Effect of diode-laser parameters on shear force of micro-joints soldered with Sn-Ag-Cu lead-free solder on Au/Ni/Cu pad
来源期刊：中国有色金属学报(英文版)2006年第6期
论文作者：王俭辛 薛松柏 方典松 鞠金龙 韩宗杰 姚立华
文章页码：1374 - 1378
Key words：diode-laser soldering; Sn-Ag-Cu lead-free solder; shear force; microstructure
Abstract: Soldering experiments with Sn-3.5Ag-0.5Cu lead-free solder on Au/Ni/Cu pad were carried out by means of diode-laser and IR reflow soldering methods respectively. The influence of different heating methods as well as output power of diode-laser on shear force of micro-joints was studied and the relationship between the shear force and microstructures of micro-joints was analyzed. The results indicate that the formation of intermetallic compound Ag3Sn is the key factor to affect the shear force and the fine eutectic network structures of micro-joints as well as the dispersion morphology of fine compound Ag3Sn, in which eutectic network band is responsible for the improvement of the shear force of micro-joints soldered with Sn-Ag-Cu lead-free solder. With the increases of output power of diode-laser, the shear force and the microstructures change obviously. The eutectic network structures of micro-joints soldered with diode-laser soldering method are more homogeneous and the grains of Ag3Sn compounds are finer in the range of near optimal output power than those soldered with IR reflow soldering method, so the shear force is also higher than that using IR reflow soldering method. When the output power value of diode-laser is about 41.0 W, the shear force exhibits the highest value that is 70% higher than that using IR reflow soldering method.
