Sections de la documentation

Calculateur de largeur de trace PCB (IPC-2221/IPC-2152)

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

Slug trace-width-current. Calculez la largeur de trace minimale du PCB pour la capacité actuelle conformément aux normes IPC-2221 et IPC-2152. Obtenez de la résistance, une chute de tension et une dissipation de puissance. Résultats instantanés et gratuits.

Entrées

Envoyez chacune de ces entrées dans inputs, dans les unités indiquées. La plupart sont obligatoires : un appel auquel il en manque une est refusé (400) et ne coûte rien ; une entrée dont le calculateur peut se passer prend la valeur par défaut indiquée. Une entrée hors de sa plage est tout de même calculée et signalée dans la provenance.

Entrées de trace-width-current
Nom	Unité	Plage	Valeur par défaut	Description
currentnombre	A	0.01 … 100	1	Courant efficace (RMS) dans la trace
copperWeightnombre	oz	0.5 … 4	1	Épaisseur du cuivre (1 oz = 35 μm = 1,378 mil)
tempRisenombre	°C	1 … 100	10	Échauffement admissible au-dessus de l'ambiante
traceLengthnombre	mm	1 … 10000	100	Longueur de la trace (pour la résistance et la chute de tension)
isExternalnombre	aucune	0 … 1	1	Les couches internes conduisent moins de courant que les couches externes, à largeur et échauffement égauxL'une de : 1 Couche externe (extérieure) · 0 Couche interne
traceWidthnombre	mm	0.01 … 100	0.5	La largeur telle que dessinée : la vérification de conformité la juge, et la résistance en continu, la chute de tension et la puissance sont calculées pour elle ; les largeurs minimales ne l'utilisent pas
boardThicknessnombre	mm	0.2 … 6	1.6	L’épaisseur de toute la carte. Seule la largeur pour cette carte (modèle thermique de rftools) l’utilise ; le modèle est validé de 1,4 à 3,2 mm
planeDistancenombre	mm	0 … 6	0	Le diélectrique entre la trace et le plan de cuivre plein le plus proche en dessous ; 0 signifie aucun plan. Seule la largeur pour cette carte l’utilise
planeCopperWeightnombre	oz	0.5 … 2	0.5	Le poids du cuivre de ce plan (35 µm par once). Seule la largeur pour cette carte l’utilise, et seulement s’il y a un plan
standardnombre	aucune	0 … 1	0	L'abaque auquel le courant est comparé : la courbe externe ou interne d'IPC-2221A, ou l'abaque prudent d'IPC-2152 pour tout conducteurL'une de : 0 IPC-2221A fig. 6-4 · 1 IPC-2152 fig. 5-1

Sorties

Renvoyées dans values, par nom. Une valeur non bornée ou non définie vaut null.

Sorties de trace-width-current
Champ	Unité	Description
width2221mm	mm	Largeur minimale (IPC-2221)
width2152mmprincipale	mm	Largeur minimale (IPC-2152 fig. 5-1)
resistance	Ω	Résistance en continu (largeur dessinée)
voltageDrop	V	Chute de tension (largeur dessinée)
powerDiss	W	Puissance dissipée (largeur dessinée)
inChartRange	aucune	Dans le domaine de la fig. 5-1 d’IPC-2152
widthBoardMm	mm	Largeur minimale (cette carte, modèle thermique)
inModelRange	aucune	Dans le domaine du modèle thermique
limitCurrent	A	Courant limite
limitPercent	%	Pourcentage de la limite
minTraceWidth	mm	Largeur conforme

Comment l'appeler

Calculer : un appel, la requête et la réponse complètes, et ses erreurs.
Calcul par lots : ce calculateur avec d'autres, ou un balayage, en une seule requête.
Résoudre pour une valeur cible : la valeur d'une entrée qui amène une sortie à une cible.

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"
    }
  ]
}

Une entrée envoyée sous forme de texte. Rien n'a été décompté.

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

Trop de requêtes en une minute, avec Retry-After.

Les mêmes entrées sur la page du calculateurCalculateur de largeur de trace PCB (IPC-2221/IPC-2152), avec ces valeurs