Conformal Coating for Drones – Which is Best?

Posted on April 15th, 2022 by

As technology advances, so do the capabilities of drones available in a range of sizes, weights, and shapes. The technological advancements in drone specifications, mapping software, cameras, and sensory applications are expanding how different markets use these remote-controlled flying devices, increasing their prevalence.

As such, there is a growing need to improve operational endurance in harsh weather conditions and enable longer missions in unpredictable environments, as sensors within the drones that measure atmospheric parameters and gas concentrations must safely and reliably function. For example, drones that operate in underground mines must be waterproof, dustproof, and shockproof and should resist pressure, temperature, and humidity. Conformal coatings can meet these requirements if applied and chosen correctly.

To choose which conformal coating is best as you design drones, you will need a thorough understanding of the application environment and associated electronic reliability challenges. You must also understand the properties of each conformal coating material to determine if these properties will meet your application requirements.

Although you may not plan on considering Parylene due to perceived challenges with scalability or cost, it may be the best conformal coating for your project. The film has long been used in the aerospace industry for its exceptional properties that significantly increase electronic reliability within aircraft.

Beneficial Parylene Coating Properties for Drones

Parylene for drones


Thinner and Lighter

The weight of the coating you choose can be critical to battery life, with lighter films increasing your drone’s lifespan. HZO Parylene coatings have passed IPC CC-830C tests at 50% thinness of other conformal coatings, proving the coatings can provide as much, if not more, insulation flexibility, flammability, thermal shock, dielectric withstanding voltage, and moisture resistance at a fraction of the weight and mass of alternatives.

Excellent Conformality, Pinhole and Defect-free

Parylene coatings are ultra-thin, lightweight, and due to the chemical vapor deposition (CVD) application process, the thin films are highly conformal, wrapping around every edge available. The vapor deposition process is performed under vacuum, with specialized equipment, including a coating chamber. As a result, all surfaces are coated evenly with the same thickness all around the objects being coated. This vapor phase coating process also leads to pinhole-free coverage free from defects.


Beneficial Parylene Conformal Coating Barrier Properties for Drones

As aircraft that need to withstand more extreme temperature and pressure conditions encountered in aerospace applications, drones can benefit from Parylene’s impressive barrier properties, particularly those that protect electronics from the repercussions of corrosion.

Water vapor transmission rate (WVTR) and gas permeability indicate barrier effectiveness for corrosion resistance. As the chart illustrates, Parylene C’s WVTR and gas permeability properties are remarkably low.

Table: Barrier Properties of Conformal Coatings

Polymer Gas Permeability at 25 °C, (cc·mm)/(m2·day·atm) WVTR,(g·mm)/(m2·day)
N2 O2 CO2 H2 H2S SO2 CI2
Parylene C 0.4 2.8 3.0 43.3 5.1 4.3 0.1 0.08
Parylene N 3.0 15.4 84.3 212.6 313 745 29.2 0.59
Parylene F (VT-4) 16.7 0.28
Epoxy (ER) 1.6 4 3.1 43.3 0.94
Polyurethane (UR) 31.5 78.7 1,181 0.93
Silicone (SR) 19,685 118,110 17,710


Download the HZO Parylene datasheet to find out more about Parylene Properties


Read an in-depth discussion of Parylene properties here


HZO Parylene Conformal Coatings for Drones

Although Parylene’s coating properties present an ideal solution to drone reliability design challenges, it has historically been used in mission-critical scenarios, such as military applications or medical implants. However, as drones become more capable and critical across markets, can you afford to compromise on your conformal coating?

HZO is a coating supplier that makes Parylene more scalable and cost-efficient through proprietary equipment and processes. If you desire the level of reliability that Parylene can provide but are unsure if it will fit within your budget or business model, please reach out to speak to one of our Applications Engineers. Our team can evaluate your project, determine if Parylene is a suitable solution, and advise how to move forward.

Mallory McGuinness

As a veteran writer with over a decade of writing experience, Mallory McGuinness has spent the last two years at HZO learning about coating technology from the best minds in the industry. Professionally, Mallory is especially interested in the process of problem-solving and watching how the engineering team develops solutions that ensure business requirements are met. In her free time, you can find Mallory walking her dog Ebbie, fueling up on coffee, watching the Simpsons, and referencing the Simpsons.

All of Mallory’s blogs are reviewed for accuracy before publication.

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