Interfacial Structure and Mechanical Properties of Lead-Free Bi-Containing Solder/Cu Microelectronic Interconnects

doi:10.1007/s11664-020-08562-4

IMR OpenIR

	Interfacial Structure and Mechanical Properties of Lead-Free Bi-Containing Solder/Cu Microelectronic Interconnects
	Liu, C. Z.; Wang, J. J.; Zhu, M. W.; Liu, X. M.; Lu, T. N.; Yang, J. R.
	2021
发表期刊	JOURNAL OF ELECTRONIC MATERIALS
卷号	50 期号:1 页码:258-262
摘要	Previous studies have shown that Bi segregation at the Cu3Sn/Cu interface in eutectic 42Sn-58Bi/Cu interconnects induces brittle fracture along this interface after aging at 120 degrees C for 7 days. To verify whether Bi can still be applied in lead-free solder alloys, compact tension tests were conducted on Sn-10Bi-0.7Cu/Cu joints in as-reflowed and aged (at 180 degrees C for 17 days) conditions, and their interfacial structure was studied by scanning electron microscopy (SEM). After aging the joints at 180 degrees C for 17 days, the average thickness of intermetallic compound (IMC) between the solder and Cu substrate in the interconnect increased from 4 +/- 1 mu m to 25 +/- 1 mu m, the average fracture toughness dropped from 0.777 +/- 0.002 MPa m(1/2) to 0.297 +/- 0.001 MPa m(1/2), while the interconnects did not fracture in fragile fashion along the Cu3Sn/Cu interface. No Bi segregation was found at the Cu3Sn/Cu interface in the Sn-10Bi-0.7Cu/Cu interconnect aged at 180 degrees C for 17 days, while Bi particles were found at the counterpart interface in the eutectic 42Sn-58Bi/Cu joint aged at 180 degrees C for 2 days. Cu3Sn formed by consumption of Cu6Sn5 during IMC growth in the interconnect. The Bi segregation was caused because the content of Bi dissolved in Cu6Sn5 was higher than the maximum solubility of Cu3Sn in the eutectic 42Sn-58Bi/Cu interconnect. Bi precipitation and segregation occurred when the Cu6Sn5 IMC turned into Cu3Sn IMC. Electron probe microanalysis revealed that the amount of Bi dissolved in the Cu6Sn5 IMC in the solder joint depended on the Bi content in the solder alloy. The test results revealed that lead-free solder alloys with Bi content less than 10 wt.% will not lead to Bi segregation, which would greatly degrade the solder/Cu joint.
DOI	10.1007/s11664-020-08562-4
WOS记录号	WOS:000584366600002
引用统计	被引频次：4[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/321006/155663
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Liu, C. Z.,Wang, J. J.,Zhu, M. W.,et al. Interfacial Structure and Mechanical Properties of Lead-Free Bi-Containing Solder/Cu Microelectronic Interconnects[J]. JOURNAL OF ELECTRONIC MATERIALS,2021,50(1):258-262.
APA	Liu, C. Z.,Wang, J. J.,Zhu, M. W.,Liu, X. M.,Lu, T. N.,&Yang, J. R..(2021).Interfacial Structure and Mechanical Properties of Lead-Free Bi-Containing Solder/Cu Microelectronic Interconnects.JOURNAL OF ELECTRONIC MATERIALS,50(1),258-262.
MLA	Liu, C. Z.,et al."Interfacial Structure and Mechanical Properties of Lead-Free Bi-Containing Solder/Cu Microelectronic Interconnects".JOURNAL OF ELECTRONIC MATERIALS 50.1(2021):258-262.