散熱鳍片幾何尺寸對高功率LED模組熱傳性能之研究

A Study of Heat-Sink Geometry on the Heat Transfer Performance of High-Power LED Modules

李東哲(Tung-Che Lee)

指導教授 ： 蔡瑞益

中原大學/工學院/機械工程學系/碩士(2007年)

https://doi.org/10.6840/cycu200700909

摘要

隨著發光二極體功率日亦增加，加上本身體積小，熱通量高，散熱條件的短缺，造成晶片接點溫度過高，而高功率LED發光介面層需維持在125℃以下，大部分高功率LED的損壞，並不是到達額定壽命，而是晶片溫度過高所造成，無法有效的將熱量帶走，熱量持續積存在晶片上，經過一段時間將造成光通量衰減，壽命降低等問題。因此如何降低接點溫度，延長使用壽命是目前研究的重點。
本文使用計算流體力學軟體Fluent/Icepak模擬高功率發光二極體(LED)陣列熱源搭配不同幾何形式散熱鰭片的熱傳性能，藉由改變散熱鰭片幾何尺寸，分析模組晶片平均接點溫度，探討兩種不同類型的LED陣列模組，分別為正向照明及向下照明兩種，搭配三種鰭片形式分別為平板型、柱型、圓柱型，分析並比較LED陣列熱源的熱行為。
結果顯示在正向照明且低鰭片高度時，搭配平板型鰭片的高功率LED模組可獲得較佳的熱性能，而隨著鰭片高度提高三種鰭片熱性能差異性不大。在向下照明時，LED模組搭配柱型或圓柱型鰭片熱性能隨著鰭片高度而提升，當鰭片流道縮小時，柱型及圓柱型鰭片熱性能較搭配平板型性能佳。

關鍵字

散熱鰭片 ； LED ； 接點溫度 ； 發光二極體 ； 自然對流

並列摘要

As the increase in power of Light Emitting Diode (LED) with small volume, high heat generation and the short comings of heat transfer may lead to junction temperature too high because the power of it is getting much bigger gradually.
This study is to simulate high power LED array with three type of heat sink by CFD (Computational Fluid Dynamics) code. To analyze average junction temperature of the module chips by changing heat sink geometry size, and compare the thermal behavior of two kinds LED array module which is forward and downward direction lighting with plate fin, square pin fin and cylinder pin fin heat sink.
The results shows LED array module that in forward direction lighting can get the better performance with plate heat sink under lower fin height. In forward direction lighting, the thermal modules performance between three kinds of heat sink in forward direction lighting as the fin height increase. In downward direction lighting, the thermal performance of LED module with square pin fin and cylinder pin fin heat sink is good when increase fin height and decrease the flow channel width between the pins.

並列關鍵字

LED ； Junction temperature ； Heat sink ； Light Emitting Diode

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