Thermal analysis of multi-chip cool white HPLED with thermal transient tester and thermal imaging camera

The junction temperature of an light emitting diode package (LED) is a parameter of consequence as electrical and optical characteristics of the packages progressive decline with increment in the junction temperature. This paper is to compare the temperature rise in p-n junction of a four-chip cool white high power light emitting diode (HPLED) by using thermal transient tester (T3ster) and thermal imaging camera (TIC) under open air condition. The measured electrical thermal resistance of the HPLED package through cumulative structure function is 3.753K/W. The optical power of the cool white HPLED package is 1.30W and is used to calculate the real thermal resistance of the package. The obtained junction temperature rise of the package by using thermal transient testing is compatible with the thermal imaging method. The measured temperature rise in the p-n junction is 16.270°C while the recorded junction temperature rise by using the camera is 16.500°C.