Once a PCB is manufactured with all components and connections in place, it is coated with a layer. This layer, known as conformal coating is applied to protect the intricate traces and components from damage. Conformal coating also keeps the traces from merging over time, reducing chances of cross talk.
Conformal Coating Application Methods
Conformal coating for PCBs is applied in the following ways:
Dip : As the name suggests, in this process, the PCB is dipped into the conformal coating solution. It is then left to drip and dry. Although it is the quickest method for application of conformal coating, it is not the most effective. It could pose problems when trying to cover connectors and other difficult-to-mask locations.
Manual : A brush or syringe is used for manual application of conformal coating on PCBs. It allows for controlled application. In this process, the scope for human error is high. It can also be expensive depending on the labor charges.
Aerosol : The conformal coating liquid is turned to fine mist and sprayed onto the PCB. However, the layer is very thin and the PCB will need to be sprayed multiple times to get a thick protective layer.
Non-aerosol : A spray bottle is used to apply the coating on the PCB. The coat is thick since the liquid is not atomized. This is one of the most effective methods of application of conformal coating on PCBs.
Conformal coating for PCBs helps in keeping moisture and contaminants like dust away from the electric circuits and components. It also keeps the circuitry from being damaged. The conformal coating used in an application is an important part of the entire PCB assembly. The manner in which the conformal coating is applied will vary depending on the material of the board, the environment it is being used in, and the requirements of the application.