In conformal coating, capillary flow is where the coating pulls or runs away from areas of a PCB thus leaving a patchy finish.
Factors that causes the capillary effect are
- Low viscosity
- Volume of coating
- Substrate cleanliness
- High surface tension
However, it is possible to reduce these effects by
- Increasing the viscosity
- Reducing the volume of coating
- Cleaning the board properly
- Using a solvent-based material
- Heating the circuit board
Read more at Conformal Coating Defects: Capillary Flow
Who is Nexus?
Nexus brings together the accumulated knowledge of a group of conformal coating and electronics material dispensing consultants who provide a unique service, focused on helping electronics manufacturing clients improve their conformal coating and electronics materials processes.
Nexus operate across North America, Europe and Asia and can provide a unique perspective to the rapidly growing conformal coating and electronics materials industry. Expertise is held in liquid and parylene coating, capital equipment sales and specifications and material, equipment and process specification, troubleshooting and training.