@tscircuit/copper-pour-solver

Solves PCB copper pour regions from Circuit JSON or from a small geometry input format, returning pcb_copper_pour-ready B-Rep shapes.

Install

bun add @tscircuit/copper-pour-solver

This package expects TypeScript 5 as a peer dependency.

Basic Usage With Circuit JSON

Initialize the geometry runtime once before solving. Then convert Circuit JSON into the solver input format, run the solver, and map the returned B-Rep shapes back into pcb_copper_pour elements.

import {
  CopperPourPipelineSolver,
  convertCircuitJsonToInputProblem,
  initializeManifoldGeometry,
} from "@tscircuit/copper-pour-solver"

await initializeManifoldGeometry()

const inputProblem = convertCircuitJsonToInputProblem(circuitJson, {
  layer: "top",
  source_net_name: "GND",
  pad_margin: 0.4,
  trace_margin: 0.2,
  board_edge_margin: 0.1,
  cutout_margin: 0.2,
})

const solver = new CopperPourPipelineSolver(inputProblem)
const { brep_shapes } = solver.getOutput()

convertCircuitJsonToInputProblem reads board bounds or outline, SMT pads, plated holes, mechanical holes, vias, traces, and cutouts for the selected layer. Pads and traces connected to the selected source net are kept connected to the pour; unrelated geometry is subtracted using the configured margins.

Selecting The Pour Net

Prefer selecting by source net name or id:

const inputProblem = convertCircuitJsonToInputProblem(circuitJson, {
  layer: "top",
  source_net_name: "GND",
  pad_margin: 0.4,
  trace_margin: 0.2,
})

You can also pass the source net's stable subcircuit_connectivity_map_key directly:

const gnd = circuitJson.find(
  (element) => element.type === "source_net" && element.name === "GND",
)

const inputProblem = convertCircuitJsonToInputProblem(circuitJson, {
  layer: "top",
  subcircuit_id: gnd.subcircuit_id,
  subcircuit_connectivity_map_key: gnd.subcircuit_connectivity_map_key,
  pad_margin: 0.4,
  trace_margin: 0.2,
})

Pass subcircuit_id when selecting a net inside a subcircuit. The converter considers that subcircuit and its child subcircuits, but it does not treat matching child subcircuit_connectivity_map_key values as connected unless the Circuit JSON connectivity actually connects them. Internally, the generated globalConnectivityMap is kept separate from the scoped subcircuitConnectivityMap; scoped solver connectivity keys are prefixed with their subcircuit id.

Do not generate or pass ids from circuit-json-to-connectivity-map. The converter handles PCB connectivity internally and normalizes it to stable subcircuit_connectivity_map_key values.

Manual Input

You can skip Circuit JSON conversion and provide the solver input directly.

import {
  CopperPourPipelineSolver,
  initializeManifoldGeometry,
  type InputProblem,
} from "@tscircuit/copper-pour-solver"

await initializeManifoldGeometry()

const input: InputProblem = {
  regionsForPour: [
    {
      shape: "rect",
      layer: "top",
      bounds: { minX: -10, minY: -5, maxX: 10, maxY: 5 },
      connectivityKey: "net:GND",
      padMargin: 0.4,
      traceMargin: 0.2,
      board_edge_margin: 0.1,
    },
  ],
  pads: [
    {
      shape: "circle",
      padId: "via_1",
      layer: "top",
      connectivityKey: "net:VCC",
      x: 0,
      y: 0,
      radius: 0.5,
    },
  ],
}

const output = new CopperPourPipelineSolver(input).getOutput()

Supported input pad shapes are rect, circle, pill, trace, and polygon. Use the same connectivityKey as the pour for pads/traces that should connect to the copper island; use a different key for blockers that should be cleared.

Output

getOutput() returns:

interface PipelineOutput {
  brep_shapes: BRepShape[]
}

Each B-Rep shape is compatible with Circuit JSON copper pour data:

interface BRepShape {
  outer_ring: {
    vertices: Array<{ x: number; y: number; bulge?: number }>
  }
  inner_rings: Array<{
    vertices: Array<{ x: number; y: number; bulge?: number }>
  }>
}

Development

bun install
bun run build
bun test
bun start
bun run build:site