本研究根據LED晶片溫度(Chip temperature)的高低以及熱阻值(Thermal resistance)的大小，比較五種不同晶片間距之『多晶片COB封裝高功率LED元件』的散熱效能。接面溫度除了以紅外線熱顯像儀做實際測量，並使用Computational Fluid Dynamics (CFD)軟體進行模擬比對。此外也探討不同材質的散熱基板、不同表面積的散熱鰭片及不同晶片尺寸對於COB封裝高功率LED元件晶片溫度的影響，同時也分析LED元件的流明數與發光效率等光學特性。結果顯示發熱功率為7.94W (350mA)時，A, B, C, D及E Type試片的晶片溫度分別是84.32℃, 82.87℃, 81.91℃, 81.36℃與81.20℃，晶片間距最小的A Type與最大的E Type，兩者的晶片溫度相差3.12℃，顯示晶片間距較小者具有較高的晶片溫度以及熱阻，當GaN-base晶片的間距從0.5 mm增加至2.0 mm時，可以有效地將晶片產生的熱能傳導出來。光學性能分析則顯示晶片擺放間距較大者流明數及發光效率皆較高，換言之較高的接面溫度導致高功率LED的光學特性下降。

Five different chip gap of multi-chip COB (chip on board) package of high power LED components were compared by the chip temperature and thermal resistance to evaluate the thermal performance of LED in this study. The chip temperature was measured not only by a IR camera but also the Computational Fluid Dynamics (CFD) simulation software for comparison. Furthermore, the effects of different heat slug, the thickness of heat sink and the chip sizes to the high power LED components chip temperature were discussed. Experimental results show for power consumption of 7.94 W (350 mA) the chip temperature of A, B, C, D and E-Type structure were 84.32℃, 82.87℃, 81.91℃, 81.36℃ and 81.20℃, respectively. The chip temperature difference between the A-Type and E-Type structure were 3.12℃. Thus, a chip with a smaller gap has a higher chip temperature and more thermal resistance. The gap of GaN-base chip increased from 0.5 mm to 2.0 mm result in heat dissipation increased efficiently. Optical performance analyses show that the LED with a larger chip gap has higher lumens and higher luminous efficiency. Thus, higher chip temperatures reduce the optical performance of high power LEDs.

[1]. Josephson, Matthew. Edison: a biography. McGraw Hill. 1959.

[2]. N. G. Chondrakis, F. V. Topalis, “Starting characteristics of fluorescent tubes and compact fluorescent lamps operating with electronic ballasts”, Measurement, Volume 42, Issue 1, January 2009, Pages 78–86.

[3]. K. Hilpert, U. Niemann, “High temperature chemistry in metal halide lamps”, Thermochimica Acta, Volume 299, Issues 1–2, 19 September 1997, Pages 49-57.

[4]. Takeru Watanabe, Norimasa Mori, Fukuzo Nakamura, “A new superbright LED stimulator: Photodiode-feedback design for linearizing and stabilizing emitted light”, Vision Research, Volume 32, Issue 5, May 1992, Pages 953-961.

[5]. Lan Kim, Woong Joon Hwang, and Moo Whan Shin, “Thermal resistance analysis of high power LEDs with multi-chip package”, Proceedings - Electronic Components and Technology Conference 2006 (2006) 1076-1081.

[6]. M. Y. Tsai, C. H. Chen, and C. S. Kang, “Thermal measurements and analyses of low-cost-power LED packages and their modules”, Microelectronics Reliability, (2011) in press.

[7]. Tetsushi Tamura, Tatsumi Setomoto, Tsunemasa Taguchi, “Illumination characteristics of lighting array using 10 candela-class white LEDs under AC 100V operation”, Journal of Luminescence 87-89 (2000) 1180-1182.

[8]. N. Narendran, Y. Gu, J. P. Freyssinier, H. Yu, L. Deng, “Solid-state lighting : failure analysis of white LEDs”, Journal of Crystal Growth 268 (2004) 449-456.

[9]. M. Arik, C. Becker, S. Weaver, J. Petroski, “Thermal management of LEDs: package to system”, Proc. SPIE 5187 (2004) 64-75.

[10]. N. Narendran, J. Bullough, N. Maliyagoda, and A. Bierman, “What is useful life for white light LEDs? ”, Journal of the Illuminating Engineering Society 30 (2001) 57-66.

[11]. Ching-Cherng Sun, Ivan Moreno, Shih-Hsun Chung, Wei-Ting Chien, Chih-To Hsieh and Tsung-Hsun Yang, “Brightness management in a direct LED backlight for LCD TVs”, Journal of the Society for Information Display 16 (2008) 519-526.

[12]. Yan Lai , Nicolás Cordero, Frank Barthel, Frank Tebbe, Jörg Kuhn, Robert Apfelbeck, Dagmar Würtenberger, “Liquid cooling of bright LEDs for automotive applications”, Applied Thermal Engineering 29 (2009) 1239-1244.

[13]. Zhang Lei, Guo Xia, Liang Ting, Gu Xiaoling, Lin Qiao Ming, Shen Guangdi, “Color rendering and Luminous efficacy of trichromatic and tetrachromatic LED-based white LEDs”, Microelectronics Journal 38 (2007) 1-6.

[14]. Francis Nguyen, “Challenges in the design of a RGB LED display for indoor applications”, Synthetic Metals, Volume 122, Issue 1, 1 May 2001, Pages 215-219.

[15]. H. B. C. Wook, T. Komine, S. Haruyama, and M. Nakagawa, “Visible Light Communication with LED-based Traffic Light using 2-Dimensional Image Sensor”, in proc. IEEE CCNC 06, Jan. 2006 vol. 1. pp.243-247.

[16]. M. Cervi, D. Pappis, T. B. Marchesan, A. Campos, and R. N. do Prado, “A Semiconductor Lighting System Controlled Through a LIN Network to Automotive Application”, in Proc, IEEE LAS 05, Oct. 2005 vol.3. pp.1603-1608.

[17]. M. Wada, T. Yendo, T. Fujii, and M. Tanimoto, “Road-to-Vehicle Communication using LED Traffic Light”, in Proc, IEEE Interlligent Vehicles Symp., June 2005, pp.601-606.

[18]. G. Weessies, “Development of a Full- Color LED Backlight”, SPIE Proceedings, vol. 1664, pp. 117-120, July 1992.

[19]. H. J. Round, “A Note on Carborundum”, Electrical World, vol. 49, p. 309, 1907.

[20]. Holonyak, N., Jr. and Bevacqua, S. F., “Coherent (Visible) Light emission from Ga(As1-xPx) Junctions”, Applied Physics Letters, 1(4), 82-83, 1962.

[21]. J. I. Pankove, E. A. Miller, D. Richman, and J. E. Berkeyheiser, “GaN electroluminescent diodes”, RCA Review, vol. 32, p. 383, 1971.

[22]. H. Amano, N. Sawaki, I. Akasaki, and T. Toyoda, “Metal organic vapor phase epitaxial growth of a high quality GaN film using an AlN buffer layer”, Appl. Phys. Lett., vol. 48, pp. 353-355, 1986.

[23]. Y. Koide, N. Itoh, K. Itoh, N. Sawaki, and I. Akasaki, “Effect of AlN buffer layer on AlGaN/a- Al2O3 heterepitaxial growth by metalorganic vapor phase epitaxy”, Jpn. J. Appl. Phys., vol.27, pp. 1156-1161, 1988.

[24]. I. Akasaki, H. Amano, Y. Koide, K. Kiramatsu, and N. Sawaki, “Effects of an AlN buffer layer on crystallographic structure and on electrical and optical properites of GaN and Ga1-xAlxN(0<x0.4)films grown on sspphire substrates by MOVPE”, J. Crystal Growth, vol. 98, pp. 209-219, 1989.

[25]. I. Akasaki, H. Amano, K. Hiramatsu, and N. Sawaki, “High efficiency blue LED utilizing GaN film with AlN buffer layer grown by MOVPE”, Inst. Phys. Conf. Ser., no.91, pp. 633-636, 1988.

[26]. H. Amano, M.Kito, K. Hiramatsu, and I. Akasaki, “P-type conduction in Mg-doped GaN treated with low-energy elecron beam irradiation,” Jpn. J. Appl. Phys., vol. 28, pp. L2112-L2114, 1989.

[27]. C. P. Kuo, R. M. Fletcher, T. D. Osentowski, M. C. Lardizabal, M. G., Craford, and V. M. Robbins, “Hight Performance AlInGaP visible Light Emitting Diodes”, Appl. Phys. Lett., vol. 57, pp 2937-2939, 1990.

[28]. H. Sugawara, M. Ishikawa and G. Hatakoshi, “High-efficiency InAlGaP/GaAs visible light-emitting diodes”, Appl Phys. Lett., vol. 58, pp. 1010-1012, 1991.

[29]. S. Nakamura, T. Mukai, M. Senoh and N. Iwasa, “Thermal annealing effects on p-type Mg-doped GaN films”, Jpn. J. Appl. Phys., vol. 31, pp. L139-L142, 1992.

[30]. S. Nakamura, M. Senoh, N. Iwasa, and S. Nagahama, “High-brightness InGaN blue, green and yellow light-emitting diodes with quantum well structures”, Jpn. J. Appl. Phys., vol. 34, pp. L797-L799, 1995.

[31]. M. G. Craford, “Visible Light-Emitting Diodes: Past, Present, and Very Bright Future”, MRS Bulletin, October 2000.

[32]. K. Eichhorn, “LEDs in Automotive Lighting”, Proc. of SPIE, Vol. 6134, pp 613405.1-613405.6, 2006.

[33]. N. Narendran and Y. Gu, “Life of LED-Based White Light Sources”, IEEE/OSA Journal of Display Technolgy, Vol.1, No.1, pp 167-170. September 2005.

[34]. A. Zukauskas, M. S. Shur, R. Caska, “Introduction to Solid-State Lighting”, New York. 2002.

[35]. PN 二極體簡介，http://ezphysics.nchu.edu.tw/prophys/electron/.

[36]. Philips LumiLEDs Lighting Website. http://www.Lumileds.com.

[37]. 劉如熹, 王健鴻, “白光發光二極體製作技術,” 全華書局 2011。

[38]. Z. H. Feng and K. M. Lau, “Enhanced Luminescence from GaN-Based Blue LEDs Grown on Grooved Sapphire Substrates”, IEEE Photonics Technol. Lett., vol. 17. No. 9, pp. 1812-1814, Sept. 2005.

[39]. N. Narendran, N. Maliyagoda, A. Bierman, R. M. Pysar, and M. Overington, “Characterizing White LEDs for General Illumination Applications”, SPIE Proceedings, vol. 3938, pp. 240-248, Apr. 2000.

[40]. http://www.osram.com/osram_com/

[41]. http://www.cree.com/

[42]. http://www.nichia.co.jp/en/about_nichia/index.html

[43]. http://www.everlight.com/

[44]. http://www.edison-opto.com.tw/

[45]. http://www.unityopto.com.tw/Chinese/index.htm

[46]. J. J. Wierer, J. C. Bhat, C. H. Chen, G. Christenson, L. W. Cook, M.G. Craford, N. F. Gardner, W. Gotz, R. S. Kern, R. Khare, A. Kim, M. R. Krames, M. J. Ludowise, R. Mann, P. S. Martin, M. Misra, J. OsHEA, “High-power AlInGaN light-emitting diodes”, SPIE 2001 vol. 4278, pp. 127-132.

[47]. J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. OShea, M. J. Ludowise, G. Christenson, “High-power AlGaInN flip-chip light –emitting diodes”, Appl. Phys. 2001 Lett., vol. 78, No. 22, pp. 3379-3381.

[48]. 劉耀聰, “錫銀銅取代金錫應用於發光二極體共晶固晶製程之研究” 崑山科技大學 電子工程研究所, 2011.

[49]. A.-L. Tiensuu, M. Bexell, J.-&Aring;. Schweitz, L. Smith, S. Johnsson, “Assembling three-dimensional microstructures using gold-silicon eutectic bonding”, Sensors and Actuators A: Physical, Volume 45, Issue 3, December 1994, Pages 227-236.

[50]. Lienhard, J. H. and Lienhard, J. H., “A Heat Transfer Textbook”, 3rdEd., Cambridge, Massachusetts, U.S.A., 2001.

[51]. Latham, C. A., “Thermal Resistance of Interface Materials as a Function of Pressure”, Electronics-Cooling, Vol. 2, No. 2, pp. 35,1996.

[52]. Lee. S.,“Calculating Spreading Resistance in Heat Sinks”, Electronics-Cooling, Vol. 4, No. 1, pp. 30-33, 1998.

[53]. Culham, J. R., Khan, W. A., Yovanovich, M. M., and Muzychka, Y. S., “The Influence of Material Properties and Spreading Resistancein the Thermal Design of Plate Fin Heat Sinks”, ASME Journal of Electronic Packaging, Vol. 129, pp. 76-81, 2007.

[54]. http://www.digitimes.com.tw/tw/dt/n/shwnws.asp

[55]. Gu, Y., Narendran, N., and Freyssinier, J.P., “White LED performance”, Society of Photographic Instrumentation Engineers 5530, 2004, 119-124.

[56]. http://www.lustrous.com.tw/en/index.php

[57]. 黃道恒，“LED封裝技術現況與未來發展” 台北市電子零件商業同業公會，新電子科技雜誌，2008。

[58]. M. Arik, C. Becker, S. Weaver, and J. Petroski, “Thermal Management of LEDs : Package to System”, Proc. of SPIE, vol. 5187, 2004.

[59]. M. Arik and S. Weaver, “Chip Scale Thermal Management of High Brightness LED Package”, Proc. of SPIE, vol. 5530, 2004.

[60]. 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.

[61]. Hwang, W. J., Lee, T. H., Kim, L., and Shin, M. W., “Determination of junction temperature and thermal resistance in the GaN-based LEDs using direct temperature measurement”, Physica Status Solidi (c), 1(10), 2429-2432, 2004.

[62]. Yoon, Y. B. and Park, J. W., “Thermal Resistance of Solder Joints in hugh Brightness Light Emitting Diode (HB LED) Package”, IEEE Transactions on Components and packaging technologies, 32(4), 825-831, 2009.

[63]. Nakwaski, W. and Kontkiewicz, A. M., “Thermal Resistance of Light-Emitting Diode”, IEEE Transactions of Electron Devices, ED-32 (11), 2282-2291, 1985.

[64]. Hyun-Ho Kim, Sang-Hyun Choi, Sang-Hyun Shin, Young-Ki Lee, Seok-Moon Choi, Sung Yi, “Thermal transient characteristics of die attach in high power LED PKG”, Microelectronics Reliability 48, 2008, pp.445-454.

[65]. Teeba, N. and Mutharasu, D. “Comparison on the thermo-optical performance of LEDs with MCPCB and FR4 PCB under various drive currents and ambient temperatures”, Advanced Materials Research, v 488-489, p 1369-1374, 2012.

[66]. Petroski, J., “Spacing of High-Brightness LEDs on Metal Substrate PCB’s for Proper Thermal Performance”, IEEE Inter Society Conference on Thermal Phenomena, 507-514, 2004.

[67]. Yang, L., Jang, S., Hwang, W., and Shin, M., “Thermal analysis of high power GaN-based LEDs with ceramic package”, Thermochimica Acta, 455, 95-99, 2007.

[68].http://www.digitimes.com.tw/tw/dt/n/shwnws.asp?cnlid=13&cat=3&id=0000214475_N4O5LT726PRM7F6LHSEVE

[69]. Yueguang Deng, Jing Liu, “A liquid metal cooling system for the thermal management of high power LEDs”, International Communications in Heat and Mass Transfer, Volume 37, Issue 7, 2010, Pages 788-791.

[70]. Nan Wang, Chang-Hong Wang, Jun-Xi Lei, Dong-Sheng Zhu, “Numerical study on thermal management of LED packaging by using thermoelectric cooling”, International Conference on Electronic Packaging Technology and High Density Packaging (2009) 433-437.

[71]. W. Elenbaas, “Heat Dissipation of Parallel Plates by Free Convection”, Physica, vol. 9, pp. 1-28, 1942.

[72]. A. Bar-cohen, “Fin Thickness for an Optimized Natural-Convection Array of Rectangular Fins”, Journal of Heat Transfer-Transactions of ASME, vol. 101, pp. 564-566, 1979.

[73]. A. T. Morrison, “Optimization of Heat Sink Fin Geometries for Heat Sinks in Natural Convection”, Inter. Society Conference on Thermal Phenomena, pp. 145-148, 1992.

[74]. G. Ledezma and A. Bejan, “Heat Sinks with Sloped Plate Fins in Natural and Forced Convection”, Internation Journal of Heat and Mass Transfer, vol. 39, pp. 1773-1783, Jun 1996.

[75]. Susheela Narasimhan and Joseph Majdalani, “Characterization of Compact Heat Sink Models in Natural Convection”, IEEE Transactios on Components and Packaging Technologines, vol. 25, no. 1, pp. 78-86, 2002.

[76]. A. Bar-Cohen, M. Iyengar, and A. D. Kraus, “Design of Optimum Plate-Fin Natural Convective Heat Sinks”, Journal of Electronic packaging, vol. 125, pp. 208-216, Jun 2003.

[77]. Huang Bin-Juine. Huang Huan-Hsiang, Chen Chun-Wei, Wu Min-Sheng, “Development of high-power LED lighting luminaires using loop heat pipe”, Journal of Light and Visual Environment, v 32, n 2, p 148-155, 2008.

[78]. Kou, Zhi-Hai, Bai, Min-Li; Yang, Hong-Wu, “Experimental investigation on a flat heat pipe radiator for cooling high power LEDs”, Guangdianzi Jiguang/Journal of Optoelectronics Laser, v 21, n 4, p 485-488, April 2010.

[79]. Lan Kim, Jong Hwa Choi, Sun Ho Jang, Moo Whan Shin, Thermal analysis of LED array system with heat pipe”, Thermochimica Acta 455, 2007, pp.21-25.

[80]. Yung, K.C. Liem, H. Choy, H.S. Lun, W.K., “Thermal performance of high brightness LED array package on PCB”, International Communications in Heat and Mass Transfer, v 37, n 9, p 1266-1272, 2010.

[81]. Jamil Wakil, Thermal performance impacts of heat spreading lids on flip chip packages: With and without heat sinks, Microelectronics Reliability 46, 2006, pp.380-385.

[82]. CFDesign ,www.cfdesign.com/

[83]. Frank Wall, Paul S. Martin, Gerard Harbers, “High power LED Package Requirments”, Third Inyernational Conference on Solid State Lighting, Proc of SPIE, vol. 5187, pp. 85-92, 2004.

[84]. Adam Christensen, Samuel Graham, Thermal effects in packaging high power light emitting diode arrays, Applied Thermal Engineering 29, 2009, 364-371.

[85]. 葉貞吟, “LED排列之最佳化設計”, 清大電子工程研究所 碩士論文，2008年。

[86]. V. Sz&eacute;kely and T.V. Bien, “Fine structure of heat flow path in semiconductor devices: a measurement and identification method,” Solid-State Electron. 31, 1988, 1363-1368.

[87]. Jin-Woo Park, Young-Bok Yoon, Sang-Hyun Shin, Sang-Hyun Choi, “Joint structure in high brightness light emitting diode (HB LED)packages,” Materials Science and Engineering A 441, 2006, 357-361.

[88]. A. E. Chernyakov, M. M. Sobolev, V. V. Ratnikov, N. M. Shmidt, E. B. Yakimov, Nonradiative recombination dynamics in InGaN/GaN LED defect system, Superlattices and Microstructures 45, 2009, pp.301-307.

[89]. J. Y. Tsao, “Light Emitting Diodes (LEDs) for General Illumination”, An OIDA Technology Roadmap Update 2002.

[90]. F. Wall, P. S. Martin and G. Harbers, “High Power LED Package Requirements”, Third International Conference on Solid State Lighting, Proc. of SPIE, Vol. 5187, pp. 85-92, 2004.

[91]. 顏嘉逸, “覆晶型功率發光二極發光效率、散熱特性及抗靜電能力提昇”, 長庚大學光電工程研究所 碩士論文, 2009.

[92]. 林育中, “一種增強光源特性的發光二極體的簡式封裝技術”, 國立中山大學光電工程研究所 碩士論文, 2008。

[93]. 黃暉盛, “以矽平台及銅電鍍技術研發之新型高功率氮化銦鎵發光二極體封裝技術”, 國立中山大學光電工程研究所 碩士論文, 2010。

[94]. 張閔智, “類鑽碳薄膜於散熱元件應用及其熱傳導特性之研究”, 國立台北科技大學材料科學與工程研究所 碩士論文, 2010。

[95]. 林柏君, “LED陶瓷基板之熱模擬與分析”, 國立台北科技大學材料及資源工程系研究所 碩士論文，2009。

[96]. K. Kikuchi, Y. Hamashima, and Y. Kobayashi, “An Approach to Predicting LED Junction Temperatures with Fluid and Thermal Analysis”, SAE Tech. Paper No.2005-01-0864.

[97]. 藍浩瑋, “蜂巢式散熱鰭片應用於高功率LED之研究”, 臺灣大學機械工程學研究所 碩士論文，2009。

[98]. 曾鈺棠, “不同的散熱鰭片幾何形狀及材料對LED嵌燈之熱傳影響分析”, 中原大學機械工程研究所 碩士論文，2009。

[99]. 曾愷中, “LED背光模組散熱鰭片之模擬與分析”, 中興大學機械工程學系所 碩士論文，2005。