Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-16T20:30:54.817Z Has data issue: false hasContentIssue false
  • English
  • Français

Phase formation at the Sn/Cu interface during room temperature aging: Microstructural evolution, whiskering, and interface thermodynamics

Published online by Cambridge University Press:  27 June 2011

Matthias Sobiech ,
Carmen Krüger ,
Udo Welzel ,
Jiang-Yang Wang ,
Eric Jan Mittemeijer  and
Werner Hügel
Matthias Sobiech
Affiliation:
Max Planck Institute for Metals Research, D-70569 Stuttgart, Germany; and Robert Bosch GmbH, D-72770 Reutlingen, Germany
Carmen Krüger
Affiliation:
Institute for Materials Science, University of Stuttgart, D-70569 Stuttgart, Germany
Udo Welzel*
Affiliation:
Max Planck Institute for Metals Research, D-70569 Stuttgart, Germany
Jiang-Yang Wang
Affiliation:
Max Planck Institute for Metals Research, D-70569 Stuttgart, Germany
Eric Jan Mittemeijer
Affiliation:
Max Planck Institute for Metals Research, D-70569 Stuttgart, Germany; and Institute for Materials Science, University of Stuttgart, D-70569 Stuttgart, Germany
Werner Hügel
Affiliation:
Robert Bosch GmbH, D-72770 Reutlingen, Germany
*
a)Address all correspondence to this author. e-mail: u.welzel@mf.mpg.de
Get access

Abstract

The time-resolved evolution of intermetallic phase formation in the system pure Sn (polycrystalline coating with a thickness of several microns) on pure Cu (polycrystalline bulk substrate) was investigated in detail by means of focused ion beam and transmission electron microscopy and x-ray diffraction during aging at room temperature for a period of about 1 year. The availability of this coherent data base allowed interpretation of the evolution of intermetallic compound (IMC) formation in terms of interface thermodynamics and interdiffusion kinetics. On this basis spontaneous Sn whiskering on the surface of the Sn coating as a consequence of intermetallic phase (Cu6Sn5) formation along, specifically, Sn grain boundaries intersecting the Sn/Cu interfaces could be discussed. Moreover, a treatment to mitigate spontaneous Sn whiskering on the basis of thermodynamic control of the IMC morphology was proposed.

Keywords

Crystal growthFilamentaryMicrostructure
Type
Articles
Information
Journal of Materials Research , Volume 26 , Issue 12 , 28 June 2011 , pp. 1482 - 1493
Copyright
Copyright © Materials Research Society 2011

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.Compton, K.G., Mendizza, A., and Arnold, S.M.: Filamentary growth on metal surfaces – whiskers. Corrosion 7, 327 (1951).CrossRefGoogle Scholar
2.Galyon, G.T.: Annotated tin whisker bibliography and anthology. IEEE Trans. Electron. Packag. Manuf. 28, 94 (2005).CrossRefGoogle Scholar
3.Herring, C. and Galt, J.K.: Elastic and plastic properties of very small metal specimens. Phys. Rev. 85, 1060 (1952).CrossRefGoogle Scholar
4.Britton, S.C.: Spontaneous growth of whiskers on tin coatings: 20 years of observation. Trans. Inst. Met. Finish. 52, 95 (1974).CrossRefGoogle Scholar
5.Lee, B.Z. and Lee, D.N.: Spontaneous growth mechanism of tin whiskers. Acta Mater. 46, 3701 (1998).CrossRefGoogle Scholar
6.Tu, K.N.: Interdiffusion and reaction in bimetallic Cu-Sn thin films. Acta Metall. 21, 347 (1973).CrossRefGoogle Scholar
7.Tu, K.N.: Irreversible processes of spontaneous whisker growth in bimetallic Cu-Sn thin-film reactions. Phys. Rev. B. 49, 2030 (1994).CrossRefGoogle ScholarPubMed
8.Koonce, S.E. and Arnold, S.M.: Metal whiskers. J. Appl. Phys. 25, 134 (1954).CrossRefGoogle Scholar
9.Ellis, W.C., Gibbons, D.F., and Treuting, R.C.: Growth of metal whiskers from the solid, in Growth and Perfection of Crystals, edited by Doremus, R.H., Roberts, B.W., and Turnbull, D. (Wiley, New York, 1958), pp. 102–120.Google Scholar
10.Furuta, N. and Hamamura, K.: Growth mechanism of proper tin whisker. Jpn. J. Appl. Phys. 9, 1404 (1969).CrossRefGoogle Scholar
11.Eshelby, J.D.: A tentative theory of metallic whisker growth. Phys. Rev. 91, 755 (1953).CrossRefGoogle Scholar
12.Frank, F.C.: On tin whiskers. Philos. Mag. 44, 854 (1953).CrossRefGoogle Scholar
13.Hasiguti, R.R.: A tentative explanation of the accelerated growth of tin whiskers. Acta Metall. 3, 200 (1955).CrossRefGoogle Scholar
14.Franks, J.: Growth of whiskers in the solid phase. Acta Metall. 6, 103 (1958).CrossRefGoogle Scholar
15.Lindborg, U.: A model for the spontaneous growth of zinc, cadmium and tin whiskers. Acta Metall. 24, 181 (1976).CrossRefGoogle Scholar
16.Boettinger, W.J., Johnson, C.E., Bendersky, L.A., Moon, K-W., Williams, M.E., and Stafford, G.R.: Whisker and hillock formation on Sn, Sn-Cu and Sn-Pb electrodeposits. Acta Mater. 53, 5033 (2005).CrossRefGoogle Scholar
17.Buchovecky, E.J., Du, N., and Bower, A.F.: A model of Sn whisker growth by coupled plastic flow and grain-boundary diffusion. Appl. Phys. Lett. 94, 191904 (2009).CrossRefGoogle Scholar
18.Tu, K.N., Chen, C., and Wu, A.T.: Stress analysis of spontaneous Sn whisker growth. J. Mater. Sci. Mater. Electron. 18, 269 (2007).CrossRefGoogle Scholar
19.Chason, E., Jadhav, N., Chan, W.L., Reinbold, L., and Kumar, K.S.: Whisker formation in Sn and Pb-Sn coatings: Role of intermetallic growth, stress evolution, and plastic deformation processes. Appl. Phys. Lett. 92, 171901 (2008).Google Scholar
20.Kumar, K.S., Reinbold, L., Bower, A.F., and Chason, E.: Plastic deformation processes in Cu/Sn bimetallic films. J. Mater. Res. 23, 2916 (2008).CrossRefGoogle Scholar
21.Sobiech, M., Welzel, U., Schuster, R., Mittemeijer, E.J., Hügel, W., Seekamp, A., and Müller, V.: The microstructure and state of stress of Sn thin films after post-plating annealing: An explanation for the suppression of whisker formation? in Proceedings of the 57th Electronic Components and Technology Conference in Reno, USA, 2007, p. 192.Google Scholar
22.Sobiech, M., Welzel, U., Mittemeijer, E.J., Hügel, W., and Seekamp, A.: Driving force for Sn whisker growth in the system Cu-Sn. Appl. Phys. Lett. 93, 011906 (2008).CrossRefGoogle Scholar
23.Sobiech, M., Wohlschlögel, M., Welzel, U., Mittemeijer, E.J., Hügel, W., Seekamp, A., Liu, W., and Ice, G.E.: Local, submicron strain gradients as the cause of Sn whisker growth. Appl. Phys. Lett. 94, 221901 (2009).Google Scholar
24.Choi, W.J., Lee, T.Y., Tu, K.N., Tamura, N., Celestre, S., MacDowell, A.A., Bong, Y.Y., and Nguyen, L.: Tin whiskers studied by synchrotron radiation scanning x-ray micro-diffraction. Acta Mater. 51, 6253 (2003).CrossRefGoogle Scholar
25.Kato, T., Akahoshi, H., Nakamura, M., Terasaki, T., Iwasaki, T., Hashimoto, T., and Nishimura, A.: Correlation between whisker initiation and compressive stress in electrodeposited tin-copper coating on copper leadframes. IEEE Trans. Electron. Packag. Manuf. 33, 165 (2010).CrossRefGoogle Scholar
26.Dyson, B.F., Anthony, T.R., and Turnbull, D.: Interstitial diffusion of copper in tin. J. Appl. Phys. 38, 3408 (1967).CrossRefGoogle Scholar
27.Anthony, T.R. and Turnbull, D.: On the theory of interstitial solutions of the noble metals in lead, tin, thallium, indium, and cadmium. Appl. Phys. Lett. 8, 120 (1966).CrossRefGoogle Scholar
28.Tu, K.N. and Thompson, R.D.: Kinetics of interfacial reaction in bimetallic Cu-Sn thin films. Acta Metall. 30, 947 (1982).Google Scholar
29.Zhang, W., Egli, A., Schwager, F., and Brown, N.: Investigation of Sn-Cu intermetallic compounds by AFM: New aspects of the role of intermetallic compounds in whisker formation. IEEE Trans. Electron. Packag. Manuf. 28, 85 (2005).CrossRefGoogle Scholar
30.Zhang, W. and Schwager, F.: Effects of lead on tin whisker elimination. J. Electrochem. Soc. 153, C337 (2006).CrossRefGoogle Scholar
31.Sobiech, M., Welzel, U., Schuster, R., Mittemeijer, E.J., Hugel, W., Seekamp, A., and Muller, V.: The microstructure and state of stress of Sn thin films after post-plating annealing: An explanation for the suppression of whisker formation? in 57th Electronic Components & Technology Conference, 2007 Proceedings 192 (IEEE, New York, 2007).Google Scholar
32.Sobiech, M., Wohlschlögel, M., Welzel, U., Mittemeijer, E.J., Hügel, W., Seekamp, A., Garza, M., Koyuncu, M., Liu, W., and Ice, G.E.: Driving force for whisker formation on Sn thin films deposited on Cu. Presentation at the 3rd International Symposium on Tin Whiskers in Denmark (2009).Google Scholar
33.Choi, W.J., Jang, S.Y., Kim, J.H., Paik, K.W., and Lee, H.M.: Grain morphology of intermetallic compounds at solder joints. J. Mater. Res. 17, 597 (2002).Google Scholar
34.Wohlschlögel, M., Schülli, T.U., Lantz, B., and Welzel, U.: Application of a single-reflection collimating multilayer optic for x-ray diffraction experiments employing parallel-beam geometry. J. Appl. Cryst. 41, 124 (2008).CrossRefGoogle Scholar
35.Sommer, F., Singh, R.N., and Mittemeijer, E.J.: Interface thermodynamics of nano-sized crystalline, amorphous and liquid metallic systems. J. Alloy. Comp. 467, 142 (2009).CrossRefGoogle Scholar
36.Jeurgens, L.P.H., Wang, Z.M., and Mittemeijer, E.J.: Thermodynamics of reactions and phase transformations at interfaces and surfaces. Int. J. Mater. Res. 100, 1281 (2009).CrossRefGoogle Scholar
37.de Boer, F.R., Boom, R., Mattens, W.C.M., Miedema, A.R., and Niessen, A.K.: Cohesion in Metals: Transition Metals Alloys (North Holland, Amsterdam, 1988).Google Scholar
38.Miedema, A.R. and Denbroeder, F.J.A.: Interfacial energy in solid-liquid and solid-solid metal combinations, Z. Metallkd. 70, 14 (1979).Google Scholar
39.Miedema, A.R. and Boom, R.: Surface tension and electron density of pure liquid metals. Z. Metallkd. 69, 183 (1978).Google Scholar
40.Hultgren, R., Desai, P.D., Hawkins, D.T., Gleiser, M., and Kelley, K.K.: Selected Values of the Thermodynamic Properties of Binary Alloys (American Society for Metals, Metals Park, OH, 1973).Google Scholar
41.Sommer, F., Singh, R.N., and Witusiewicz, V.: On the entropy of mixing. J. Alloy. Comp. 325, 118 (2001).CrossRefGoogle Scholar
42.Li, M., Du, Z., Guo, C., and Li, C.: Thermodynamic optimization of the Cu–Sn and Cu–Nb–Sn systems. J. Alloy. Comp. 477, 104 (2009).CrossRefGoogle Scholar
43.Liu, X.J., Wang, C.P., Ohnuma, I., Kainuma, R., and Ishida, K.: Experimental investigation and thermodynamic calculation of the phase equilibria in the Cu-Sn and Cu-Sn-Mn systems. Metall. Mater. Trans., A 35, 1641 (2004).CrossRefGoogle Scholar
44.Dinsdale, A.T.: SGTE data for pure elements. Calphad 15, 317 (1991).CrossRefGoogle Scholar
45.Song, J.Y., Tu, J., and Lee, T.Y.: Effects of reactive diffusion on stress evolution in Cu–Sn films. Scr. Mater. 51, 167 (2004).CrossRefGoogle Scholar
46.Kittel, C.: Introduction to Solid State Physics (Wiley, Hoboken, NJ, 2005).Google Scholar
47.Wawra, H.: Surface energy of solid materials as measured by ultrasonic and conventional test methods. Z. Metallkd. 66, 395 (1975).Google Scholar
48.Osenbach, J.W., DeLucca, J.M., Potteiger, B.D., Amin, A., Shook, R.L., and Baiocchi, F.A.: Sn corrosion and its influence on whisker growth. IEEE Trans. Electron. Packag. Manuf. 30, 23 (2007).CrossRefGoogle Scholar
49.Sheng, G.T.T., Hu, C.F., Choi, W.J., Tu, K.N., Bong, Y.Y., and Nguyen, L.: Tin whiskers studied by focused ion beam imaging and transmission electron microscopy. J. Appl. Phys. 92, 64 (2002).CrossRefGoogle Scholar
50.Williams, M.E., Moon, K-W., Boettinger, W.J., Josell, D., and Deal, A.D.: Hillock and whisker growth on Sn and SnCu electrodeposits on s substrate not forming interfacial intermetallic compounds. J. Electron. Mater. 36, 214 (2007).CrossRefGoogle Scholar
51.Arnold, S.M.: Repressing the growth of tin whiskers. Plating 53, 96 (1966).Google Scholar
52.Sobiech, M., Teufel, J., Welzel, U., Mittemeijer, E.J., and Hügel, W.: Stress relaxation mechanisms of Sn and SnPb coatings electro-deposited on Cu: Avoidance of whiskering. J. Electron. Mater. (2011) (submitted).CrossRefGoogle Scholar
53.Gupta, D., Vieregge, K., and Gust, W.: Interface diffusion in eutectic Pb-Sn solder. Acta Metall. 47, 5 (1998).Google Scholar