About LEDs technical question - very hard to solve

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In a COB product with an FR-4 substrate, the interaction between blue light chips and yellow phosphor results in white light, but room temperature aging shows higher attenuation than aging at 85 degrees Celsius and 85% relative humidity. After 1000 hours of lighting, the attenuation at room temperature is 7%, compared to just 1% at elevated conditions. Heat may facilitate the recovery of damage in the materials, potentially aiding electron flow in insulators. Additionally, high temperature and humidity may impact the phosphor and colloid, possibly reducing the attenuation caused by the phosphor. Understanding these factors is crucial for improving LED longevity and performance.
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In a COB product with FR-4 substrate, blue light chip excites yellow phosphor to form white light.
Why is room temperature aging attenuation higher than 85 degree/85% RH aging attenuation?
(After 1000h lighting, Attr=7% while Att85=1%)

(If you have further questions about how I do the experiment, ask me here)
 
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I'd suppose heat heals some damage. For instance when hot electrons are injected into insulators, heat helps the electrons flow back.
 
Enthalpy said:
I'd suppose heat heals some damage. For instance when hot electrons are injected into insulators, heat helps the electrons flow back.

Good thought!
I was thinking whether high temperature and humidity affects phosphor and colloid so that the possibility of attenuation caused by phosphor might be lowered.
 
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