Park Junghyun, Kim Donghyun, Kim Hyunsik, Lee Junghoon, Chung Wonsub
Department of Materials Science and Engineering, Pusan National University, Busan 46241, Korea.
Analysis Technical Center, Korea Institute of Ceramic Engineering and Technology, Jinju 52851, Korea.
Nanomaterials (Basel). 2021 Oct 24;11(11):2819. doi: 10.3390/nano11112819.
The heat dissipation of a metal heat sink for passive cooling can be enhanced by surface modifications to increase its thermal emissivity, which is reflected by a darker surface appearance. In this study, copper electrodeposition followed by heat treatment was applied to a copper substrate. The heat treatment formed a nanoporous oxide layer containing CuO and CuO, which has a dark blackish color and therefore increased the thermal emissivity of the surface. The heat dissipation performance was evaluated using the sample as a heat sink for an LED module. The surface-treated copper heat sink with a high thermal emissivity oxide layer enhanced the heat dissipation of the LED module and allowed it to be operated at a lower temperature. With an increase in the heat treatment, the thermal emissivity increases to 0.865, but the thermal diffusivity is lower than the copper substrate by ~12%. These results indicate that the oxide layer is a thermal barrier for heat transfer, thus optimization between the oxide thickness and thermal emissivity is required by evaluating heat dissipation performance in operating conditions. In this study, an oxide layer with an emissivity of 0.857 and ~5% lower thermal diffusivity than the copper substrate showed the lowest LED operating temperature.
通过表面改性以提高其热发射率，可增强用于被动冷却的金属散热器的散热能力，这表现为表面颜色变深。在本研究中，在铜基板上进行了铜电沉积并随后进行热处理。热处理形成了包含CuO和Cu₂O的纳米多孔氧化层，该氧化层呈深黑色，因此提高了表面的热发射率。使用该样品作为LED模块的散热器来评估散热性能。具有高发射率氧化层的表面处理铜散热器增强了LED模块的散热能力，并使其能够在较低温度下工作。随着热处理程度的增加，热发射率增加到0.865，但热扩散率比铜基板低约12%。这些结果表明，氧化层是热传递的热障，因此需要通过在工作条件下评估散热性能来优化氧化层厚度和热发射率之间的关系。在本研究中，发射率为0.857且热扩散率比铜基板低约5%的氧化层使LED的工作温度最低。
