摘要随着无铅钎料在电子封装中的应用越来越多，应用最广泛的是Sn-Ag-Cu（SAC）钎料。同时，SnBi钎料凭借其低熔点、良好的润湿性能、较高的力学性能、优异的抗蠕变性能和可以阶段焊接等优点也受到世界各国电子行业者的青睐。86469

   本文主要研究对Bi含量对Sn-Bi/Cu界面化合物生长影响，文中从组织观察、IMC厚度等几个方面来进行比较分析。本实验采用超景深显微镜和扫描电镜（SEM）观察SnBi钎料抛光后界面，进行分析，结果表明不同成分、不同时效温度的钎料IMC厚度不同。然后对不同的时效时间、不同温度的Sn-Bi钎料的测试，结果发现，钎料的界面处IMC厚度随时效时间的增加而增大；随老化时间的增长而增大。

   综上所述，通过研究Bi含量对Sn-Bi/Cu界面化合物生长的影响，可以得到以下结论：界面处IMC的厚度随着老化温度的升高而增大，随着时效时间的增长而增大，在所有的这五种成分中，Sn58Bi的IMC厚度最大。

毕业论文关键词：无铅钎料；显微组织；力学性能；IMC厚度

Abstract   As is known to all, lead-free solder has been used more and more widely in electronic packaging。Meanwhile,SnBi solder has also been favored by the world because of its low melting point, good wetting properties, high mechanical properties, excellent creep resistance and stage welding and so on。

  This paper is about the effect of Bi content on the growth of Sn-Bi/Cu interface compound。In this paper,the comparison and analysis are made onthe aspects of tissue observation, IMC thickness and so on。This experiment,the polished interface of  SnBi solder is observed by microscope and scanning electron microscope (SEM),then carry on analysising。 The results show that the IMC thickness of solder with different composition and aging temperature is different。Then, the tests of Sn-Bi solder with different aging time and different temperatures are tested。It is found that the thickness of the IMC on the interface of the solder increases with the increase of aging time and temperature。

  In summary,by studying the effect of Bi content on Sn-Bi/Cu interfacial compound growth,we can obtain the following conclusions the thickness of IMC on the interface increases with the increase of aging temperature and increases with the increase of aging time。 the thickness of IMC of Sn58Bi is the largest in all these five components of SnBi border。

Key words:lead free solder; microstructure; mechanical properties; the thickness of IMC

目  录

第一章 绪论 1

1。1 钎料无铅化的发展 1

1。1。1研究无铅钎料的意义 1

1。1。2 无铅钎料的研究现状 1

1。1。3 钎料可靠性的要求 2

1。2 Sn-Bi无铅钎料 2

       1。2。1 Sn-Bi无铅钎料微观结构和力学性能 2

1。2。2 添加合金元素对Sn-Bi钎料的影响 4

1。2。3 添加合金元素对界面的反应 5

1。2。4 Sn-Bi钎料的局限性 8

1。3 课题来源与主要内容 8

第二章 试验材料、设备与方法 10

2。1 实验材料 10

2。2 实验材料的制备 10

2。3 扫描电子显微镜仪器