2 Pad Recommendation

There are two types of Ball Grid Array (BGA) pads:
Non-Solder Mask Defined (NSMD)
NSMD type of pads help to achieve balanced stress on solder joints.
Solder Mask Defined (SMD).
The solder mask essentially defines the boundaries of the pad.
Important: Microchip recommends NSMD type of pads for all the devices.
The following figure illustrates the two BGA types.
Figure 2-1. BGA Pad Types