Manual

Introduction 1-3
Nordson ASYMTEK offers an automated solution to the conformal coating process by offering
Automated Selective Coating. Unlike other methods, Automated Selective Coating achieves high
throughput, dispensing consistency, and material savings with little or no masking.
After the conformal coating has been applied, it must be cured or hardened (Step 2). The curing method
depends on the coating material. Most materials are cured by one of the following processes:
• Heat (infrared), using an infrared or convection oven
• UV (ultraviolet) light, using a UV oven
• Moisture (humidity), using ambient conditions or a humidity controlled environment
Nordson ASYMTEK offers the curing systems listed in Table 1-1.
Table 1-1 Nordson ASYMTEK Conformal Coating Curing Systems
Curing Systems Process
Flexible IR/Convection Module Infrared
Select Cure UV-5 Cure Module UV
Select Cure UV-6 Cure Module UV
7 ft. Humidified Conveyor Moisture
1.6.2 Coating Materials
There are several materials commonly used for conformal coating purposes. These include:
•
AR = Acrylics
•
UR = Urethanes
•
SR = Silicones
•
ER = Epoxy
•
XY = Paralyne
•
The selection of a coating material is application dependent and is based on a variety of factors: Material
considerations include the following:
• Why are you applying conformal coating? (humidity, vibration, thermal shock,
solvents, etc.)
• Will the PCB be cleaned prior to coating?
• What type of cure mechanism are you planning to use? (UV, IR, Convection, Humidity)
• Will the coating selected meet the environmental requirements of your industry or location?
• Are Volatile Organic Compounds (VOC’s) a major concern for your facility?
• Will you be reworking the PCB?