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.

Advertisements

Elder masking tapes give a clear advantage in conformal coating

Elder conformal coating masking tapes and dotsThe need to see the area being masked to ensure complete coverage and adhesion is paramount in ensuring that your conformal coating is masked correctly and does not creep under the masking tape. ET501G is not only the only commercially available ‘Silicone Free’ tape but is translucent allowing a clear view of what is masked and its full adhesion.

Elder supply ET501G as slit rolls or Dots and are able to convert to your required size’s in order to suit your every masking requirement.

Find out more about Elder and conformal coating masking materials here.

Nexus Conformal Coating Video Library: An operator de-masking or removing a masking boot from a header component

Nexus, the Conformal Coating Resource, have a section which has videos showing processes for conformal coating and also company video’s of which Nexus feels offer technical information to users of conformal coating.

This video shows an operator de-masking or removing a masking boot from a header component after the Conformal Coating application process

Click through to see the full range of Conformal Coating Videos at the Nexus Website.