Pad cratering

Pad cratering is a mechanically induced fracture in the resin between copper foil and outermost layer of fiberglass of a printed circuit board (PCB). It may be within the resin or at the resin to fiberglass interface.

The pad remains connected to the component (usually a Ball Grid Array, BGA) and leaves a "crater" on the surface of the printed circuit board.

IPC T-50, Revision H, Terms and Definitions for Interconnecting and Packaging Electronic Circuits, 96.2176 - Pad Cratering. A separation of the pad from the printed board resin/weave composite or within the composite immediately adjacent to the pad as a result of mechanical and/or thermal stress.

BGA pad and solder ball exhibiting pad cratering.
Magnified view of cross section of BGA pad and solder ball. Dielectric has cracked and the pad has started to lift, eventually creating pad cratering.
Pad crater left on printed circuit board after copper pad from a BGA connection has been pulled away.

External links

Additional information on pad cratering in printed circuit boards can be found in the following links:

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