Guidance:
•Land pads = 20 mils for signal and grounds for BGA balls
•Anti-pads for signals = 34 mils
•Anti-pads for grounds = 30 mils
•Micro via for layer 2 routes = 6 mil drill
•Via for layer 4 routes = 8 mil drill (back-drilled)
•Add extra horizontal ground vias between ground solder balls at 20 mil pitch (see This Figure)
•Ground vias = 8 mil drill
•Land pad for extra grounds = 16 mils
•Thermal relief for ground pads (5 mil width vertical route and 9 mil width horizontal route)