Thermal Transient Analysis of High-Power Green LED Fixed on BN Coated Al Substrates as Heatsink

Boron nitride (BN) thin film was deposited over Al substrate and used as a heatsink for high-power LED. The rise in junction temperature T_J was evaluated from transient cooling curve and observed as a low value for BN coated substrates rather than for bare and thermal paste (TP) applied substrate measured at 700 mA. Total thermal resistance (R_th-tot) was also observed as a low value for BN samples. The BN thin film interface influenced the wavelength peak shift toward a higher value. Noticeable increment on luminosity of the LED was also observed for BN coated Al substrate with respect to driving currents. The observed results were suggested the use of BN thin film as thermal interface materials as an alternative for TP.