Abstract
Alloys that undergo solidification over a wide range of temperatures generally exhibit a difference in the contraction behavior of the ensuing solid and liquid phases. Furthermore, dissolution of substrate metals during process reflow can lead to shifts in phase composition, additional primary phases, and volumetric contraction artifacts. The extent and frequency of surface roughness, shrinkage voids, fillet lifting, and hot tearing seen in lead-free solders are different than for eutectic tin lead solder. Shrinkage effects have been reported in Sn/Pb, Sn/Pb/Ag, Sn/Ag/Cu, and Sn/Cu/Ni solders for various components, but few studies have examined their impact on solder joint reliability. Nevertheless, they warrant proper identification due to the shift toward lead-free solders. This article is a review of the effects of shrinkage in Sn-Pb and lead-free solders as well as a discussion of some of the factors that contribute to their formation.
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For more information, contact Girish S. Wable, Jabil Circuit, Inc., Advanced Manufacturing Technology 10800 Roosevelt Blvd. St. Petersburg, FL 33716 USA: (727) 803-6888; fax (727) 230-5888; e-mail girish_wable@jabil.com.
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Wable, G.S., Chada, S., Neal, B. et al. Solidification shrinkage defects in electronic solders. JOM 57, 38–42 (2005). https://doi.org/10.1007/s11837-005-0134-x
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DOI: https://doi.org/10.1007/s11837-005-0134-x