Parylene Coating Blog by Diamond-MT

Ruggedizing UAV Electronics with Parylene

Posted by Sean Horn on Fri, May 05, 2017 @ 07:37 AM

The acronym UAV stands for an unmanned aerial vehicle, an aircraft piloted by remote control or onboard computers.  UAVs are an integral element of America’s unmanned aircraft system (UAS), consisting of three basic components:

  • the UAV,
  • a ground-based controller, and
  • a system of communications between the two.

Also called drones, UAVs are often used for military or rescue missions.  The electronic assemblies guiding their performance operate under extreme duress and benefit from system ruggedization.  Watchkeeper_Thales_2.jpg

          Compared to manned aircraft, UAVs are often preferred for missions too "dull, dirty or dangerous" for humans.  Originated primarily for military applications, UAV use now encompasses agricultural, commercial, recreational, and scientific applications, like aerial photography, assisting agriculture management/production, drone-racing, policing/surveillance, and product deliveries.  With more than one million estimated to have been sold by 2015, civilian/commercial drones outnumber military drones by a significant total.

          However, military uses remain most familiar to the public.  UAVs’ functional categories require demanding operational conditions, supporting component ruggedization: 

  • Combat missions use UAVs’ attack capability for high-risk aerial, unmanned combat missions.
  • Reconnaissance missions use UAVs to acquire battlefield intelligence.
  • Logistics assignments use UAVs to deliver cargo.
  • Target/decoy missions use UAVs as targets simulating enemy aircraft or missiles ground and aerial gunnery.
  • Research and development assignments employ UAVs-in-use as a source of R&D, to improve UAV technologies; not always militarily-generated.
  • Civil and commercial UAVs have a range of agricultural, aerial photography, and data collection functions.

Ruggedizing UAV 

            Designed to ensure ongoing, superior performance during extreme operating conditions, ruggedized products function through severe operating conditions that include:

  • exceptional disparity in temperature range,
  • material intrusions of substances like chemicals dust, rain, salt spray, soot, water or wind during operation,
  • persistent, intensive vibrations both internally and external to the device, and
  • numerous other working circumstances that generate wear, stress, and abuse.

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Of primary importance is safeguarding the printed circuit boards (PCBs) and similar electronic assemblies that power or guide airborne UAV.  Practically, successfully ruggedized UAV electronics meet MIL-STD-810F specifications, where testing procedures determine

The MIL-STD-810F spec is especially relevant for UAVs; the punishing performance ecosystems characterizing their operational expectations demand internal ruggedization to safeguard their installed electronics.  MIL-STD-810F details procedures that test UAVs’ capacity to function:

among a variety of difficult operational circumstances.

UAV-flight functions with various degrees of autonomy:  either under remote control by a human operator, or fully or intermittently autonomously, by onboard computers.  Required to function without fail through these conditions, UAV electronics systems include these protected devices:

  • accelerometers,
  • embedded software, managing multiple devices -- closed-loop control, image processing, video data sampling/compression (wireless transmission), and Wi-Fi communications,
  • flight control units,
  • gyroscopes,
  • inertial sensors,
  • mother/navigation boards,
  • onboard calibration systems,
  • telemetry/command systems (GPRS modem, satellite communications link),
  • UA communicators, and
  • vision algorithms technology.

Parylene for UAV Ruggedization                                                   

          In comparison to liquid coatings, parylene conformal films are recommended for ruggedized products where reliable, dedicated electrical, and environmental protection is requiredNo other conformal coatings display parylene's versatility for ruggedized applications.  Parylene is mil-spec approved, in use for years for custom-device military/aerospace applications, fully able to enhance UAVs’ functional integrity and performance. 

          In addition to helping manufacturer’s meet MIL-STD-810F spec-standards, parylene coatings are:

  • RoHS-compliant,
  • meet IPC-CC-830 requirements, and
  • are itemized on the Defense Supply Center Qualified Parts List (QPL) for MIL-I-46058.

By helping to meet or surpass these requirements, parylene conformal films provide UAV assemblies/components with verifiable, and specialized, in-depth protection.

          Parylene’s unique CVD application process deposits parylene vapor onto the substrate surface on a molecule-by-molecule basis; this insulating, dielectric film protects electronics from beneath the substrate surface to its outermost layer.  Exceptionally durable, yet flexibly ultra-thin, parylene uniform conformal film won’t decompose at upper range temperatures; nor will it become brittle as brush/dip/spray-coated liquid substances (like epoxy or urethane) can under severe, frigid temperatures.  Parylene coating remains adherent and intact, preserving the dielectric and insulation properties essential to UAV component performance.

Conclusion

Parylene coatings add to UAV-ruggedization, enhancing the performance of electrical components and systems that depend on faultless operation, under often extreme environmental conditions.  Ruggedized parylene protection maintains the functional integrity of UAV electronics as the drones travel by air through a range of inflight ecosystems and changing atmospheric surroundings.   The resistance to harsh working environments provided by parylene supports functionality where unprotected devices would otherwise fail.  

Parylene types C, F, or N are particularly recommended for UAV ruggedization.  They provide UAV electronics superior barrier and conductive properties, suitable for withstanding ruggedized performance expectations, combining strength with minimal added weight and surface resiliency, representing the optimal conformal choice for UAV-ruggedization.

To learn more about conformal coating for military electronics, download our whitepaper:

COTS Conformal Coating

Tags: parylene, rugged electronics, COTS, ruggedization, military electronics