Reduction of Structural Thermal Resistance for Deep Ultraviolet Light-Emitting Diodes Fabricated on AlN Ceramic Substrate via Copper- Filled Thermal Holes

In this paper, a structure was proposed to promote thermal management of deep ultraviolet light-emitting diodes (DUV-LEDs) by introducing the aluminum nitride (AlN) ceramic substrate fabricated with copper-filled thermal holes (CFTHs). Different numbers of CFTHs (0,2 × 2,3 × 3, and 4 × 4) were formed in AlN ceramic substrates using direct-plated-copper process. The thermal resistance of DUVLEDs was determined by a thermal transient tester. Meanwhile, to validate the experiment results, thermal simulation using finite element analysis was developed by considering the various model of AlN ceramic substrates. Experimental results indicated that the thermal resistance and junction temperature decreased with the increasing number of CFTHs. Compared with a conventional structure, the thermal resistance of DUV-LED-based 4 × 4 CFTHs was reduced by 34.6% and its junction temperature was decreased by 7.3 °C at 100 mA. This approach is believed to provide a simple and effective strategy for improving the heat dissipation and thermal reliability of DUV-LEDs.