A cover plate for a solid state radiation imager having a substrate on which are disposed a photosensor array and a scintillator optically coupled to the photosensor array. The cover plate has a lip adjacent a periphery thereof, at least a portion of the lip comprising a hermetic barrier, the cover plate and lip extending over the scintillator and photosensor array, the lip being adhered and sealed to the substrate. Methods of forming a cover plate with a lip and of assembling the cover plate having a lip with a substrate so as to enclose a photosensor array coupled to a scintillator are also disclosed.