Performance of 9.0 W light-emitting diode on various layers of magnesium oxide thin film thermal interface material

Abstract

MgO thin films were spin coated on aluminum (Al) substrate and used between LED package and heat sink as thin-film heat spreader. Crystallographic studies showed the presence of (111), (200) and (220) orientations related to MgO phases. From the XRD analysis, 10-layers of MgO showed a favorable film thickness (424 nm), crystal size (11.6 nm), microstrain (0.4860 nm) and dislocation density (0.0078 lines/m2). Similarly, low surface roughness (14.6 nm) and depth of peak–valley (71.6 nm) were recorded from 10-layers MgO thin film using Atomic Force Microscopy (AFM) analysis. Relative thermal conductivity of 22.93 W/mK was recorded from the 10-layers MgO film. High value of the difference in total thermal resistance (ΔRth-tot = 3.01 K/W) and rise in junction temperature (ΔTJ = 18.92 °C) were recorded along with good thermal impedance (35 °C) from the 10-layers MgO thin film measured at 700 mA using thermal transient analysis. Overall, MgO thin film coated Al substrates showed an improved performance for the tested LED and, therefore, can be considered as an alternative thermal substrate for LED thermal management.