Choosing parylene gets you half way to protecting your company's products with the best possible conformal coating. To close the circle, unless you have invested in the proper equipment and training, you also need to choose the right service to apply the coating. The Parylene coating industry, while it is a fairly niche business, is still a competitive market, but the very few top-quality providers are relatively easy to identify. Here are some of the attributes that you should actively seek:
Liquid Coating Capabilities
While it might seem counterintuitive, look for a parylene coating service that can also apply liquid coatings. This way, you can use a single vendor for more of your conformal coating projects. More importantly, you also get the benefit of having an outside party that can tell you if there is a better choice than parylene for a given project. Too often, conformal coating services will only provide either a liquid coating service or a parylene coating service, but not both. When trying to evaluate which coating makes the most sense for your project, you will benefit tremendously from having an unbiased coating expert make the right choice with you.
It's unlikely that a best-in-class parylene coating company is located next door or maybe even in the same state as your production facility. As such, your priority should be to find a facility that is well connected to road and air networks. That way, you can truck or air freight products in and out with as few connections as possible.
The Right Certifications
Even if the item that you are getting coated will not be used inside the human body, in combat or in space, look for a parylene coating service that holds the certifications that will allow their work to be used in these challenging settings. As Aristotle said, "Excellence, then, is not an act, but a habit," so the companies that have the habit of doing certified work are likely to carry those processes into your work -- whether or not you need it to be at certification level. Important certifications to hold include the following:
- Quality certifications. The ISO 9001 standard was once the gold standard for an organization that has quality control processes in place and is a good minimum. Organizations that meet the more stringent AS9100 standard, though, are held to the even more extreme requirements of the aerospace industry. Their higher quality can benefit you even if your projects stay on the ground
- NASA-STD-8739.1. Before an item can be launched into space, its coating must meet NASA's quality standards. This standard not only describes what has to be done to create a compliant coating but how to document the work, since documentation is one of the best ways to know that the coating was done right (other than waiting and seeing).
- Bio-medical certification. While the USP Class VI certification applies to coating compounds (like Parylene) and not to services, the best Parylene coating companies have other certifications that show that their materials are safe for bio-medical applications.
- IPC Standards. The IPC is the electronics industry's trade association, and they publish a range of standards that define quality standards for conformal coatings of electronic items. Their Class 3 Standard for Coating Requirements is especially important since it helps to ensure that coated items can maintain high levels of performance even in challenging situations.
- Joint Certification Program Approval and ITAR Registration. A Parylene coating service that holds Joint Certification Program Approval meets US and Canadian military standards for quality and security. ITAR registration is a sign of trustworthiness, as it means the facility is trusted by the federal government to participate in arms exporting activities.
Experienced, Skilled Workforce
Applying Parylene coatings can be a complicated process and there are a lot of items that can be parylene coated. Look for a company with at least 10 years' experience in the field and with a dedicated workforce that is fully trained and highly skilled.
Rapid Turnaround Capability
Many of parylene's benefits come from its unique vapor-based deposition method. Unfortunately, vapor deposition is relatively slow and it is not uncommon for items to spend 24 hours just in the deposition chamber. Due to this, a two week turnaround time is a good goal to shoot for if you need non-expedited service. The best services have the capacity that gives them the ability to expedite when you need it. Typically, expedited services take five business days, all the way down to 24 hour turn arounds.