LED平面背光模組散熱機構研究

A Study of LED Back Light Thermal Module

廖昀瑄(Yun-Hsuan Liao)

指導教授 ： 蘇艾

共同指導教授 ： 劉英傑

元智大學/工程學院/機械工程學系/碩士(2007年)

https://doi.org/10.6838/YZU.2007.00115

摘要

本文中利用散熱鰭片(Heat sink)以自然對流作為散熱方式，研究散熱裝置於不同擺
放方式下以及以不同之LED數量佈置於相同散熱面積的散熱座上，觀察其熱傳導效果。
實驗結果得知，散熱裝置以直立式擺置方式時，LED鋁基板溫度，與T3之間的溫
差隨著總功率增加而上升，隨著LED電功率增加，熱阻值亦做緩慢的提升後降低。在散
熱裝置上(T1)、中(T4)、下(T7)溫度變化部分顯示，散熱座溫度差異大時，亦增加自然
對流之驅動力。熱阻值方面，位於下部(T7)的熱阻值低於T4、T1，LED在發光效率1W
以下時，溫差與功率同步變化，大於1W時熱阻值漸漸下降，其最大轉折點溫差約為30
℃。
LED數量控制方面，以30顆LED散熱座的溫度上升率最快， 45顆與60顆之LED散
熱座，功率接近1W時，二者溫度非常接近，60顆LED散熱座上升率最慢。在光源亮度
需求下，60顆LED所能提供之背光源可獲得較低的模組溫度，降低系統的熱防護措施。
藉由本文結果可了解不同光源密度對於此散熱機構之影響，與LED散熱裝置上溫度
之差異，作為未來評估背光模組以及LED光源模組的散熱設計上之考量。

關鍵字

自然對流、熱傳導、熱阻

並列摘要

In the present study that using the radiator (heat sink) by the natural convection took the
radiation way for research the different places of heat sink and arrange different LED
quantity onto same radiating surface to monitor its performance of thermal conduction.
According to the experimental result, when radiator arrangement by stand condition,
LED aluminum plate temperature is difference with the T3 that is rising along with the total
power increasing, and the thermal resistance also makes the slow rising along an then decline
with the LED electric power increasing. As for temperature change demonstration of T1, T4
and T7, when the temperature difference of radiating plate is big, it is also increasing the
thrust of the natural convection. For the thermal resistance portion, the environmental
thermal resistance of T7 is lower than T4, T1, so when LED luminous efficiency under 1W,
the temperature difference and the power will be synchronous change, once it is above 1W,
the thermal resistance drops gradually, its maximum turning point of temperature difference
is approximately 30℃.
Regarding to LED quantity control, the rising rate is quickest of 30 LED radiating plate,
and the temperature is extremely approach for radiating plate of 45 and 60 LED when the
power approaches 1W; besides the rising rate is slowest of 60 LED radiating plate. Depend
on brightness requirement, the illuminant which provide by 60 LED to obtain a lower
temperature so that system can reduce the thermal protective measures.
Through this present study may understand influence in different illuminant density to
radiating structure and the temperature difference in LED radiating device for the radiation
design of backlight module and LED illuminant module evaluation.

並列關鍵字

natural convection、thermal conduction、thermal-resistance

參考文獻

9.曾愷中,“LED背光模組散熱鰭片之模擬與分析”,中興大學機械系

10.蘇艾,劉英傑,陳楨鈺,“發光二極體最佳化散熱模組研究”,第三

14.劉彥志,“熱導管於低溫散熱環境之應用研究”台灣大學機械系

15.“Thermal Design Considerations for Luxeon 5 Watt Power

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