Journal of Electronic Materials

, Volume 31, Issue 2, pp 161–167 | Cite as

Determination of the eutectic structure in the Ag-Cu-Sn system

  • Daniel Lewis
  • Sarah Allen
  • Michael Notis
  • Adam Scotch
Regular Issue Paper


A search for lead-free solder alloys has produced an alloy in the Ag-Cu-Sn system. This alloy is of great importance to the soldering community, and proper determination of structure, processing, and properties will be significant. In the present study, tin-rich alloys were fabricated to better determine the much-debated morphology of secondary and tertiary phases in the eutectic structure. A deep etching procedure was used to reveal the growth structure of monovariant “eutectic-like” reactions as well as the ternary eutectic reaction. Scanning electron microscopy (SEM) and electron-probe microanalysis (EPMA) verified the three-phase nature of the eutectic. The rodlike eutectic structure in this system is consistent with the more simplified volume fraction and surface energy models that have been presented in the literature.

Key words

Lead-free solder alloy silver-copper-tin eutectic microstructure 


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Copyright information

© TMS-The Minerals, Metals and Materials Society 2002

Authors and Affiliations

  • Daniel Lewis
    • 1
  • Sarah Allen
    • 2
  • Michael Notis
    • 1
  • Adam Scotch
    • 1
  1. 1.Department of Materials Science and EngineeringLehigh UniversityBethlehem
  2. 2.Manchester Materials Science CentreUniversity of Manchester and University of Manchester Institute of Science and TechnologyManchesterUnited Kingdom

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