A site by the name of AppleLeaks today posted photos of what is claimed to be the logic board from a next-generation iPhone model. The report is unsure about whether the board is from an upgraded iPhone 5 model or a cheaper "iPhone 4S" model Apple is also said to be planning to launch, but the images do add more detail to the picture that is beginning to come together.
Comparing the pictures to the ones of the logic boards for the CDMA and GSM iPhone 4 models as seen in teardowns by iFixit (see steps 13 and 14), it is interesting to note that this new logic board carries a form factor more similar to that of the CDMA iPhone 4 but with a SIM-card slot also squeezed onto the board. That inclusion of the SIM-card slot on the new logic board has resulted in a reshuffling of the chip locations on the front of the board, while the back side remains quite similar to the CDMA iPhone 4 logic board.
Front of CDMA (top) and GSM (bottom) iPhone 4 logic boards
Notably, the relatively large area on the front of the logic board designed to house the main processor for the device is rectangular in nature on the new board, suggesting that it is designed for the rectangular A5 system-on-a-chip found in the iPad 2 rather than the square A4 chip found in the iPhone 4 and original iPad. Apple is of course expected to use the A5 in the iPhone 5, but there has been some question as to whether Apple would step up to the A5 for its cheaper iPhone 4S model or continue to use the A4 in order to hold costs down.
The iPhone 5 is expected to be a "world-mode" phone capable of running on both GSM and CDMA networks. The presence of a SIM-card slot on the new logic board does indeed confirm GSM compatibility for this device, whether it be an iPhone 5 or 4S, and CDMA compatibility would come from the inclusion of a specific chip supporting the dual standards. Such a chip from Qualcomm is already used on the CDMA iPhone 4, but accommodation for a similar chip on this new logic board can not be confirmed given that the board is unlabeled.
One of the more prominent differences in the actual logic board form factor between the GSM and CDMA iPhone 4 is a semicircular cutout at the bottom of the board. That cutout fits around the new circular vibrator used in the CDMA version, a change from the vibrator used in the GSM version. The presence of the cutout on this new logic board suggests that Apple will continue to use the circular vibrator found in the CDMA iPhone 4.