Definition

Routing is the process of creating copper traces that connect component pins according to the schematic netlist. Manual routing gives full control for critical signals; auto-routing handles bulk connections. Key considerations: signal integrity (controlled impedance, length matching), power delivery (wide traces, multiple vias), manufacturability (minimum trace/space, acid traps), and EMI (return paths, shielding). Route critical signals first - clocks, high-speed differentials, power. Layer assignment affects crosstalk and impedance. Good routing is the difference between a working board and EMI failures.