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Electrochemical behavior of metal interconnects in electronic assemblies

Published online by Cambridge University Press:  31 January 2011

Ling Chunxian Zou
Affiliation:
National Physical Laboratory, Teddington, Middlesex TW11 0LW, United Kingdom
Christopher Hunt*
Affiliation:
National Physical Laboratory, Teddington, Middlesex TW11 0LW, United Kingdom
*
a)Address all correspondence to this author. e-mail: chris.hunt@npl.co.uk
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Abstract

The electrochemical and corrosion behaviors of solder alloys—SnAgCu (SAC), SnZnBi, SnPb, and Sn—and printed circuit board finish materials Cu and AuNi were investigated in carboxylic acids (flux) and NaCl solutions using the potentiodynamic scanning technique. The results show that SAC and Sn are passivated in the diluted flux solution, but SnPb, SnZnBi, Cu, and AuNi are under active dissolution when anodically polarized. However, passivation of SAC alloy is not observed in concentrated flux solution. Although a passive film forms on SAC in a 2% NaCl solution, the film is less stable than in the flux solution. In addition, oxidation of the most commonly used lead-free and lead solders, SAC and SnPb, at high temperature was evaluated via sequential electrochemical reduction analysis (SERA). The SERA results revealed that the SAC alloy oxidized more significantly than SnPb under hot, dry conditions.

Type
Articles
Copyright
Copyright © Materials Research Society 2008

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References

REFERENCES

1Chan, H.A.: Surface insulation resistance methodology for today’s manufacturing technology. IEEE Trans. Compon. Packag. Manuf. Technol. Part C 19, 300 1996CrossRefGoogle Scholar
2Hunt, C., Zou, C.L.: The impact of temperature and humidity condition on surface insulation resistance values for various fluxes. Soldering Surf. Mount Technol. 11, 21 1999CrossRefGoogle Scholar
3Sohn, J.E.: Evaluation of no-clean fluxes using surface insulation resistance testing. Proc. NEPCON West 93, 1325 1993Google Scholar
4Zou, C.L., Hunt, C.: The effect of test voltage, test pattern and board finish on surface insulation resistance (SIR) measurements for various fluxes, NPL report CMMT(A)222 National Physical Laboratory Teddington, UK 1999Google Scholar
5Warwick, M.E., Hampshire, W.B.: Atmospheric corrosion of tin and tin alloys in Atmospheric Corrosion edited by W.H. Ailor John Wiley New York509–527Google Scholar
6Maykuth, D.J., Hampshire, W.B.: Corrosion of tin and tin alloys in Corrosion, ASM Handbook Vol. 13ASM International Materials Park, OH 1987 770–783Google Scholar
7Cho, S., Yu, J.: Oxidation study of pure tin and its alloys via electrochemical reduction analysis. J. Electron. Mater. 34, 635 2005CrossRefGoogle Scholar
8Galic, K., Pavic, M., Cikovic, N.: The effect of inhibitors on the corrosion of tin in sodium chloride solution. Corros. Sci. 36, 785 1994CrossRefGoogle Scholar
9Brusic, V., Dimilia, D.D., Macinnes, R.: Corrosion of lead, tin, and their alloys. Corrosion 47, 509 1991CrossRefGoogle Scholar
10Mohanty, U.S., Lin, K.L.: Electrochemical corrosion study on Sn–XAg–0.5Cu alloys in 3.5% NaCl solution. J. Mater. Res. 22, 2573 2007CrossRefGoogle Scholar
11Hillman, D.D., Chumbley, L.S.: Characterization of tin oxidation products using sequential electrochemical reduction analysis (SERA). Soldering Surf. Mount Technol. 18, 31 2006CrossRefGoogle Scholar
12Zamanzadeh, M.: Electrochemical examination of dendrite growth on electronic devices in HCl electrolytes. Corrosion 46, 665 1990CrossRefGoogle Scholar
13Brewin, A., Zou, C.L., Hunt, C.: Development of new solderability test fluxes, NPL Report MATC(A) 122 National Physical Laboratory Teddington, UK 2002Google Scholar
14Bratin, P., Pavlov, M., Chalyt, G.: Study of precious metal coating using sequential electrochemical reduction analysis.Metal Finish, 94, 10 1996CrossRefGoogle Scholar