ZnO nanostructure as an efficient heat spreader in electronic packaging

The purpose of this study is to reduce the material and increase the heat transfer performance for efficient thermal management in electronic devices. Consequently, various types of ZnO nanostructures were synthesized using various zinc acetate dihydrate (ZAD) concentrations (0.001 M, 0.01 M & 0.1 M) and the number of layers (6, 7 & 8), followed by annealing at 350 °C for 1 hr. The various nanostructures such as nano-walls (NWs), nano-leaves (NLs), and nanoflakes (NFs) were observed due to the formation of more aggregation of ZnO nucleation centers at various ZAD concentrations. Surface analysis showed decreased roughness (0.168 to 0.14 μm) with increased concentration and increased roughness (0.14 to 0.32 μm) with an increased number of layers. Among the nanostructures produced, the ZnO NW structure from 0.1 M solution with 7 layers effectively conducted the heat by observing a low LED temperature of 34.48 °C at 0.8 W.

The surface quality was examined with an Atomic Force Microscope (AFM) and showed decreased roughness from 0.168 μm to 0.14 μm with increased concentration and increased roughness from 0.14 μm to 0.32 μm with an increased number of layers. The heat-spreading behavior of each nanostructure was evaluated by an infrared (IR) thermal imaging camera and displayed the surface-dependent heat distribution concerning the Zn concentration, number of layers, and testing current. Among the nanostructures produced, the ZnO NW structure prepared using 0.1 M ZAD solution with 7 layers effectively conducted the heat via through- and in-plane direction, which was proved by observing a low LED temperature of 34.48 °C at 0.8 W. Overall, ZnO nanostructures, especially NWs, offer promising potential for thermal management due to their unique properties at high power density. Consequently, ZnO nanostructures would be considered thermally efficient heat spreaders in electronic devices.