An X-ray detector including a plurality of chips on a printed circuit board, each of the plurality of chips including a plurality of pixel pads on a center portion of the printed circuit board and a plurality of pin pads surrounding the plurality of pixel pads, a plurality of pixel electrodes on and corresponding to the plurality of chips, a redistribution layer electrically connecting the plurality of pixel electrodes and the plurality of pixel pads, a plurality of first electrode pads on a surface opposite to a surface of the plurality of chips including the plurality of pin pads, a wire electrically connecting the plurality of first electrode pads and the plurality of pin pads, a photoconductor on the plurality of pixel electrodes, and a common electrode on the photoconductor.
