With the rapid development of the electronics industry, PCBA assembly processing has become a common part of daily production. In PCBA processing, the application of conformal coating is also an indispensable part. So what exactly is conformal coating? How many types of conformal coating can be chosen? Today China PCBA manufacturer SysPCB will explain this to everyone.
Conformal coating is mainly used to protect circuit boards and related equipment from environmental erosion, improve and extend their service life, and ensure safety and reliability during use. Its main functions include moisture resistance, waterproofing, dustproofing, anti-static protection, anti-corrosion, anti-aging, high-temperature resistance, insulation, and so on. When choosing a conformal coating, the decision should be made according to the specific application environment and usage requirements. For example, in humid and harsh environments, it is more appropriate to choose a conformal coating with good waterproof and anti-corrosion performance.
Table of Contents
1.Epoxy Conformal Coating
Characteristics: Good moisture resistance.
Application limitations: However, due to its relatively high curing stress, its application on high-density PCBs that extensively use stress-sensitive components such as surface-mount multilayer ceramic capacitors, glass-encapsulated diodes, and ceramic-packaged chips is increasingly declining.
2.Acrylic Conformal Coating
Characteristics: Good waterproof and dustproof performance.
Application scope: Suitable for a wide range of electronic devices.
3.Silicone Conformal Coating
Characteristics: Excellent high-temperature resistance, weather resistance, and low dielectric constant, as well as elasticity.
Application scenarios: Especially suitable for high-speed signal transmission, high-frequency, and microwave circuit assemblies, as well as PCBA that need to operate under high-temperature conditions for long periods. In addition, silicone elastomeric coatings are particularly suitable for airborne products that experience large temperature variations during service.
4.Polyurethane Conformal Coating
Characteristics: Good overall performance in the three-proof functions, especially salt-spray resistance.
Application recommendation: For PCBA conformal coatings used in shipborne, coastal, and island/reef equipment, polyurethane types are usually preferred.
Application Methods and Maintenance Recommendations for Conformal Coating
The application methods for conformal coating include dipping, brushing, spraying, selective coating, and other methods. Before application, ensure that the circuit board surface is clean and dust-free. After application, sufficient curing treatment is required. For maintenance, regularly inspect the coating condition and promptly repair damaged or peeled areas to ensure the coating remains intact and effective.
