This paper discusses the process-design principles for creating hyperlarge-format mosaic photodetectors (MPDs), based on the butt-joining process of silicon chips with uncooled small-format microbolometer detector arrays (MBDAs). The basic unit is investigated and optimized for the process operations of laser scribing as part of the high-precision butt-joining process of chips in which the process part of the blind zone between the photosensitive edge elements of adjacent MBDA chips has a total size no greater than 30 μm. The design and layout are synthesized for 384 × 288-format silicon multiplexers, from which a 3072 × 576-format MPD fabricated using the butt-joining process developed here can provide better than 99% image-conversion efficiency for IR microbolometers and up to 100% for terahertz-range microbolometers.