Sn–Ag–Cu nanosolders: Melting behavior and phase diagram prediction in the Sn-rich corner of the ternary system

• Published in: Calphad Vol. 49; pp. 101 - 109
• Main Authors: Roshanghias, Ali, Vrestal, Jan, Yakymovych, Andriy, Richter, Klaus W., Ipser, Herbert
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.06.2015; Elsevier B.V
• Subjects: CALPHAD; COMPUTER SIMULATION; Corners; Lead free solders; MATHEMATICAL ANALYSIS; Mathematical models; Melting; Melting point depression; MICROSTRUCTURES; Nanoparticles; Nanostructure; Phase diagrams; Phase transformations; Size effect; Tin; TIN ALLOYS (50 TO 99 SN); Tin base alloys; Nanoparticles; CALPHAD; Lead free solders; Size effect; Melting point depression
• ISSN: 0364-5916; 1873-2984
• DOI: 10.1016/j.calphad.2015.04.003

Melting temperatures of Sn–Ag–Cu (SAC) alloys in the Sn-rich corner are of interest for lead-free soldering. At the same time, nanoparticle solders with depressed melting temperatures close to the Sn–Pb eutectic temperature have received increasing attention. Recently, the phase stability of nanoparticles has been the subject of plenty of theoretical and empirical investigations. In the present study, SAC nanoparticles of various sizes have been synthesized via chemical reduction and the size dependent melting point depression of these particles has been specified experimentally. The liquidus projection in the Sn-rich corner of the ternary SAC system has also been calculated as a function of particle size, based on the CALPHAD-approach. The calculated melting temperatures were compared with those obtained experimentally and with values reported in the literature, which revealed good agreement. The model also predicts that with decreasing particle size, the eutectic composition shifts towards the Sn-rich corner. •The first CALPHAD-type modeling of a ternary system that includes the size effect.•Sn–3.8Ag–0.7Cu nanoparticles of different size were synthesized via chemical reduction.•The liquidus projection in the Sn-rich corner was calculated as a function of particle size.•The size dependent melting depression behavior of nanoparticles was verified.•The eutectic composition changed towards the Sn-rich corner with decreasing particle size.