Heat Spreading Properties of CVD Diamond Coated Al Heat Sink

Autor: Min Young Yoon, Chan Hyoung Kang, Jong Hwan Im
Rok vydání: 2015
Předmět:
Zdroj: Journal of the Korean institute of surface engineering. 48:297-302
ISSN: 1225-8024
DOI: 10.5695/jkise.2015.48.6.297
Popis: Nanocrystalline diamond(NCD) coated aluminium plates were prepared and applied as heat sinks for LED modules. NCD films were deposited on 1 mm thick Al plates for times of 2 - 10 h in a microwave plasma chemical vapor deposition reactor. Deposition parameters were the microwave power of 1.2 kW, the working pressure of 90 Torr, the CH4/Ar gas ratio of 2/200 sccm. In order to enhance diamond nucleation, DC bias voltage of �90 V was applied to the substrate during deposition without external heating. NCD film was identified by X-ray diffraction and Raman spectroscopy. The Al plates with about 300 nm thick NCD film were attached to LED modules and thermal analysis was carried out using Thermal Transient Tester (T3ster) in a still air box. Thermal resistance of the module with NCD/Al plate was 3.88 K/W while that with Al plate was 5.55 K/W. The smaller the thermal resistance, the better the heat emission. From structure function analysis, the differences between junction and ambient temperatures were 12.1 o C for NCD/Al plate and 15.5 o C for Al plate. The hot spot size of infrared images was larger on NCD/Al than Al plate for a given period of LED operation. In conclusion, NCD coated Al plate exhibited better thermal spreading performance than conventional Al heat sink.
Databáze: OpenAIRE