高功率AC LED交流電壓驅動特性研究

Study of Alternating electricity voltage for High Power AC LED

林明德(MING-TE LIN)

指導教授 ： 孫慶成

國立中央大學/理學院/光電科學研究所碩士在職專班/碩士(2007年)

摘要

本論文研究交流電(Alternating current ;簡稱 AC)驅動之交流發光二極體(Alternating current Light Emitting Diode;簡稱AC LED)並以等效電路研究推論出AC LED電特性模型，並使用『ITRI 立體導熱LED封裝結構(Limited LED package) 』來確認AC LED市電驅動之特性，在室溫不考慮熱偏移之條件，獲得交流電壓下驅動AC LED推論出當微晶粒20-30%失效時雖發光面積下降30%，但由於臨界電壓下降與平均電流與輸入功率的上升，致使光輸出通量維持與初始亮度相仿或以上，也就是說AC驅動之AC LED微晶粒20-30%以內失效時之表現，在效率下降而非輸出光通量下降，此種特性極適合應用於有安全預警要求之應用的照明系統如車燈與隧道或號誌燈只要監控輸入功率或電流變化就可預估微晶粒失效百分比，而此時光源依然維持不變之光通量，提供光源亮度下降前安全替換的時間。

關鍵字

高功率 ； ITRI 立體導熱LED封裝結構 ； 發光二極體

並列摘要

In this thesis, we study so-called AC-LEDs, which can be driven by AC electrical power directly. We build up an equivalent circuit to model the electrical characteristic of the AC-LED. We apply "ITRI''s limited LED package" on AC-LEDs to study the effect by driving the LEDs with the general electrical power system. In room temperature, we obtain that the output brightness holds at the same level or above when the 20%-30% chips fail since the critical voltage drops but the drive current and power increase. Such characteristic enables AC-LED suitable to security-required lighting systems because the variation of the drive current and power can be applied to failure estimation so that the damage LEDs can be replaced before the lighting brightness drops.

並列關鍵字

Alternating current Light Emitting Diode ； AC LED

參考文獻

1. N. Holonyak, Jr. and S. F. Bevacqua, “Coherent (Visible) Light Emission from Ga(As1-xPx) Junction”, Applied Physics Letters, Vol. 1, No. 4, pp. 82 (1962).

4. Ian T. Ferguson , John C. Carrano , Tsunemasa Taguchi , Ian E. Ashdown , Editors ,“ LEDs for solid state lighting and other emerging applications: status , trends , and challenges”, on Solid State Lighting , 594101 M. , George Craford Lumileds Lighting, LLC (2005).

9. Hyunsoo Kim, Ji- Myon Lee, Chul Huh,Sang-Woo Kim , Dong-Joon Kim ,Seong-Ju Park,and Hyunsang Hwang,“ Modeling of a GaN-based light-emitting diode for uniform current spreading,”App. Phys .Lett.77,1903,(2000).

11. X. Guo, Y.-L. Li,and E. F. Schubert ，“Efficiency of GaN / InGaN light-emitting diodes with interdigitated mesa geometry,”App.Phys.Lett.79, 1936(2001).

12. STURART M. SPRITZER,NORMAN E. SCHUMAKER , LOUIS A.KOSZI,JAMES C.NORTH , “Multi junction AC or DC integrated GaP light emitting diode array”, IEEE TRANSACTION ON ELECTRON DEVICE ,701-706(1975).