A radiation detector for detecting radiation such as x-rays. The radiation detector includes a detector having a plurality of pixels, wherein each of the pixels is used for detecting the radiation. The radiation detector also includes a ball grid array (BGA) package having a plurality of solder balls formed on a first side and a plurality of contacts formed on a second side. The BGA package also has a cavity, in which at least one integrated circuit (IC) chip is mounted. The IC chip has a plurality of readout channels, each of the readout channels being coupled to a corresponding one of the pixels via a corresponding one of the solder balls to receive an electrical signal corresponding to the radiation detected by the corresponding one of the pixels.