Breakout has two meanings on a PCB. In fabrication it is a drilled hole so far off center that it cuts through the edge of its pad, leaving no annular ring on one side; inspection standards set how much is acceptable for each class. In layout it is the routing that brings signals out from under a dense component such as a BGA to open board area, usually through dog-bone fanouts and vias, also called escape routing.
BGA breakout took six layers, but the real problem is drill breakout on the 8 mil vias at the panel corner.
Also heard as
- drill breakout
- escape routing
Related terms
Annular ring
Ring of pad copper left around a drilled hole, which must stay wide enough after the drill wanders.
Fanout
Short connections that bring each pin of a dense part out to a via so it can be routed on other layers.
Dog bone
Short trace from a surface mount pad to a nearby via, shaped like a cartoon bone, used to fan out parts.