A printed circuit board (PCB) will often host dozens of delicate components that must be protected from moisture, contaminants, and other threats. There are a variety of ways of coating printed circuit boards, but techniques involving the deposition of materials suspended in a chemical vapor are the most commonly employed today.
When having a coating applied via chemical vapor deposition (CVD), the nature of the particular formulation chosen will always impact the quality of the results. Coatings based on the polymer parylene have rapidly become some of the most popular choices.
Parylene’s Many Strengths Make It a Top Choice for Many CVD Projects
Some coatings that can be applied using CVD end up excelling in certain respects but coming up short in others. Coatings that incorporate parylene tend to be some of the most well rounded, a fact that accounts for the impressive popularity of this class of materials. Some of the ways by which parylene-based coatings most often shine in practice include their:
- Reliability. CVD is a well developed technique that has become dominant over other options, like dipping and spraying, in many contexts. At the same time, it is possible for a particular CVD process to give rise to unacceptable defect rates if conditions are not optimal. Coatings based on parylene tend to be easy enough to apply using CVD that such problems become less likely to arise than if some alternative had been chosen instead.
- Uniformity. A conformal coating that is excessively thick in certain places will contribute to waste and could lead to other undesirable outcomes. If a coating should be too thin in a particular area, it could end up not providing the required protection for components and substrate. The thickness of parylene-based conformal coatings can be calibrated and maintained very precisely, enabling high levels of uniformity.
Often an Excellent Option When a Conformal Coating is Needed
Strengths like these and others help make parylene-based coatings highly suitable for many applications. While there are other, more specialized options that will sometimes win out in particular cases, parylene is a CVD coating material whose well-balanced nature makes it the best choice in many situations.