We proposed a novel wafer-level white LED packaging technology, which enables both extremely low cost and small size for future solid state lighting. We carried out from growth of the GaN layer, over formation of inter layer dielectric (ILD), wiring layer formed directly on the p/n electrodes by Cu deposition process for solder pad to printing the phosphor layer on a whole wafer. It was clearly demonstrated that our wafer-level LED package has an excellent thermal resistance as low as 24.2K/W in the 0603 prototype structure because of the direct connection of Cu wiring to the light emitting layer and a maximum injection power density was as high as 1157W/cm~2 in a difference of 50°C between junction temperature and ambient temperature on the aluminum board. No crack and no exfoliation were observed in the device at 1000 cycles progress time in temperature cycle test (TCT). It was verified that the novel LED device structure is robust against thermal and mechanical stress.
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