高亮度LED是一種節約能源的環保照明光源，比起傳統照明光源具有省電及壽命長等優點，但事實上，LED卻是一種高熱的發光元件，其中，高亮度LED的發熱量遠遠超越傳統之LED。但於轉換效能上面，白熾燈泡在100W的輸出功率下，約有12%轉換成熱，83%轉成紅外線輻射，僅5%轉成可見光。相較之下，LED約有15%~30%可轉換成可見光，其餘全轉換成熱，但因LED封裝體小並因封裝灌膠之影響，P/N接面發光時會產生高熱量與高溫度，因此若散熱設計不佳，將導致LED發光產生之熱量累積於其P/N接面上，造成其亮度減低、壽命降低與波長漂移，且溫度過高，亦會因為內部各元件的熱膨脹係數不均，導致元件間承受過大機械應力而損毀。因此，LED之散熱需求變成提升其使用效率之重要條件。
本實驗採用田口設計方法，分別針對1瓦、3瓦和5瓦的高亮度LED散熱模組之操作變因搭配散熱效益與發光效率做進一步的研究與探討，期望以較少模擬次數來達到一定水準之統計分析，求得較佳LED模組散熱設計之參數，可以對於高亮度LED散熱系統之散熱效益有更進一步的了解。期待這些結論，對於解決現今與未來之LED高發熱量問題有所助益。

High power LED is an illuminating light source of environmental protection, which can save more power and have longer life than the traditional light source. However, the LED is a lighting component of high heat generation, producing much larger heat than the traditional LED under high illumination. Based on the conversion efficiency, the incandescent light bulb of 100 W has 12% heat dissipation, 83% infrared radiation and 5 % visible light. The LED has 15%~30% visible light and heat generated from the remainder. Because of the small LED package and the mold-filling plastic effect, the heat produced by lighting the LED is accumulated around the PN junction, which leads to the decreases of luminance and life, the drift of wavelength and too high temperature. Due to uneven thermal expansion coefficients in the LED, large enough thermal stresses caused by the high temperature result in the LED damage. Consequently, how to improve the heat dissipation becomes an important issue in increasing the efficiency of the LED.
In this experimental study, the Taguchi design method is used to investigate the effects of the operating variables of heat dissipation modules applied to the 1W, 3W and 5W high power LEDs, incorporated with the efficiencies of heat dissipation and illumination. It is expected that the results of this work can reach a certain level of statistical analysis and obtain the optimum designed parameters of the heat dissipation module. The results can help us to further understand the heat-dissipated performance of high power LED. It is also anticipated that the conclusions of this study can assist in solving the problem of high heat generation of the current and future LEDs.

[1]I.Niki,Y.Narukawa,D.Morita,S.sonobe,T.Mitani,H.Tamaki,Y.Murazaki,M.Yamata,and T.Mukai,“White LEDs for Solid State Lighting”Proc.of SPIE,vol.5187,2004.
[2]G.Murtaza and J.M.Senior,“Method for Extracting Thermally Stable Optical Singals from a CaAlAs LED Source,”IEEE Photonics Technol.Lett,vol.479,1995.
[3]Y.Gu,N.Narendran,and J.P.Freyssinier,“White LED Performance,”Proc.of SPIE,vol.5530,2004.
[4]N.Narendran and Y.Gu,“Life of LED-Based White Light Source,”IEEE/OSA Journal of Display,vol.1,no.1,2005.
[5]S.C.Bera,R.V.Singh,V.K.Garg,“Temperature Behavior and Compensation of Light-Emitting Diode,”IEEE Photonics Technol.Lett,pp.2286-2288,2005.
[6]J.Petroski,“Spacing of High-brightness LEDs on Metal Substrate PCBs for Proper Thermal Performance,”IEEE Inter Society Conference on Thermal Phenomena,pp.507-514,2004.
[7]F.Wall,P.S.Martin,and G.Harbers,“High Power LED Package Requirment,”Proc.of SPIE,vol.5187,2004.
[8]J.Petroski,“Thermal Challenges Facing New Generation Light Emitting Diodes(LEDs) for Lighting Applications,”Proc.of SPIE,vol.4776,2002.
[9]M.Shatalove,A.Chitnis,P.Yadav,M.F.Hasan,J.Khan,V.Adivarhan,H.P.Maruska,W.H.Sun,and M.A.Khan,“Thermal Analysis of Filp-Chip Packaged 280 nm Nitride-Based Deep Ultraviolet Light-Emitting Diodes,”Applied Physics Letters, vol. 86,2005.
[10]M.Arik, C.Becker, S.Weaver,and J.petroski,“Thermal Management of LEDs:Package to System,”Proc.of SPIE, vol.5187,2004.
[11]M.Arik and S.Weaver,“Chip Scale Thermal Management of High Brightness LED Package,”Proc.of SPIE,vol.5530,2004.
[12]www.lumiled.com/technology,2007.
[13]PN二極體簡介,http://ezphysics.nchu.edu.tw/prophys/electron/
[14]劉如熹,王健源,2001,“白光發光二極體製作技術,＂全華書局.
[15]S. Muthu, F. J. P. Schuurmans, and M. D. Pashley, “Red, Green, and Blue LEDs for white light illumination,”IEEE J.Select. Topics Quantum Electron.,pp.333–338, Mar.–Apr., 2002.
[16]R. Mueller-Mach, G. O. Mueller, M. R. Krames, and T. Trottier,“High-Power Phosphor-Converted Light-Emitting Diodes Based on III–Nitrides,”IEEE J.Select.Topics Quantum Electron.,pp.339–345,Mar.–Apr.,2002.
[17]徐瑞富,“以田口方法改善金線偏移之銲線製程問題,”中原大學機械工程系碩士論文, 2005.
[18]陳信華, “利用田口式動態訊雜比進行表面聲波氣體感測器之穩健設計,” 屏東科技大學機械工程系碩士論文, 2005.
[19] A Nyaluke, B. Nasser, H. R. Leep and H. R. Parsaei, “Rapid Prototyping Work Space Optimization,” Computer ind. Engng, Vol.31, No.1/2, pp.103-106, 1996.
[20] H. J. Jeea, E. Sachsb, “A Visual Simulation Technique For 3D Printing, ” Advances in Engineering Software, Vol.31, pp.97-106, 2000.
[21]李輝煌, “田口方法-品質設計的原理與實務,” 高立圖書, 2005/8/5二版修訂.
[22]蔡國山, “利用田口法于預力鋼襯混凝土管(PCCP)設計參數之分析,” 屏東科技大學機械工程系碩士論文, 2004.
[23]盧俊廷, “薄殼射出成型品翹曲變形之量測與分析,”中興大學應用數學系碩士論文, 2005.
[24]黃光鵬, “新型工具機之幾何參數識別與精度分析,”台灣科技大學機械工程系碩士論文, 2000.
[25]李育嘉, “對堆疊式晶片構裝疲勞壽命之最佳化探討,”成功大學工程科學系碩士論文, 2005.
[26] X. Guo, Y.-L. Li, and E. F. Schubert, “Efficiency of GaN/InGaN light-emitting diodes with interdigitated mesa geometry,” Applied Physics Letters, Vol. 79, pp.1936-1938, 2001.