Simplified methods for characterizing thermal parameters of high-power automotive LEDs

This study outlines a new methodology for experimental determination of the key parameters required for designing LED thermal management hardware, using a case study of the Nichia NC5W093AT Light Emitting Diode (LED), a light used in automotive headlamps. The method provides the junction temperature, the efficiency, and the package thermal resistance of the LED. For the studied LED, it was found that efficiency decreased from 36% to 25% with increasing junction temperature from 30°C to 120°C; efficiency was also insensitive to supply current. The thermal resistance, which spanned from the LED junction to the copper base, was determined to be 3.2 K/W and was insensitive to supply current and operating temperature.