I'm designing now a PCB board for a certain system. One of the components is SAMB11 which consists of 48 pins/pads. However, the data sheet mentions that there is an exposed paddle that should be connected to the system board ground. I could not really understand this point!!
In the footprint, will I make the pads 48 pins or 49 pins. In the data sheet, the chip drawing package has only 48 pins. but in the schematic, they show an extra pin that is connected to the ground.
Do I need to consider that paddle as a pad/pin when drawing the schematic and the footprint? Or will I solder that paddle to the ground when doing the experiment?
Grounding the paddle is important to provide good thermal contact to the PCB, that is, for heatsinking the IC. For that purpose alone, it's not necessary to include it in the schematic. However, it often also serves as an electrical ground and shield, and that should be indicated in the schematic.
As to the footprint, since the pad acts as a contact area for heat transfer, it has to be included in the component footprint.