3.2.3 Mounting Holes

The mounting holes on Xplained Pro should be designed to fit a M2.5 screw, the recommended hole diameter is 2.7mm. The clearance to other components should be 3mm from the hole center to allow the mounting of screws and/or spacers. A typical hexagonal spacer for M2.5 screws has a diameter of 4.5mm when measured from side to side (5.2mm when measured from edge to edge) so a 3mm clearance works well. The hole center should be placed 2.35mm from the board edges. All mounting holes should be plated and connected to GND. The pads around the mounting hole must be large enough to provide a good ground connection if a grounding cable or metal post is connected to the hole. More information about mounting hole placement is available in the board design templates.