Conformal Coatings – Challenging Environments Lead to Growth

By Cynthia Challener

Advances in technology have resulted in the need for electronic devices to continue functioning even when placed in harsh environments. Widespread use of cell phones, laptop computers, and other personal electronic devices, the increased number of electronic controls in home appliances, and the ever more extensive utilization of digital technology in the automotive industry have led to a growing demand for printed circuit boards (PCBs) that can perform under difficult conditions.

Conformal coatings provide a protective barrier that enables the PCBs to function in these demanding environments. This growth in demand comes despite the cost and numerous difficulties associated with the application of these coatings. Many conformal coatings manufacturers are investing in the development of new technologies that minimize these difficulties. Others are involved in developing disruptive technologies that will serve as alternatives to traditional conformal coatings processes.

The main function of conformal coatings is to protect PCBs from humidity, corrosive gases and solvents, dust, fungi, and other contaminants. They also provide stress relief and protection for the insulation resistance of the circuit board, minimize dendritic growth and the electromigration of metal between conductors, and act as a design tool due to their excellent electrical properties.

Selection of a conformal coating depends on the specific application. Typically, the dielectric properties, abrasion, solvent, and thermal resistance, and ease of application of the coating are considered. Coatings are applied in thin layers of a few mils to a fraction of a millimeter.