LED performance is a temperature story. Junction temperature drives light output, colour shift and lifetime simultaneously — and in fine-pitch and Mini-LED designs the board is too dense for the heat to escape sideways, so it has to go down through the interface.
Three things junction temperature costs you
| Effect | Typical magnitude | Design consequence |
|---|---|---|
| Luminous flux depreciation | Noticeable output loss over life, accelerated by heat | Over-specify lumen output, or cool better |
| Colour / wavelength shift | Measurable shift with junction temperature | Visible mismatch across a display |
| Lifetime (L70) | Commonly halved per ~10 °C rise | Warranty exposure and replacement cost |
Mini-LED and fine pitch: why the old approach fails
Conventional LED boards had room to spread heat in the copper. Mini-LED backlights and fine-pitch direct-view panels place thousands of emitters at sub-millimetre pitch on a board with limited copper, so lateral spreading is weak and each emitter depends on the vertical path through the board and the interface to the chassis.
Practical guidance
Control thickness, then conductivity
Die-cut to a specified thickness across the whole panel. A uniform 0.5 mm beats a variable 0.3 mm.
Keep the assembly pressure realistic
Large panels cannot be clamped hard across their whole area. Low-pressure performance matters — see our pressure-resistance data.
Do not use grease near optics
Migrating silicone oil fogs lenses and diffusers permanently. Solid pads eliminate the failure mode.
Check the colour-shift budget first
If your spec is driven by chromaticity rather than lumen maintenance, tell us the target ΔT and we will size the interface to it.