Conformal coating is a thin transparent polymeric coating applied to PCB’s to provide protection from the end-use environment. Common types of conformal coatings include acrylics, urethanes, epoxies, silicones and polyparaxylylene. They are typically applied at 1-5 mil thickness. Conformal coatings have many common functions, such as inhibiting current leakage due to environmental contamination, inhibiting corrosion, improving fatigue resistance of solder joints, inhibiting arcing and corona, providing mechanical support. Meanwhile GOLOHO conformal coating products can meet the critical demands with the reduction in component size, pitch, circuitry spacing, and laminate thickness.
The PCB products with conformal coating are reliability that is the ability to function under specific conditions for a specified period of time without failure. GOLOHO conformal coating products are used in different fields including aerospace, military, automotive, electronics industry. The kinds of GOLOHO conformal coating products are solvent-based and solvent-free, which can be cured at room temperature or heat and UV. They meet different coating application techniques such as brushing, dipping, selective flood coating, needle dispensing, manual spray, automated selective coating. The methods of application have different advantages and disadvantages. The advantages of brushing are low capital investment, no masking required and good for rework, while disadvantages are inconsistent thickness, difficult to control voids and bubbles, and very dependent on operator technique. The advantages of dipping are low volume throughput, coverage on complex shapes, while disadvantages are impacted by ambient conditions (temperature and humidity) and must be kept free of contamination. The advantages of manual spray are low capital investment, simple process and can coat complicated board designs, while disadvantages are hard to contain overspray, difficult to control coating thickness and required multiple cure. GOLOHO conformal coating products own very good resistance against moisture and condensation, thus enabling an excellent corrosion protection for assembled PCBs (e.g. e-corrosion and migration), typical dry layer thickness < 80 µm, suitable for coating flexible circuits ("flex-to-install"); can be soldered through for repair or mechanically removed (blasting method); colored-transparent, opaque or fluorescent adjustments permit a simple checking of the coating layer for completeness with daylight or UV light (black light).