Why Parylene’s Dielectric Properties Actually Matter
If you’ve ever wrestled with board layout constraints, unpredictable insulation failures, or a sudden arc event during validation, you know how crucial electrical isolation is—especially as devices keep getting smaller and more capable. This is where parylene coatings really shine.
Unlike traditional conformal coatings like acrylics or silicones, parylene is applied via a vapor deposition process. That means it forms an ultra-thin, even layer over everything, including complex geometries and sharp edges, without pooling or bridging. But what makes parylene stand out for many is its dielectric strength.
Depending on the variant, parylene films can withstand between 5,600 to 7,000 volts per mil. This is high-performance insulation, especially considering that you’re typically only applying 5 to 25 microns of material. For context, even at 25 microns (~1 mil), you’re getting protection in the multi-kilovolt range, without any bulk.
As a result, parylene is an exceptionally valuable tool when you’re working on miniaturized electronics, tight PCBA assemblies, or components that need to survive high voltages in a compact footprint.
So what does that mean in practice?
For engineers, it’s the ability to insulate densely packed parts without having to leave wide creepage distances or add protective layers that mess with thermal or mechanical performance. Parylene’s low dielectric constant ( 2.65 for Parylene N, 2.20 for F, and 3.15 for C) also makes it attractive in RF or high-speed digital circuits, where signal loss is an issue. And because it’s applied at room temperature, it won’t damage delicate components like wire bonds or MEMS devices.
For product managers, this kind of electrical performance supports reliability claims and performance specs that can actually set a product apart, specifically in regulated markets like medical devices or aerospace, where failure isn’t an option. It also opens the door to more compact, integrated designs without sacrificing insulation or durability.
For buyers, the consistency and scale matter too. Established parylene suppliers, like VSi Parylene, can deliver repeatable results, validated processes, and flexible capacity that fits into demanding manufacturing environments.
What about cost?
At first glance parylene may not be the cheapest coating on paper,but if you zoom out and look at the benefits that parylene offers such as fewer field failures, longer product life, less rework during assembly, it often pays for itself. This is particularly true when you’re dealing with high-value devices or low tolerance for returns.
Bottom line
Parylene coatings aren’t for every application, but for applications requiring dielectric reliability, combined with tight physical or performance constraints, they’re worth strong consideration. Parylene coatings simply let you insulate without compromising space or introducing new failure modes. Isn’t that what you wanted from a conformal coating in the first place?
Getting Started
Need clarity on the right conformal coating solution? Schedule a free consult with a VSi expert—we’ll help you understand your dielectric options so you can make the best choice for your application and goals.
Contact Us