The work reported here concerns the effect of an imposed current on the creep of simple Sn-Ag-Cu interconnects. The samples employed were double-shear specimens that contained paired solder joints, 400 μm × 400 μm in cross-section, 200 μm in thickness, on Cu. Different representative microstructures were prepared by electromigration and isothermal aging. Samples were tested with and without an imposed current, and at a variety of temperatures. These tests consistently yield two unexpected results. First, the relative increase in creep rate with current was nearly the same over a range of temperatures and variety of starting microstructures. Second, when tests were done at the same temperature (including the effect of Joule heating), the rate of creep was lower under imposed current than under isothermal conditions. These results are explained in the light of new data that show that the temperature within the joint is almost constant, even under a relatively high current density of 5500 A/cm2. Given constant temperature and a microstructure that includes interfacial voids, the current depletes the joint of vacancies, lowering the␣average creep rate, and introducing observable heterogeneities in the creep pattern. The usual Dorn equation then provides a very useful basis for evaluating the change of creep rate with current.
Article PDF
Similar content being viewed by others
References
Kinney C., Morris J.W., Lee T.K., Liu K.C., Jie X., Towne D. (2009) JEM 38, 221-226 doi:10.1007/s11664-008-0568-3
Lee T.K., Hua F, Morris J.W. (2006) Electron. Mater. Lett. 2, 157-160
Yamanaka K, Tsukada Y, Suganuma K. (2007) Microelectron Reliab. 47, 1280-1287. doi:10.1016/j.microrel.2006.09.028
Song H.G., Morris J.W., Hua F. (2002) JOM 54, 30-32. doi:10.1007/BF02701846
Park S, Dhakal R, Lehman L, Cotts E. (2007) Acta Mater. 55, 3253-3260. doi:10.1016/j.actamat.2007.01.028
Sundelin J, Nurmi S, Lepisto T, Ristolainen E. (2006) Mater Sci Eng. 420, 55-62. doi:10.1016/j.msea.2006.01.065
Wiese S, Wolter K.-J. (2004) Microelectron Reliab. 44, 1923-1931. doi:10.1016/j.microrel.2004.04.016
Wiese S, Wolter K.-J. (2007) Microelectron Reliab. 47, 223-232. doi:10.1016/j.microrel.2006.09.006
W. Peng, E. Monlevade, and M. Marques, Microelectron. Reliab. 47, 2161 (2007).
Huntington H.B., Grone A.R. (1961) J. Phys. Chem. Solids 20, 76-87. doi:10.1016/0022-3697(61)90138-X
Blech I.A., (1972) Thin Solid Films, 13, 117-129. doi:10.1016/0040-6090(72)90164-2
Blech I.A., (1998) Acta mater. 46, 3717-3723. doi:10.1016/S1359-6454(97)00446-1
Dorn J.E. (1954) J. Mech. Phys. Solids 3, 85
Harper J, Dorn J.E. (1957) Acta Metal 5, 654. doi:10.1016/0001-6160(57)90112-8
Acknowledgement
This research was supported by the Component Quality and Technology Group, Cisco Systems.
Open Access
This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
Open Access This is an open access article distributed under the terms of the Creative Commons Attribution Noncommercial License (https://creativecommons.org/licenses/by-nc/2.0), which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.
About this article
Cite this article
Kinney, C., Lee, TK., Liu, KC. et al. The Interaction Between an Imposed Current and the Creep of Idealized Sn-Ag-Cu Solder Interconnects. J. Electron. Mater. 38, 2585–2591 (2009). https://doi.org/10.1007/s11664-009-0851-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11664-009-0851-y