Implementation of side effects in thermal characterization of RGB full-color LEDs

This letter presents a useful thermal-characterization method for RGB full-color light-emitting diodes (LEDs). The superposition method was employed to calculate thermal resistances of a high-power RGB full-color LED package to implement the side effect. Independent driving of a single chip in the RGB package clearly exhibited a side effect on the other two chips. It was shown that driving a red chip at 350 mA, current induced 4.8 degrees C temperature rise for the green and blue chips, which is about 30% of the temperature rise in the red chip itself. A thermal-resistance-coupling matrix was structured and used for the calculation of the junction temperatures of the chips. It was demonstrated that the superposition method can be employed for an accurate prediction of the junction temperature rises for the RGB full-color LED package.