Kil-Won Moon, William J. Boettinger, Ursula R. Kattner, Frank S. Biancaniello, C A. Handwerker
New measurements using precision thermal analysis and existing experimental data for the Sn-Ag-Cu system are summarized. For Sn-Ag-Cu alloys, the location of the ternary eutectic involving L, Sn, Ag3Sn, and Cu6Sn5 phases in the Sn-rich corner is of critical interest. From the thermal analysis, the ternary eutectic is located at a composition of (3.57 plus or minus 0.05) mass % Ag and (0.9 plus or minus 0.04) mass % Cu at a temperature of (217.2 plus or minus 0.2) degrees C (2 sigma). A thermodynamic calculation of the Sn-rich part of the diagram from the three constituent binary systems and the available ternary data using the CALPHAD method is conducted. The best fit to the experimental data is 3.66 mass % Ag and 0.91 mass % Cu at a temperature of 216.3 degrees C. Finally, using the assessed ternary thermodynamics, solidification paths and freezing ranges will be presented for various solder compositions.
Proceedings of the Surface Mount Technology Association
, Boettinger, W.
, Kattner, U.
, Biancaniello, F.
and Handwerker, C.
The Ternary Eutectic of Sn-Ag-Cu Solder Alloys, Proceedings of the Surface Mount Technology Association
(Accessed September 25, 2023)