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Padstack

Calculate pad diameters, annular rings, BGA lands and conductor fit between pads.

Inputs

Choose a padstack mode.

Mode
Through-hole pad
mm
mm
mm

Result

Enter your values to calculate a result.

Hole, pad and annular ring
Hole, pad and annular ring

The annular ring is the copper left around the finished hole. Allow for drill and layer registration tolerances. Check the finished dimensions with your PCB manufacturer.

Illustration only. Not to scale.

External layer pad

N/A

N/AN/A
N/AN/A
N/AN/A
N/AN/A
Method and assumptions

Through-hole pads use pad = hole + 2 × annular ring. Plane pads add the thermal isolation on both sides.

Conductor fit compares the chosen pad diameter with the available space between pads, allowing for the conductor width and spacing constraints.

  • BGA land sizes are approximate. Use the applicable IPC-7351 land-pattern data for production.
  • Drill suggestions for corner-to-corner sizing are a starting point, not a fabrication guarantee.
  • Check the padstack against your PCB manufacturer's minimum annular ring and drill capability.

Choose a pad size your manufacturer can produce

Start with the finished hole and the minimum annular ring your PCB manufacturer can produce. Then check that the pad still leaves room for the conductors and spacing you need.