Protection film structure for functional devices

摘要

An inorganic protection film (12) such as of silicon nitride for protecting humidity-sensitive functional devices (16) on the substrate from water molecules (15) is formed on an organic substrate (11) such as one made of polycarbonate plastic material, with a soft buffer interface film (13) between the substrate and the protection film, and the buffer film releases stress due to the difference of thermal expansion coefficients of the organic substrate and the protection film.