Reliability engineers no longer deal with endurance problems for LED but rather with sudden failures which are due to design or process defects. It is therefore highly important to be able to detect such potential failures during reliability tests instead of using the too poor pass/fail analysis. Indeed, if commonly used parameters like flux and forward voltage are sufficient to estimate the LED lifetime, they show low efficiency in proving LED robustness and limiting the risk for warranty returns. We present here a new sensor test bench and the critical measurements that could be conducted before and after test.
- Thermal parameters: junction temperature (Tj) monitoring, structure function of the heat path.
- Electrical parameters: IV curves, low current luminescence, low current Vf.
- Optical parameters: spectrum, blue/white ratio.
junction temperature (Tj), JEDEC51-1., SSL/LED, thermal management, lifetime, reliability, sensor test bench.
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