Pad

A pad is a primitive design object that are used to provide both mechanical mounting and electrical connections to the component pins. Pads are used for fixing the component to the board and for creating the interconnection points from the component pins to the routing on the board. Pads can exist on a single layer, for example, as a Surface Mount Device pad, or they can be a three-dimensional through-hole pad, having a barrel-shaped body in the Z-plane (vertical) with a flat area on each (horizontal) copper layer. The barrel-shaped body of the pad is formed when the board is drilled and through-plated during fabrication. In the X and Y planes, pads can have a circular, rectangular, octagonal, or rounded rectangular shape. Pads can be used individually as free pads in a design, or more typically, they are used in the PCB Library editor, where they are incorporated with other primitives into component footprints.