KiCAD PCB Layout Workflow

This skill guides Claude to perform PCB layout using Konnect MCP tools. ALL modifications go through MCP tools — never edit .kicad_pcb files directly.

Prerequisites

PCB layout operations require KiCAD to be running with the board file open. The IPC connection communicates with the running KiCAD instance in real-time.

If connection fails:

• Tell the user to open KiCAD and load the project
• The board (.kicad_pcb) must be open in the PCB editor
• KiCAD's IPC API must be enabled (default in KiCAD 8+)

Toolset Loading

Before any PCB work, load the required toolsets:

load_toolset('pcb_board')        # board outline, layers, setup, stackup
load_toolset('pcb_components')   # place, move, rotate, align footprints
load_toolset('pcb_routing')      # traces, vias, differential pairs

Zones (pcb_board: add_zone; pcb_routing: add_copper_pour), component/net queries (pcb_components: find_component, get_component_list; pcb_board: get_board_info), and bulk placement (pcb_components: place_component_array, align_components, duplicate_component) are already covered by the toolsets loaded above.

Load additional toolsets as needed:

load_toolset('config')           # design rule storage: add_design_rule, list_design_rules
load_toolset('verification')     # run_drc, set_design_rules, get_design_rules, check_clearance

Always call get_active_toolsets() first to see what is already loaded.

Layout Order

Follow this sequence for a clean PCB workflow:

1. Board outline — set_board_size or draw Edge.Cuts geometry
2. Import netlist — sync with schematic (update_pcb_from_schematic)
3. Place components — position all footprints
4. Route traces — connect all nets
5. Copper pour — add ground/power zones last
6. DRC — run design rule check
7. Save — save_project

Do NOT add copper pours before routing is complete — they interfere with interactive routing.

Placement

Strategy

• Group components by functional block (power, digital, analog, connectors)
• Place ICs first, then their associated passives
• Decoupling caps: within 2mm of their IC power pins, on same layer
• Connectors: at board edges, accessible for cables
• High-frequency components: minimize trace lengths between them
• Thermal considerations: power components away from sensitive analog

Placement Tools

Placement Tips

• Use mm coordinates (KiCAD default for PCB)
• Standard grid: 0.5mm for placement, 0.25mm for fine adjustment
• Check component courtyard overlaps after placement
• Reference designator text: F.SilkS layer, 1mm height default

Routing

Routing Tools

route_pad_to_pad

The primary routing tool. Automatically creates an L-shaped trace between two pads.

route_pad_to_pad(from_reference, from_pad, to_reference, to_pad, width, layer)

• Handles 90-degree bends automatically
• Specify width in mm (e.g., 0.25 for signal, 0.5 for power)
• Will use vias if pads are on different layers

route_trace

For manual control over trace path. Specify waypoints.

route_trace(net_name, points, width, layer)

• Use when auto-routing creates suboptimal paths
• Provide intermediate points for complex routes
• Each segment is a straight line between points

route_differential_pair

For high-speed differential signals (USB, HDMI, Ethernet, LVDS).

route_differential_pair(net_positive, net_negative, width, spacing)

• Maintains constant spacing between P and N traces
• Matches trace lengths automatically
• Common pairs: USB_D+/USB_D-, LVDS_P/LVDS_N

Netclasses

Define routing rules for groups of nets:

create_netclass(name, track_width, clearance, via_drill, via_diameter)

Common netclass configurations:

• Signal: 0.25mm track, 0.2mm clearance
• Power: 0.5-1.0mm track, 0.3mm clearance
• USB: 0.3mm track, 0.15mm spacing (90 ohm differential)

Via Defaults

• Standard signal via: 0.4mm drill, 0.8mm pad diameter
• Power via: 0.6mm drill, 1.0mm pad diameter
• Micro via (HDI): 0.1mm drill, 0.3mm pad diameter

Copper Pour

Zone tools live in the pcb_board toolset.

add_zone

Creates a copper pour area (polygon fill).

add_zone(net_name, layer, outline_points, priority)

• Almost always GND net on both F.Cu and B.Cu
• Define outline slightly inside board edge (0.5mm inset)
• Priority: higher number fills on top of lower
• Add thermal relief to pads (default behavior)

refill_zones

Must call refill_zones after any change that affects copper pour:

• After adding/moving components
• After routing new traces
• After modifying zone outlines
• After changing design rules

Zones do not auto-update — stale fills cause DRC errors.

Zone Tips

• GND pour on both layers is standard practice
• Leave spoke thermal reliefs for through-hole pads (easier soldering)
• Use keepout zones to prevent copper in sensitive areas
• Zone clearance typically 0.3-0.5mm from traces

Layer Reference

Layer Usage Guidelines

• Route signals on F.Cu and B.Cu (2-layer) or add inner layers for complex boards
• Board outline MUST be on Edge.Cuts (closed polygon or rectangle)
• Silkscreen for reference designators and polarity marks
• Courtyard defines minimum spacing between components
• Use F.Fab/B.Fab for assembly drawings and component outlines

Design Rule Check

After completing layout:

run_drc()

Common DRC errors and fixes:

• Clearance violation: move trace or component further apart
• Unconnected net: route missing connection
• Track too close to edge: move inward from board outline
• Courtyard overlap: increase spacing between components
• Zone fill error: run refill_zones

Rules

1. Never edit .kicad_pcb directly — all changes go through MCP tools
2. Always verify placement after moves — components may snap to unexpected positions
3. Board outline first — define the physical boundary before placing anything
4. Refill zones after changes — stale zone fills cause phantom DRC errors
5. Check DRC before finishing — run run_drc() and resolve all errors
6. Use netclasses for consistency — define track widths per net type, not per trace
7. KiCAD must be running — PCB tools require the live IPC connection
8. Save frequently — call save_project after major operations
9. Load toolsets first — check get_active_toolsets() and load what you need
10. Copper pour last — add zones only after routing is substantially complete