7.2 PCB Rules

The following design rules are recommended for the PCB area below and near the MPU package:

• Through hole vias: 0.35 mm diameter and 0.15 mm hole size
• BGA land size: 0.25 mm diameter with 0.04 mm solder mask expansion
• Trace width/clearance: 0.1/0.087 mm

Further away from the MPU package (clearance larger than 5 to 10 mm), more relaxed rules can be adopted, such as:

• Through hole vias: 0.4 mm diameter and 0.2 mm hole size
• Trace width/clearance: 0.125/0.15 mm