Enhanced heat dissipation using flip-chip geometry in InGaN laser diodes

InGaN high power laser diodes (LDs) with flip-chip geometry were investigated, which was a useful method to achieve an efficient dissipation of the generated heat. We found that the height difference between electrodes in a submount had to be controlled precisely and the surface roughness of the submount had to be reduced. In the thermal response measurement, we found that the ambient gas during soldering was another factor to affect a bonding interface. The flip-chip geometry allows us to manufacture efficient, reliable InGaN LDs having high power of 50 mW at cw operation condition.