Design and technology for fluxless die bonding of high power laser bars using Au(80)Sn(20)-solder

Laser bars typically have a size of 10/spl times/0.6/spl times/0.1 mm/sup 3/ and an optical output power of more than 10 watt. Commercially these bars are bonded using soft solders like In or eutectic PbSn-solder. Soft solders lead to migration, whiskers at the bond and an increasing of the thermal resistance. Commercial manufactures using such packaging technique only guarantee a lifetime in the range of 5,000 hours. Instead we use a highly reliable and fluxless contact can be achieved by using the eutectic Au(80)Sn(20)-solder.