Posted by Jake Hinojoza on Feb 27, 2018 9:00:00 AM

PCB and conformal coating

Printed circuit boards(PCB) make a large majority of our everyday items run. When producing a PCB, you want to make sure that it functions without error. A conformal coating covers the PCB, and it is up to you to choose which coating will do the best job.

Types of Conformal Coating

Conformal coating can be applied as a liquid or as a vapor. Liquid applications include acrylic, epoxy, silicone, and urethane while parylene uses a chemical vapor deposition process. For the function of the PCB, it’s essential that all surface area is coated. Liquid and vapor conformal coatings each have their strengths and weaknesses.

Surface defects that cannot be present are air bubbles, cloudy surfaces, irregular leveling, and gaps in the coating where the surface of the PCB may be uneven. Parylene conformal coatings, deposited as a chemical vapor, are regarded for their ability to cover even the most irregular surface area completely.

Selecting a Conformal Coating

Before using a conformal coating, it’s essential to recognize the type of coating that will be most effective, how the application will affect the PCB’s function, and how long the coating needs to last. Examples of examining coating needs include liquid coatings that are sensitive to water infiltration, while others are used for their durability and flexibility. Parylene is easier to decide if it is the most effective choice. It is applied thinner and can be used for nano-equipment and is extremely resistant.


Choosing the right conformal coating is all about the PCB you will be applying it to. While there are cost and workability considerations, you will want to focus mainly on if the conformal coating you choose will allow the PCB to do its job. For any other questions on selecting conformal coating, call us today.

Jake Hinojoza

Written by Jake Hinojoza

Jake received his Bachelors of Business Administration from California State Polytechnic and has been with Advanced Coating since 2009.

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