Influence of gas flow rate on the thermal performance of AlNB alloy as a solid thermal interface material for thermal management applications (heat spreading)

The AlNB alloy is grown on aluminium alloy substrates (5052) in a thickness ratio of Al:B (8:2) using reactive sputtering at room temperature and annealed at 400°C. The Ar:N2 ratios were optimised to establish a quality growth of the material. (225) orientations of cubic aluminium nitride (c-AlN) structures are confirmed from the X-ray diffractometer (XRD) analysis, the particle sizes of the samples are measured with field emission scanning electron microscopy (FESEM) in the range between ~100 and 450 nm, while the roughness of the samples ~(49 - 84) nm are measured using atomic force microscopy (AFM) and analysed with Nanoscope software. On the other hand, the thermal performance based on the grown material's thermal impedance from junction to ambient with high power light emitting diode (LED) attached to it through the substrate was established to show the best performing growth based on the gas ratios at annealing temperature of 400°C. The material grown based on the (12 : 8) gas ratio is observed to have grown with better favourable properties (particle size and roughness) and tends to develop lower thermal impedance of 6.1 compared to other materials grown together and it is believed to be a better candidate for thermal management of LED and other solid-state devices.