Conformal Coating
Conformal coating is the application of a thin protective film against moisture, dust and chemical effects onto a board whose assembly has been completed. The coating follows the surface shape of the board and makes it harder for condensation-related leakage current paths to form between conductors; it does not replace a waterproof enclosure.
Coating is a common protection layer on boards working outdoors or in a humid environment. The points that need to be known in practice are:
- What it does: it prevents condensing moisture from directly contacting conductive surfaces and slows down the corrosive effect of dust and salty air.
- What it does not do: it does not save a board submerged in water, it does not provide protection against mechanical impact and it does not remove the need for the enclosure to be sealed.
- Masking: connector contact surfaces, adjustment potentiometers, fuse holders and programming headers must not be coated; these areas are masked beforehand.
- Effect on service: on a coated board, replacing a component requires the coating to be locally removed and reapplied after the operation.
The decision is generally made according to the environmental conditions: a board that will work inside a closed and dry panel and a board that will be under a vehicle or in a marine environment do not have the same protection need. That is why the definition of the environment is important in the requirements analysis.
The context in which this term is used: Our Services