Diagnostic quality control of LEDs by thermal characteristics

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