High thermal conductive AlN substrate for heat dissipation in high-power LEDs

Heat dissipation is important in high-power LEDs and depends on the thermal conductivity of the substrate. This work investigates the heat dissipation performance of AlN ceramic substrate in high-power LEDs. AlN substrate with a thermal conductivity of 193 W m(-1) K-1 and flexural strength of 380 MPa has been prepared by pressureless sintering, and then bonded with a Cu film by direct plating copper (DPC). By using the AlN substrate for heat dissipation, the junction temperature (78 degrees C) is lowered by 42 degrees C compared with the case using Al2O3 substrate and well below the upper limit of the operation temperature of the LEDs. From the experimental results, AlN ceramic substrate with a high thermal conductivity is a promising candidate for heat dissipation in high-power LEDs.