A Novel Cooling System for LED Module Using an Ultrasonic Piezoelectric Microjet

A novel active cooling design for power LED modules integrated with an ultrasonic piezoelectric microjet is investigated in this study. The cooling performance of a microjet was analyzed under varying distances, driving voltages, and operating currents to optimize heat dissipation in the LED module. The experimental results show that the optimal cooling performance is obtained at D=50 mm under varying operating currents and driving voltages. The slopes between chip temperature and driving voltage show approximately linear relationship. The temperature non-uniformity on the LED module is found to decrease with driving voltages but increase with operating current. At high heat power of 4.75 W, the microjet significantly reduced chip temperature by 21.5 ℃ and increased efficiency by 20% compared to a LED module that used a heat sink. The Nusselt number increased from 7.0 to 9.8 as driving voltage was increased from 10 to 20 V. The present experimental results are useful for designing a high efficient active cooling system for power LED modules.

關鍵字

Piezoelectric ； Microjet ； LED ； Efficiency

並列摘要

本論文應用一微型壓電式噴嘴於高功率LED模組之散熱設計，探討在不同距離、噴嘴驅動電壓、及操作電流下之最佳散熱條件。實驗結果發現在距離為50 mm，LED模組在不同的驅動電壓及電流下得到最佳效能，溫度與驅動電壓間的關係呈現線性關係且斜率與電流及距離有關。溫度不均勻性隨著噴嘴的電壓增加而下降，但隨著電流上升而增加。在最佳散熱條件下，在功率4.75 W下，使用壓電噴嘴可降低晶粒溫度達21.5℃並且提升20%的效率。當驅動電壓由10V增加至20V時，Nusselt number由7.0增加至9.8，本文研究可用於結合微型超音波壓電噴嘴及LED模組，設計微型化高效率之散熱模組。

並列關鍵字

壓電；微型噴嘴；發光二極體；效率

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