Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-23T04:25:40.175Z Has data issue: false hasContentIssue false

Electrochemical corrosion study of Pb-free solders

Published online by Cambridge University Press:  01 January 2006

B.Y. Wu
Affiliation:
Department of Electronic Engineering, City University of Hong Kong, Kowloon Tong, Hong Kong, People's Republic of China
Y.C. Chan*
Affiliation:
Department of Electronic Engineering, City University of Hong Kong, Kowloon Tong, Hong Kong, People's Republic of China
M.O. Alam
Affiliation:
Department of Electronic Engineering, City University of Hong Kong, Kowloon Tong, Hong Kong, People's Republic of China
W. Jillek
Affiliation:
Department of EFI, Georg Simon Ohm University of Applied Science, 90489 Nürnberg, Germany
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

This paper presents an investigation on the corrosion behavior of five solders by means of polarization and electrochemical impedance spectroscopy (EIS) measurements. The Sn–9Zn and Sn–8Zn–3Bi solder, in comparison with the Sn–3.5Ag–0.5Cu and Sn–3.5Ag–0.5Cu–9In solder, were tested in 3.5 wt% NaCl solution and 0.1 wt% adipic acid solution, respectively. The Sn–37Pb solder was for reference in this work. The polarization curves indicated that the Sn–9Zn and Sn–8Zn–3Bi solder showed the worst corrosion resistance both in the salt and acid solutions, in terms of corrosion-current density, corrosion potential, linear polarization resistance, and passivation-current density. Meanwhile, the Sn–3.5Ag–0.5Cu solder remained the best corrosion characteristics in both solutions. It was found that due to microstructure alteration, Bi additive to the Sn–9Zn solder improved the corrosion behavior in the salt solution, whereas decreased that in the acid solution. However, the additive of In degraded the Sn–3.5Ag–0.5Cu solder in both solutions. The EIS results agreed well with the noble sequence of the five solders subjected to the two solutions with polarization. The equivalent circuits were also determined. Nevertheless, the four Pb-free solders exhibited acceptable corrosion properties since there was not much difference of key corrosion parameters between them and the Sn–37Pb solder.

Type
Articles
Copyright
Copyright © Materials Research Society 2006

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.Hwang, J.S.: Environment-Friendly Electronics: Lead-Free Technology (Electrochemical Publications Ltd., U.K., 2001).Google Scholar
2.Abtew, M. and Selvaduray, G.: Lead-free solders in microelectronics. Mater. Sci. Eng. Rep. 27, 95 (2000).CrossRefGoogle Scholar
3.Wu, C.M.L., Yu, D.Q., Law, C.M.T. and Wang, L.: The properties of Sn–9Zn lead-free solder alloys doped with trace rare element. J. Electron. Mater. 31, 921 (2002).CrossRefGoogle Scholar
4.Lin, K.L. and Liu, T.P.: High-temperature oxidation of a Sn–Zn–Al solder. Oxid. Metals 50, 255 (1998).CrossRefGoogle Scholar
5.Shiue, R.K., Tsay, L.W., Lin, C.L. and Ou, J.L.: The reliability study of selected Sn-Zn based lead-free solders on Au/Ni–P/Cu substrate. Microelectron. Reliab. 43, 453 (2003).CrossRefGoogle Scholar
6.Mori, M., Miura, K., Sasaki, T. and Ohtsuka, T.: Corrosion of tin alloys in sulfuric and nitric acids. Corros. Sci. 44, 887 (2002).CrossRefGoogle Scholar
7.Oulfajrite, H., Sabbar, A., Boulghallat, M., Jouaiti, A., Lbibb, R. and Zrineh, A.: Electrochemical behavior of a new solder material Sn–In–Ag. Mater. Lett. 57, 4368 (2003).CrossRefGoogle Scholar
8.Lin, K.L. and Liu, T.P.: The electrochemical corrosion behaviour of Pb-Free Al–Zn–Sn solders in NaCl solution. Mater. Chem. Phys. 56, 171 (1998).CrossRefGoogle Scholar
9.Lin, K.L., Chung, F.C. and Liu, T.P.: The potentiodynamic polarization behavior of Pb-free XIn–9(5Al–Zn)–YSn solders. Mater. Chem. Phys. 53, 55 (1998).CrossRefGoogle Scholar
10.Qiu, J.H.: Polarisation Curves of Passivating Metals, www.ntu.edu.sg/home/asjqiu/me/ME303L11.HTM (accessed June, 2004).Google Scholar
11. Gamry Instruments, PA: Electrochemical Impedance Spectroscopy Primer, www.gamry.com/App_Notes/EIS_Primer/EIS_Primer.pdf (accessed July, 2005).Google Scholar
12. Corrosion Doctors’ Site Map: Polarization Diagram of a Passivable System, www.corrosion-doctors.org/index.htm (accessed February, 2004).Google Scholar
13.Yu, D.Q., Wu, C.M.L. and Wang, L. The electrochemical corrosion behavior of Sn-9Zn and Sn-8Zn-3Bi lead-free solder alloys in NaCl solution. 16th International Corrosion Congress on September 19–24, 2005, Beijing, P.R. China, 1408.Google Scholar
14.Fontana, M.G.: Corrosion Engineering (McGraw-Hill, New York, 1986), pp. 499502.Google Scholar
15.Munoz, A.G., Saidman, S.B. and Bessone, J.B.: Influence of In on the corrosion of Zn–In alloys. Corros. Sci. 43, 1245 (2001).CrossRefGoogle Scholar