Silicone Conformal Coatings for Protection of Automotive Electronics

Conformal coatings are liquid curable coatings that protect electronic printed circuit boards from moisture and contaminants, which can cause short circuits and corrosion of conductors and solder joints. Moisture also accelerates dendritic growth and the electro migration of metal between conductors, damaging the circuitry of uncoated PCBs. These materials are commonly used to protect printed circuit boards used in automotive electronics from environmental factors, mainly against the action of debris and moisture. There are some curing systems available, but the moisture curable silicone conformal coatings are often the choice for electronics used in harsh environments, like under-the-hood automotive electronics. However, in general these materials require long cure times, due to their need of exposition to moisture from the air to cure, a process that can take several hours. Because of this, they have not always been selected for high volume electronics production. Fortunately, new materials and cure procedures available today are allowing curing times close to 1 minute (depending upon the temperature, coating thickness and relative humidity), helping electronics manufacturers to increase throughput and productivity.