摘要：随着最近几年来电子封装行业的快速发展，行业中对钎料材料的选择逐渐成为了研究的热点，近几年对无铅钎料的研究一直都是热点课题。虽然现在对于无铅材料的研究很多，要想完全实现无铅材料的大批量商业化生产和应用，在实际过程中还是存在很多问题。本文主要使用的是Sn-1.0Ag-0.5Cu作为主要的研究对象，并向其中加入了Bi元素对其改性，然后对改性后的样品借助SEM进行表征，对比各组样的表征结果，研究了微量Bi元素的加入对Sn-1.0Ag-0.5Cu无铅钎料的显微组织的影响。研究结果表明：经过再流焊，钎料与Ni基体在界面处形成Ni3Sn4金属间化合物，随着时效时间的增加，四种钎料界面处金属间化合物的生长速率都增大，且金属间化合物的厚度增加；含Bi的钎料与Ni基体发生反应后，在较高温度下时效时，钎料基体中的Bi在靠近界面处发生偏聚现象；含Bi钎料接头处金属间化合物的生长速率要低于不含Bi钎料接头界面处化合物的生长速率，且随Bi含量的增加化合物的生长速率降低比较明显。

关键词：Sn-Ag-Cu-Bi钎料；液态时效；显微组织；金属间化合物

Abstract：With the rapid development of the electronic packaging industry in recent years, the choice of materials for brazing filler metal has become a hot research topic. In recent years, the research on lead-free solder has always been a hot topic. Although there are many researches on lead-free materials, there are still many problems in the actual process in order to fully realize the mass production and application of lead-free materials. In this paper, Sn-1.0Ag-0.5Cu is mainly used as the main research object, and the modification of the Bi element is carried out. Then, the modified sample is labeled with SEM, and the results of each group are compared. The effects of the addition of trace elements on the microstructure of Sn-1.0Ag-0.5Cu lead-free solder were studied. The results show that the Ni3Sn4 intermetallic compound is formed at the interface between the brazing filler metal and the Ni matrix. The growth rate of the intermetallic compound increases with the increase of the aging time, and the intermetallic compound the Bi in the brazing filler metal reacts with the Ni matrix, and when it is aged at a higher temperature, the Bi in the solder matrix is segregated near the interface; the growth of the intermetallic compound at the Bi-containing solder joint The rate of growth is lower than that of the compound without the Bi solder joint interface, and the growth rate of the compound decreases with the increase of the Bi content.

Keywords: Sn-Ag-Cu-Bi solder; liquid aging; microstructure; intermetallic compounds

目 录

第一章 绪论 1

1.1微电子封装的发展 1

1.2无铅钎料概述 1

1.2.1无铅钎料的定义与性能要求 1

1.2.2无铅钎料的研究现状 2

1.3低银无铅钎料 5

1.4钎料与基板的作用 6

1.5焊点可靠性及其时效机制 8

1.5.1焊点可靠性 8

1.5.2钎料和界面IMC对焊点可靠性的影响 9

1.6研究目的和内容 9

第二章 试验方法 11

2.1试验材料的制备 11

2.1.1Sn-1.0Ag-0.5Cu-xBi钎料的制备所需材料