Abstract
The results of measurements of the current dependences of the thermal resistance of the junction-case of LEDs of various types and manufacturers are presented. It is determined that the thermal resistance increases with increasing current, and for many samples there is a noticeable break in the current dependence of thermal resistance at currents close to the nominal one. It has been experimentally shown that the steepness of the current dependence of the junction-case thermal resistance can be used as a diagnostic parameter that makes it possible to estimate the degree of temperature distribution inhomogeneity. According to the results of tests of red low-power LEDs TLCR5800 under direct current for 8,000 h, a correlation was established between the magnitude of the power drop and the steepness of the current dependence of the junction-case thermal resistance: the correlation coefficient of these values was 0.538. The relative change in thermal resistance during testing is strongly correlated with the absolute value of thermal resistance before testing: the correlation coefficient is -0.685. On the basis of the experimental results obtained, a method for quality control of LEDs was developed by the steepness of the current dependence of the thermal resistance of the junction-case. The developed methods for quality control of LEDs can be recommended for use at the input control of enterprises-manufacturers of LED products.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call