Industries
Aerospace & defence
Wide thermal excursions, low-pressure operation, sustained vibration and a documentation trail that matters as much as the coating itself.
What the environment does
The stresses that decide the specification
Altitude and reduced pressure
Lower air pressure reduces the voltage at which air breaks down between conductors. A conformal coating that fills the gap with solid dielectric rather than air is part of how an assembly keeps its creepage and clearance margins at altitude.
Wide, repeated thermal excursions
Ground-to-altitude cycling covers a far wider range than most industrial equipment sees, and repeats it constantly. Coating flexibility across that whole range matters more than performance at any single temperature.
Condensation on descent
A cold assembly meeting warmer, moister air condenses water directly onto the board. Coverage at board edges, under tall components and at connector shrouds is where that condensation does its damage.
Vibration and mechanical shock
Airframe and vehicle vibration runs continuously, with shock events on top. A brittle film concentrates that energy at solder fillets, which is why elasticity is valued over hardness here.
Traceability
In this sector the record of what was applied, at what thickness, inspected how, and by whom is part of the deliverable. A coating process that cannot produce that record is not usable regardless of how well it performs.
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)
The widest temperature range with retained flexibility — the usual choice where thermal excursion and vibration dominate.
Polyurethane (UR)
Where fluid, solvent or abrasion exposure is present alongside the environmental load.
Acrylic (AR)
Where field repairability and rapid rework outweigh chemical exposure — common on ground support and test equipment.
Full comparison: acrylic vs polyurethane vs silicone · Selection method: how to choose a conformal coating
ESD packing
Getting the assembly there intact
- Static shielding bags and aluminium MBB with desiccant and humidity indicator cards for controlled storage.
- ESD thermoformed trays holding assemblies in fixed orientation for handling and inspection.
- Conductive foam inserts for boards and modules with exposed connector pins.
- VCI packaging where machined metal parts and hardware ship alongside the electronics.
Standards
What gets specified
Aerospace and defence programmes typically specify IPC-A-610 Class 3 acceptance — continued performance on demand, no tolerable downtime. Material is qualified against IPC-CC-830B; legacy drawings frequently still call out the cancelled MIL-I-46058C, which should be resolved in writing to an IPC-CC-830B equivalent before work starts. Expect a customer or programme specification on top of both.
Standards explainerFrequently asked
Aerospace & defence questions
What acceptance class applies to aerospace conformal coating?
IPC-A-610 Class 3 is the usual requirement for aerospace and defence assemblies: high-performance electronics where continued performance on demand is essential and downtime cannot be tolerated. Class 3 tightens the acceptance criteria for coverage, thickness and defects, and it should be stated on the drawing rather than assumed by the supplier.
Our drawing calls out MIL-I-46058C. Is that still usable?
MIL-I-46058C was cancelled and its Qualified Products List discontinued, with IPC-CC-830 named as the superseding specification. Legacy drawings still reference it constantly. The practical route is to treat the callout as a request for an equivalently qualified material, agree in writing that the lot will be judged against IPC-CC-830B, and record that on the process sheet before any board is coated.
What documentation does EMS provide with coated aerospace assemblies?
Each lot is run to the process sheet agreed at sign-off — coating system, application method, masking scheme, thickness target and band, cure schedule and acceptance class — and the UV inspection and thickness results are compiled for the batch. Any record format a programme specification requires beyond that should be raised at enquiry so it can be agreed before production.
Coating for aerospace & defence?
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.