ABSTRACT
All the design choices that affected the functionality and reliability of the low-speed digital boards of the 1980s could be designed by hardware engineers entirely in the logic design or schematic domain. Then the actual physical implementation was like the necessary plumbing. In more modern PCBs the traces and other 3D geometry structures start to interact with the functionality and reliability of higher-speed digital circuits. This is why the person responsible for functionality and reliability—the hardware engineer—has to closely control the PCB layout (physical) implementation.
