不同钎料对激光钎焊焊点力学性能的影响

采用半导体激光再流焊系统研究SnAgCu／SnAgCuCe在铜基板的润湿性以及焊点的力学性能，同时对比红外再流焊，研究两种焊点在热循环过程中的可靠性．结果表明，随着激光输出功率的增加，无铅钎料的铺展面积逐渐增加；当激光输出功率增加到某一特定范围时，无铅钎料的润湿铺展性能达到最佳．同时，随着激光加热时间的增加，无铅钎料的...

Effects of different solders on mechanical properties of micro-joints soldered with diode-laser soldering system

Wettability of SnAgCu/SnAgCuCe solders on Cu substrate and properties of solder joints were tested by diode laser soldering system. The solder joints reliability during thermal cycling test was investigated by diode laser soldering system and IR reflow soldering method respectively. The results indicate that, as the laser output power increases, the spreading area of lead-free solder increases, the optimal wettability and spreadability are obtained while the laser output power increases to a certain range. Moreover, the results indicate that the wettability and spreadability of the two kinds of solders on Cu substrate are improved with the increase of heating time under the condition of selected laser output power. For QFP256 devices soldered with diode laser soldering system, optimum power can be found, the optimum power for SnAgCu solders is 16.7 W, for SnAgCuCe solders, it is 17 W. Moreover, during thermal cycling, the reliability of soldered joints obtained by diode laser soldering is higher than that by IR reflow soldering.