Described herein is a method of depositing a conformal, optically transparent coating onto a surface of one or more internal components that are enclosed within an assembled device using a non-line-of-sight deposition process without altering a structure of the assembled device or impacting functionality of the assembled device. Also described is an assembled device including one or more internal components enclosed within the assembled device and a coating deposited onto a surface of the internal components enclosed within the assembled device, where the coating is a conformal, optically transparent coating that is resistant to corrosion by at least one of fluorine-, chlorine-, sulfur-, hydrogen-, bromine-, or nitrogen-based acids and that does not negatively impact functionality of the internal components.