陣列式排列LED面光源熱傳特性研究

Thermal module of surface light source using aligned array led

王芷琳(Chih-Lin Wang)

指導教授 ： 蘇艾

元智大學/工程學院/機械工程學系/碩士(2008年)

摘要

本實驗利用不同的熱對流模式及光源密度，進行散熱座溫度均勻性研究。固定散熱鰭片面積，分別佈設30顆、45顆及60顆LED，調整散熱鰭片末端與遮罩板的間距，改變熱對流的流道截面積大小等因素，並加裝熱導管，與熱浮力效應的相反傳熱方向，改善面板均溫性。
由實驗得知，無遮罩板的散熱座散熱條件較佳，散熱座的平均溫度較低。由於熱浮力效應，散熱座上下部區域最大溫度差約為6℃。當散熱片與環境溫度差達到約30℃時，由熱浮力引起的熱對流效應逐漸增強。限制氣流場流道截面積，結果顯示當遮罩板間距為0.5H時，上下部區域最大溫度差可達12℃。而隨著總功率增加，預期RGB型LED在超過1.5倍額定功率時，輸出照度會逐漸下降。加裝熱導管改善散熱座上下部區域熱分佈情形，在有遮罩板的模式下，整體平均溫度可降低10℃。
實驗結果顯示，散熱鰭片末端與遮罩板的間距，限制熱對流流道截面積，增加散熱座的平均溫度，及加大散熱座上、下部區域的溫度差。間距大於1H以上時，有利於降低上、下部區域的溫差；若再加裝熱導管，可發揮整體散熱鰭片的功能，降低平均溫度，及縮小散熱座上、下部區域的溫度差。

關鍵字

光源密度、氣流場流道截面積、熱導管、熱對流

並列摘要

The experiment is used of the different heat convection and the light density to research the temperature uniformity of the heat sink. Fixing the heat fins area, and load 30, 45 and 60 LEDs on the heat sink. To improve the temperature uniformity of the heat sink, it is adjusted the pitch of the heat fins and the shield and to change the airflow field of the heat convection, and to install the heat pipe which has the heat transfer buoyancy effect of the opposite direction.
From the experiment, it is better when the heat sink without the shield and the average temperature is lower on the heat sink. Due to the heat buoyancy effect, the largest temperature difference of the top-and-bottom regions of the heat sink is about 6℃. When the temperature difference of the heat sink and the ambient is about 30℃, the heat buoyancy is caused gradually by the heat convection. Restricting the airflow field, the result shows that when the pitch of the heat fins and the shield is 0.5H, the largest temperature difference of the top-and-bottom regions of the heat sink is up to 12℃. With the power increases, it is expected that when the rated power is more than 1.5 times of the RGB-LED, the luminance will gradually decline. Installing the heat pipe to improve the heat distribution of the heat sink, it can reduce 10℃ of the average temperature when the heat sink with the shield.
The result shows that the airflow field is restricted by the pitch of the heat fins and the shield, and increase the average temperature of the heat sink, and increase the temperature difference of the top-and-bottom regions of the sink. When the pitch is greater than 1H, it is useful to decrease the temperature difference of the top-and-bottom regions. If the installation of the heat pipe, it can play the function of the heat fins, and reduce the average temperature, and reduce the temperature difference of the top-and-bottom regions of the heat sink.

並列關鍵字

source density、airflow field、heat pipe、thermal convection

參考文獻

3. 史光國，「半導體發光二極體及固體照明」，全華，2005。

8. M.Arik,J.Petroski,S.Weaver,”Thermal Challenges in The Future Generation Solid State Lighting Application:Light Emitting Diodes”,Thermomechanical Phenomena in Electronic Systems-Proceedings of the Intersociety Conference,pp.113-120,2002.

9. 蘇艾、劉英傑、陳楨鈺，「發光二極體散熱模組研究」，第三十屆全國力學會議，2006。

12. N.Narendran,Y.Gu,J.P.Freyssinier,H.Yu,L.Deng,”Solid-state Lighting: Failure Analysis of White LEDs”,Journal of Crystal Growth,v268.n3-4.,pp.449-56,2004.

13. E.Hong,N.Narendran,”A Method for Projecting Useful Life of LED Lighting Systems”,Proceedings of the SPIE-The International Society for Optical Engineering,v5187.n1., pp.93-99,2004.