Co-authors and contributors

  • Dr Lee Hitchens, Nexus
  • Jason Delaney, Curtiss-Wright
  • Craig Barter, Paratronix

There are many alternative coatings to traditional conformal coatings such as Parylene, fluoropolymers, MVD and ALD
There are many alternative coatings available to the traditional conformal coating materials that can provide extremely high protection to circuit boards.

These alternative coatings include:

Nexus examines them in detail.

Parylene (XY) coatings

Parylene is the trade name for a variety of chemical vapor deposited poly(p-xylylene) polymers used as moisture and dielectric barriers.

Parylene is a conformal coating that is deposited as a gas in a vacuum chamber.

It is a dry process compared to the standard “wet” liquid conformal coatings.

Paratronix Parylene Process
The application of Parylenes is a vapour deposition process over four stages. Image courtesy of Paratronix

Find out more here by clicking What is Parylene?

Fluoropolymer (FC) surface modifier coatings

Surface Modifiers are ultra thin coatings that are applied at less than a few microns in thickness.

Liquid conformal coatings are applied in the range of 25-75um so they are considerably thicker in nature.

There are several variations in ultra thin conformal coatings out in the market now but two of the most popular types are liquid materials and partial vacuum deposition.

water repelled from a connector due to coating cropped
Water repelled from a connector due to a fluoropolymer coating. Image courtesy of SCH Technologies

Find out more here by clicking What is a Surface Modifier Coating?

Atomic layer deposition (ALD)

Atomic Layer Deposition (ALD) belongs to the family of chemical vapor deposition methods (CVD).

It is a deposition process at a nano-scale level within a vacuum chamber.

The deposition process forms ultra-thin films (atomic layers) with extremely reliable film thickness control.

This provides for highly conformal and dense films at extremely thin layers (1-100nm).

Find out more here by clicking what is atomic layer deposition?

Molecular vapour deposition (MVD)

MVD belongs to both the families of chemical vapor deposition (CVD) and atomic layer deposition (ALD) methods.

Unlike traditional CVD and ALD flow systems, the MVD reaction takes place in a chamber under static pressure resulting in extremely low chemical use.

The MVD process will produce a highly conformal thin film coatings, typically less than 100nm in thickness.

The coating provides excellent barrier properties and surface energy control.

Find out more here by clicking what is Molecular Vapour Deposition Coating?

Useful Links



Molecular vapour deposition

Atomic Layer Deposition