Conformal Coating for Electronics

Conformal coating is an acrylic, polyurethane or silicone varnish that is applied to electronic boards, thus acting as a protective shield.

CTA has a department equipped with a selective conformal coating machine and regularly carries out tropicalisation processes in different ways, depending on the characteristics of the boards to be coated.

Working with us means having at your disposal an experienced and competent Partner, able to manage all the phases involved in the protective coating cycle with accuracy, competence and proactivity.

In the following we delve into relevant aspects to better understand what conformal coating is, what benefits it brings and through which methods it is delivered.

Coating, also known as tropicalisation, consists of a protective chemical shielding that shields electronic circuits and components from external agents, mechanical or thermal stress and environmental factors of various kinds.

There are different methods and different types of instrumentation to apply the coating.

Application methods for conformal coating

The most traditional application methods are as follows:

• Immersion Coating, which consists of dipping the parts that need to be covered inside the substance that will act as a protective layer.
• Selective Robot Coating, which consists of a series of fully automated processes entrusted to specific industrial machinery.
• Spray Coating, through which the coating is atomised, through special nozzles, onto selected areas.
• Brush Coating, through which special brush tools are used to distribute the polymers on the surface of the boards.

Each method has its own strengths, and the choice of a method strongly depends on the precise application case. At CTA Electronics, we routinely carry out coating processes within a dedicated production area, equipped with everything needed for the application of conformal coating through all four methods described, with special emphasis on the selective robot.

Different substances for different types of coating

The primary reason for the existence of different types of conformal coating lies in the fact that each polymer possesses specific characteristics. To simplify, we can say that there are four families in particular:

• Acrylic polymers, which are particularly resistant to environmental influences but not as good in terms of chemical resistance;
• Polyurethane polymers, which combine excellent chemical resistance with considerable protection against external aggression and various agents such as humidity and extreme temperatures;
• Silicone polymers, which are extremely difficult to remove and re-process, yet guarantee an excellent seal;
• UV polymers, which are activated by a photochemical reaction arising from UV light and provide virtually unbeatable resistance to abrasion and chemicals.

The benefits conformal coating brings to industrial electronics and electronic boards as a whole

Among the major benefits are:

Protection from external agents and environmental variables

In certain fields of application, it is essential to keep printed circuit boards intact and preserve their integrity in the face of external agents and particular environmental variables. In this, conformal coating plays an essential role, acting as a robust shield, safeguarding boards and sensitive components from moisture, dirt, dust and other external contaminants.

Long-term board preservation

Thanks to conformal coating, electronic boards are preserved intact for longer. The protective coating prevents wear and tear, significantly increasing the life of the electronics and keeping them performing over an extended period of time.

Increased stability of certain electronic components

Our experience shows that the application of conformal coating results in increased stability of certain components. This increased resistance is crucial to ensure efficiency and performance over time, especially when the elements are exposed to mechanical or thermal stress, such as vibration or temperature-related shocks.

For more in-depth information on this topic, please read the following article and the answers to frequently asked questions below.

• Five things to know about Conformal Coating

FAQs on Conformal Coating