What Are Conformal Coatings and How Are They Used?

Today, manufacturers add thin polymer coatings to electronic circuitry. The overlays are known as conformal coatings, and they protect against harm from chemicals, dust, moisture, and harsh weather. There are several kinds of materials that can be used as coatings. Producers might add them by dispensing, spraying, brushing, or dipping. Each type of material has its own characteristics and is suited to specific environments. Because so many enterprises rely on the protective finishes, industry professionals estimate that demand will increase, and expect business growth of 5.76% from 2020 to 2027.

Polymers Have Protective Qualities

Originally, conformal coatings were designed for the U.S. military, which needed a way to protect expensive electronics from harsh conditions. Researchers developed breathable coatings that allow moisture trapped in electronic boards to escape while guarding delicate circuitry against airborne contamination. The polymer coverings are not sealants and can degrade in certain circumstances. Since their inception, conformal coatings have been adapted for hundreds of applications. They can protect metal, glass, paper, resin, plastic, ceramic, ferrite, and silicon.

Types of Protective Coatings

Manufactures offer five types of coatings that have an almost unlimited range of uses. Coatings include:

  • Silicone. A soft, transparent, flexible covering that is exceptionally resistant to moisture, humidity, and corrosion. It has superior light transmission capabilities, making it ideal for solar applications. Silicone also protects against salt spray and chemicals. A UV-resistant material, it can be repaired by soldering.
  • Acrylic. An especially popular coating, acrylic is easy to apply and remove. Because they dry quickly, acrylics can reach optimum physical properties in just minutes. Materials give off almost no heat during the curing process, which protects delicate components.
  • Parylene. A unique product, Parylene is a generic name for a group of polymers created with paraxylene. Parylene coating is done in a vacuum, and it is in a gas form. The gas is diffused through a chamber and targets surfaces, forming a clear plastic film.
  • Epoxy. Most epoxy is applied as a two-part compound that begins curing when it is mixed. There are also single-compound epoxies that may be cured via UV exposure or thermally. Epoxies have excellent abrasion and chemical resistance and are nearly impossible to remove. They are typically applied by dip-coating, spraying, or brushing.
  • Polyurethane. Available in one or two-component compounds, polyurethanes offer superior chemical and humidity resistance. Single component polyurethane is easy to apply but can take a long time to cure. Manufacturers sometimes use heat to accelerate the process.

Industrial Use of Polymer Coatings

Conformal coatings are still heavily used for military purposes and are also in-demand by the automotive, medical, and consumer electronics industries. Coatings are essential elements of wearable technology, LEDs, and printed circuit boards. Parylene also provides solutions for clients in various industries that create products requiring protection for elastomer parts. The products that polymers shield include seals, gaskets, medical catheters, and keyboards.

The delicate electronic circuitry found in thousands of products is coated with a protective polymer during manufacturing. There are several types of polymers available, and each has qualities that make it ideal for a wide range of applications. Many industries use coated components, including the military and aerospace, medical, and consumer electronics manufacturers.