Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-26T10:17:36.347Z Has data issue: false hasContentIssue false

Effect of Zn, Au, and In on the polymorphic phase transformation in Cu6Sn5 intermetallics

Published online by Cambridge University Press:  31 July 2012

Guang Zeng*
Affiliation:
Nihon Superior Centre for the Manufacture of Electronic Materials (CMEM), School of Mechanical and Mining Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia
Stuart D. McDonald
Affiliation:
Nihon Superior Centre for the Manufacture of Electronic Materials (CMEM), School of Mechanical and Mining Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia
Qinfen Gu
Affiliation:
Powder Diffraction Beamline, The Australian Synchrotron, Clayton, Victoria 3168, Australia
Kazuhiro Nogita
Affiliation:
Nihon Superior Centre for the Manufacture of Electronic Materials (CMEM), School of Mechanical and Mining Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Cu6Sn5 is a critical intermetallic compound in soldering operations. Conventional equilibrium phase diagrams show that this compound is of either a hexagonal or monoclinic structure at temperatures above and below 186 °C, respectively. Under nonequilibrium conditions, the crystal structure is dependent on composition, temperature, and processing history. The effect of Zn, Au, and In on the hexagonal to monoclinic polymorphic transformation in Cu6Sn5 intermetallics is investigated using variable temperature synchrotron powder x-ray diffraction and differential scanning calorimetry. It is revealed that, as in the case of trace Ni additions, the alloying elements Zn and Au completely stabilize the hexagonal Cu6Sn5 and prevent the phase transformation. In contrast, In additions only partially stabilize the hexagonal Cu6Sn5.

Type
Articles
Copyright
Copyright © Materials Research Society 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1.Nogita, K., Gourlay, C.M., McDonald, S.D., Wu, Y.Q., Read, J., and Gu, Q.F.: Kinetics of the η–η′ transformation in Cu6Sn5. Scr. Mater. 65, 922 (2011).CrossRefGoogle Scholar
2.Nogita, K.: Stabilization of Cu6Sn5 by Ni in Sn-0.7Cu-0.05Ni lead-free solder alloys. Intermetallics 18, 145 (2010).CrossRefGoogle Scholar
3.Yu, C.Y. and Duh, J.G.: Stabilization of hexagonal Cu6(Sn, Zn)5 by minor Zn doping of Sn-based solder joints. Scr. Mater. 65, 783 (2011).CrossRefGoogle Scholar
4.Ghosh, G. and Asta, M.: Phase stability, phase transformations, and elastic properties of Cu6Sn5: Ab initio calculations and experimental results. J. Mater. Res. 20, 3102 (2005).CrossRefGoogle Scholar
5.Larsson, A.K., Stenberg, L., and Lidin, S.: Crystal structure modulations in η-Cu5Sn4. Z. für Kristallographie 210, 832 (1995).CrossRefGoogle Scholar
6.Okamoto, H.: Phase Diagrams of Dilute Binary Alloys (ASM International, Materials Park, OH, 2002).Google Scholar
7.Li, M., Zhang, Z., and Kim, J.: Polymorphic transformation mechanism of η and η′ in single crystalline Cu6Sn5. Appl. Phys. Lett. 98, 201901 (2011).CrossRefGoogle Scholar
8.Schwingenschlögl, U., Di Paola, C., Nogita, K., and Gourlay, C.M.: The influence of Ni additions on the relative stability of η and η’ Cu6Sn5. Appl. Phys. Lett. 96, 061908 (2010).CrossRefGoogle Scholar
9.Laurila, T., Vuorinen, V., and Paulasto-Kröckel, M.: Impurity and alloying effects on interfacial reaction layers in Pb-free soldering. Mater. Sci. Eng., R 68, 1 (2010).CrossRefGoogle Scholar
10.Luo, Z., Wang, L., Fu, Q., Cheng, C., and Zhao, J.: Formation of interfacial η′-Cu6Sn5 in Sn–0.7Cu/Cu solder joints during isothermal aging. J. Mater. Res. 26, 1468 (2011).CrossRefGoogle Scholar
11.Mu, D., Read, J., Yang, Y., and Nogita, K.: Thermal expansion of Cu6Sn5 and (Cu, Ni)6Sn5. J. Mater. Res. 26, 2660 (2011).CrossRefGoogle Scholar
12.Chou, C.Y. and Chen, S.W.: Phase equilibria of the Sn–Zn–Cu ternary system. Acta Mater. 54, 2393 (2006).CrossRefGoogle Scholar
13.Nogita, K. and Nishimura, T.: Nickel-stabilized hexagonal (Cu, Ni)6Sn5 in Sn–Cu–Ni lead-free solder alloys. Scr. Mater. 59, 191 (2008).CrossRefGoogle Scholar
14.Nogita, K., Gourlay, C., and Nishimura, T.: Cracking and phase stability in reaction layers between Sn-Cu-Ni solders and Cu substrates. JOM 61, 45 (2009).CrossRefGoogle Scholar
15.Nogita, K., Mu, D., McDonald, S.D., Read, J., and Wu, Y.Q.: Effect of Ni on phase stability and thermal expansion of Cu6-xNixSn5 (X = 0, 0.5, 1, 1.5 and 2). Intermetallics 26, 78 (2012).CrossRefGoogle Scholar
16.Lidin, S. and Piao, S.Y.: The structure of Cu6Sn5-xSbx – Large effects of subtle doping. Z. für anorganische und allgemeine Chemie 635, 611 (2009).CrossRefGoogle Scholar
17.Wang, F., Ma, X., and Qian, Y.: Improvement of microstructure and interface structure of eutectic Sn–0.7 Cu solder with small amount of Zn addition. Scr. Mater. 53, 699 (2005).CrossRefGoogle Scholar
18.Izumi, F. and Momma, K.: Three-dimensional visualization in powder diffraction. Solid State Phenom. 130, 15 (2007).CrossRefGoogle Scholar
19.Lee, K.O., Morris, J.W., and Hua, F.: Martensitic transformation in Sn-rich SnIn solder joints. J. Electron. Mater. 41, 336 (2011).CrossRefGoogle Scholar