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Formation mechanism of Sn-patch between SnAgCu solder and Ti/Ni(V)/Cu under bump metallization

Published online by Cambridge University Press:  31 January 2011

Jenq-Gong Duh*
Affiliation:
Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan
Toung-Yi Shih
Affiliation:
Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan; and United Microelectronics Corporation, Hsinchu 300, Taiwan
*
a) Address all correspondence to this author. e-mail: jgd@mx.nthu.edu.tw
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Abstract

An Sn-patch formed in Ni(V)-based under bump metallization during reflow and aging. To elucidate the evolution of the Sn-patch, the detailed compositions and microstructure in Sn–Ag–Cu and Ti/Ni(V)/Cu joints were analyzed by a field emission electron probe microanalyzer (EPMA) and transmission electron microscope (TEM), respectively. There existed a concentration redistribution in the Sn-patch, and its microstructure also varied with aging. The Sn-patch consisted of crystalline Ni and an amorphous Sn-rich phase after reflow, whereas V2Sn3 formed with amorphous an Sn-rich phase during aging. A possible formation mechanism of the Sn-patch was proposed.

Type
Articles
Copyright
Copyright © Materials Research Society 2009

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References

1Totta, P.A. and Sopher, R.P.: SLT device metallurgy and ITS monolithic extension. IBM J. Develop. 13, 226 (1969).CrossRefGoogle Scholar
2Liu, A.A., Kim, H.K., Tu, K.N., and Totta, P.A.: Spalling of Cu6Sn5 spheroids in the soldering reaction of eutectic SnPb on Cr/Cu/Au thin films. J. Appl. Phys. 80, 2774 (1996).CrossRefGoogle Scholar
3Wang, K.Z. and Chen, C.M.: Intermetallic compound formation and morphology evolution in the 95Pb5Sn flip-chip solder joint with Ti/Cu/Ni under bump metallization during reflow soldering. J. Electron Mater. 34, 1543 (2005).CrossRefGoogle Scholar
4Chen, C.M., Wang, K.J., and Chen, K.C.: Isothermal solid-state aging of Pb-5Sn solder bump on Ni/Cu/Ti under bump metallization. J. Alloys Compd. 432, 122 (2007).CrossRefGoogle Scholar
5Tung, C.H., Teo, P.S., and Lee, C.: Interface microstructure evolution of lead-free solder on Ni-based under bump metallizations during reflow and high temperature storage. IEEE Trans. Device Mater. Reliab. 5, 212 (2005).CrossRefGoogle Scholar
6Li, M., Zhang, F., Chen, W.T., Zeng, K., Tu, K.N., Balkan, H., and Elenius, P.: Interfacial microstructure evolution between eutectic SnAgCu solder and Al/Ni(V)/Cu thin films. J. Mater. Res. 17, 1612 (2002).CrossRefGoogle Scholar
7Zhang, F., Li, M., Balakrisnan, B., and Chen, W.T.: Failure mechanism of lead-free solder joints in flip chip packages. J. Electron. Mater. 31, 1256 (2002).CrossRefGoogle Scholar
8Liu, C.Y., Tu, K.N., Sheng, T.T., Tung, C.H., Frear, D.R., and Elenius, P.: Electron microscopy study of interfacial reaction between eutectic SnPb and Cu/Ni(V)/Al thin film metallization. J. Appl. Phys. 87, 750 (2000).CrossRefGoogle Scholar
9Zhang, F., Li, M., Chum, C.C., and Tu, K.N.: Influence of substrate metallization on diffusion and reaction at the under-bump metallization/ solder interface in flip-chip packages. J. Mater. Res. 17, 2757 (2002).CrossRefGoogle Scholar
10Wu, A.T. and Hua, F.: Interfacial stability of eutectic SnPb solder and composite 60Pb40Sn solder on Cu/Ni(V)/Ti under-bump metallization. J. Mater. Res. 22, 735 (2007).CrossRefGoogle Scholar
11Jang, G.Y. and Duh, J.G.: Elemental redistribution and interfacial reaction mechanism for the flip chip Sn-3.0Ag-(0.5 or 1.5)Cu solder bump with Al/Ni(V)/Cu under-bump metallization during aging. J. Electron. Mater. 35, 2061 (2006).CrossRefGoogle Scholar
12Chen, S.W. and Chen, C.C.: Interfacial reactions in Sn-0.7wt%Cu/ Ni-V couples at 250 °C. J. Electron. Mater. 36, 1121 (2007).CrossRefGoogle Scholar
13Chen, S.W., Chen, C.C., and Chang, C.H.: Interfacial reactions in Sn/Ni-7 wt%V couple. Scr. Mater. 56, 453 (2007).CrossRefGoogle Scholar
14Ho, C.E., Lin, Y.W., Yang, S.C., Kao, C.R., and Jiang, D.S.: Effects of limited Cu supply on soldering reactions between SnAgCu and Ni. J. Electron Mater. 35, 1017 (2006).CrossRefGoogle Scholar
15Li, C.Y. and Duh, J.G.: Phase equilibria in the Sn-rich corner of the Sn-Cu-Ni ternary alloy system at 240 °C. J. Mater. Res. 20, 3118 (2005).CrossRefGoogle Scholar
16Li, C.Y., Chiou, G.J., and Duh, J.G.: Phase distribution and phase analysis in Cu6Sn5, Ni3Sn4, and the Sn-rich corner in the ternary Sn-Cu-Ni isotherm at 240 °C. J. Electron. Mater. 35, 343 (2006).CrossRefGoogle Scholar
17Zhang, Z.J. and Liu, B.X.: Solid-state reaction to synthesize Ni-Mo metastable alloys. J. Appl. Phys. 76, 3351 (1994).CrossRefGoogle Scholar
18Kwon, K.W., Lee, H.J., and Sinclair, R.: Solid-state amorphization at tetragonal-Ta/Cu interfaces. Appl. Phys. Lett. 75, 935 (1999).CrossRefGoogle Scholar