Thermal Parameter Extraction Method for Light-Emitting Diode (LED) Systems

This paper proposes a thermal parameter extraction method for light-emitting diode (LED) devices and LED systems (LEDs mounted on a heatsink). The proposed method provides a simple tool to find out the essential thermal parameters involved in the LED systems, including thermal resistance of LEDs, thermal capacitance of LEDs and thermal time constant of LEDs. All of these thermal parameters are essential for both reliability research and optimal design of LEDs. The concept and significance of the Tau (thermal time constant) of LEDs are emphasized in this paper. Heat transfer equations are initially used for LED devices and LED systems to predict the rising-up junction temperature and cooling-down junction temperature of the LED device and the LED system. Experiments on several LEDs and heatsinks at different time frames are conducted and the practical measurements confirmed the validity of this method and accuracy of the predicted thermal parameters of LEDs.

[1]  S.Y.R. Hui,et al.  A Simple Method for Comparative Study on the Thermal Performance of Light Emitting Diodes (LED) and Fluorescent Lamps , 2009, 2009 Twenty-Fourth Annual IEEE Applied Power Electronics Conference and Exposition.

[2]  C. Biber.  LED Light Emission as a Function of Thermal Conditions , 2008, 2008 Twenty-fourth Annual IEEE Semiconductor Thermal Measurement and Management Symposium.

[3]  T. Zahner,et al.  Thermal management and thermal resistance of high power LEDs , 2007, 2007 13th International Workshop on Thermal Investigation of ICs and Systems (THERMINIC).

[4]  S. Hui,et al.  A General Photo-Electro-Thermal Theory for Light Emitting Diode (LED) Systems , 2009, IEEE Transactions on Power Electronics.

[5]  Xuehui Tao,et al.  Dynamic Photoelectrothermal Theory for Light-Emitting Diode Systems , 2012, IEEE Transactions on Industrial Electronics.

[6]  S. Hui,et al.  Estimation of Optical Power and Heat-Dissipation Coefficient for the Photo-Electro-Thermal Theory for LED Systems , 2012, IEEE Transactions on Power Electronics.

[7]  Wei Yan,et al.  Experimental investigation on the performance characteristics of white LEDs used in illumination application , 2007, 2007 IEEE Power Electronics Specialists Conference.

[8]  B. Ackermann,et al.  Control of LEDs , 2006, Conference Record of the 2006 IEEE Industry Applications Conference Forty-First IAS Annual Meeting.

[9]  M. F. da Silva,et al.  Compact emergency lamp using power LEDs , 2009, 2009 35th Annual Conference of IEEE Industrial Electronics.

[10]  Deyan Lin,et al.  A Simple Method for Comparative Study on the Thermal Performance of LEDs and Fluorescent Lamps , 2009, IEEE transactions on power electronics.

[11]  Ra-Min Tain,et al.  Cooling performance of silicon-based thermoelectric device on high power LED , 2005, ICT 2005. 24th International Conference on Thermoelectrics, 2005..