Thermal Analysis and Lifetime Study of High Power White LED

• Main Authors: Jian-Hao Lin, 林建豪
• Other Authors: Shao-Shu Chu
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/69201817630270283673

碩士 === 崑山科技大學 === 機械工程研究所 === 101 === With elevating luminous efficiency and development of the high power light-emitted-diode (LED) chip, LEDs are gradually becoming a solid-state lighting mainstream in the marketing. LED possessed many well-known characteristics, such as safety issue, highly reliability, low power consumption, high luminous efficiency, wide applicability, environmental friendly, etc.. LEDs has been widely used in our real world because their performance is continuously to improve and the overwhelming energy saving. With outstanding performances, LED have a highly prospect market in the future to compare with conventional light sources. However, they are existing a low luminous efficiency and high thermal dissipating needed. To increase LED power, the chip will also generate a large amount of heat. It is not only cause a low luminous efficiency but also result LED’s chip failure. In order to prevent those catastrophe incidents, the thermal management is became a necessary process to achieve engineering designs. How to keep the LED junction temperature within an allowance working temperature span so that the LED is able to provide a stable light output and to maintain a normal lifetime. It is an issue for urgent to be solved. The purpose of this research is to study the thermal effect related with lifetime for a high-power white LED module, a commercial software, COMSOL, is used to simulate and to analyze the temperature distribution of LED module under different ambient conditions. Through the experiment and numerical simulation results, the coupling effect of varying ambient temperatures, junction temperature and thermal resistance are investigated. The monitored temperature on LED module and frame can be measured. Based on the thermal resistance between chip and frame, the lifetime of LED module can be estimated. It can prevent LEDs failure when they are subjected to an unfriendly environment. To investigate the characteristics of LEDs which can provide several parameters for engineering designs.