A preparatory step for PCB manufacturing is the routing of the traces. It is based on the circuit diagram and serves the optimal positioning of the electronic components and the guidance of the tracks on the PCB.
For PCB routing, there are various layout programs that calculate the exact positioning of electronic components, chips, microprocessors, connectors and interconnects, as well as the position of pads, solder pads, vias and microvias. They also calculate the number of PCB layers, the ground planes and traces on each layer, their widths and cross-free routing, vias and location for embedded components. Current-carrying traces have different priorities than signal-carrying ones. Both should be as short as possible and have minimum distances to other conductors.
For the PCB calculation, the electronic components are stored in a component database with their dimensions, power ratings and connection positions. In addition to routing the traces, solder masks, drill holes and registration marks are provided for later board exposure during this operation.
The layout for the PCB routing is output by the layout systems as a Gerber file.