The backside of the motherboard doesn't have any chips, but it does have two Wi-Fi antennas, the ambient light sensor, a couple microphones, and a precarious wire running most of its length.

Ambient light sensor

Wolfson WM7220 Microphones

Precarious wire

The Wi-Fi antennas are labeled:

Antenova A10416-WIFI-A2

Antenova A10416-WIFI-A1