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Sensible Design: Automotive Conformal Coating Applications

Conformal coatings are all around us. The benefits they offer are discreet but intensely purposeful, as they protect electronic circuitry against harsh environments and help to extend the reliability and lifetime of our devices. We can find conformal coatings in household appliances, white goods, and other electronics in and around our homes, as well as in our workspaces, in manufacturing, and other industrial applications.

With a surge in connectivity adoption via IoT, smart cities, and smart infrastructure networks, the need to protect electronics in different devices is becoming increasingly important. As dependence on devices increases, protecting the security and physicality of electronics is of significant interest to many. This is where conformal coatings can make such a big difference. Protection of electronics is particularly important in the the automotive industry, with the range of advanced driver assistance systems (ADAS) and electric vehicles currently available.

In this column, I will discuss how conformal coatings can make a difference in electric and hybrid vehicles, as well as other automotive applications, areas where we have seen a vast increase in demand for conformal coatings.

A Need for Coatings

Coatings are used extensively in diesel and petrol vehicles. Will there be as much of a need for coatings in hybrid or electric vehicles?

The rapid adoption of EVs and ADAS, autonomous driving, and the vast increase in infotainment solutions in vehicles has created enormous demands on the electronics involved in these vehicles. At the same time, the requirements for conformal coatings are rising. One target, to increase the range per charge of an electric vehicle, is to make the vehicle as light as possible. Electronic design engineers are feeling the pressure to minimize their electronics through a finer pitch on the board. In ADAS, as well as other applications, the tolerance to failures is extremely low, which means the electronics on the board will require a high level of protection against environmental influences like humidity, condensation, thermal changes, corrosive gases, and other contaminants. But not only is it important to protect the electronics against the environment, it is also necessary to insulate the different components on the board from each other. A high dielectric strength material, capable of resisting a greater voltage before it breaks down, is of crucial importance.

Conformal coatings can deliver on these challenges. Not only do they provide a strong protective barrier to the outside world, but they also deliver on the insulation resistance that is required to allow a finer component pitch on the board. All this provides a high level of protection in a lightweight solution.

There is a huge need for conformal coatings in hybrid and electric vehicles, but these applications also have very strict requirements, which means there is also much more pressure to get things right.

Typical Applications

What are some of the typical applications for coatings within the automotive industry?

The potential applications for conformal coatings are almost limitless. Wherever there’s an electronic circuit board that needs lightweight protection, a conformal coating can be an ideal solution. Coating applications in automotive can be in sensors used in ADAS and other supporting applications. Examples of this include the ADAS control unit PCB or powertrain applications, like the battery management system PCB, charger PCB, inverter, DC/DC converter, and transmission switches, just to name a few. Also, there’s a requirement for coatings to protect electronics in the vehicle infotainment system, alongside external and interior lighting, climate control systems, and other electric controls. There are many more applications for electronics in vehicles; the list seems endless

For instance, if we move away from the vehicle itself to the charging infrastructure, we are faced with charging stations that are exposed to all weathers: heat, cold, humidity, and corrosive environments—especially near coastlines. If we look at the need for a reliable network of charging points that enables EV drivers to charge their vehicles, we must include the electronics in the charging point in our list of potential applications for conformal coatings.

Bio-based coatings, especially those with a higher content of raw materials from sustainable sources, have shown to perform well in future-proofing the conformal coatings process in EV and automotive applications. Lighter-weight coatings that meet the sustainability requirements of manufacturers and end users have shown improved condensation resistance, thermal stability, flexibility, and adhesion compared to many petrochemical-derived polymers.

This column originally appeared in the January 2023 issue of Design007 Magazine.