Influences of Substrate Alloying and Reflow Temperature on Bi Segregation Behaviors at Sn-Bi/Cu Interface

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	Influences of Substrate Alloying and Reflow Temperature on Bi Segregation Behaviors at Sn-Bi/Cu Interface
	Q. K. Zhang; H. F. Zou; Z. F. Zhang
	2011
发表期刊	Journal of Electronic Materials
ISSN	0361-5235
卷号	40 期号:11 页码:2320-2328
摘要	In this study, the influences of substrate alloying and reflow temperature on the Bi segregation behaviors at the Sn-Bi/Cu interface were investigated. Cu and Cu-Ag alloys with different Ag contents were reflowed with Sn-Bi solder at 180A degrees C, 200A degrees C or 220A degrees C, and then aged at 120A degrees C for different times. The evolution of their interfacial morphologies during the aging process was observed, and tensile tests of some solder joints were conducted. The experimental results reveal that the Bi atoms that dissolved in the Cu(6)Sn(5) during the reflow process are expelled when the Cu(6)Sn(5) transforms into Cu(3)Sn and then segregate around the Cu(3)Sn/Cu interface, inducing interfacial embrittlement. Alloying the Cu substrate with Ag can alleviate the Bi segregation by suppressing Cu(3)Sn formation and dissolving the Bi atoms in the Cu-Ag substrate; the critical Ag content to eliminate the Bi segregation is about 1 at.% for the interface reflowed at 200A degrees C. For interfaces reflowed at 180A degrees C, the Bi segregation is less serious because less Bi is dissolved in the Cu(6)Sn(5), and 0.6 at.% Ag can eliminate it. Tensile tests demonstrate that the embrittlement will not occur at Sn-Bi/Cu-Ag joints once the Bi segregation is eliminated. Based on this understanding, aging embrittlement of Sn-Bi/Cu solder joints can be prevented by decreasing the reflow temperature and adding a small amount of Ag to the Cu substrate.
部门归属	[zhang, q. k.; zou, h. f.; zhang, z. f.] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china.;zhang, zf (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china;zhfzhang@imr.ac.cn
关键词	Sn-bi Solder Bi Segregation Interfacial Embrittlement Substrate Alloying Reflow Temperature Tensile Strength Lead-free Solders Joints Microstructure Embrittlement Interconnect Bismuth Ag
URL	查看原文
WOS记录号	WOS:000295365500019
引用统计	被引频次：29[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/30905
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Q. K. Zhang,H. F. Zou,Z. F. Zhang. Influences of Substrate Alloying and Reflow Temperature on Bi Segregation Behaviors at Sn-Bi/Cu Interface[J]. Journal of Electronic Materials,2011,40(11):2320-2328.
APA	Q. K. Zhang,H. F. Zou,&Z. F. Zhang.(2011).Influences of Substrate Alloying and Reflow Temperature on Bi Segregation Behaviors at Sn-Bi/Cu Interface.Journal of Electronic Materials,40(11),2320-2328.
MLA	Q. K. Zhang,et al."Influences of Substrate Alloying and Reflow Temperature on Bi Segregation Behaviors at Sn-Bi/Cu Interface".Journal of Electronic Materials 40.11(2011):2320-2328.