The PCB circuit board, after being coated with conformal coating, can effectively prevent moisture from damaging the circuit board. Prolonged exposure to moisture can significantly reduce the insulation resistance between conductors, accelerate high-speed decomposition, lower the Q factor, and corrode the conductors. Coating with conformal coating can effectively protect the performance of the circuit board and also prevent the erosion of water vapor and oxygen. With the widespread application of conformal coatings on circuit boards in various fields, they have become increasingly favored, but this has also brought some technical issues. How long does it take for a circuit board coated with conformal coating to dry?
The curing time parameters for conformal coatings mainly include surface dry time, initial cure time, and complete cure time. The curing methods for conformal coatings can be divided into room temperature curing, heat curing, and UV curing, and the curing times vary significantly between different methods.
1. Room Temperature Curing
Whether it is silicone, polyurethane, or acrylic conformal coating, the surface dry time at room temperature is generally 10-15 minutes, during which a protective film forms on the surface, but the internal conformal coating has not yet cured, so the circuit board should not be moved at this time; the initial cure time is generally 3-4 hours, at which point the conformal coating reaches initial curing, and the customer can transfer the circuit board to a designated drying area for complete curing; the complete curing time is generally 24 hours, after which it can be put into normal use.
2. Heat Curing
Heat curing refers to the process of accelerating the curing of the conformal coating by raising the surrounding environment’s temperature after the circuit board is sprayed with conformal coating. So, how long does it take for the conformal coating on the electronic circuit board to dry under heat curing conditions? Generally, when the temperature is around 60-80°C, it can achieve complete curing in about 15 minutes, and after cooling to room temperature for about 15 minutes, it can be used. Silicone-based conformal coatings that do not meet room temperature curing conditions will take longer to cure.
3. UV Curing
UV curing is mainly reflected in UV conformal coatings, and the curing time is primarily related to the power of the UV lamp, with a curing time of about 10 seconds. Of course, some companies also perform triple curing on the circuit board after UV curing—moisture curing, with specific curing times depending on the environment. Due to the surface oxygen inhibition of UV adhesive coatings, higher light intensity is required to achieve forced curing.
Choosing the right conformal coating and the appropriate curing method can achieve twice the result with half the effort. If you have questions about conformal coating curing or need a customized adhesive solution, you can contact our AI assistant for help.