A flat panel readout chip with 13-bit single counting for direct conversion of X-rays into a digital image

This paper describes the functions and circuitry of a flat panel readout chip for a direct conversion X-rays into a 13-bit digital image. The readout circuit and the sensor are located on the same standard CMOS device. Sensor and circuit are arranged as a sandwich structure. The direct converting sensor material, here a polycrystalline Hgl2 layer, is directly mounted on the 32x32 pixel readout chip. Metal electrodes at the surface of the readout chip represent the cathode pins of the Hgl2 sensor pixels. The readout chip is suitable for both sensors with Hgl2 - layers, deposited by PVD directly on the uppermost metal layer, and for separate sensors with pixel structure, which can be ball grid bonded to the metal layer ( for example GaAs-single crystal diodes).