Microstructure development during directional solidification of Sn–Ag–Cu ternary alloys

Fornaro, Osvaldo
Morando, Carina Noemi

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Publication date

March 2018

DOI

10.1080/13640461.2017.1379261

Publisher

Informa UK Limited

ISSN

1364-0461

Journal

International Journal of Cast Metals Research

Citation count (estimate)

Abstract

Replace of Pb–Sn with Pb-free solders (LFS) is one of the most important issues in the electronic industry. Eutectic and near-eutectic Sn–Ag–Cu (SAC) alloys are recommended as lead-free replacement in welding processes of electronic devices. Close to the eutectic ternary composition, the solidification occurs with three distinctive phases: Sn-rich dendritic primary phase, and the intermetallic phases (Formula presented.) and (Formula presented.), showing a limited solubility into the Sn-rich phase. Given the key role of the solidification process in the microstructure development of the alloy, samples of Sn–Ag–Cu with a composition close to the ternary eutectic were directionally grown to analyze the mechanisms involved in the solidificatio...