半导体激光钎焊Sn-Ag-Cu焊点的力学性能和显微组织分析

Influence of diode-laser soldering procedure on mechanical properties and microstructure of Sn-Ag-Cu soldered joint

关键词:  半导体激光软钎焊  无铅焊点  金属间化合物  显微组织

Key words:  diode laser soldering  lead-free soldered joint  intermetallic compound  microstructure

摘要:

选取不同激光钎焊工艺参数,利用半导体激光软钎焊系统对Sn-Ag-Cu无铅钎料在铜基板上进行了钎焊试验,并研究了Sn-Ag-Cu焊点显微组织中金属间化合物形成规律。结果表明,当激光钎焊时间选择为1s,激光输出功率为38.3W时,焊点力学性能最佳。随着激光工艺参数的改变,焊点显微组织发生相应的变化。当使用最佳激光工艺参数钎焊时,形成的焊点晶粒细小,避免了焊点内金属间化合物Cu₆Sn₅的过度生长,此外还形成了厚度适中的金属间化合物层。对比试验结果发现,激光软钎焊方法比传统红外再流焊所形成的金属间化合物层更为平缓,能够获得力学性能更为优良的焊点。

Abstract:

Using different diode-laser soldering parameters, soldering experiments of Sn-Ag-Cu lead-free solder was carried out on Cu substrate using diode-laser soldering system, and the forming rules of the intermetallic compound were also analyzed in Sn-Ag-Cu soldered joints.The results show that, when the laser soldering time is 1s and the laser output power is 38.3W, the mechanical properties of soldered joints are the best.With the change of laser soldering parameters, microstructures of soldered joints are relevantly changed.With the optimum laser soldering parameters, microstructures of soldered joint are fine and no excessive grow of Cu₆Sn₅ intermetallic compound, and the appropriate thickness of Cu₆Sn₅ layer is also got.Competitive experiments results show the intermetallic compound layer with laser soldering system is smoother than that with the IR soldering method, and the excellent mechanical properties can be abtained for the soldered joints.