Commenced in January 2007
Paper Count: 31168
Study of Reactive Wetting of Sn–0.7Cu and Sn–0.3Ag–0.7Cu Lead Free Solders during Solidification on Nickel Coated Al Substrates
Abstract:Microstructure, wetting behavior and interfacial reactions between Sn–0.7Cu and Sn–0.3Ag–0.7Cu (SAC0307) solders solidified on Ni coated Al substrates were compared and investigated. Microstructure of Sn–0.7Cu alloy exhibited a eutectic matrix composed of primary β-Sn dendrites with a fine dispersion of Cu6Sn5 intermetallics whereas microstructure of SAC0307 alloy exhibited coarser Cu6Sn5 and finer Ag3Sn precipitates of IMCs with decreased tin dendrites. Contact angles ranging from 22° to 26° were obtained for Sn–0.7Cu solder solidified on substrate surface whereas for SAC0307 solder alloy contact angles were found to be in the range of 20° to 22°. Sn–0.7Cu solder/substrate interfacial region exhibited faceted (Cu, Ni)6Sn5 IMCs protruding into the solder matrix and a small amount of (Cu, Ni)3Sn4 intermetallics at the interface. SAC0307 solder/substrate interfacial region showed mainly (Cu, Ni)3Sn4 intermetallics adjacent to the coating layer and (Cu, Ni)6Sn5 IMCs in the solder matrix. The improvement in the wettability of SAC0307 solder alloy on substrate surface is attributed to the formation of cylindrical shape (Cu,Ni)6Sn5 and a layer of (Cu, Ni)3Sn4 IMCs at the interface.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1073036Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2236
 J.S. Hwang, "Implementing lead-free electronics", New York: McGraw- Hill, 2005, pp.1-40.
 M.J. Rizvi, C. Bailey, Y.C. Chan, M.N. Islam, H. Lu, J., "Effect of adding 0.3 wt% Ni into the Sn-0.7 wt% Cu solder Part II. Growth of intermetallic layer with Cu during wetting and aging", Alloys Compd. 438 (2007) pp.122-28
 K. Sweatman, S. Suenaga, and T. Nishimura, "Strength of lead-free BGA spheres in high speed loading", Proceedings Pan Pacific, 2008, pp.127-133.
 G. Zeng, S. Xue, L. Zhang and L. Gao, "Recent advances on Sn-Cu solders with alloying elements: review", J Mater Sci: Mater Electron, 22(2011) pp. 565-578.
 A.A. El-Daly, F. El-Tantawy, A.E. Hammad, M.S. Gaafar, E.H. El- Mossalamy, A.A. Al-Ghamdi, "Structural and elastic properties of eutectic Sn-Cu lead-free solder alloy containing small amount of Ag and In", J. Alloys Compd., 509 (2011) pp.7238-7246.
 X. Liu, L. Wang, J. Wang and Y. Lv, "Effects of Ce Addition on Properties of Sn-0.3Ag-0.7Cu Low-Ag Lead-free Solder",11th International Conference on Electronic Packaging Technology & High Density Packaging 2010, pp. 176-180.
 N. Mookam and K. Kanlayasiri, "Evolution of Intermetallic Compounds between Sn-0.3Ag-0.7Cu Low-silver Lead-free Solder and Cu Substrate during Thermal Aging", J. Mater. Sci. Technol.: 28(1)2012, pp.53-59.
 F. Cheng, F. Gao, J. Zhang, W. Jin and X. Xiao, "Tensile properties and wettability of SAC0307 and SAC105 low Ag lead-free solder alloys", J Mater Sci, 46 (2011) pp.3424-3429.
 S. K. Huh, K. S. Kim and Suganuma, "Effect of Ag addition on the Microstructural and mechanical properties of Sn-Cu eutectic solder", Materials transactions, 42(5)(2001), pp.739-744.
 R. Zhang, F. Guo, J. Liu, H. Shen, and F. Tai, "Morphology and Growth of Intermetallics at the Interface of Sn-based Solders and Cu with Different Surface Finishes", J. Electron. Mater., 38(2)(2009), pp.241- 251..
 C.E. Ho, R.Y. Tsai, Y.L. Lin, and C.R. Kao, "Effect of Cu Concentration on the Reactions between Sn-Ag-Cu Solders and Ni", J. Electron. Mater., 31(6)(2002), pp. 584-590.
 G. Wei, D. Luo,, L. Shi, G. He, "Influence of multiple reflows and thermal shock on interfacial IMC of solder joints between Sn0.3Ag0.7Cu solder/pads(HASL,OSP, electrolytic Ni/Au and ENIG PCB finishes)", International Symposium on Advanced Packaging Materials (APM 2011), 2011, pp. 302- 307.