The Thermal Spreading Resistance Effects Analysis of LEDs

• Main Authors: Ding, Wei-Ting, 丁韋廷
• Other Authors: Wang, Chi-Chuan
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/37728400153465637921

碩士 === 國立交通大學 === 機械工程系所 === 103 === The present study investigates the thermal spreading resistance effects of LEDs by experiments. The thermal transient tester and integrating sphere are used to measure the thermal and optical characteristics of LEDs mounting on different kinds of metal substrates. The result shows that the thermal resistance of LEDs increase as electric power increase before optical correction, but after the optical correction is conducted by integrating sphere, the thermal resistance of LEDs does not affect by electric power. Besides, the meaning of the cooling side temperature in the structure function is confirmed by infrared camera. On the other hand, the results also show that the lighting performance has something to with the thermal management. The wall plug efficiency of LEDs decrease when increasing the electric power or junction temperature. The radiant power will increase as electric power increasing. The correlated color temperature will increase as electric power increasing and decrease as junction temperature increasing. Due to the thermal spreading resistance effect, the thermal resistance of compound different dual plates will be different if two materials are changed up side down. Finally, by taking the X ray pictures, we find void in the solder region which will increase the thermal resistance of LED package.