How does Parylene material differ from liquid conformal coatings and where can you buy it?


Parylene is very different to typical liquid conformal coatings like acrylic, epoxy, silicone and polyurethane resin based materials.

When you buy Parylene it is a white powdered dimer.

This powder cannot be applied to circuit boards in its current state. The dimer requires specialist Parylene equipment that uses a Chemical Vapour Deposition (CVD) process. That is the dimer is placed inside the machine, a vacuum created and the dimer is then transformed to a gas vapour by being heated up.

This vapour created during the pyrolysis process can then be deposited on the printed circuit board as the Parylene coating.

This is very different to liquid conformal coatings. They start off as a “varnish” in a can or container and are applied to circuit boards by brushing, dipping or spraying. They then dry either naturally or artificially in some manner and the circuit board is now protected.

Where to buy Parylene

When purchasing Parylene it is important to find a source that provides a quality product. The purity of the coating is one of the key points in creating a successful Parylene process. Neglecting this fact can cause endless problems.

Remember that buying Parylene cheaply is easy. Buying cheap Parylene that is pure enough to protect the circuit board is another issue.

Thin film Partners can inform you of the right vendors who supply high-quality material and the pricing for each type. Then you can compare which vendor you would like to buy from.

This is a cost effective method to ensure you get the right Parylene coating at the right price.

Want to find out more about Parylene?

Contact us to discuss your needs and let us explain how we can help you.

Contact us now.

Why use acrylic conformal coatings to protect a circuit board assembly from the environment?


There are many reasons for an acrylic conformal coating being the most popular protective film for electronic circuit boards in the world.

Acrylic conformal coatings have the following features:

  • Acrylic coatings provide an excellent barrier to moisture and humidity providing one of the highest levels of protection possible
  • They are one of the lowest cost coatings to purchase
  • They have minimal chemical resistance making it ideal for reworking and removal
  • Acrylic conformal coatings can be soldered through with minimal problems
  • Acrylics dry to the touch very quickly and typically cure much faster than most coatings.
  • They can be easily applied with a brush, sprayed by aerosol, spray gun or robot or by dipping.

Acrylic conformal coatings are generally the main choice in the majority of conformal coating applications.

Where is acrylic conformal coating used in protecting circuit boards?

Acrylic conformal coatings are used in many  different applications and industrial sectors including:

  • Aerospace
  • Automotive
  • Controls and drives
  • Defence
  • LED Lighting & display panels
  • Medical
  • MEMS (Microphones and devices)
  • Mobile phones
  • Military
  • Oil & gas
  • Solar panels
  • Tablets
  • Telecommunications
  • Transport
  • White goods

In fact, they are used in just about every electronics application there is.

Need to find out more?

Click acrylic and other types of conformal coatings to find out further information or contact us directly and we can help you.

If you are new to Nexus and our work on conformal coatings then a good place to go is our Start Here page or our free conformal coating eBook.

Why is it harder to mask and de-mask Parylene on a circuit board assembly compared to traditional liquid conformal coatings?

There are four key reasons why Parylene masking and de-masking is more difficult compared to liquid conformal coatings.

These are:

  1. Parylene is a vapour. When you are masking against a gas rather than a liquid then there is more of a challenge. So you need to provide a much better barrier with the masking process compared to the liquid coatings.
  2. Parylene is immersion. Most liquid conformal coatings are sprayed and so the capillary is less compared to immersion in a limitless supply of material.
  3. Stripping Parylene is hard. It is much harder to remove unwanted Parylene material on components that should not have been coated. Parylene is chemically inert (therefore harder to strip off or remove) and more difficult to see (no UV trace in most Parylene coatings). Mistakes can be more costly.
  4. The Parylene can bond more to the masking materials. When the Parylene is deposited on the masking materials and circuit board it can bind the two together and it can take significant effort and care to remove the masking materials without damaging the board or the Parylene coating integrity.

Need to find out more?

Click Parylene coating to protect electronic circuit boards to find out further information or contact us directly and we can help you.

If you are new to Nexus and our work on conformal coatings then a good place to go is our Start Here page or our free conformal coating eBook.