What is the Price of Parylene Conformal Coating?

Parylene stands out as the premium conformal coating choice for safeguarding devices, components and surfaces across electronics, instrumentation, aerospace, medical and engineering sectors. Renowned for its chemical stability, Parylene serves as an exceptional barrier material, displaying resistance to solvents and moisture, remarkable dielectric strength and uniform coverage.

Engineers generally have a strong affinity for Parylene due to the reasons above. Nonetheless, the perceived high cost of Parylene can occasionally temper their enthusiasm, as it is frequently cited as the priciest among all available coating choices for a project.

So, how much does Parylene cost? The cost of Parylene hinges on two key factors: raw material costs and labor costs. In essence, it varies depending on specific circumstances.

What Is Parylene?

Parylene, a family of polymers, is utilized to coat and safeguard objects from environmental damage like moisture and dielectric effects. The raw Parylene, known as “dimer,” is in powder form. During a Parylene coating run, approximately a pound of raw Parylene, ranging in cost from a few hundred to several thousand dollars per pound, is employed. The powder is vaporized, drawn into specialized vacuum coating chambers along with the objects to be coated, where the Parylene vapor is deposited on all exposed surfaces. This results in a thin, protective coating that perfectly conforms to the object, earning Parylene the title “conformal coating.”

The Parylene layer shields objects from moisture, extreme temperatures, dielectric interference, mold and various other issues that could lead to device failure. Engineers employ Parylene as a protective shield to safeguard circuit boards and other items from environmental harm. This protective coating enables circuit boards and electronic devices to operate in environments previously unsuitable. Its applications range from NASA spacecraft to medical implants designed for internal use in the human body.

How Parylene Is Different than Other Coatings

Parylene is not the only choice engineers have for conformal coating. There are four other major “wet” conformal coatings: polyurethane, silicone, acrylic and epoxy. The four wet coatings are applied as a liquid, either by brushing, dipping or spraying the object with the coating material. A drying process allows the wet coatings to cure, resulting in a protective coating layer on the device. Each coating has advantages and disadvantages.

When it comes to coatings, Parylene frequently outperforms wet coatings, particularly when a pinhole-free coating is crucial or tight tolerances are in play. Although Parylene excels in many scenarios, it may not be the optimal choice for every situation. It is recommended to collaborate with a seasoned conformal coating provider to assess your unique requirements.

When seeking a coating partner, opt for one with proficiency in applying all five primary coating types. This ensures you will not be pressured into selecting a coating that may not align with your project requirements or budget constraints.

The Impact of Object Size on the Final Cost

To reduce the cost per item of Parylene, aim to coat multiple devices in one run. The cost of a pound of Parylene dimer ranges from a few hundred to several thousand dollars, depending on type and quality. The Parylene coating process involves a vacuum chamber with fixed capacity. The number of items that fit in the chamber varies based on size and shape. Increasing the items per run decreases the cost per item in that batch.

Parylene Labor Costs

Like all coating processes, masking is usually the most labor-intensive step. Parylene, however, requires especially careful masking. Parylene molecules will penetrate anywhere that air can. As a result, great care needs to be taken during the masking process to ensure every connector is adequately sealed and all tape is firmly pressed against the coating keep-out areas.

Another factor that will result in increased labor costs is the increased time spent per part to increase Parylene adhesion. Spending extra time cleaning products and applying different adhesion promotion mediums will result in increased labor times—and increased costs.

The Top Way to Manage Costs in Parylene Coating

The top way to keep your costs in line with a coating project is to avoid mistakes in the first place. The importance of properly preparing your device cannot be stressed enough. As you work with your coating provider, here are three questions you need to answer in order to ensure Parylene coating success:

1. Is Parylene Really the Best Choice for My Project?
Every project is unique. Parylene is often the best choice for conformal coating protection, but sometimes your performance requirements mean a different coating is better suited to your project.

Before you go any further, make sure you are working with a conformal coating provider with experience in all five major coating types. They will be in the best position to help you make the right conformal coating choice.

2. Have I Provided All Necessary Information?
Ensure your coating provider is well-informed about your requirements. Document your expectations for the coating and its process, detailing your current situation, past challenges and whether it’s a one-time task or an ongoing project. Discuss performance expectations before starting the coating process to prevent costly fixes post-initiation.

3. How will the Device be Cleaned Prior to Parylene Coating?
Water will remove most ionic contaminants, but the water must be pure. Otherwise, it can leave behind salt and other compounds when it evaporates. Your coating provider should also thoroughly clean your device using a solvent or a surfactant in order to remove nonionic contaminants.

Conclusion

To prevent Parylene coating failures and manage costs efficiently, it is crucial to engage a seasoned conformal coating provider. When selecting a conformal coating partner, seek one capable of addressing the key questions outlined here. This indicates the company’s ability to provide the necessary protection for your device.