Protection of exposed semiconductor chip using thin polymer coatings

摘要

A touch-sensitive semiconductor chip having a physical interface to the environment, where the surface of the physical interface is coated with a fluorocarbon polymer. The polymer is highly scratch resistant and has a characteristic low dielectric constant for providing a low attenuation to electric fields. The polymer can be used instead of conventional passivation layers, thereby allowing a thin, low dielectric constant layer between the object touching the physical interface, and the capacitive sensing circuits underlying the polymer.