As noted by Macotakara, Japanese parts firm Moumantai has posted three photos of what may be the bare logic board from the iPhone 5S. Unsurprisingly, the shape of the board is nearly identical to that of the iPhone 5 logic board, although it appears to have a slightly different curve along the bottom edge where the logic board would meet the speaker enclosure.
Few details can be obtained from the part, as there are no chips or other components attached to the board, although it does contain a somewhat different placement of screw holes and a tweaked chip layout. The main A-series chip appears as if it will be slightly larger in area than the A6 seen in the iPhone 5, as it takes up a greater width of the logic board.
Apple's iPhone 5S is expected to launch later this year, perhaps around the September timeframe. Following Apple's pattern of two-year body style cycles, the iPhone 5S will reportedly appear very similar to the iPhone 5 and focus on internal improvements. One differentiating feature may, however, be a fingerprint sensor, which is rumored to be location on or near the device's home button.