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Co alloying and size effects on solidification and interfacial reactions in the Sn–Zn–(Co)/Cu couples

Published online by Cambridge University Press:  31 January 2011

Yu-chih Huang
Affiliation:
Department of Chemical Engineering, National Tsing Hua University, Hsin-Chu 300, Taiwan
Sinn-wen Chen*
Affiliation:
Department of Chemical Engineering, National Tsing Hua University, Hsin-Chu 300, Taiwan
*
a)Address all correspondence to this author. e-mail: swchen@mx.nthu.edu.tw
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Abstract

Sn–Zn based alloys are promising as Pb-free solders, and Cu is commonly used in electronic products. Solidification and interfacial reactions of Sn–8.8wt%Zn, Sn–8.8wt%Zn–0.05wt%Co, and Sn–8.8wt%Zn–0.5wt%Co solders on Cu substrates are investigated. Two different masses of solders are used. The degrees of undercooling increase with increasing Co additions in the Sn–8.8wt%Zn alloys. The reaction products evolve with reaction time, and the timing of different reaction stages is influenced by both the minor Co alloying and the mass of solders. In the initial reaction stage, two reaction phases, γ-Cu5Zn8 and ε-CuZn5, are observed in the Sn–8.8wt%Zn/Cu and Sn–8.8wt%Zn-0.05wt%Co/Cu couples, and only the γ-Cu5Zn8 phase is found when the Co addition is up to 0.5 wt%. The reaction layers are thinner with higher Co alloying. The addition of Co into the Sn–Zn alloys consumes Zn, and this depletion of Zn in the Sn–Zn solders is the primary reason for the changes of reaction products and the thinner reaction layers.

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Copyright
Copyright © Materials Research Society 2010

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References

REFERENCES

1.Glazer, J.: Metallurgy of low temperature Pb-free solders for electronic assembly. Int. Mater. Rev. 40, (2)65 (1995)CrossRefGoogle Scholar
2.Abtew, M., Selvaduary, G.: Lead-free solders in microelectronics. Mater. Sci. Eng., R 27, 95 (2000)CrossRefGoogle Scholar
3.Huang, C.W., Lin, K.L.: Interfacial reactions of lead-free Sn-Zn based solders on Cu and Cu plated electroless Ni–P/Au layer under aging at 150 °C. J. Mater. Res. 19, (12)3560 (2004)CrossRefGoogle Scholar
4.Chen, S.W., Wang, C.H., Lin, S.K., Chiu, C.N.: Phase diagrams of Pb-free solders and their related materials systems. J. Mater. Sci.- Mater. Electron. 18, 19 (2007)CrossRefGoogle Scholar
5.Kim, K.S., Huh, S.H., Suganuma, K.: Effects of fourth alloying additive on microstructures and tensile properties of Sn–Ag–Cu alloy and joints with Cu. Microelectron. Reliab. 43, 259 (2003)CrossRefGoogle Scholar
6.Song, J.M., Huang, C.F., Chung, H.Y.: Microstructural characteristics and vibration fracture properties of Sn–Ag–Cu–TM (TM = Co, Ni, and Zn) alloys. J. Electron. Mater. 35, (12)2154 (2006)CrossRefGoogle Scholar
7.Nishikawa, H., Komatsu, A., Takemoto, T.: Morphology and pull strength of Sn–Ag–(Co) solder joint with copper pad. J. Electron. Mater. 36, (9)1137 (2007)CrossRefGoogle Scholar
8.Anderson, I.E.: Development of Sn–Ag–Cu and Sn–Ag–Cu–X alloys for Pb-free electronic solder applications. J. Mater. Sci.-Mater. Electron. 18, 55 (2007)CrossRefGoogle Scholar
9.Wang, Y.W., Lin, Y.W., Wu, C.T., Kao, C.R.: Effects of minor Fe, Co, Ni additions on the reaction between SnAgCu solder and Cu. J. Alloys Compd. 478, 121 (2009)CrossRefGoogle Scholar
10.Kim, D.H., Cho, M.G., Seo, S.K., Lee, H.M.: Effects of Co addition on bulk properties of Sn–3.5Ag solder and interfacial reactions with Ni-P UBM. J. Electron. Mater. 38, (1)39 (2009)CrossRefGoogle Scholar
11.Chou, C.Y., Chen, S.W., Chang, Y.S.: Interfacial reactions in the Sn–9Zn–(xCu)/Cu and Sn–9Zn–(xCu)/Ni couples. J. Mater. Res. 21, (7)1849 (2006)CrossRefGoogle Scholar
12.Lee, J.E., Kim, K.S., Inoue, M., Jiang, J., Suganuma, K.: Effects of Ag and Cu addition on microstructural properties and oxidation resistance of Sn–Zn eutectic alloy. J. Alloys Compd. 454, 310 (2008)CrossRefGoogle Scholar
13.Liou, W.K., Yen, Y.W., Jao, C.C.: Interfacial reactions of Sn–9Zn–xCu (x = 1, 4, 7, 10) solders with Ni substrate. J. Electron. Mater. 38, (11)2222 (2009)CrossRefGoogle Scholar
14.Wang, C.W., Chen, S.W.: Sn–0.7wt%Cu/Ni interfacial reactions at 250 °C. Acta Mater. 54, 247 (2006)CrossRefGoogle Scholar
15.Ho, C.E., Lin, Y.W., Yang, S.C., Kao, C.R., Jiang, D.S.: Effects of limited Cu supply on soldering reactions between SnAgCu and Ni. J. Electron. Mater. 35, (5)1017 (2006)CrossRefGoogle Scholar
16.Chen, S.W., Lin, C.C., Chen, C.M.: Determination of the melting and solidification characteristics of solders by using DSC. Metall. Mater. Trans. A 29, 1965 (1998)CrossRefGoogle Scholar
17.Boettinger, W.J., Kattner, U.R., Moon, K-W., Perepezko, J.H.: DTA and Heat-Flux DSC Measurements of Alloy Melting and Freezing (NIST, Washington, DC 2006)Google Scholar
18.Huang, Y.C., Chen, S.W., Wu, K.S.: Size and substrate effects upon undercooling of Pb-free solders. J. Electron. Mater. 39, (1)109 (2010)CrossRefGoogle Scholar
19.Moser, Z., Dutkiewicz, J., Gasior, W., Salawa, J.: Binary Alloy Phase Diagram 2nd ed edited by T.B. Massalski ASM International, Materials Park, OH 1990)3416 Google Scholar
20.Okamoto, H.: Co–Sn (cobalt–tin). J. Phase Equilib. Diffus. 27, (3)308 (2006)CrossRefGoogle Scholar
21.Massalski, T.B.: Binary Alloy Phase Diagram 2nd ed edited by H. Okamoto, P.R. Subramanian, and L. Kacprzak (ASM International, Materials Park, OH 1990)1261 Google Scholar
22.Anderson, I.E., Walleser, J., Harringa, J.L.: Observations of nucleation catalysis effects during solidification of SnAgCuX solder joints. JOM 59, (7)38 (2007)CrossRefGoogle Scholar
23.Kinyanjui, R., Lehman, L.P., Zavalij, L., Cotts, E.: Effect of sample size on the solidification temperature and microstructure of SnAgCu near eutectic alloys. J. Mater. Res. 20, (11)2914 (2005)CrossRefGoogle Scholar
24.Huang, Y.C., Chen, S.W., Chou, C.Y., Gierlotka, W.: Liquidus projection and thermodynamic modeling of Sn–Zn–Cu ternary system. J. Alloys Compd. 477, 283 (2009)CrossRefGoogle Scholar
25.Yang, S.C., Ho, C.E., Chang, C.W., Kao, C.R.: Strong Zn concentration effect on the soldering reactions between Sn-based solders and Cu. J. Mater. Res. 21, (10)2436 (2006)CrossRefGoogle Scholar
26.Rahn, A.: The Basics of Soldering (Wiley-Interscience Publications, New York, NY 1993)Google Scholar
27.Suganuma, K., Murata, T., Noguchi, H., Toyoda, Y.: Heat resistance of Sn–9Zn solder/Cu interface with or without coating. J. Mater. Res. 15, (4)884 (2000)CrossRefGoogle Scholar
28.Date, M., Tu, K.N., Shoji, T., Fujiyoshi, M., Sato, K.: Interfacial reactions and impact reliability of Sn–Zn solder joints on Cu or electroless Au/Ni(P) bond-pads. J. Mater. Res. 19, (10)2887 (2004)CrossRefGoogle Scholar