Laser welding was made for electronic components, and is the single biggest user of Lasers in the world.  Carr’s have welded prototype semi-conductors for I.R and have welded small production runs of batteries for Motorola.  Copper and aluminium are welded easily and cleanly with the Laser and although it makes both materials soft in the process, joint design can make up for any lack of material.  For example if a wire connection is to be welded, allowing excess wire through the connection will leave a domed welded connection.  The bigger the dome required, the more you stick through the hole.