Schematic capture or schematic entry is done through an EDA tool.

Card dimensions and template are decided based on required circuitry and case of the PCB. Determine the fixed components and heat sinks if required.

Deciding stack layers of the PCB. 4 to 12 layers or more depending on design complexity. Ground plane and Power plane are decided. Signal planes where signals are routed are in top layer as well as internal layers.

Line impedance determination using dielectric layer thickness, routing copper thickness and trace-width. Trace separation also taken into account in case of differential signals. Microstrip, stripline or dual stripline can be used to route signals.

Placement of the components. Thermal considerations and geometry are taken into account. Vias and lands are marked.

Routing the signal trace. For optimal EMI performance high frequency signals are routed in internal layers between power or ground planes as power plane behaves as ground for AC.

Gerber file generation for manufacturing.