A WeiPhone forums user posts a couple of photos of what is apparently claimed to be a motherboard/logicboard for the next-generation iPhone. If legitimate, the part appears to be a prototype unit because it is missing much of the typical labeling.
The SIM card slot, the most-centered component on the motherboard, does appear slightly smaller in size compared to the 4/4S, according to iDeviceGuys, iPhone parts specialists that we spoke to. The connection points are also more closely connected. This may or may not point to the new device using the new Nano-SIM format.
While we wouldn’t normally put too much faith in an unverified forum post, we looked a bit more into the poster of the photographs. It seems that the same user posted legitimate photos of an iPhone 4S motherboard in August 2011. That is a couple months prior to the device’s announcement and launch.
In addition, now that a good amount of other parts (including back plates) have leaked out for this new iPhone, NoWhereElse.fr made a GIF that compares the size and connections of the motherboard in the photos to the already leaked parts:
As you can see, the connection points on the motherboard seem to match up with the connectors on the leaked back parts.