Journal of Electronic Materials

, Volume 35, Issue 3, pp 479–485

Interfacial reactions of Sn-Ag-Cu solders modified by minor Zn alloying addition

  • Sung K. Kang
  • Donovan Leonard
  • Da-Yuan Shih
  • Lynne Gignac
  • D. W. Henderson
  • Sungil Cho
  • Jin Yu
Article

DOI: 10.1007/BF02690535

Cite this article as:
Kang, S.K., Leonard, D., Shih, DY. et al. Journal of Elec Materi (2006) 35: 479. doi:10.1007/BF02690535

Abstract

The near-ternary eutectic Sn-Ag-Cu alloys have been identified as leading Pb-free solder candidates to replace Pb-bearing solders in microelectronic applications. However, recent investigations on the processing behavior and solder joints reliability assessment have revealed several potential reliability risk factors associated with the alloy system. The formation of large Ag3Sn plates in Sn-Ag-Cu joints, especially when solidified in a relatively slow cooling rate, is one issue of concern. The implications of large Ag3Sn plates on solder joint performance and several methods to control them have been discussed in previous studies. The minor Zn addition was found to be effective in reducing the amount of undercooling required for tin solidification and thereby to suppress the formation of large Ag3Sn plates. The Zn addition also caused the changes in the bulk microstructure as well as the interfacial reaction. In this paper, an in-depth characterization of the interfacial reaction of Zn-added Sn-Ag-Cu solders on Cu and Au/Ni(P) surface finishes is reported. The effects of a Zn addition on modification of the interfacial IMCs and their growth kinetics are also discussed.

Key words

Pb-free solders Sn-Ag-Cu alloys Ag3Sn plates interfacial reactions reflow reaction 

Copyright information

© TMS-The Minerals, Metals and Materials Society 2006

Authors and Affiliations

  • Sung K. Kang
    • 1
  • Donovan Leonard
    • 1
  • Da-Yuan Shih
    • 1
  • Lynne Gignac
    • 1
  • D. W. Henderson
    • 2
  • Sungil Cho
    • 3
  • Jin Yu
    • 3
  1. 1.IBM T.J. Watson Research CenterYorktown Heights
  2. 2.IBM MicroelectronicsEndicott
  3. 3.KAIST, Department of Materials Science & EngineeringDaejonKorea

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