Circuit boards need to be protected; otherwise they are susceptible to damage. Without protection they can corrode and malfunction. To keep circuit boards up and running, a process called conformal coating is used.
What is conformal coating?
Conformal coating is a protectant that coats the topology of a circuit board. It is made of a chemical or polymer film that is designed to keep electronic circuits free of environmental elements like moisture, and chemical contaminants in the air. Conformal coating works as an electrical insulation and ensures that the operational integrity of the circuit board assembly remains intact. Moreover, conformal coating is able to maintain good levels of long-term surface insulation resistance, protecting the circuit board from corrosion and electrical shorts.
How is conformal coating applied?
Conformal coating needs to cover the assembly completely to ensure that components, component leads and solder joints are protected, as well as the edges of the circuit board. The coating must wet all surfaces of the board before it is cured without leaving any surface defects.
Coating can be applied in four distinct ways:
- Dipping: Where a board is dipped into the coating. However, this technique can only be done on materials that aren’t susceptible to quick curing via moisture, oxidation and light.
- Selective robotic coating: This is an electronic dispensing coating system.
- Spraying: This is done using an aerosol-type hand spray or spray booth.
- Brushing: Only a skilled operator can be charged with brushing conformal coating onto a board; otherwise it may not be suitable for production.
Drying methods include UV light curing and oven and air drying. The coating application used will determine what method will be used for the drying process.
How does conformal coating play a large role in electronics manufacturing?
Circuit boards require a protective barrier to ensure that the sensitive components are safeguarded from moisture, chemicals and other debris. Because conformal coating is breathable yet protective, it creates a sealant of sorts that keeps these elements out. Plus, should moisture get into the circuit board, conformal coating will allow it to escape. Additionally, conformal coating plays an important role in electronics manufacturing because it is lightweight and flexible, possesses insulating properties, easy to remove and replace if necessary, protects against shocks (thermal and mechanical), and eliminates the need for complex enclosures to the circuit board.
Contact us to learn more about conformal coating and the circuit board manufacturing process.