Blistering is the formation of circular-shaped bubbles of the coating film held away from the substrate which can be the beginning of the conformal coating deliminating.
Some factors that cause blistering in conformal coating include:
- Cleanliness of the surface
- Compatibility of the conformal coating and the surface
- Permeability to moisture
- Degree of coating cure
Using techniques such as the following can help minimize blistering:
- Cleaning the surface of the board
- Matching the conformal coating to the solder resist
- Choosing a less permeable conformal coating
- Reducing the thickness of the coating
- Lowering the cure temperature
- Applying a primer to the surface of the board
Read more at Conformal Coating Defects: Blistering
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.