Rapid thermal cycling by eddy current inducted heating on optical property and thermostability of high power LED

The effect of rapid thermal cycling by eddy current inducted heating on optical property and thermostability of high power light emitting diode(LED)is investigated in the present study. With the application of high-frequency power device, the specimen that was being operated life test in the experiment was rapidly heated and cooled based on a control system that employs a fuzzy logic algorithm. The high and low temperature distribution in LED chip was simulated by finite element modeling(FEM). The optical properties of single LED was tested and analyzed by integrating sphere. It was found that rapid thermal cycling has an evident influence on luminous flux and luminous efficiency and radiant power. The results showed that the color purity of LED was also descended, but the correlated color temperature (CCT) was risen. The results indicate that this approach to rapid thermal cycling by eddy current is feasible to investigate optical property and thermostability of high power LED, so it can also effectively verify the reliability of LED devices.