Definition
A PCB trace is a flat copper conductor etched onto a printed circuit board that carries current or signal from one point to another, replacing the discrete wires used in older hand-built electronics. Traces are the wiring of a modern board, and on an ASIC hashboard they route everything from low-current data lines to the heavy power buses that feed the chip domains.
Width, thickness, and current
A trace's current-carrying capacity depends on its cross-sectional area, which is set by its width and the copper weight of the layer (commonly expressed in ounces per square foot). Power nets use wide traces or copper pours to avoid excessive heating, while signal nets can be narrow. Pushing too much current through an undersized trace raises its temperature and, in extreme cases, can lift or vaporize the copper. The IPC-2221 standard provides the charts designers use to size traces for a target temperature rise.
Repairing damaged traces
Traces are thin and bond to the board only through a layer of adhesive resin, so heat, mechanical stress, or over-aggressive rework can lift or sever them. A broken trace can be bridged with a short jumper wire soldered between two exposed points on the same net, after scraping back the solder mask to reach bare copper. Because adjacent traces may be only fractions of a millimetre apart, this work demands magnification and a fine-tipped iron.
Trace damage frequently accompanies a lifted pad, and the protective solder mask over a trace must be removed before any repair. Wide power traces often merge into a copper pour region.
In Simple Terms
A PCB trace is a flat copper conductor etched onto a printed circuit board that carries current or signal from one point to another, replacing…