Specific Heat Capacities of Sn-Zn-Based Solders and Sn-Ag-Cu Solders Measured Using Differential Scanning Calorimetry

The specific heat capacities (Cp) of Sn-Zn-based solders and Sn-Ag-Cu solders have been studied using differential scanning calorimetry. The procedure of measuring the specific heat capacity followed the standard test method designed by the American Society for Testing and Materials (ASTM) E1269-05. The results of this work are lists of specific heat capacities of Sn-9Zn, Sn-9Zn-xAg (x = 0.1, 0.5, 1, 2, and 3), Sn-9Zn-0.5Ag-yAl (y = 0.1, 0.2, and 0.5), Sn-9Zn-0.5Ag-yGa (y = 0.1, 0.2, and 0.5), Sn-8.5Zn-0.5Ag-0.01Al-0.1Ga, and Sn-zAg-0.5Cu (z = 1.0, 2.0, 3.0, and 3.5). The study also found that Cp increased with increasing heating temperature. Furthermore, the lead-free solders investigated have a higher specific heat capacity than the traditional Sn-37Pb solder. Among the studied lead-free solders, Sn-3.5Ag-0.5Cu has the lowest Cp and Sn-9Zn-0.1Ag has the highest Cp. Increased silver content in the Sn-9Zn-xAg and Sn-xAg-0.5Cu solder alloys was also found to effectively lower their Cp.