Effect of heating method on microstructure of Sn-3.0Ag-0.5Cu solder on Cu substrate

With the miniaturization of electronic productions and the use of heat sensitive electronic components, the traditional reflow soldering process often has difficulties. As an alternative soldering process, the laser soldering process has been recently proposed. The laser soldering process brings several advantages in terms of localized heating, rapid rise and fall in temperature, non-contact and easily automated process. In this study, we investigated the effects of heating method such as reflow soldering and laser soldering on the microstructure of Sn-3.0Ag-0.5Cu solder on Cu substrate and the impact properties of the solder joint. In the as-soldered condition, the intermetallic compound layer at the joint interface formed during the laser soldering process was very thin. Therefore, the impact properties of joints formed with the laser process were superior to those of joints formed with the reflow process.