What does a fluoropolymer coating do?

Co-authors and contributors

  • Dr Lee Hitchens, Nexus

A circuit board protected by a fluoropolymer coatingThe fluoropolymer surface modifier films effectively change the surface energy of the substrate they are applied to so that water and oil do not wet the surface.

This is very different to the way the traditional liquid coatings work.

This change in surface energy makes it harder for liquids like water and oils to wet the surface and cause corrosion.

PCB coated in a fluoropolymer
A fluoropolymer actually changes the surface energy of the circuit board.

Here in the image above the circuit on the left hand side was coated with a traditional liquid conformal coating and the water droplet wets the board.

On the right hand side the board was coated in fluoropolymer coating and the water does not wet the board so well and the wetting angle is more severe.

When we consider the actual value of surface energy the surface modifier has we are in the range of Polytetrafluoroethylene or PTFE as its better known.

The best-known brand name of PTFE-based formulas is Teflon by DuPont Co., which discovered the compound.

As we all know Teflon helps avoid “things” sticking or wetting to it.

So, these coatings work on the same principle.