1. Capture the schematic
Everything starts in the schematic editor. You place symbols for each component, wire them together, and assign each one a value and a reference designator (R1, C1, U1, and so on). A clean schematic is worth the effort: label your nets, group related circuitry, and add notes. The schematic is the source of truth — the layout is derived from it, not the other way around.
2. Assign footprints
A symbol describes a component electrically; a footprint describes its physical pads and dimensions on the board. Every symbol must be linked to the correct footprint — an 0805 resistor, a SOT-23 transistor, a specific connector. This is the step where mistakes are most expensive, because a wrong footprint means a part that physically will not fit the board you ordered. Double-check package sizes against the datasheet.
3. Run the electrical rules check
Before moving on, run the ERC. It catches unconnected pins, conflicting outputs, and power nets without a source. Fixing these on the screen costs nothing; fixing them after manufacturing costs a re-spin.
4. Lay out the board
Import the netlist into the PCB editor and the layout begins. The sequence I follow:
- Define the board outline — the physical shape and size.
- Place components logically: decoupling capacitors right next to the IC pins they serve, connectors at the edges, related parts grouped together.
- Route the traces, keeping power and ground solid, and signal traces as short and direct as practical.
- Pour copper for ground planes, which improve noise performance and simplify routing.
5. Respect the design rules
Every fabricator publishes minimum trace widths, clearances, and hole sizes they can reliably produce. Enter these into KiCad's design rules and run the DRC. Designing inside your fab's capabilities is the difference between a board that works and one that arrives with shorts or broken traces.
Decoupling capacitors belong as close to the IC's power pins as the layout allows. It is the cheapest reliability upgrade in electronics.
6. Generate manufacturing files
When the DRC passes, export Gerber files (the copper, mask, and silkscreen layers) plus a drill file. Most fabs accept a zipped set of Gerbers directly. Use KiCad's built-in 3D viewer first — seeing the populated board in three dimensions catches silkscreen overlaps and placement issues a flat view hides.
Why KiCad
KiCad removes the cost barrier to designing real hardware. It is free, cross-platform, and good enough for serious work, with an enormous community library of symbols and footprints. If you can read a datasheet and follow a process, you can design a board that a factory will manufacture for a few dollars.
Always order a board with a ground pour and proper decoupling. Most "it works on the breadboard but not on the PCB" problems trace back to power integrity.