Large Formatted and High Resolution Cmos Flat Panel Sensors for X-ray

The CMOS panel sensors developed for detecting high quality X-ray images, feature large formatted active area and high resolution. The purpose of this study was to assess the performances of imager have a diagonal size of 6.9 inches (non-tiled monolithic chip) and made of monocrystalline silicon optimized for use in digital radiography associated with two kind of thallium doped cesium iodide scintillator. The C7942CA-02 has 50 um pixels, 2400 × 2400 pixel array (5,760,000 pixels) features high resolution of 8 lp/mm with single pixel drive. The C7943CA-02 has 100 um pixels, 1248 × 1248 pixel array delivers in a high frame rate of 30 frames/sec achieved by means of 4×4 binning readout. Both sensors utilize an FSP (flipped scintillator plate) made from high resolution, high luminance CsI crystals grown into a needle structure and coupled to a photodiode array for indirect detection of X-ray images. Furthermore, needle structure CsI was directly deposited upon the sensor chip to accomplish optimum resolution. The CsI scintillation spectrum well matches the spectral response range of the large formatted photodiode array. These image sensors are manufactured in a standard CMOS process rule allowing a high fill factor of 79 % for the C7942CA-02 and 87 % for the C7943CA-02. The monolithic amplifier blocks have 2400 channels of charge amplifiers with internal CDS (correlated double sampling) circuit has an optimal design, yielding a high gain of 1.07 uV per electron and a data transfer speed of 23 M bytes per second in sufficient low noise.