When a problem occurs on the coating line and a circuit board is defective there is generally a good reason for the occurence. This week Nexus takes a look at Capillary Flow.
Capillary flow (or scavenging) in conformal coating processing is where the coating pulls or runs away from certain areas of a PCB to more favourable areas.
This is due to a combination of effects which leave a patchy finish on the surface of the board around the defective area.
There are several options to resolve this issue and prevent this occurring in production.
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