Thermodynamics of Oxidation on Pb-free Solders at Elevated Temperature
Based on the available thermodynamic and phase equilibria data, the thermodynamic criteria for oxidation in tin-based lead-free solders under soldering condition was deduced. The dependence of Gibbs free energy on temperature in Pb-free solder oxidation reaction was calculated by applying MATLAB program. The characteristics of oxidation reaction of a varity of solder alloy systems such as Sn-Ag, Sn-Cu, Sn-Sb, Sn-Zn, Sn-Ag-Cu and Sn-Pb eutectic alloys at elevated temperature were analyzed. The results suggested that zinc preferentially oxidized in Sn-Zn solder alloys in the elevated temperature state, while tin preferentially oxidized in the other alloys. The oxidation potential of the Sn-Zn eutectic alloys was higher than that of the pure tin at elevated temperature, whereas the oxidation potentials of Sn-Ag, Sn-Cu, Sn-Sb and Sn-Ag-Cu eutectic alloys were approxiately equal to that of the pure tin. All tin-based Pb-free solder alloys more easily oxidized than the Sn-Pb solder alloys. Oxidizability of these alloys followed in a decreasing order: Sn-Zn＞ Sn-Sb＞Sn-Cu＞Sn-Ag＞Sn-Ag-Cu＞Sn-Pb.
Lead-free Solders Oxidation Thermodynamics Elevated Temperature
Fang CHEN Yunfei DU Rongchang ZENG Guisheng GAN Changhua DU
School of Materials Science and Engineering, Chongqing Institute of Technology,Chongqing 400050, Chi Chongqing Electromechanical Vocational Institute, Chongqing 400050, China
国际会议
重庆
英文
526-530
2008-06-09（万方平台首次上网日期，不代表论文的发表时间）