We are completing the design of a PCB and have a mounting/assembly issue with the NRF52840. We In looking at the mechanical spec on your datasheet w find that A row of 24 solder balls with a pitch of 0.5mm cannot fit into a 7mm package.so what is our alternative
span = 23(pitch)*(0.5mm) = 11.5mm
I am not sure if I quite get what you mean. Our aQFN73 7x7 mm package does not have a row of 24 solder balls. Rather it has, along each edge, two rows of up to 12 balls, the two rows offset by half a pitch, where the pitch is 0.5 mm. See aQFN73 7 x 7 mm package.