The research on improving extraction efficiency packaging technology for high power white light light-emitting diodes

• Main Authors: Chun-Chieh Chang, 張鈞傑
• Other Authors: Yun-Li Li
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/75357754049078015460

碩士 === 國立臺灣大學 === 光電工程學研究所 === 96 === In this thesis, we changed the LED packaging to improve the light extraction efficiency and light characteristic of a white light LED module. The optical software TracePro was used to design the LED module. The radiant flux was optimized by designed different cups, phosphor applying methods, and lens shapes of LED modules. Higher radiant intensity was obtained by designing the reflector or the condensing lens of a LED module. At first we successfully established the simulation model by TracePro software for the white light LED using a blue LED chip with Ce:YAG phosphor. In the study of high extraction efficiency of a LED module, the highest radiant flux was obtained by using remote phosphor on type B cup (top diameter 4.2 mm, bottom diameter 3.2 mm, depth 1 mm) with a semi-sphere shape lens. The efficiency enhancement was 38% compared with the conventional LED structure. In the study of high radiant intensity of LED module, higher radiant intensity was obtained by using the LED module with a designed reflector. The radiant intensity of the LED module with a designed condensing lens was enhanced by a factor of 6.36 compared with the radiant intensity of a LED module without a reflector, but high light radiant flux loss was caused (6.33%) at the same time. Another method to get higher radiant intensity was using the condensing lens. The radiant intensity of the LED module with a designed condensing lens was enhanced by a factor of 5.27 compared with the radiant intensity of a LED module without a condensing lens. However, lower light radiant flux loss caused by the LED module with a condensing lens was lower than the value got from the LED module with a reflector.