Interfacial characteristics of Sn3.5Ag solder on copper after Nd:YAG laser surface irradiation

Abstract

Nd:YAG laser surface irradiation of copperplate was found to affect the interfacial characteristics and wettability of SnAg eutectic solder on copperplate. Scanning electron microscopy (SEM) was used to analyze the interfacial reaction between SnAg eutectic solder and copperplate before and after laser irradiation. The microstructure changes in the surface layer of copperplate were determined using X-ray diffraction techniques; results showed that the distribution of crystal face in the surface of copperplate was changed after laser irradiation, which affected the surface energy of copperplate. The increase of surface energy reinforced the interfacial reaction and promoted the growth of intermetallics, which, however, was proved to have little impact on the morphology of intermetallics by aging.