Hello everyone,
I’m currently designing a PCB with radial LEDs (model WS2812B‑4020, powered at 5 V). My goal is to obtain a clean and uniform light output through a material placed on top of the PCB.
The top material hasn’t been finalized yet; it will be either PMMA, PET, or polycarbonate. I know that, in general, the distance between the LEDs and the visible surface has a much greater impact on light uniformity than the diffuser itself. Unfortunately, in my case, this distance is fixed at 2 mm and can no longer be changed.
To improve diffusion, I’ve already tested several approaches on small PMMA samples I have:
- Sanding the surface (grits 500 / 800 / 1000)
- Machining grooves into the material (V-shaped and circular patterns)
But none of thoses solutions are good enough.
This brings me to my main questions:
- What type of diffuser would be the most suitable in this situation? I’ve seen different recommendations: some suggest using a PET diffuser film, while others say that epoxy resin alone can do the job. I’m a bit confused, as I’m new to LEDs and optical diffusion.
- Is it possible to properly diffuse light while keeping the material clear or transparent, or does diffusion always require an opal / milky material?
Any advice, feedback, or experience would be greatly appreciated.
Thanks in advance everyone !