ABSTRACT
This chapter focuses on finding a way to conformally coat thousands of Printed wiring board per day without adding new floor space or expensive curing equipment. The Delco engineers had a second important insight. Perhaps, a reactive hot melt material might be formulated such that it processes like a hot melt, but contains reactants, which gradually convert it into a three-dimensional polymer network. Hot melts need little in the way of application equipment; simply a small heating chamber to melt the hot melt and dispense it in its liquid state. The applied hot melt material quickly cools to a solid, allowing the next process to take place. Conformal coatings are commonly used to protect electronic assemblies from contamination, moisture, corrosive chemicals, and shock and vibration. The automotive industry and the defense/aerospace industry especially need conformal coatings to protect circuitry from hostile environments. The majority of traditional conformal coating cures to become three-dimensional polymer networks.
