Conformal Coating System – The Various Types to Know

The continued miniaturization of electronics and their circuitry has skyrocketed the necessity of conformal coating. And choosing the accurate coating type and application method for your application is vital. But scrolling through the vast array of information available online can be daunting.

However, not anymore! In this post, we will give you all the information that you will need to identify the ideal conformal coating for your application’s requirements.

Elecflex’s selective conformal coating systems and equipment provide advantages for electronics manufacturers at every level of production. From batch to in-line and high-volume processing, a robust line of precision applicators meet the needs of various conformal coating applications.

3-Axis Selective Coating Machine SC-800

Conformal coating is a polymeric film-forming product that protects electronic devices, circuit boards, and components from adverse environmental conditions. These coatings conform to the irregular landscape of the PCB providing operational integrity, increased dielectric resistance, and protection from airborne contamination like dust and dirt, and corrosive atmospheres, heat, fungus, and humidity.

CONFORMAL COATING TYPES

There are several options for coating technologies, and the best choice depends mainly on the protection required. Ease of rework and application method are also important factors but should be secondarily considered to the protective performance needed.

Traditional Conformal Coatings

What we are calling traditional conformal coatings are 1-part systems that have a resin base, and maybe diluted with either solvent or water. They are semi-permeable, so are not fully water-proof or seal the coated electronics. They are resistant to environmental exposure, which enhances PCB durability, keeping application and repair procedures practical. Choosing the correct conformal coating for your application depends on the operational requirements of the electronics.

Acrylic Resin (AR): AR coating provides good elasticity and general protection. The conformal coating is recognized for its high dielectric strength, abrasion resistance, and fair moisture. What differentiates acrylic coating from other resins is ease of removal. They can be quickly and easily removed by a variety of solvents, often without the need for agitation. This makes field repair and reworks practical and economical.

Silicone Resin (SR): The conformal coating provides excellent protection in a wide variety of temperature range. Silicone Resin provides good chemical, moisture, and salt spray resistance, and is very flexible. SR coatings are commonly used in high humidity environments, such as outdoor signage. Removal is tough, requiring specialized solvents, long time soak, and forms agitation.

4-Axis Selective Coating Machine SC-900

Urethane (Polyurethane) Resin (UR): This conformal coating is known for its excellent chemical resistance and moisture. They are also very abrasion-resistant. Because of this and their solvent resistance, they are very difficult to remove. It is commonly specified for application in the aerospace industry where exposure to fuel vapors is a primary concern.

Epoxy Formal Coating: They are usually available as two-part compounds and create a tough coating. The conformal coating provides excellent humidity resistance and is generally not permeable. They also have a high abrasion and chemical resistance. They are common in potting compounds and completely cover the electronics in a robust and level layer of material.

Parylene Conformal Coatings: This unique type of coating is applied by vapor phase deposition. It provides excellent dielectric strength and superior resistance to extreme temperatures, solvents, and moisture. They can be applied very thin and still provide excellent circuit board protection.

Fluorocarbon Conformal Coatings: The coating is dissolved in a fluorocarbon‐based carrier solvent and applied with a spray to create a very thin coat. They are commonly used to provide a minimal amount of hydrophobicity, which may prevent shortages from quick exposure to water.

At 1ClickSMT, we provide a full range of high-performance conformal coating systems to ensure high speed and stable running. Our professional coating software easily meets the various requirement of the coating process. To know our selective coating line advantage, visit us today!