Effects of Alloy Elements on the Interfacial Microstructure and Shear Strength of Sn-Ag-Cu Solder

doi:10.11900/0412.1961.2019.00033

Acta Metall Sin

2019, Vol. 55

Issue (12): 1606-1614 DOI: 10.11900/0412.1961.2019.00033

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Effects of Alloy Elements on the Interfacial Microstructure and Shear Strength of Sn-Ag-Cu Solder

CAO Lihua¹,CHEN Yinbo^1,²,SHI Qiyuan¹,YUAN Jie^1,²,LIU Zhiquan^1,^2,³(

)

1. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
2. School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China
3. Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China

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CAO Lihua, CHEN Yinbo, SHI Qiyuan, YUAN Jie, LIU Zhiquan. Effects of Alloy Elements on the Interfacial Microstructure and Shear Strength of Sn-Ag-Cu Solder. Acta Metall Sin, 2019, 55(12): 1606-1614.

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Abstract

The eutectic Sn-Ag-Cu (SAC) alloy is the most widely used solder alloy in consuming electronic devices owing to its good wettability and mechanical properties. However, the growth of automotive electronics working at a higher temperature than consuming electronics, requires more reliable solder alloy during microelectronic packaging, which can be achieved by elemental alloying. In this work, the modified Sn-Ag-Cu alloy with Ni, Sb and Bi addition was soldered on the surface of NiSn, NiAu and NiPdAu coating layer respectively, and the effects of elemental addition on the interfacial microstructure and shear strength were investigated systematically. It was found that compared to the commercial SAC305 solder joint, the modified Sn-Ag-Cu solder joint has a thinner interfacial IMC layer while a higher shear strength under the same reflowing conditions, although the formed IMC species are all (Cu, Ni)₆Sn₅ at both the chip side and the printed circuit board (PCB) sides. The addition of Ni, Sb and Au elements can reduce the IMC growth rate, while the addition of Pd increases the IMC growth. For the same solder alloy and reflowing process, the thickness of IMC layer on NiPdAu is the largest, while that on NiAu coating layer is the smallest. Au or Pd addition in the coating layer affects the distribution of Ag₃Sn from dispersive particles to net-like morphology, resulting in an improvement of solder shear strength. The addition of Ag and Cu elements can increase the volume proportion of (Cu, Ni)₆Sn₅ and Ag₃Sn in the solder alloy, hence to increase the shear strength of the solder joints. The solution and precipitation of Bi in the solder alloy can also contribute to the higher shear strength of the modified Sn-Ag-Cu solder joint, although its melting point is decreased to about 213 ℃. Therefore, the shear strength of modified solder alloy with Ni, Sb and Bi elements is higher than that of commercial SAC305.

Key words: alloy element Sn-Ag-Cu solder intermetallic compound interfacial morphology shear strength

Received: 02 February 2019

ZTFLH:

TF777.1

Fund: National Key Research and Development Program of China(No.2017YFB0305700)

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	CAO Lihua
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	LIU Zhiquan

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https://www.ams.org.cn/EN/10.11900/0412.1961.2019.00033 OR https://www.ams.org.cn/EN/Y2019/V55/I12/1606

Fig.1 Cross sectional SEM images of chip sides (a~c) and PCB sides (d~f) of S1 (a, d), S2 (b, e) and S3 (c, f) samples (PCB—printed circuit board, IMC—intermetallic compound)

Fig.2 SEM images of Ag₃Sn in S1 (a), S2 (b) and S3 (c) samples

Fig.3 Cross sectional SEM images of S2 (a) and M2 (b) samples

Fig.4 Cross sectional SEM image of S3 sample (a) and the corresponding elemental mapping of Sn (b), Ag (c), Cu (d), Ni (e), Au (f) and Pd (g) by EPMA analyses

Fig.5 Interfacial image of S3 sample at the chip side (a) and the corresponding EDS line scans of Cu (b), Au (c), Sn (d), Ni (e) and Pd (f) across the line in Fig.5a

Fig.6 Cross sectional SEM image of M3 sample (a) and the corresponding elemental mapping of Sn (b), Ag (c), Cu (d), Sb (e), Bi (f), Ni (g), Au (h) and Pd (i) by EPMA analyses

Fig.7 TEM images of the M3 interface (a) and Ag₃Sn morphology (b), as well as the SAED pattern of Ag₃Sn in [010] zone axis (c)

Fig.8 Bi precipitation in the solder of M3 sample with the corresponding EDS analysis

Fig.9 DSC heating (a) and cooling (b) curves of M solder alloy

[1]	Katsuaki S, translated by Liu Z Q, Li M Y. Introduction to Lead-Free Soldering [M]. Beijing: Science Press, 2017: 3
[1]	(Katsuaki S著，刘志权，李明雨译. 无铅软钎焊技术基础 [M]. 北京: 科学出版社, 2017: 3)
[2]	Zeng K, Tu K N. Six cases of reliability study of Pb-free solder joints in electronic packaging technology [J]. Mater. Sci. Eng., 2002, R38: 55
[3]	Li P, Han J, Wang Y, et al. Microstructure and intermetallic compounds in Sn-3Ag-3Bi-3In solder joints on Cu matrix [A]. 2017 18th International Conference on Electronic Packaging Technology (ICEPT) [C]. Harbin: IEEE, 2017: 655
[4]	Ho C E, Yang S C, Kao C R. Interfacial reaction issues for lead-free electronic solders [J]. J. Mater. Sci. Mater. Electron., 2007, 18: 155
[5]	Ma X, Qian Y Y, Yoshida F. Effect of La on the Cu-Sn intermetallic compound (IMC) growth and solder joint reliability [J]. J. Alloys Compd., 2002, 334: 224
[6]	Harris P G, Chaggar K S. The role of intermetallic compounds in lead-free soldering [J]. Solder. Surf. Mount Technol., 1998, 10(3): 38
[7]	Wu C M L, Yu D Q, Law C M T, et al. Properties of lead-free solder alloys with rare earth element additions [J]. Mater. Sci. Eng., 2004, R44: 1
[8]	Krammer O, Hurtony T, á Hadarits. Investigating intermetallic layer growth in Innolot solder alloy [A]. 2017 40th International Spring Seminar on Electronics Technology [C]. Sofia: IEEE, 2017: 1
[9]	Chowdhury M R, Ahmed S, Fahim A, et al. Mechanical characterization of doped SAC solder materials at high temperature [A]. 2016 15th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems [C]. Las Vegas: IEEE, 2016: 1202
[10]	Blair H D, Pan T Y, Nicholson J M. Intermetallic compound growth on Ni, Au/Ni, and Pd/Ni substrates with Sn/Pb, Sn/Ag, and Sn solders [PWBs] [A]. 1998 48th Electronic Components and Technology Conference [C]. Seattle: IEEE, 1998: 259
[11]	Gyenes A, Benke M, Teglas N, et al. Investigation of multi-component lead-free solders [J]. Arch. Metall. Mater., 2017, 62: 1071
[12]	Geng J, Zhang H W, Mutuku F, et al. Novel solder alloy with wide service temperature capability for automotive applications [A]. 2017 18th International Conference on Electronic Packaging Technology [C]. Harbin: IEEE, 2017: 1700
[13]	Ghosh G. Interfacial reaction between multicomponent lead-free solders and Ag, Cu, Ni and Pd substrates [J]. J. Electron. Mater., 2004, 33: 1080
[14]	Laurila T, Hurtig J, Vuorinen V, et al. Effect of Ag, Fe, Au and Ni on the growth kinetics of Sn-Cu intermetallic compound layers [J]. Microelectron. Reliab., 2009, 49: 242
[15]	Huang M L, Chen L D, Zhao Y. Effect of Cu-Ni cross-solder interaction on liquid-solid interfacial reaction in Cu/Sn/Ni solder joint [J]. Chin. J. Nonferrous Met., 2012, 23: 1073
[15]	(黄明亮, 陈雷达, 赵宇. Cu-Ni交互作用对Cu/Sn/Ni焊点液固界面反应的影响 [J]. 中国有色金属学报, 2012, 23: 1073)
[16]	Roy A K, Chabra R P. Prediction of solute diffusion coefficients in liquid metals [J]. Metall. Trans., 1988, 19A: 273
[17]	Laurila T, Vuorinen V, Paulasto-Kr?ckel M. Impurity and alloying effects on interfacial reaction layers in Pb-free soldering [J]. Mater. Sci. Eng., 2010, R68: 1
[18]	Sharma G, Eichfeld C M, Mohney S E. Intermetallic growth between lead-free solders and palladium [J]. J. Electron. Mater., 2003, 32: 1209
[19]	Hirose A, Fujii T, Imamura T, et al. Influence of interfacial reaction on reliability of QFP joints with Sn-Ag based Pb free solders [J]. Mater. Trans., 2001, 42: 794
[20]	Cho M G, Kang S K, Seo S K, et al. Effects of under bump metallization and nickel alloying element on the undercooling behavior of Sn-based, Pb-free solders [J]. J. Mater. Res., 2009, 24: 534
[21]	Huang Y C, Chen S W, Wu K S. Size and substrate effects upon undercooling of Pb-free solders [J]. J. Electron. Mater., 2010, 39: 109
[22]	Zhou M B, Qin H B, Ma X, et al. Interfacial reaction and melting/solidifications characteristics between Sn and different metallization of Cu, Ag, Ni and Co [A]. Proceedings of the 11th International Conference on Electronic Packaging Technology and High Density Packaging [C]. Xi'an: IEEE, 2010: 202
[23]	Gao L L, Xue S B, Zhang L, et al. Effect of alloying elements on properties and microstructures of SnAgCu solders [J]. Microelectron. Eng., 2010, 87: 2025
[24]	Luo F. Effects of Bi, Sb on microstructures and propensity of Sn-Ag-Cu solder alloys [D]. Zhenjiang: Jiangsu University of Science and Technology, 2010
[24]	(罗飞. 微量Bi, Sb对Sn-3.5Ag-0.5Cu无铅钎料组织与性能的影响 [D]. 镇江: 江苏科技大学, 2010)
[25]	Liu A A, Kim H K, Tu K N, et al. Spalling of Cu6Sn5 spheroids in the soldering reaction of eutectic SnPb on Cr/Cu/Au thin films [J]. J. Appl. Phys., 1996, 80: 2774
[26]	Kim H K, Tu K N. Rate of consumption of Cu in soldering accompanied by ripening [J]. Appl. Phys. Lett., 1995, 67: 2002
[27]	Shnawah D A, Sabri Mohd Faizul M, Badruddin I A, et al. Effect of Ag content and the minor alloying element Fe on the mechanical properties and microstructural stability of Sn-Ag-Cu solder alloy under high-temperature annealing [J]. J. Electron. Mater., 2013, 42: 470
[28]	Pereira P D, Spinelli J E, Garcia A. Combined effects of Ag content and cooling rate on microstructure and mechanical behavior of Sn-Ag-Cu solders [J]. Mater. Des., 2013, 45: 377

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