Influence of Heat Sink Material and Surface Coatings on Passive Cooling Thermal Performance

Abstract Effective thermal management of compact heat sinks is essential in electronic packaging. A thorough understanding of the surface coating’s impact on thermal performance is crucial for optimal heat sink design. This paper investigates the effect of different heat sink materials and two types of surface coatings applied to small heat sink. The materials considered included silver, copper, gold, aluminum, tungsten, zinc, tin, and iron. Two coatings are evaluated, namely a high-emissivity composite coating composed of SiO 2 /multi-walled carbon nanotubes (MWCNT)/acrylic, and a low-emissivity silver nanoparticle (AgNP) coating. The thermal performance of coated and uncoated heat sinks under natural convection is simulated using the Ansys Fluent software. The simulation results are validated against previously published experimental results, showing good agreement with temperature deviations below 4% across three measured positions on the heat sink. This study examines the combined effects of material thermal conductivity and surface emissivity on heat dissipation capacity. The findings revealed that superior thermal conductivity promotes heat dissipation, but it becomes less significant at high thermal conductivity. The high-emissivity composite coating enhances the heat sink’s thermal performance by enhancing the radiative heat loss. The AgNP-coated heat sink only shows superior performance when the convective heat transfer coefficient is compared. These findings provide valuable guidelines for engineers and designers in the electronic packaging industry to select suitable coating and heat sink materials, hence contributing to developing more effective and reliable electronic systems with improved thermal management.