{
  "capability_id": "electrical.pcb.trace_width",
  "tool_id": "pcb-trace-width",
  "engine": "pcb-trace-width",
  "calculation_version": "1.1.1",
  "generated_at": "2026-09-16T22:03:43.715Z",
  "engine_build": "2026-09-12",
  "test_count": 15,
  "passed": 15,
  "failed": 0,
  "tests_summary": {
    "golden": {
      "total": 3,
      "passed": 3
    },
    "boundary": {
      "total": 6,
      "passed": 6
    },
    "property": {
      "total": 6,
      "passed": 6
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  "engine_tested": true,
  "expert_reviewed": true,
  "internally_reviewed": false,
  "review_kind": "expert",
  "source_checked": true,
  "reviewed_by": "CalculatorX electrical review",
  "reviewer_role": "electrical-engineer",
  "last_reviewed": "2026-08-10",
  "expert_review": {
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      "role": "electrical-engineer"
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    "reviewed_at": "2026-08-10",
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      "sources",
      "tests"
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  "internal_review": {
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  "page": "https://www.calculatorx.com/calc/electric/pcb-trace-width",
  "api": "https://www.calculatorx.com/api/v1/calc/pcb-trace-width",
  "schema_input": "https://www.calculatorx.com/schemas/electrical.pcb.trace_width.input.json",
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  "assumptions": [
    "Classic IPC-2221 closed form; not IPC-2152 charts.",
    "1 oz/ft² ≡ 1.378 mil thickness.",
    "Steady current; no via heating or nearby power planes.",
    "When u_* are set, first-order GUM sensitivity with independent inputs (no ρ on this page)."
  ],
  "limitations": [
    "IPC-2221 closed form only — not IPC-2152 chart interpolation",
    "1 oz/ft² modeled as 1.378 mil thickness",
    "Bad mode/layer → INVALID_MODE; non-positive → VALUE_MUST_BE_POSITIVE",
    "Optional u_* use GUM sensitivity on the primary result only; uncertainty_k is coverage (not IPC k)"
  ],
  "boundary_conditions": [
    "Missing I/width_mil/dT → MISSING_REQUIRED_INPUT",
    "≤ 0 → VALUE_MUST_BE_POSITIVE",
    "Bad mode/layer → INVALID_MODE",
    "Non-finite → INVALID_NUMBER",
    "uncertainty_k without any u_* → INVALID_INPUT"
  ],
  "sources": [
    {
      "title": "IPC-2221 — Generic Standard on Printed Board Design",
      "section": "Conductor width and current capacity (external/internal k factors)",
      "supports": "I = k·ΔT^0.44·A^0.725 with k=0.048 / 0.024",
      "kind": "standard"
    },
    {
      "title": "IPC-2152 — Standard for Determining Current-Carrying Capacity in Printed Board Design",
      "section": "Updated current-carrying methodology",
      "supports": "Context that IPC-2221 is a legacy closed-form estimate vs newer charts",
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        "copper_oz": 1,
        "layer": "external"
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        "thickness_mil": 1.378,
        "k": 0.048
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      "tol": 1e-9
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      "id": "current-roundtrip",
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    {
      "id": "missing-I",
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      "expectError": "MISSING_REQUIRED_INPUT",
      "code": "MISSING_REQUIRED_INPUT",
      "error": "I is required"
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    {
      "id": "zero-dT",
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      "error": "dT must be greater than zero"
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    {
      "id": "bad-layer",
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        "layer": "mid"
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    {
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