摘要
本研究針對高功率發光二極體(light-emitting diode)做光衰老化探討，LED熱阻主要是由傳導熱阻與擴散熱阻組成，對流熱阻在自然對流情況下非常小，可以忽略不計；考慮其熱傳導系數、散熱面積與材料厚度，在此發現晶片與銀膠是最主要的傳導熱阻來源；本次實驗分別針對兩種封裝方式做比較，發現一般高功率封裝形式(Standard Single Chip)的擴散熱阻較COB封裝型式(Chip On Board)來的大，原因是COB封裝型式有效的利用熱傳途徑縮短來減少擴散熱阻發生的機會；模擬溫度部分，可以由等溫線判斷溫度分佈狀況，其中銀膠部分的溫度差最大，而發熱與散熱面積產生差異的部分也可以很明顯的觀察到先前估算的擴散熱阻所帶來的影響；實驗結果顯示出在常溫與相同的輸出功率下，Lustrous的性能表現最佳，Liteon次之，Huyia最差，與理論估算與模擬結果符合；加速老化實驗的部分，與常溫老化實驗相比，可以發現實驗樣本封裝老化的影響遠小於晶片性能老化的影響。 針對高功率LED的應用上，欲保持較佳光效能表現，晶片、銀膠與封裝方式的選擇是相當重要的，如何有效的降低整體元件熱阻，使得接合點維持在較低的溫度，在設計與選購高功率LED時都是相重要的參考因素。
並列摘要
In this study , we discuss the light decay by high-flux LEDs . LED thermal resistance are mainly consist of the conduction thermal resistance and the spread of resistance . In the case of natural convection , the convection thermal resistance is very small , so it can be ignored . We consider the thermal conductivity, heat dissipation area and material thickness , and we found that the chip and silver conductive glue is the most important source of resistance . The experiment compared two types of package , we found that the thermal resistance of Standard Single Chip are more than Chip on Board(COB) , The reason is that COB package type use effective way to reduce the thermal path to reduce the chance of spread of resistance . We can use isotherm observed the impact of the conduction resistance and the spread of resistance in simulation . At room temperature with the same output power , experimental results show that the performance of Lustrous which is the best, Liteon is the second and Huyia is the worst , it is consistent with theoretical estimates and simulation . Package of the impact is much smaller than Chip performance degradation . For high-flux LEDs applications , how to chose chip , silver conductive glue and package type are very important .