摘要：在本实验进行之前，已经有研究发现在Sn-Ag-Cu钎料中添加元素Bi，能提高钎料原有的力学性能。所以本实验主要通过在Sn-Ag-Cu钎料的基础上加入含量分别为0；0.5%；1%；2%的元素Bi，每种钎料都分别时效10天，20天，30天，40天，以及不时效。将钎料制成试样，对试样进行打磨以及抛光等程序。对试样进行剪切强度的测试，观察试样剪切强度随时间的变化曲线，实验发现在Bi含量为2%时焊接接接头剪切强度最大。另外，通过对钎料与基板界面处金属间化合物进行超景深显微镜的拍摄，观察界面处金属间化合物的微观组织形貌，发现随着时效时间的延长IMC层厚度会增加，并且接头的剪切强度也会增大。同时不管对于那种钎料，时效20天时，钎料剪切强度最大，时效过长时间，剪切强度反而下降。

关键字：剪切强度；显微组织；时效

Abstract：Before this experiment, it has been found that the addition of elemental to Sn-Ag-Cu solder, can improve the original mechanical properties of solder.Therefore, the experiment mainly through the Sn-Ag-Cu solder on the basis of the content were added 0; 0.5%; 1%; 2% element Bi. each solder is aged for 10 days, 20 days, 30 days, 40 days, and not aging. The solder l is made into a sample, and then the sample is sanded and polished and other procedures. The shear strength of the specimen was tested and observe the shear curve of the specimen with time, it was found that the shear strength of the welded joint was the highest when the Bi content was 2%. In addition, by scanning the intermetallic    compound at the interface between the solder and the substrate, observe microstructure Morphology of Intermetallic Compounds at the Interface, it was found that the thickness of IMC layer increased with the aging time, and the shear strength of the joint will increase. At the same time,regardless of the kind of solder, aging 20 days, the shear strength of the solder is the biggest. Aging for too long, the shear strength even decreased.

Keywords: shear strength; microstructure; aging

目录

第一章 绪论 1

1.1研究背景 1

1.2无铅钎料的发展进程 2

1.3无铅钎料的研究现状与存在问题 4

1.4无铅钎料的生产性能要求 5

1.5本文研究的目的和内容 6

1.5.1本文研究的目的和意义 6

1.5.2本文研究思路与内容 7

第二章实验过程及方法 10

2.1实验所需材料和设备 10

2.1.1钎料的熔炼 10

2.1.2钎料的焊接 10

2.1.3试样的制备 10

2.2实验方法 11

2.2.1试样剪切强度的测试 11

2.2.2试样超景深显微镜的拍摄 11

第三章实验结果与分析 12

3.1时效时间对焊接接头IMC显微形貌以及剪切强度的影响分析 12

3.1.1时效时间对界面处IMC的SEM显微形貌的影响 12

3.1.2时效时间对接头剪切强度的影响规律 14

3.1.3时效时间影响接头IMC显微形貌和剪切强度的原因与总结