An improved design for a solid state X-ray detector that decreases the amount of moisture diffusion that occurs through seals used to attach a cover to a glass substrate panel, thereby protecting the scintillator from moisture damage. In one embodiment, a second hermetic or semi-hermetic seal is introduced between the scintillator and the outside environment to increase the path moisture must travel to reach the scintillator. In another embodiment, a metal frame, preferably a Kovar® frame, is hermetically or semi-hermetically sealed to the cover and glass substrate panel, thereby decreasing the amount of moisture diffusion through the semi-hermetic seal as compared to the prior art.