What aluminium channel and diffuser do you need for a wide high-output LED strip?
Use an aluminium channel whose internal width matches the board and makes continuous full-length contact, then set the diffuser depth from the emitter pitch rather than the board width. Opal covers transmit about 60-70% and hide dots at shallow depth; frosted covers transmit 80-90% but need more depth or a denser pitch. Above 20 W/m the channel is a heat sink rather than trim: it must have mass, sit in free air, and never be buried in a sealed plaster void.
The profile is part of the thermal design
On a high-output wide board, the copper spreads heat along the strip and the profile takes it away. That only works with continuous mechanical contact: thermal tape across the full length, no air gaps, no mounting on plasterboard or timber above roughly 20 W/m. A profile buried in a sealed plaster void loses most of its value because there is no air movement to carry the heat away.
Size the profile mass to the load. A slim 8 mm channel cannot absorb 45 W/m; a deep extrusion with fins can. Where the architecture forbids a large profile, the honest answer is to lower the drive current and add a second run rather than to over-drive one board.
Diffuser selection
The diffuser decides both uniformity and how much of the light survives:
- Opal — 60–70% transmittance, hides dots at shallow depth, the usual safe choice
- Frosted — 80–90% transmittance, needs more depth or a denser pitch
- Clear — maximum output, only for indirect details where the board is unseen
- Always compute lux after diffuser losses, not from the bare-board datasheet
Industry references and standards
- Engineering standards — IEC 62717 — LED Modules for General Lighting — Performance and lumen-maintenance requirements for LED modules.
- Metrology & laboratories — NIST Optical Radiation Measurement — Traceable photometric and spectroradiometric measurement references.
- Energy & compliance — EU Regulation 2019/2020 (ErP for Light Sources) — Efficacy, flicker (Pst LM) and SVM limits that apply to strips sold in the EU.
More wide PCB answers
- What are the brightest LED strip lights you can actually buy?
- How many lumens per metre and per foot does a high lumen LED strip give?
- How many watts per foot does a high power LED strip use, and how hot does it get?
- Are super bright LED strip lights available in 12V, or do you need 24V?
- Are the brightest LED strip lights available waterproof for outdoor use?
- Is a double row LED strip brighter than a high density single row?