Industries
LED & lighting electronics
Continuous heat at the junction, outdoor humidity and UV exposure, and one requirement the other sectors do not have: the coating must not discolour or dim the light it sits near.
What the environment does
The stresses that decide the specification
Sustained junction heat
LED modules and their drivers run hot continuously rather than in bursts. Sustained temperature ages a coating faster than any single peak, and a chemistry chosen for its maximum rating may still discolour after a year at 85 °C.
Optical clarity and yellowing
A coating anywhere near the emitter must stay clear. Yellowing costs measurable lumen output and shifts colour temperature — a warranty problem in luminaires sold on a specified CCT.
Outdoor exposure
Street lighting, façade and signage assemblies face UV, rain, dust, temperature swing and condensation continuously. Coverage at the driver board edges and connector entries is where ingress starts.
Outgassing and contamination
Volatiles released from a curing or ageing coating can deposit on optics and reflectors inside a sealed luminaire, dimming the fixture without any component failing. Low-outgassing behaviour is a real selection criterion here.
Driver-side stress
The driver board carries the mains-side voltage, the heat and the electrolytic capacitors. It is frequently the assembly that fails first, and frequently the one whose coating specification received the least attention.
Coating systems
What is typically specified here
Sector convention is a starting point, not an answer — the environment specification decides. Our engineers will confirm the grade against your actual assembly.
Silicone (SR)
Wide temperature range, retained flexibility and good optical stability — the usual choice on and around the LED module itself.
Polyurethane (UR)
Outdoor drivers and control gear where moisture, dust and chemical exposure govern.
UV thick-film (DSL)
High-volume module production on selective coating lines, where cure time dictates throughput.
Full comparison: acrylic vs polyurethane vs silicone · Selection method: how to choose a conformal coating
ESD packing
Getting the assembly there intact
- Anti-static bubble bags and dissipative trays for populated LED boards, which are easily damaged by point contact.
- ESD thermoformed trays with cavities matched to module outline, protecting the emitter surface from contact.
- PP corrugated bins and dividers for driver assemblies circulating between plants.
- Moisture barrier packing where modules are stored before final assembly.
Standards
What gets specified
Lighting assemblies usually sit at IPC-A-610 Class 2, with material qualified to IPC-CC-830B. The sector-specific requirements are commonly imposed by the luminaire specification rather than the coating standard — non-yellowing behaviour, low outgassing and compatibility with optical components sealed in the same enclosure. State them explicitly; no IPC class covers them.
Standards explainerFrequently asked
LED & lighting electronics questions
Will conformal coating reduce LED light output?
A correctly selected coating should not. The risks are two: a coating that yellows with sustained heat and UV, which reduces output and shifts colour temperature; and one that outgasses volatiles inside a sealed luminaire, which deposit on optics and dim the fixture without any component failing. Both are selection criteria that need to be stated, because no IPC class covers them.
What coating is best for outdoor LED drivers?
Polyurethane is the common choice for outdoor driver and control-gear boards, where moisture, dust, temperature swing and chemical exposure govern. Where the board also runs hot continuously or cycles hard, silicone is preferred for its temperature range and retained flexibility. In practice the driver deserves at least as much specification attention as the LED module, since it usually fails first.
Can the LED emitter area be left uncoated?
Yes, and it usually should be. The emitter surface, optical interfaces, thermal pads and connectors are treated as keep-out areas, marked on the drawing and either masked or programmed around on selective coating equipment — then verified clear after cure rather than only after masking.
Coating for led & lighting electronics?
Send us the assembly, the environment it has to survive and the standard you are working to. Our engineers come back with a coating system, an application method and a window.