钎焊金刚石磨料片工艺的研究

用AgCuNi、AgCuCr和AgCuTi钎料,在自行研制的钎焊装置中,采用二次钎焊和两级加热工艺,实现了一次焊接20片金刚石磨料片。     

Fügeverfahren im Vergleich: Löten,Kleben, Mechanisches Fügen von Magnesium

Comparison of Joining Techniques: Soldering, Adhesive Bonding, Mechanical Joining of Magnesium Due to their light weight construction potential magnesium sheets are of increasing interest during recent years. During the production process appropriated joining technologies are necessary for sheets to obtain various knot, profile, and sheet structures. Thus studies to develop appropriated joining technologies are of high importance.     

微带板高钎透率大面积钎焊技术研究

研究了不同焊接工艺方法、焊膏量以及焊接材料(Sn37Pb、Sn3.5Ag)对微带板与垫板之间大面积钎焊质量的影响。X光检测结果表明,采用优化后的焊接工艺方法及焊膏量,微带板与垫板之间大面积钎焊钎透率可达95%以上;焊点微观组织分析结果表明,Sn3.5Ag焊点内部存在较大尺寸的脆性金属间化合物相,对焊点的力学性能有不利影响,建议使用Sn37Pb焊料进行微带板的焊接。     

波峰焊接工艺技术的研究

作为一种传统焊接技术,目前波峰焊依然在电子制造领域发挥着积极作用。本文介绍了波峰焊接技术的原理,以及一种新型波峰焊接技术的特点,与传统波峰焊情况不同,它可以保护表面贴装元件来实现对通孔元件焊接。最后本文分别从焊接前的质量控制、生产工艺材料及工艺参数这三个方面探讨了提高波峰焊质量的有效方法。     

无铅焊技术的发展及其应用

介绍了目前使用较多的三种无铅焊料体系：Sn-Ag系列、Sn-Zn系列、Sn-Bi系列及其特点；探讨了无铅焊接技术应用中的元器件选定、PCB应用、模板设计、助焊剂、再流焊温度曲线、氮气保护再流焊：最后分析了由有铅焊接到无铅焊接工艺转变所带来的新问题在检测和测试方面的应对措施。     

Critical properties of Cu6Sn5 in electronic devices: Recent progress and a review

As the most common of the intermetallic compounds (IMCs) formed between Sn-based solders and Cu substrates during the packaging of integrated circuits (ICs), Cu₆Sn₅ is frequently involved in the fabrication of solder joints and plays an important role in the integrity of electronic devices. This is especially true for recently developed micro-bumps in 3-dimensional (3D) high-density integrated circuits (ICs), in which the volume fraction of Cu₆Sn₅ is significantly higher than in conventional ball grid array (BGA) or through hole pin (THP) arrangements. Recently, with the use of advanced characterization techniques, significant progress has been made in the understanding of Cu₆Sn₅ intermetallics in terms of their crystal structure, solidification behaviour, role in interface reactions, thermal expansion and mechanical properties. This improved understanding is of fundamental importance for the production of next generation electronic devices, however there is no existing comprehensive summary of this research available. Here, we provide a review on the properties of Cu₆Sn₅ with a focus on: (1) identification of crystal structure and possible phase transformations of Cu₆Sn₅ in real solder joints; (2) formation of Cu₆Sn₅ during solidification of commonly used Pb-free alloys and its influence on the final microstructure; (3) the formation and growth texture of interfacial Cu₆Sn₅; (4) thermal expansion and mechanical properties of Cu₆Sn₅ and the relationship between crystal structure and temperature. The effects of selected alloying elements that have remarkable influences on the above properties are also discussed. The aim of this paper is to identify the key factors that affect the properties of this important IMC and the relationship between these properties and the integrity of solder joints under various conditions.     

小型制冷空调设备管道的钎焊工艺

本文针对小型制冷空调设备中管道的钎焊要求，介绍了钎焊的工艺，总结其钎焊中焊料及焊剂的选用、火焰性质和焊接范围、管道焊接的结构形式、焊接方法、火候的掌握、常见的焊接缺陷和原因。实践证明，只要遵循其焊接要点，管道的钎焊质量是较稳定的。     

压铸模与铝铸件焊合区的特征及形成机理

模具焊合区的表面上,存在着一定数量的显微孔洞、显微凹陷及裂纹等表面缺陷,大大增加了模具与铸件间的真实接触面积,焊合区的截面主要由焊合的铝合金、过渡层、氮化层及钢基体组成。对模具与铸件不同的焊合模式及形成机理进行了分析,将焊合分为物理化学焊合、机械焊合和混合焊合,并分析了压铸生产中焊合的形成及扩展过程。     

氮气保护对无铅再流焊焊点外观质量的影响

由于无铅钎料润湿性较差,在实际生产中普遍采用氮气保护。通过新制定的氮气保护无铅再流焊工艺,对焊点外观质量进行了统计分析。其结果显示氮气保护可以减少元件偏移和桥连等缺陷,对竖碑、焊球和锡珠等缺陷也有一定影响。