摘要
本論文探討發光二極體在自然對流環境下全功率的操作情形，希望藉由不同的排列，使其接面溫度上升最少，對總體光通量的影響最小。如果可能，甚至可以在不損及額定規格的情形下減少LED使用的顆數，以達到節能、提高LED壽命、及降低成本的目的。研究方法是利用廠商放在網路的規格表，此規格表需包含3個重要的熱電光的參數及各色光LED光譜分佈圖，此3個參數分別是溫度敏感參數(TSP，代表熱電耦合關係的溫度參數), 溫度升高對光通量(流明)的衰退曲線圖，及溫度升高對主波長紅移的正比例係數，經熱電耦合疊代到收斂，即可得到其亮度的衰減與其顏色的變化(混光，用相關色溫來表示)，希望藉由這套分析LED排列的方法，可以達到降低成本(減少LED個數)，並且在維持一定的發光效率下減少光通量的衰減。由模擬與程式，可得到在這樣散熱相當困難的情形下，若將3W高功率LED由15顆減少為14顆，則LED成本少了6%~7%，但需要改變結構到能將間距拉大很多(0.5cm,1cm拉大到超過3cm，例如4.5cm,7cm,10cm)。並希望這個可找到熱源減少下限與其所搭配的間距之方法以後可以應用在更高瓦數或更小散熱面積的照明上。
並列摘要
This thesis conferring LED that operates in full power and nature convection circumstance. By changing the different arrangements, we hope to improve its performance, less junction temperature increase and less influence on total luminous flux. If possible, we hope to decrease the number of LED, and still maintain its own regulation specifications, achieving the purpose of energy saving, extending its life and cost down. The method for analysis is using datasheet on internet which is supplied by LED manufacturers. The datasheet has to include three important parameters that relate to thermal, electrical, and optical properties, and its optical spectrum distribution diagram. The three parameters is TSP (it is a coefficient which stands for the relationship of thermal-electrical coupling), the decline curve illustration that describes the increase of temperature, and the decrease of luminous flux, and the directly proportional coefficient to the red shift of dominant wavelength when the temperature is increasing. After finishing thermal-electrical coupling iterations till convergence, one can get the reduction of luminous flux and the change of mixing color that represent by correlated color temperature Hoping this analysis method of LED arrangement will achieve the aim of cost down by decreasing the number of LED. With simulation and programming, we can obtain the result that under such difficult conditions, if we can decrease 3W LED from 15 to 14 by pulling up the lager distance of structure(for example: from 0.5cm, 1cm to more than 3cm, like 4.5cm,7cm, or 10cm). Also we hope this method which can find out the limit of number decreasing and the distance it should has would apply to illumination which owns more power or fewer heat dissipation area.