Ultimate Guide to PCB trace | Printed Circuit Boards Canada What is PCB Trace? A PCB trace is a copper conductor on the PCB that conducts signals on the surface of the PCB. It is the flat, narrow portion of the copper foil that is left behind after etching. The electricity that flows through the copper traces generates a significant amount of heat. Correctly calibrated PCB trace width and thickness help minimize the buildup of heat in your board.PCB trace is a vital part of almost every Printed Circuit Board. If PCB trace is