circuit-json-to-lbrn

Convert Circuit JSON to LBRN XML for PCB fabrication via laser ablation.

Usage

import { convertCircuitJsonToLbrn } from "circuit-json-to-lbrn"

// Generate copper layer only
const copperLbrn = convertCircuitJsonToLbrn(circuitJson, {
  includeCopper: true,
  includeSoldermask: false,
})

// Generate soldermask layer only (for cutting polyimide sheet)
const soldermaskLbrn = convertCircuitJsonToLbrn(circuitJson, {
  includeCopper: false,
  includeSoldermask: true,
})

// Generate both layers together in one file
const bothLbrn = convertCircuitJsonToLbrn(circuitJson, {
  includeCopper: true,
  includeSoldermask: true,
})

// Default behavior (copper only, backward compatible)
const defaultLbrn = convertCircuitJsonToLbrn(circuitJson)

Options

• includeCopper?: boolean - Include copper traces and pads (default: true)
• includeSoldermask?: boolean - Include soldermask openings for cutting polyimide sheet (default: false)
• includeSilkscreen?: boolean - Include silkscreen layer (not implemented yet)
• origin?: { x: number; y: number } - Set the origin point for the conversion
• margin?: number - Set the margin around the PCB

Soldermask Support

The includeSoldermask flag enables generation of soldermask openings for cutting Kapton tape (polyimide sheet). When enabled:

• SMT pads and plated holes will have soldermask openings
• Traces are NOT included in the soldermask layer (to avoid accidental bridging during soldering)
• Holes are always cut through the board regardless of the mode
• Soldermask shapes are filled (Scan mode) instead of outlined, which is required for laser-cutting Kapton tape masks where the laser needs to remove material from the pad areas

Laser Cutting Workflow

The soldermask layer uses LightBurn's "Scan" mode with filled shapes. This is designed for the following workflow:

1. Generate LBRN file: Use includeSoldermask: true to export filled pad shapes
2. Laser cut Kapton tape: The laser will fill/ablate the pad areas.

You can generate:

• Copper only: { includeCopper: true, includeSoldermask: false } - Traditional copper cutting
• Soldermask only: { includeCopper: false, includeSoldermask: true } - Just Kapton tape (polyimide) cutting patterns (filled shapes)
• Both: { includeCopper: true, includeSoldermask: true } - Complete fabrication file with both layers