Abschnitte der Dokumentation

PCB-Leiterbahnbreitenrechner (IPC-2221/IPC-2152)

POSThttps://rftools.io/api/py/v1/calculate

Slug trace-width-current. Berechnen Sie die minimale Leiterbahnbreite für die Strombelastbarkeit laut IPC-2221 und IPC-2152. Ermitteln Sie Widerstand, Spannungsabfall und Verlustleistung. Kostenlose, sofortige Ergebnisse.

Eingaben

Senden Sie jede dieser Eingaben in inputs, in den gezeigten Einheiten. Die meisten sind erforderlich: Ein Aufruf, dem eine davon fehlt, wird abgelehnt (400) und kostet nichts; eine, auf die der Rechner verzichten kann, erhält den gezeigten Standardwert. Eine Eingabe außerhalb ihres Bereichs wird trotzdem berechnet und in der Provenienz markiert.

Eingaben von trace-width-current
Name	Einheit	Bereich	Standardwert	Beschreibung
currentZahl	A	0.01 … 100	1	RMS-Strom durch die Leiterbahn
copperWeightZahl	oz	0.5 … 4	1	Kupferdicke (1 oz = 35 μm = 1,378 mil)
tempRiseZahl	°C	1 … 100	10	Zulässige Temperaturerhöhung über die Umgebungstemperatur
traceLengthZahl	mm	1 … 10000	100	Länge der Leiterbahn (für Widerstand/Spannungsabfall)
isExternalZahl	keine	0 … 1	1	Innenlagen führen bei gleicher Breite und Temperaturerhöhung weniger Strom als AußenlagenEiner von: 1 Außenlage · 0 Innenlage
traceWidthZahl	mm	0.01 … 100	0.5	Die Breite wie gezeichnet: Die Normprüfung bewertet sie, und DC-Widerstand, Spannungsabfall und Verlustleistung werden für sie berechnet; die Mindestbreiten verwenden sie nicht
boardThicknessZahl	mm	0.2 … 6	1.6	Die Dicke der ganzen Leiterplatte. Nur die Breite für diese Leiterplatte (thermisches Modell von rftools) verwendet sie; das Modell ist von 1,4 bis 3,2 mm validiert
planeDistanceZahl	mm	0 … 6	0	Das Dielektrikum zwischen der Leiterbahn und der nächsten durchgehenden Kupferfläche darunter; 0 bedeutet keine Kupferfläche. Nur die Breite für diese Leiterplatte verwendet es
planeCopperWeightZahl	oz	0.5 … 2	0.5	Das Kupfergewicht dieser Kupferfläche (35 µm pro Unze). Nur die Breite für diese Leiterplatte verwendet es, und nur, wenn eine Kupferfläche vorhanden ist
standardZahl	keine	0 … 1	0	Das Diagramm, gegen das der Strom geprüft wird: die Kurve für Außen- oder Innenlagen aus IPC-2221A oder das konservative Diagramm aus IPC-2152 für alle LeiterEiner von: 0 IPC-2221A Abb. 6-4 · 1 IPC-2152 Abb. 5-1

Ausgaben

Zurückgegeben in values, nach Namen. Ein Wert, der unbegrenzt oder nicht definiert ist, ist null.

Ausgaben von trace-width-current
Feld	Einheit	Beschreibung
width2221mm	mm	Minimale Breite (IPC-2221)
width2152mmHauptwert	mm	Minimale Breite (IPC-2152 Abb. 5-1)
resistance	Ω	DC-Widerstand (gezeichnete Breite)
voltageDrop	V	Spannungsabfall (gezeichnete Breite)
powerDiss	W	Verlustleistung (gezeichnete Breite)
inChartRange	keine	Im Bereich von IPC-2152 Abb. 5-1
widthBoardMm	mm	Minimale Breite (diese Leiterplatte, thermisches Modell)
inModelRange	keine	Im Bereich des thermischen Modells
limitCurrent	A	Stromgrenzwert
limitPercent	%	Prozent des Grenzwerts
minTraceWidth	mm	Konforme Breite

Aufruf

Berechnen: ein Aufruf, Anfrage und Antwort vollständig, und seine Fehler.
Batch: dieser Rechner zusammen mit anderen oder ein Sweep, in einer Anfrage.
Nach einem Zielwert auflösen: der Wert einer Eingabe, der eine Ausgabe auf einen Zielwert bringt.

curl -X POST https://rftools.io/api/py/v1/calculate \
  -H "X-API-Key: $RFTOOLS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "slug": "trace-width-current",
    "inputs": {
      "current": 1,
      "copperWeight": 1,
      "tempRise": 10,
      "traceLength": 100,
      "isExternal": 1,
      "traceWidth": 0.5,
      "boardThickness": 1.6,
      "planeDistance": 0,
      "planeCopperWeight": 0.5,
      "standard": 0
    }
  }'

import rftools

client = rftools.Client()  # reads RFTOOLS_API_KEY, or the key `rftools login` saved

result = client.calculate("trace-width-current", {
    "current": 1,
    "copperWeight": 1,
    "tempRise": 10,
    "traceLength": 100,
    "isExternal": 1,
    "traceWidth": 0.5,
    "boardThickness": 1.6,
    "planeDistance": 0,
    "planeCopperWeight": 0.5,
    "standard": 0,
})
print(result.values)
print(result.warnings, result.provenance.formula_ref)

const response = await fetch("https://rftools.io/api/py/v1/calculate", {
  method: "POST",
  headers: {
    "X-API-Key": process.env.RFTOOLS_API_KEY,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "slug": "trace-width-current",
    "inputs": {
      "current": 1,
      "copperWeight": 1,
      "tempRise": 10,
      "traceLength": 100,
      "isExternal": 1,
      "traceWidth": 0.5,
      "boardThickness": 1.6,
      "planeDistance": 0,
      "planeCopperWeight": 0.5,
      "standard": 0
    }
  }),
});
console.log(response.status, await response.json());

package main

import (
	"bytes"
	"fmt"
	"io"
	"net/http"
	"os"
)

func main() {
	body := []byte(`{
	  "slug": "trace-width-current",
	  "inputs": {
	    "current": 1,
	    "copperWeight": 1,
	    "tempRise": 10,
	    "traceLength": 100,
	    "isExternal": 1,
	    "traceWidth": 0.5,
	    "boardThickness": 1.6,
	    "planeDistance": 0,
	    "planeCopperWeight": 0.5,
	    "standard": 0
	  }
	}`)
	req, err := http.NewRequest("POST", "https://rftools.io/api/py/v1/calculate", bytes.NewReader(body))
	if err != nil {
		panic(err)
	}
	req.Header.Set("X-API-Key", os.Getenv("RFTOOLS_API_KEY"))
	req.Header.Set("Content-Type", "application/json")
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()
	out, _ := io.ReadAll(res.Body)
	fmt.Println(res.Status, string(out))
}

application/json

{
  "slug": "trace-width-current",
  "values": {
    "width2221mm": 0.30038652083330486,
    "width2152mm": 0.7814374629086279,
    "resistance": 0.10433004926108375,
    "voltageDrop": 0.10433004926108375,
    "powerDiss": 0.10433004926108375,
    "limitCurrent": 1.4468880626650513,
    "limitPercent": 69.11384686926509,
    "minTraceWidth": 0.30038652083330486,
    "inChartRange": 1,
    "widthBoardMm": 0.3021150755977321,
    "inModelRange": 1
  },
  "warnings": [],
  "errors": [],
  "provenance": {
    "method": "calculator:trace-width-current",
    "version": "api@3f2c1a9b04de",
    "formulaRef": "IPC-2221A (May 2003) §6.2, Figure 6-4 (the chart of IPC-2221, February 1998), through its published fit; IPC-2152 (August 2009) §5, Figure 5-1; the board-specific width: rftools thermal model (board-specific), fitted to its own 2-D solver and checked against Brooks & Adam (2015), Jouppi (2010) and Olson (2010)",
    "assumptions": [
      {
        "code": "ipc-2221-fit",
        "text": "The IPC-2221 width is IPC-2221 Figure 6-4 through its published fit A = (I/(k·ΔT^0.44))^(1/0.725), with A in mil², k = 0.048 for an external layer (chart A) and 0.024 for an internal one (chart C). Chart A draws 10 to 100 °C and chart C 10 to 45 °C, both to 700 sq mil; the curves include IPC-2221’s 10 % derating, and its note 2 (a further 15 % for boards 0.8 mm or thinner or copper 108 µm or thicker) is not applied."
      },
      {
        "code": "ipc-2152-figure-5-1",
        "text": "The IPC-2152 width is read on IPC-2152 Figure 5-1, the chart IPC-2152 recommends for internal and external conductors in all environments, through the same fit with k = 0.024 on either layer. It is the conservative answer for a board about which nothing else is known: IPC-2152’s detailed method, which narrows the trace for the board’s thickness and a copper plane under it, is not applied."
      },
      {
        "code": "steady-state-dc",
        "text": "Steady DC (or RMS) current in a single trace: pulsed currents, skin effect and heating from neighbouring traces are not modelled."
      },
      {
        "code": "copper-weight",
        "text": "Copper is 35 µm (1.378 mil) thick per ounce, and the trace cross-section is a rectangle of that thickness."
      },
      {
        "code": "standards-check-chart",
        "text": "The standards check reads the drawn width on IPC-2221A Figure 6-4’s curve for the layer, or on IPC-2152’s conservative Figure 5-1, which is IPC-2221’s internal curve, for either layer. It applies neither the further 15 % derating Figure 6-4 suggests for boards 0.8 mm thick or less and copper 108 µm thick or more, nor IPC-2152’s detailed charts and modifiers."
      },
      {
        "code": "resistance-at-temperature",
        "text": "Resistance, voltage drop and power are for the drawn trace width, with ρ = 1/58 Ω·mm²/m (IEC 60028, 1.7241×10⁻⁸ Ω·m) at 20 °C and α = 0.00393 /°C, evaluated at a 25 °C ambient plus the allowed rise."
      },
      {
        "code": "thermal-model-own-method",
        "text": "The board-specific width is the rftools thermal model (board-specific): the site's own steady-state model of a long trace on an FR-4 board in still air, with an optional copper plane under it. It is not IPC-2152 and does not read IPC-2152's charts; it is a closed form fitted to a committed 2-D solver, which is checked against published results (Brooks & Adam 2015; Jouppi 2010; Olson 2010)."
      },
      {
        "code": "thermal-model-fr4",
        "text": "The laminate is FR-4, conducting 0.8 W/(m·K) in the plane of the board and 0.3 W/(m·K) through it (Graebner 1995; Azar & Graebner 1996). A laminate that conducts less runs hotter."
      },
      {
        "code": "thermal-model-still-air",
        "text": "The board is horizontal, in still air at sea level. Its faces lose heat by natural convection (the McAdams horizontal-plate correlations, over the 51.2 mm length of the IPC-TM-650 2.5.4.1A test board) and by radiation, with an emissivity of 0.9 for the laminate and 0.1 for the bare copper trace. Forced air, an enclosure and other orientations are not modelled."
      },
      {
        "code": "thermal-model-long-trace",
        "text": "The trace is long and alone. Heat drawn off through pads, vias and leads at its ends, and heat from neighbouring traces and components, are not modelled; a short trace with heat-sunk ends runs cooler."
      },
      {
        "code": "thermal-model-plane",
        "text": "An internal trace lies at the middle of the board's thickness. A plane is one solid copper layer under the trace, across a 76.2 mm (3 in) wide board, the stated distance of dielectric below the trace. A plane above the trace, a second plane, or a plane cut away under the trace is not modelled."
      },
      {
        "code": "thermal-model-margin",
        "text": "The board-specific width includes a 15 % margin for the model's measured disagreement with published data: it is the width at which the model's rise is the allowed rise divided by 1.15."
      },
      {
        "code": "thermal-model-heat",
        "text": "The model's Joule heat uses the copper resistivity of IPC-TM-650 2.5.4.1A, 10.827 Ω·cmil/ft at 25 °C for 1 oz and heavier copper and 11.529 Ω·cmil/ft for lighter, rising 0.393 % per °C. The resistance and power outputs keep 1/58 Ω·mm²/m."
      },
      {
        "code": "thermal-model-ambient",
        "text": "The board-specific width is computed at a 25 °C ambient, the temperature IPC-TM-650 2.5.4.1A tests at; the allowed rise is above that ambient."
      },
      {
        "code": "thermal-model-range",
        "text": "Outside the model's validated range (Width 0.25–5.1 mm (internal from 1.27 mm), copper ½–3 oz, board 1.4–3.2 mm, a plane from 0.1 mm under the trace to where it fits, plane copper ½–2 oz, rise 5–100 °C, ambient 0–85 °C) the board-specific width is still reported, flagged with a warning naming the bound. On boards thinner than 1.4 mm, IPC-2152's published thickness data show traces running hotter than the model predicts, so the IPC-2152 Figure 5-1 width is the one to use there."
      }
    ],
    "validRange": {
      "status": "inside",
      "bounds": {
        "current": {
          "min": 0.01,
          "max": 100,
          "unit": "A"
        },
        "copperWeight": {
          "min": 0.5,
          "max": 4,
          "unit": "oz"
        },
        "tempRise": {
          "min": 1,
          "max": 100,
          "unit": "°C"
        },
        "traceLength": {
          "min": 1,
          "max": 10000,
          "unit": "mm"
        },
        "isExternal": {
          "min": 0,
          "max": 1,
          "unit": ""
        },
        "traceWidth": {
          "min": 0.01,
          "max": 100,
          "unit": "mm"
        },
        "boardThickness": {
          "min": 0.2,
          "max": 6,
          "unit": "mm"
        },
        "planeDistance": {
          "min": 0,
          "max": 6,
          "unit": "mm"
        },
        "planeCopperWeight": {
          "min": 0.5,
          "max": 2,
          "unit": "oz"
        },
        "standard": {
          "min": 0,
          "max": 1,
          "unit": ""
        }
      },
      "outside": [],
      "model": {
        "description": "IPC-2152 Figure 5-1 through I = 0.024·ΔT^0.44·A^0.725, checked against IPC-2221 (1998) Figure 6-4 chart C (the same chart) at 10 to 45 °C and up to 700 sq mil: the cross-section is within −3.5 % to +4.4 % of 12 chart readings, and 11.3 % short at 10 °C and 700 sq mil",
        "worstCaseError": 0.12,
        "inside": true
      },
      "models": [
        {
          "description": "IPC-2152 Figure 5-1 through I = 0.024·ΔT^0.44·A^0.725, checked against IPC-2221 (1998) Figure 6-4 chart C (the same chart) at 10 to 45 °C and up to 700 sq mil: the cross-section is within −3.5 % to +4.4 % of 12 chart readings, and 11.3 % short at 10 °C and 700 sq mil",
          "worstCaseError": 0.12,
          "inside": true
        },
        {
          "description": "rftools thermal model (board-specific), a closed-form thermal network fitted to rftools' own committed 2-D solver of the trace's cross-section: Width 0.25–5.1 mm (internal from 1.27 mm), copper ½–3 oz, board 1.4–3.2 mm, a plane from 0.1 mm under the trace to where it fits, plane copper ½–2 oz, rise 5–100 °C, ambient 0–85 °C (the rise before the margin). Inside that range its rise is within 2.81 % of 3,168 solver results",
          "worstCaseError": 0.029,
          "inside": true
        }
      ]
    },
    "computedAt": "2026-09-24T14:05:11.003Z",
    "inputs": {
      "current": 1,
      "copperWeight": 1,
      "tempRise": 10,
      "traceLength": 100,
      "isExternal": 1,
      "traceWidth": 0.5,
      "boardThickness": 1.6,
      "planeDistance": 0,
      "planeCopperWeight": 0.5,
      "standard": 0
    },
    "seed": null,
    "elapsedSeconds": 0.003
  }
}

{
  "detail": [
    {
      "type": "float_parsing",
      "loc": [
        "body",
        "inputs",
        "current"
      ],
      "msg": "Input should be a valid number, unable to parse string as a number",
      "input": "abc"
    }
  ]
}

Eine als Text gesendete Eingabe. Es wurde nichts gezählt.

{
  "detail": "More than 120 requests in 60 seconds from this address.",
  "errorKind": "rate_limited",
  "limit": 120,
  "windowSeconds": 60,
  "upgradeUrl": "https://rftools.io/pricing/"
}

Zu viele Anfragen in einer Minute, mit Retry-After.

Dieselben Eingaben auf der RechnerseitePCB-Leiterbahnbreitenrechner (IPC-2221/IPC-2152), mit diesen Werten