Parylene conformal films are considered superior to traditional liquid coatings, such as urethane, silicone, epoxy, and acrylic. In fact, this material offers unparalleled protection for several aerospace components, including PCBs (printed circuit boards) and other similar electronic assemblies. Thanks to the total encapsulation when applied to any device surfaces; edged, creviced, round, or flat, all while adding virtually no weight to the device being covered.
These unique properties are partly the result of the unique CVD or chemical vapor deposition process. This applies the gaseous parylene deep into the PCB surfaces, which generates a micro-thin, conformal coating. Keep reading to learn more about how the aerospace industry benefits from this material. It is also possible to learn more by visiting https://pctconformalcoating.com/.
More About Parylene
Along with the benefits mentioned above, parylene coatings will also adhere to most surfaces well, reduce ionic conduction at a substrate interface, provide a low dielectric constant, which minimizes high-frequency loading, and increases the functionality and lifespan of the PCB. It also helps to strengthen wire bonds, circuit links, and solder joints, while providing an interior coating.
Parylene is also able to be attached in smaller spaces. It is highly resistant to solvents and fungi, making it a popular product for use in this industry.
Additionally, parylene is considered a military specification conformal coating, MIL-I-46058, which makes it suitable for use with various aerospace assemblies. These are not often protected using a standard spray, dip, or brush-on coating methods. Generally speaking, the liquid coatings working on consumer devices do not offer the ruggedized, longer-term resilience that is needed for prolonged use for aerospace applications. The highly durable, lightweight parylene conformal coating alternative provides much higher levels of protection for the service life in the aerospace industry, no matter where and how it is used. Also, parylene is considered hydrophobic. This means it can withstand a 100-hour salt spray test, which exceeds the military standards.
- MEMS or Microelectromechanical Applications
One of the main aerospace applications for these parylene conformal coatings is to protect nano-tech, MEMS, and other types of instrumentation featuring multiple-layer circuits. Usually, these include engine management, sensor systems, flight control, and cockpit systems that are found in the in-flight vehicle. In these types of situations, the PCBs will benefit from the superior level of thermal stability that is created by parylene film. This is an essential part of keeping things running properly.
- UV or Ultraviolet Protection
If components are exposed to higher energy UV radiation for prolonged amounts of time, they can generate extensive surface damage while leading to the eventual equipment malfunction of, for example, light-generating LED assemblies and electrical assemblies within. With the new, high-temperature parylene formulations that are UV-stable, the challenges created by UV degradation for aircraft LED lighting are prevented. This helps to prevent LED-yellowing, along with surface discoloration due to prolonged exposure to this UV radiation. When the UV light is filtered from the item coated, the parylene will protect the internal LED assemblies from potential operational malfunction, which results from the UV radiation. It also works to sustain the performance of these components thanks to its longer-lasting and energy-efficient materials. This material is ideal for landing gear lighting, navigation lighting, and cabin lighting.
With the parylene, there is a pinhole-free, lightweight, and conformal covering that is UV and heat resistant. It also generates enhanced LED protection that is necessary for aerospace environments. The minute surface thicknesses range from just 500 angstroms up to 75 microns. When compared to other types of parylene options, AF-4 offers 2,000 or more hours of total UV usage without experiencing any type of decomposition or the appearance of surface yellowing. It is also effective with much thinner coatings, making it a smart option for this industry.
- Electronics and Communication Devices
Modern aerospace electronic systems are often subjected to temperature extremes, along with vibration extremes. They can also be impacted by in-flight particulates of a questionable origin. The radio and computerized external and internal communications equipment require the very highest levels of protection to help ensure ongoing, proper functioning. Some of the other electronic systems that may be impacted include inertial sensors, onboard calibration systems, flight control units, navigation boards, mother boards, vision algorithms technology, command or telemetry systems, multiple device management solutions for video data, image processing, and closed-loop control.
Parylene will adhere mechanically, not chemically to a certain substrate. This allows it to provide a high level of protection demanded by more specialized aerospace electrical systems. The dielectric properties will prevent interference and crosstalk for these types of protected devices.
- External Operations
The presence of reliable and ruggedized protection is essential for any outside circuit. For example, the aircraft tail and wing applications are exposed to non-controlled, rapid-change operating environments. They are often exposed to these types of extreme atmospheric changes. The conditions will often exceed the given security parameters that are provided by a liquid conformal coating. With a parylene coating, all these assemblies are fully protected. This helps to ensure the proper function as an aircraft moves from the sea level to the upper atmospheric operating altitudes. With this coating, it is possible for the sensors and PCBs, along with any like devices to perform as expected for industrial, commercial, and military applications in the aerospace industry.
The high strength, temperature resistance, and low permeability of parylene film provide superior protection for exposed surfaces. This includes everything from radar transmitters, radiation detectors, and optical windows. It can also effectively repel any corrosive liquids, chemicals, moisture, and abrasive substances all while offering a lightweight barrier of protection without the mass or dimension created by traditional liquid coatings that are commonly used.
Parylene coating technologies are an essential part of modern aerospace applications. This has led to improved performance and increased lifespan of the essential PCBs, power supplies, communication devices, satellite electronics, and detection or radar equipment. All this leads to an essential element that is now widely used throughout the aerospace industry for many uses and purposes.
Image Credits: Louisajb