My conformal coating has changed colour over time. Is this a problem?

Discolouration of a conformal coating can be a natural phenomenon due to the nature of the resin used. For example, a polyurethane conformal coating will naturally darken and go brown with time due to its inherent properties.

However, a change in the colour or loss of transparency of the conformal coating that adversely affects the performance or the identification of the components below the coating can be classed as a defect.

Causes of discolouration in conformal coating include UV light exposure and prolonged exposure to contaminants. But, this problem can be prevented with the right measures.

Click to find out more about discolouration of a conformal coating as a defect and how to prevent it.


Need help with your process?

Contact us at Nexus and we can help solve your issues.

Subscribe to the Nexus Newsletter now.


What is the role of the Standards in conformal coating processing?

The role of the standard is to give a guideline for users on the quality of the product.

There are International, National, National Trade Bodies and internal company standards for conformal coating processing and inspection.

For Conformal Coating there are two areas that the Standards cover. These are:

  • Material Qualification
  • Process Control

These two types of standard are very different and it is important to use the right one for your process.

Click Conformal Coating Standards to find out more about the different standards, how they are used and how they can help you in your conformal coating production?

Need help with your process?

Contact us at Nexus and we can help solve your issues.

Subscribe to the Nexus Newsletter now.




The Newsletter for April is ready from Nexus

The April Newsletter for Nexus has been published.

Summary of content

  • The Rise of the Hybrid Coating Process: Mixing FC and AR!
  • What is Atomic Layer Deposition (ALD)?
  • NEW Website and Ebook Launch

Click to read the Nexus Newsletter.

Circuit board dual coated in CC and FC low res
Hybrid coating of a circuit board is where the traditional conformal coating is applied and then a fluoropolymer is applied on top. There are some great benefits potentially for this process. Read more in the newsletter

Coming up in Mays Newsletter

  • Molecular Vapour Deposition (MVD) – How does this compare with Parylene and other vapour deposition coatings?
  • Tin Whiskers – What’s the current understanding in conformal coating?
  • NEW Atomic Layer Deposition (ALD) Coating Section
  • NEW Molecular Vapour Deposition (MVD) Coating Section
  • Practical masking for conformal coating Section
  • Design for conformal coating Section
  • NEW Spotlight Service

Subscribe to the Nexus Newsletter now.

How to avoid de-wetting of conformal coating

De-wetting is the where the conformal coating material refuses to wet the surface of the circuit board that it has been applied to in an even way. The coating ends up being patchy.

The de-wetting effect tends to act locally due to local contamination.But, it can be a global affect right across the board.


De-wetting of the conformal coating can be localised or all over the circuit board.

There are many causes of De-wetting in Conformal Coating.

These include contaminants such as residues and oils, and processes such as soldering and cleaning.

To find out more click conformal coating de-wetting.

Need help with your process?

Contact us at Nexus and we can help solve your issues.

Subscribe to the Nexus Newsletter now.



Nexus launch a new website for thin film technologies

To keep in line with mobile friendly sites and expand their range of coatings examined, Nexus has launched a new website to replace the current one.

Dr Lee Hitchens from Nexus explains,

No longer do engineers consider automatically using conventional liquid conformal coatings and Parylene in electronics manufacture to protect circuits.

Now, they turn to the material suppliers and say we have a problem. What can you offer us as the conventional materials don’t do the job?

So, alternative coatings are being considered and they are being taken from other industries. This is making it very confusing to the end user.

Nexus is there to bridge the gap in knowledge found with the ever changing range of coatings available to engineers.

Therefore, we had to expand the site to include other coatings to meet this need.

Why Use Nexus?

Nexus are here to help you understand all the different conventional and new thin film coatings available right now that could work well in protecting your product.

Everyone understands that technology industries are changing at a rapid pace.

However, what is less clear is that the requirements for a particular protective coating on a certain product are becoming less defined.

Boundaries are blurring and coatings can be used in a much wider variety of ways to protect the devices in the field.

Nexus can help bridge the gap in knowledge by explaining the different coatings available, how they are being used in new novel applications, and show how these materials could be used to provide protection for your projects.

Who is Nexus?

Nexus is an independent website and service providing technical information on thin film coatings that include conformal coatings, fluoropolymers, metal oxides and other ultra thin coatings, plus encapsulates and potting compounds.

These specialist materials are used to protect high value products such as circuit boards exposed to aggressive elements in the environment.

We also examine the application methods and processes involved in these coating techniques, with both a technical and commercial, practical view point.

Try out our new Website now.

What are the seven key stages of conformal coating production?

There are seven key stages when considering the conformal coating production process.

Not all stages may be used in a production line. But, each stage should be considered for use when setting up a new coating process.

The seven key stages are:

  • Cleaning
  • Priming
  • Masking
  • Application
  • De-masking
  • Drying
  • Inspection

Click the seven key stages of the conformal coating production process to find out more.

What are the critical physical properties for a conformal coating when dry?

Sticking conformal coating reduced sizeThe physical conformal coatings properties can be subdivided into three key areas.

These are:

  • Liquid
  • Process
  • Dry State

They can be further subdivided into many different individual properties dependent on the type of chemistry of the coating.

Dry State

Once the conformal coating is applied and is fully dried / cured then it will have reached its full potential physical properties. This is the dry state.

Critical properties include:

  • Edge Loss
  • Refractive Index
  • Glass Transition Temperature
  • Coefficient of Thermal Expansion
  • Temperature Gradient
  • Flammability
  • Flexibility
  • Abrasion Resistance
  • Hydrolysis Stability
  • Permeability
  • Chemical Compatibility and Resistance
  • Corrosion Resistance
  • Fungus Resistance
  • UV Stability
  • Outgassing
  • Thermal Stability
  • Thermal Shock

Click to find out more on the dry state properties of conformal coatings.