摘要随着人们对环保意识的增强，以Sn-Pb为首的有铅钎料逐渐被无铅钎料取代。常用的无铅钎料有Sn-Ag系、Sn-Cu系、Sn-Zn系、Sn-Bi系等。本文主要研究In-Sn钎料，因其有着一系列优点包括：熔点低、润湿性好、延展性好以及更长的疲劳寿命等，这对实现低温封装等特殊封装有着重要意义。本文首先将In-Sn钎料BGA小球在Cu基板和Ni基板上润湿铺展，从而测试其润湿铺展性能；接着制备BGA小球并将其焊接至印刷电路板上，经固态时效后进行BGA焊点的剪切性能测试分析；同时将模拟Cu板利用该钎料进行对接，经液态时效后进行剪切性能测试分析；最后对52In-48Sn钎料/Cu界面显微组织进行研究。实验结果表明铺展性能与温度有关，温度越高，铺展性越好；BGA焊点的剪切力与时效时间有关；液态时效后的In-Sn钎料的剪切力随着时效时间的增大先不断增大，当达到峰值以后就开始慢慢的减小。金属间化合物层的厚度随着时效时间的增加而变厚。86467

毕业论文关键词：无铅钎料；In-Sn钎料；铺展性；剪切强度；界面组织

Abstract With the enhancement of people's awareness of environmental protection, lead by Sn-Pb is gradually replaced by lead-free solder。 Commonly used lead-free solders include Sn-Ag、Sn-Cu、Sn-Zn and Sn-Bi solder etc。 This paper mainly studies In-Sn solder, because it has a series of advantages including low melting temperature, better ductile properties, longer fatigue life and so on, which has an important significance for the realization of low-temperature packaging and other special packaging。 In this paper, firstly putting the In-Sn ball on the Cu and Ni substrate wetting and spreading to test its wettability and spreadability; then preparing BGA balls and soldering BGA balls to the printed circuit board, testing and analyzing the shear strength of BGA solder joint after solid-state aging; at the same time, In-Sn solder is bonded to the Cu board, after liquid-state aging, testing and analysing the shear strength; finally, carrying on a research about the interfacial microstructure of 52In-48Sn solder/Cu。 It is concluded that the spreading properties related to temperature, the higher the temperature, better the spreading properties。 the shear force of BGA solder point is related to aging time; after liquid-state aging, the shear force of In-Sn solder firstly increases with the increase of aging time, when it arrives at the peak ,it begans to slowly decrease; The thickness of intermetallic compound layer increases with the increase of aging time。

Keywords: Lead-free solder; In-Sn solder; Spreadability; Shear strength; Interfacial microstructure

目  录

第一章 绪论 1

1。1引言 1

1。2无铅钎料的研究现状 2

1。3无铅钎料的性能要求及其存在的问题 6

1。3。1无铅钎料的性能要求 6

1。3。2无铅钎料存在的问题 7

1。4铟的性质、来源及其应用 7

1。4。1铟的性质 7

1。4。2铟的来源 8

1。4。3掺铟合金的应用 8

1。4。4掺铟钎料的应用 8

1。5钎料的润湿与铺展 9

1。6课题研究的内容 10

第二章 实验方法 11

2。1钎料铺展性能的测试 11

2。2 BGA焊点剪切性能测试