Laser soldering using lead free solder

In recent years the drive to adopt environmentally friendly solders and fluxes has been at the forefront of the electronics industry concerns. In parallel, the demands on soldering technology have increased rapidly, with footprint sizes reducing and boards becoming more heavily populated, in the drive towards miniaturisation. With these changes some of the existing equipment currently used in the soldering industry (reflow or wave ovens) may struggle. In an attempt to resolve some of the manufacturing issues presented to the industry, CSIRO Manufacturing and Infrastructure Technology (CMIT) conducted a project to examine the use of a 30W diode laser to manufacture some of the soldered joints currently made using the mass reflow techniques. Work was conducted on both traditional lead containing solder and the new environmentally friendly lead free containing solders.The advantages perceived by using lasers included low heat input processing, improved mechanical properties due to the reduced grain size, muc...