Effects of Sn-Ag-x leveling layers on the microstructure and mechanical properties of SnBi low-temperature solder joints

IF 1.7 4区材料科学 Q3 ENGINEERING, ELECTRICAL & ELECTRONIC

Soldering & Surface Mount Technology Pub Date : 2021-11-01 DOI:10.1108/ssmt-08-2021-0052

Yang Liu, Yuxiong Xue, Min Zhou, Rongxing Cao, Xiaoliang Zeng, Hongxia Li, S. Zheng, Shuang Zhang

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引用次数: 3

Abstract

Purpose The purpose of this paper is to investigate the effects of Sn-Ag-x leveling layers on the mechanical properties of SnBi solder joints. Four Sn-Ag-x (Sn-3.0Ag-0.5Cu, Sn-0.3Ag-0.7Cu, Sn-0.3Ag-0.7Cu-0.5 Bi-0.05Ni and Sn-3.0Ag-3.0 Bi-3.0In) leveling layers were coated on Cu pads to prepare SnBi/Sn-Ag-x/Cu solder joints. The microstructure, hardness, shear strength and fracture morphology of solder joints before and after aging were studied. Design/methodology/approach The interfacial brittleness of the SnBi low-temperature solder joint is a key problem affecting its reliability. The purpose of this study is to improve the mechanical properties of the SnBi solder joint. Findings Owing to the addition of the leveling layers, the grain size of the ß-Sn phase in the SnBi/Sn-Ag-x/Cu solder joint is significantly larger than that in the SnBi/Cu eutectic solder joint. Meanwhile, the hardness of the solder bulk in the SnBi/Cu solder joint shows a decrease trend because of the addition of the leveling layers. The SnBi/Cu solder joint shows obvious strength drop and interfacial brittle fracture after aging. Through the addition of the Sn-Ag-x layers, the brittle failure caused by aging is effectively suppressed. In addition, the Sn-Ag-x leveling layers improve the shear strength of the SnBi/Cu solder joint after aging. Among them, the SnBi/SACBN/Cu solder joint shows the highest shear strength. Originality/value This work suppresses the interfacial brittleness of the SnBi/Cu solder joint after isothermal aging by adding Sn-Ag-x leveling layers on the Cu pads. It provides a way to improve the mechanical performances of the SnBi solder joint.

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Sn-Ag-x找平层对SnBi低温焊点组织和力学性能的影响

目的研究Sn-Ag-x平整层对SnBi焊点力学性能的影响。四种Sn-Ag-x（Sn-3.0Ag-0.5Cu、Sn-0.3Ag-0.7Cu、Sn-0.13Ag-0.7Cu-0.5 Bi-0.05Ni和Sn-3.0Ag-3.0 Bi-3.0In）找平层涂覆在Cu焊盘上以制备SnBi/Sn-Ag-x/Cu焊点。研究了时效前后焊点的微观组织、硬度、剪切强度和断裂形态。设计/方法/途径SnBi低温焊点的界面脆性是影响其可靠性的关键问题。本研究旨在改善SnBi焊点的力学性能。结果由于添加了整平层，SnBi/Sn-Ag-x/Cu焊点中的ß-Sn相的晶粒尺寸明显大于SnBi/Cu共晶焊点中的晶粒尺寸。同时，由于添加了整平层，SnBi/Cu焊点中焊料块的硬度呈现下降趋势。SnBi/Cu焊点时效后出现明显的强度下降和界面脆性断裂。通过添加Sn-Ag-x层，有效地抑制了由老化引起的脆性破坏。此外，Sn-Ag-x均化层提高了SnBi/Cu焊点老化后的剪切强度。其中，SnBi/SACBN/Cu焊点的抗剪强度最高。独创性/价值这项工作通过在Cu焊盘上添加Sn-Ag-x整平层来抑制SnBi/Cu焊点在等温老化后的界面脆性。为提高SnBi焊点的力学性能提供了一条途径。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Soldering & Surface Mount Technology 工程技术-材料科学：综合

CiteScore

4.10

自引率

15.00%

发文量

审稿时长

>12 weeks

期刊介绍： Soldering & Surface Mount Technology seeks to make an important contribution to the advancement of research and application within the technical body of knowledge and expertise in this vital area. Soldering & Surface Mount Technology compliments its sister publications; Circuit World and Microelectronics International. The journal covers all aspects of SMT from alloys, pastes and fluxes, to reliability and environmental effects, and is currently providing an important dissemination route for new knowledge on lead-free solders and processes. The journal comprises a multidisciplinary study of the key materials and technologies used to assemble state of the art functional electronic devices. The key focus is on assembling devices and interconnecting components via soldering, whilst also embracing a broad range of related approaches.