AC LED的設計原理是將多顆微晶粒串聯為一組，兩組正負反接並聯且可以直接使用交流電壓源驅動而不需外接轉換器的新式LED。因此以直流電定電流模式驅動的傳統LED的接面溫度量測方法並不適用於量測AC LED的接面溫度，所以本篇論文主要在設計一種可以找出AC LED接面溫度的方法，並且計算AC LED的熱阻與分析其溫度震盪。本研究除了開發一套AC LED接面溫度與熱阻量測系統外，也找出AC LED接面溫度與能量輸入的關係，並且利用這一套方法找出AC LED在交流電驅動下的接面溫度與熱阻，最後分析AC LED的接面溫度震盪情形，發現本實驗所使用的AC LED在頻率60HZ及輸入交流電壓VRMS 23V與室溫30℃的條件下其溫度震盪大約在7℃左右。 The AC LED, which can be operated under alternating current without converter, is fabricated by several microchips in series and parallel. The conventional DC LED junction temperature and thermal resistance measurement system cannot be applied to AC LED, because of the different operation mode. In this study, the author built a system which can measure the highest junction temperature of AC LED. Besides, we also proposed a method for determining the average junction temperature and thermal resistance of AC LED. Furthermore, the junction temperature oscillation of AC LED can also be found using this method, and we found that the AC LED junction temperature oscillation of this experiment is about 7 ℃ under alternating current VRMS 23V with frequency of 60 HZ at room temperature 30℃.
