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Fracture of SnBi/Ni(P) interfaces

  • P.L. Liu (a1) and J.K. Shang (a1)


Fracture resistance of the interface between electroless Ni(P) and the eutectic SnBi solder alloy was examined in the as-reflowed and aged conditions, to investigate the potential role of Ni in inhibiting interfacial segregation of Bi in SnBi–Cu interconnect. In the as-reflowed condition, the fracture resistance of the SnBi/Ni(P) interface was about the same as that of the SnBi/Cu interface. Upon aging at 120 °C for 7 days the fracture resistance of the SnBi/Ni(P) interface was much higher than that of the SnBi/Cu interface. Such a difference was shown to result from the difference in fracture mechanism as the crack remained along the solder–intermetallic interface in the aged SnBi–Ni interconnect but propagated along the intermetallic–substrate interface in the aged SnBi–Cu interconnect. While fracture of the intermetallic–substrate interface in SnBi–Cu interconnect was due to Bi segregation onto that interface, no Bi was detected at the intermetallic-substrate interface in SnBi–Ni interconnects, implying that Ni(P) was effective in inhibiting the interfacial segregation of Bi.


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1.Hua, F., Mei, Z.C., and Glazer, J.: Eutectic Sn–Bi as an alternative to Pb-free solders, in Proceedings—Electronic Components and Technology Conference (1998), p. 277.
2.Vianco, P.T., Kilgo, A.C. and Grant, R.: Intermetallic compound layer growth by solid state reactions between 58Bi–42Sn solder and copper. J. Electron. Mater. 24, 1493 (1995).
3.Miao, H.W. and Buh, J.G.: Microstructure evolution in Sn–Bi and Sn–Bi–Cu solder joints under thermal aging. Mater. Chem. Phys. 71, 255 (2001).
4.Hwang, C.W., Lee, J.G., Suganuma, K. and Mori, H.: Interfacial microstructure between Sn–3Ag–xBi alloy and Cu substrate with or without electrolytic Ni plating. J. Electron. Mater. 32, 52 (2003).
5.Glazer, J.: Metallurgy of low temperature Pb-free solders for electronic assembly. Int. Mater. Rev. 40, 65 (1995).
6.Mei, Z., Morris, J.W. Jr.: Characterization of eutectic Sn–Bi solder joints. J. Electron. Mater. 21, 599 (1992).
7.Tomlinson, W.J. and Collier, I.J.: The mechanical properties and microstructures of copper and brass joints soldered with eutectic tin-bismuth solder. J. Mater. Sci. 22, 1835 (1987).
8.Felton, L.E., Raeder, C.H. and Knorr, D.B.: The properties of tin-bismuth alloy solders. J. Metals 45, 28 (1993).
9.Guan, Z.M., Liu, G.X. and Liu, T.: Kinetics of interface reaction in 40Sn–Bi/Cu and 40Sn–Bi-2Ag/Cu systems during aging in solid state. IEEE Trans. Adv. Packaging 23, 737 (2000).
10.Liu, P.L. and Shang, J.K.: Interfacial segregation of bismuth in copper/tin-bismuth solder interconnect. Scripta Mater. 44, 1019 (2001).
11.Liu, P.L. and Shang, J.K.: Interfacial embrittlement by bismuth segregation in copper/tin-bismuth Pb-free solder interconnect. J. Mater. Res. 16, 1651 (2001).
12.Lin, K.L. and Lee, C.Y.: Preparation of solder bumps incorporation electroless nickel-boron deposit and investigation on the interfacial interaction behavior and wetting kinetics. J. Mater. Sci. Electron. 8, 377 (1997).
13.Lee, C.Y. and Lin, K.L.: The interaction kinetics and compound formation between electroless Ni–P and solder. Thin Solid Films 249, 201 (1994).
14.Tomlinson, W.J. and Rhodes, H.G.: Kinetics of intermetallic compound growth between nickel, electroless Ni–P, electroless Ni–B and tin at 453 to 493 K. J. Mater. Sci. 22, 1769 (1987).
15.Tu, K.N. and Zheng, K.: Tin-lead (SnPb) solder reaction in flip chip technology. Mater. Sci. Eng. R 34, 1 (2001).
16.Yoon, J.W., Lee, C.B. and Jong, S.B.: Growth of an intermetallic compound layer with Sn–3.5Ag–5Bi on Cu and Ni-P/Cu during aging treatment. J. Electron. Mater. 32, 1195 (2003).
17.Mallory, G.O. and Hajdu, J.B.: Electroless Plating, Fundamentals and Application (Noyes Publications, Park Ridge, NJ, 1990).
18.Riedel, W.: Electroless Nickel Plating (Finishing Publications, Herts, U.K., 1991).
19.Dennis, J.K. and Such, T.E.: Nickel and Chromium Plating, (University Press, Cambridge, U.K., 1986).
20.Jang, J.W., Kim, P.G., Tu, K.N., Frear, D.R. and Thompson, P.: Solder reaction-assisted crystallization of electroless Ni–P under bump metallization in low cost flip chip technology. J. Appl. Phys. 85, 8456 (1999).
21.Liu, P.L., Xu, Z. and Shang, J.K.: Thermal stability of electroless-nickel/solder interface: Part A. Interfacial chemistry and microstructure. Metall. Mater. Trans. 31A, 2857 (2000).
22.Young, B.Y. and Duh, J.G.: Interfacial reaction and microstructural evolution for electroplated Ni and electroless Ni in the under bump metallurgy with 42Sn-58Bi solder during annealing. J. Electron. Mater. 30, 878 (2001).
23.Huang, C.S., Yeh, J.H., Young, B.L. and Duh, J.G.: Phenomena of electroless Ni–P and intermetallic-compound stripping and dissolving in Sn–Bi and Sn–Pb solder joints with Au/EN/Cu metallization. J. Electron. Mater. 31, 1230 (2002).
24.Alam, M.O., Chan, Y.C. and Tu, K.N.: Effect of reaction time and P content on mechanical strength of the interface formed between eutectic Sn–Ag solder and Au/electroless Ni(P)/Cu bond pad. J. Appl. Phys. 94, 4108 (2003).
25.Song, J.Y., Yu, J. and Lee, T.Y.: Analysis of phase transformation kinetics by intrinsic stress evolutions during the isothermal aging of amorphous Ni(P) and Sn/Ni(P) films. J. Mater. Res. 19, 1257 (2004).
26.Duchenko, O.V. and Dybkov, V.I.: Determination of NiBi3 reaction-diffusion constants in Ni-Bi couples. J. Mater. Sci. Lett. 14, 1725 (1995).
27.Lee, M.S., Liu, C.M. and Kao, C.R.: Interfacial reactions between Ni substrate and the component Bi in solder. J. Electron. Mater. 23, 57 (1999).
28.Lee, J.I., Chen, S.W., Chang, H.Y. and Chen, C.M.: Reactive wetting between molten Sn–Bi and Ni substrate. J. Electron. Mater. 32, 117 (2003).
29.Zhang, Z. and Shang, J.K.: Subcritical crack growth at bimaterial interfaces: Part I. Flexural peel technique. Metall. Mater. Trans. 27A, 205 (1996).
30.Yao, D. and Shang, J.K.: Effect of aging on fatigue crack growth at Sn-Pb/Cu interfaces. Metall. Mater. Trans. 26A, 2677 (1995).
31.Frear, D.R. and Vianco, P.T.: Intermetallic growth and mechanical behavior of low and high melting temperature solder alloys. Metall. Mater. Trans. 25A, 1509 (1994).
32.Sunwoo, A.J., Morris, J.W. Jr., Lucey, G.K. Jr.: The growth of Cu–Sn intermetallics at a pretinned copper-solder interface. Metall. Mater. Trans. 23A, 1323 (1992).
33.Powell, B.D. and Mykura, H.: The segregation of bismuth to grain boundaries in copper-bismuth alloys. Acta Mater. 21, 1151 (1973).
34.Alber, U., Mullejans, H. and Ruhle, M.: Bismuth segregation at copper grain boundaries. Acta Mater. 47, 4047 (1999).
35.Chang, L.S., Rabkin, E., Hofmann, S. and Gust, W.: Kinetic aspects of the grain boundary segregation in Cu(Bi) alloys. Acta Mater. 47, 2951 (1999).
36.Hondros, E.D. and Seah, M.P.: Segregation to interfaces. Int. Metal Rev. 22, 262 (1977).
37.Seah, M.P. and Lea, C.: Surface segregation and its relation to grain boundary segregation. Philos. Mag. 31, 627 (1975).
38.Hondros, E.D. and McLean, D.: Surface Phenomena of Metals (Society of Chemical Industry, London, U.K., 1968).
39.Miedema, A.R. and Dorleijn, J.W.F.: Quantitative predictions of the heat of adsorption of metals on metallic substrates. Surf. Sci. 95, 447 (1980).
40.Balluffi, R.W.: in Interfacial Segregation, edited by Johnson, W.C. and Blakely, J.M. (Metals Park, OH, 1977), p. 193.


Fracture of SnBi/Ni(P) interfaces

  • P.L. Liu (a1) and J.K. Shang (a1)


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