Conformal Coating for Military Applications

Posted by Jake Hinojoza on Mar 21, 2018 9:00:00 AM
Jake Hinojoza

Conformal coatings are all around us in everyday objects and still most people don’t know what it is. Electronics need to be protected from environmental threats such as dust, water, temperature, and chemicals. To protect the printed circuit boards (PCBs) that make these electronics run, they are covered in non-conductive film, otherwise known as a conformal coating.

Like in every other industry, military technology is always growing, always changing, and always demanding more advanced protection. As our devices get more intricate and capable of bigger and better things, they also get more susceptible to environmental hazards, chemicals, extreme temperatures, and more. That's where conformal coatings come in. 

Capable of defending even the most irregularly-shaped objects from a wide range of dangers, conformal coatings have been providing reliable, safe protection for decades. Although our troops and military leaders carry the weight of defending our country, you can bet that conformal coatings are right there with them, helping out everywhere from communication to transportation.

Military Technology

The United States military operates with intricate and innovative technology, top-of-the-line tools, and delicate mechanics, all with the sole purpose of protecting our country. However, if the tools, tech, and machinery themselves aren't protected, then the military is at a severe disadvantage--one that may have life-threatening consequences. 

As a result, it is crucial for the military to use conformal coatings that provide reliable protection without sacrificing any aspect of performance or freedom of motion, and the only coating capable of offering both of these things and unrivaled longevity and dependability is the ever-popular parylene. Parylene conformal coatings are used throughout the military, in everything from vehicles to robotics to communication.

Where Parylene Conformal Coating Comes In

Here are a few of the unique circumstances that warrant a conformal coating that can stand up to almost anything. 

  • Harsh terrain. The men and women of the military have to be ready to face the harshest terrain on Earth, and so do their tools. Luckily, parylene conformal coatings have characteristics that provide protection from gasses, severe environmental conditions, salt water, and more.
  • Unique shapes. Because the military's tools, communication devices, vehicles, and weapons come in all shapes and sizes, it's crucial to have a conformal coating that can adapt seamlessly to everything from sharp edges to oddly-shaped crevices. Parylene is unique in that it can coat any shape and surface, without once sacrificing performance or interrupting motion.
  • Reliability. Overall, parylene conformal coatings are trusted because their natural characteristics make them so deeply reliable. Parylene is resistant to thinners and solvents, meaning that it won't weaken to dissolve; it is also pinhole-free, lightweight, resistant to chemical and environmental extremes, and created in a unique way that minimizes the air bubbles that can cause malfunctions and failures.
  • Variety. Since the military has a wide variety of needs, it requires conformal coatings with a wide variety of benefits. Coatings like parylene can be controlled for precise thickness, come in clear and colored varieties, and withstand pressure, chemicals, moisture, and more.
  • Voice. Communication within the military is both intricate and crucial, and this is one place where conformal coatings really shine. By protecting certain parts of the technology, coatings ensure that no noise or other communications interrupt the device, providing protection and reliability.
  • Transport. Military transportation isn't just about speed; it's also about precision. This precision is provided by a variety of digital systems with countless intricate parts, and conformal coating is protecting every one of them. By protecting against everything from changes in air pressure to extreme environments, coatings save the day

How Parylene Works in Military Settings

Parylene conformal coating is one of many types of compounds that can be used to coat various materials, but it stands out from the pack. Parylene is applied as a vapor, allowing it to adhere to difficult-to-reach areas of equipment and machinery. This incredible compound can attach itself to areas of only 0.01 mm. The application of Parylene is also done at room temperature to reduce the risk of compromising matter which may be sensitive already to chemicals and varied extreme temperatures.

Once applied, parylene has withstood some incredible tests, such as a 100-hour salt spray.

Some military coating examples would be:

  • portable radios
  • motor vehicle electronics
  • lighting for aircraft
  • any exposed surfaces

In each of the above situations, whether it be a portable radio set or lighting for aircraft, they all need to be durable, withstanding varied temperatures and contact with acids, bases, salts, fungi, sand, you name it. Parylene is up for the challenge.

Conformal coatings are used to protect printed circuit boards within electronics. Without this protection, electronics would fail after contact with chemicals, water, or other environmental hazards. Many industries use conformal coatings, but the military is an example of an industry that needs their devices protected from extreme situations.

Why Conformal Coatings

Printed circuit boards (PCBs) that are used in military technology undergo a lot of stress. To protect them from various threats they are covered with a conformal coating. Battlefield conditions leave PCBs open to contact with chemicals, dust, water, and temperature fluctuations. They are also exposed to intense vibrations that can affect the device internally and externally. In general, military devices with PCBs are in circumstances that generate wear, tear, and stress. A conformal coating will act as a protective insulator.

Choosing a Conformal Coating

There are three conformal coating types: acrylic, urethane, and parylene. Each has unique benefits and reasons they might be selected over the others.

  • Acrylic: Post-application flexibility, humidity resistant, easily repairable, and meets approval standards for electrical, mechanical, and specialized military applications.
  • Urethane: Chemical solvent resistant, hard and durable.
  • Parylene: Dielectric, non-conductive, assures the device can function under extreme temperatures.

Parylene conformal coatings are the most versatile of the three and are recommended for military applications. Military electronics need to be able to function under all kinds of circumstances and must be protected from environmental threats reliably. Parylene is applied in a vapor form which means it can reach all areas of the surface without leaving any spaces unprotected.

Military devices cannot run the risk of failing. Conformal coatings make sure that PCBs are protected from all kinds of environmental and situational harm.

Commercial Off-The-Shelf Assemblies

PCBs used for defense and aeronautic applications undergo extreme conditions. Due to these circumstances, they benefit significantly from ruggedization (making a piece of equipment rugged or strengthening to resist wear or abuse). This process makes electronics suitable for extreme weather environments, intense vibrations, and high levels of dryness or moisture. A rugged coating will make the PCB durable and perform in versatile situations.

Defense electronics are expensive though and as such alternatives are sought out by military establishments. Commercial off-the-shelf (COTS) assemblies are often used in place of expensive defense electronics. Because they are not designed for military use, they require a custom design. Conformal coatings can add the extra layer of protection need for ruggedization. These conformal coatings will provide resistance to varying altitudes, temperature extremes, and vehicle acceleration.

Conformal Coating for Defensive Electronics

There are standards and specifications for an electronic to qualify as a reliable product ruggedization. Conformal coating applications used to ruggedize PCBs are office acrylic, urethane, and parylene. Parylene differs from the others as it is the only coating applied as a vapor. Industry experts favor parylene for its ability to thoroughly coat a PCB without leaving any uncovered surfaces. It meets all critical requirements for a COT as well. As a conformal coating, parylene increases the durability and ruggedness of COTs. When it comes to creating a versatile defense electronic, it’s the coating of choice.

For more information on conformal coatings and military applications, contact us today.

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Topics: Conformal Coating Types