一些经验体会。     

Analysis of Intermetallic Phases Formed on Surface Vapor Oxidized H13 Hot Work Steels in Molten Aluminum

In this paper, the author dipped surface vapor oxidized H13 steel specimens into 700℃ molten aluminum liquid for a certain period of time. Analyze the intermetallic phases formed on the H13 samples surface with optical microscope and X-ray diffraction method. The observation of immersion test sample's cross-section shows that Fe3O4 film will protect die substrate from molten aluminum erosion. The identification of the intermetallic phases reveals that they consist of 2parts, which is named as the composite layer and the compact layer. Further investigations are made in order to know the phase constituents of the 2 layers, they are Al8Fe2Si (outer composite layer), (AlCuMg) and Al5Fe2 (compact layer),respectively. The experimental results show that on the same specimen, a convex surface with bigger radius of curvature is more likely to be molten and the melting loss speed is also faster than a flat and smooth surface. The thickness of compact layer on a smooth surface is much bigger than that of the convex surface. Therefore, the author supposes the compact layer is favorable in stabilizing the die surface material from further melting loss, as their formation on the die surface, the melting loss speed will decrease.     

SMT建模仿真研究现状及发展

概述了SMT再流焊工艺过程、所用组装件以及形成的焊点3方面的仿真进展，充分展现了计算机模拟在再流焊研究中的重要作用。     

Interfacial reactions of liquid Sn and Sn-3.5Ag solders with Ag thick films

The interfacial reactions of liquid Sn and Sn-3.5Ag solders with Ag thick films are investigated in the temperature range from 250–325 °C, and the morphology of intermetallic compounds formed after such soldering reactions is observed. In kinetics analysis of the growths of intermetallic compounds, it was found that both Sn/Ag and Sn-3.5Ag/Ag reactions were interfacial-controlled, and the growth rates for both cases were similar. The rate of Ag dissolution into liquid solder attendant on the formation of interfacial intermetallic compounds after Sn/Ag reaction was about four times higher than that after Sn-3.5Ag/Ag reaction, as evidenced by experimental results.     

Bi-Sr-Ca-Cu-O高温超导材料的连接技术

Bi-Sr-Ca-Cu-O（BSCCO）高温超导材料在电力工程中拥有广阔的应用前景。本文全面概述了国内外研究Bi系高温超导材料连接技术的现状和不足，重点介绍了BSCCO带材常规冷压成形后再高温反应退火的扩散焊连接技术，另外，阐述了近几年采用高温加压直接扩散连接的最新研究成果。