Structural and thermal performance of Ag, Ni, and Ag/Ni thin films as thermal interface material for light-emitting diode application

Abstract

Silver (Ag), Nickel (Ni), and their stack (Ag/Ni) were prepared at various thicknesses on Al substrates by sputtering process and used as thermal interface material (TIM). The structural and thermal properties of prepared thin films were studied by XRD and transient method, respectively. XRD spectra confirmed the presence of cubic phase of both Ag and Ni. Phase changes from hexagonal to cubic were also noticed with Ni thin film in Ag/Ni stack. From transient analysis, low total thermal resistance (Rth) and low rise in junction temperature (Tj) of LED were observed with Ag (50 nm) thin film interface measured at >350 mA and recorded difference in Tj (ΔTj) was high as 11.28 °C as compared with bare Al boundary condition. Overall, the performance of Ag thin film with low thickness was good on reducing Rth and Tj of device under test and can be used as thin film thermal interface material in electronic packaging.