本文所研究是使用多孔碳化矽陶瓷散熱鰭片作為LED的背光散熱,以開放式空間的自然對流,並探討該多孔碳化矽陶瓷散熱鰭片的熱傳性能、熱對流的變化,實驗利用LED當作熱源,經由多孔碳化矽陶瓷散熱片來進行散熱。 結果顯示:LED燈在未加上散熱鰭片情況下,溫度將上升到近120 ℃;若加上多孔陶瓷散熱鰭片,溫度可大幅下降至將近40 ~ 50 ℃左右。LED燈在加上平板型、鰭片型、波浪型三種不同的多孔陶瓷散熱鰭片,整體的總熱阻抗表現最佳的為波浪型散熱片。依其散熱效能推估能獲得最長使用壽命時間的為波浪型。探討三種鰭片的對流熱傳係數,最高為鰭片,其次為波浪型,最後是平板型;因為鰭片型表面積為6.15 cm,而波浪型表面積為4.9 cm,因此鰭片型的對流熱傳係數最高。
In this study porous silicon carbide ceramic heat sink is used as the LED backlight cooling. Natural convection experiments were conducted in an open space, to explore the heat transfer performance of the porous silicon carbide ceramic heat sink, using LEDas heat source. The results show that the temperature of LED light without the heat sink can rise to nearly 120℃. If it was coupled with a porous ceramic heat sink, the temperature dropped sharply to about 40-50℃. LED lights with flat-plate, fin-type, or wavy porous ceramic heat sink can get longer life time. The installation of wave-type heat sink on LED lights yielded lowest the total thermal resistance. Comparing the convective heat transfer coefficient of the three heat sinks, fin-type heat sink yielded the highest value, followed by the wave type, and finally flat-plate, because that the surface area of the fin-type is 6.15 (cm), and the wavy type, surface area is 4.9 (cm). Therefore fin the film type have a higher effective convective heat transfer coefficient.