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PCB トレースの温度上昇

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

スラッグ pcb-trace-temp。IPC-2221 の外層近似式を使用して、負荷電流下でのPCBの銅トレース温度上昇を計算します。トレースの幅、厚さ、電流を入力すると、周囲温度よりΔT高い値が得られます。サーマルPCBの設計と信頼性エンジニアリングに不可欠です。無料で即時に結果が得られます。

入力

これらの入力を、表示されている単位ですべて inputs に入れて送ってください。ほとんどは必須で、1 つでも欠けた呼び出しは拒否され（400）、費用はかかりません。省略しても計算できる入力は、表示されている既定値を使います。範囲外の入力も計算され、来歴で示されます。

pcb-trace-temp の入力
名前	単位	範囲	既定値	説明
current数値	A	0 以上	3	電流
traceWidth数値	mm	0.1 以上	2	トレース幅
copperWeight数値	oz	0.5 以上	1	銅箔重量
ambientTemp数値	°C	制限なし	25	周囲温度
traceLength数値	mm	1 以上	100	トレース長
boardThickness数値	mm	0.2 … 6	1.6	基板全体の厚さ。この基板での上昇（rftools の熱モデル）だけが使います。モデルの検証範囲は1.4～3.2mmです
planeDistance数値	mm	0 … 6	0	トレースとその下にある最も近いベタの銅プレーンとの間の誘電体。0は銅プレーンなし。この基板での上昇だけが使います
planeCopperWeight数値	oz	0.5 … 2	0.5	その銅プレーンの銅の重量（1オンスあたり35µm）。この基板での上昇だけが、銅プレーンがある場合にのみ使います
isExternal数値	なし	0 … 1	1	変わるのはこの基板での上昇だけです。IPC-2221 の上昇は常にチャート A (外層) を使い、図 5-1 はどちらの層でも同じです次のいずれか：1 外層 · 0 内層
laminate数値	なし	0 … 3	0	積層板と基板の総誘電体厚。これらが最高使用温度を決めます次のいずれか：0 FR-4、≥ 0.4 mm · 1 FR-4、0.1–0.4 mm · 2 ポリイミド、≥ 1.6 mm · 3 ポリイミド、0.1–1.6 mm
standard数値	なし	0 … 1	0	温度上昇を読み取るチャート: IPC-2221A の外層曲線（温度上昇として）、または IPC-2152 の保守的なチャート。どちらの場合も、制限値は積層板の最高使用温度から周囲温度を引いた値です。次のいずれか：0 IPC-2221A 図 6-4 · 1 IPC-2152 図 5-1

出力

values に名前ごとに返されます。上限がない値や定義されない値は null です。

pcb-trace-temp の出力
フィールド	単位	説明
tempRise主要値	°C	温度上昇 (IPC-2221)
maxTemp	°C	最大トレース温度 (IPC-2221)
traceResistance	mΩ	トレース抵抗
powerDissipated	mW	消費電力
currentCapacity	A	電流容量 (IPC-2221, ΔT=10°C)
tempRise2152	°C	温度上昇 (IPC-2152 図5-1)
maxTemp2152	°C	最大トレース温度 (IPC-2152 図5-1)
inChartRange	なし	IPC-2152 図5-1 の範囲内
tempRiseBoard	°C	温度上昇 (この基板、熱モデル)
maxTempBoard	°C	最大トレース温度 (この基板、熱モデル)
inModelRange	なし	熱モデルの範囲内
chartRise	°C	チャート上の温度上昇
limitRise	°C	許容温度上昇
limitPercent	%	制限値に対する割合
minTraceWidth	mm	適合幅
maxCurrent	A	適合電流

呼び出し方

計算：1 回の呼び出し、リクエストとレスポンスの全体、そのエラー。
バッチ：この計算ツールをほかと組み合わせて、または掃引を、1 リクエストで。
目標値からの逆算：出力を目標値にする入力の値。

curl -X POST https://rftools.io/api/py/v1/calculate \
  -H "X-API-Key: $RFTOOLS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "slug": "pcb-trace-temp",
    "inputs": {
      "current": 3,
      "traceWidth": 2,
      "copperWeight": 1,
      "ambientTemp": 25,
      "traceLength": 100,
      "boardThickness": 1.6,
      "planeDistance": 0,
      "planeCopperWeight": 0.5,
      "isExternal": 1,
      "laminate": 0,
      "standard": 0
    }
  }'

import rftools

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

result = client.calculate("pcb-trace-temp", {
    "current": 3,
    "traceWidth": 2,
    "copperWeight": 1,
    "ambientTemp": 25,
    "traceLength": 100,
    "boardThickness": 1.6,
    "planeDistance": 0,
    "planeCopperWeight": 0.5,
    "isExternal": 1,
    "laminate": 0,
    "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": "pcb-trace-temp",
    "inputs": {
      "current": 3,
      "traceWidth": 2,
      "copperWeight": 1,
      "ambientTemp": 25,
      "traceLength": 100,
      "boardThickness": 1.6,
      "planeDistance": 0,
      "planeCopperWeight": 0.5,
      "isExternal": 1,
      "laminate": 0,
      "standard": 0
    }
  }),
});
console.log(response.status, await response.json());

package main

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

func main() {
	body := []byte(`{
	  "slug": "pcb-trace-temp",
	  "inputs": {
	    "current": 3,
	    "traceWidth": 2,
	    "copperWeight": 1,
	    "ambientTemp": 25,
	    "traceLength": 100,
	    "boardThickness": 1.6,
	    "planeDistance": 0,
	    "planeCopperWeight": 0.5,
	    "isExternal": 1,
	    "laminate": 0,
	    "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": "pcb-trace-temp",
  "values": {
    "tempRise": 5.342104787621994,
    "maxTemp": 30.342104787621995,
    "traceResistance": 24.63054187192118,
    "powerDissipated": 221.67487684729062,
    "currentCapacity": 3.953008949362809,
    "chartRise": 5.342104787621994,
    "limitRise": 105,
    "limitPercent": 5.0877188453542805,
    "minTraceWidth": 0.3281129167384957,
    "maxCurrent": 11.12374665416563,
    "tempRise2152": 25.814961619314374,
    "maxTemp2152": 50.814961619314374,
    "inChartRange": 1,
    "tempRiseBoard": 10.281805774783722,
    "maxTempBoard": 35.28180577478372,
    "inModelRange": 1
  },
  "warnings": [],
  "errors": [],
  "provenance": {
    "method": "calculator:pcb-trace-temp",
    "version": "api@3f2c1a9b04de",
    "formulaRef": "IPC-2221A (May 2003) §6.2, Figure 6-4, chart A (the chart of IPC-2221, February 1998), through its published fit; IPC-2152 (August 2009) §5, Figure 5-1; the board-specific rise: 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-external-fit",
        "text": "The IPC-2221 rise is IPC-2221 Figure 6-4 chart A, the external-layer chart, through its published fit with k = 0.048; chart A draws 10 to 100 °C up to 700 sq mil, and the internal-layer chart is not applied to this rise."
      },
      {
        "code": "ipc-2152-figure-5-1",
        "text": "The IPC-2152 rise 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; IPC-2152’s corrections for board thickness and a nearby copper plane are not applied."
      },
      {
        "code": "copper-weight",
        "text": "Copper is 35 µm thick per ounce, and the trace cross-section is a rectangle of that thickness."
      },
      {
        "code": "resistance-at-20c",
        "text": "The trace resistance and power use ρ = 1/58 Ω·mm²/m (IEC 60028, 1.7241×10⁻⁸ Ω·m) at 20 °C, not corrected for the trace’s temperature."
      },
      {
        "code": "thermal-model-own-method",
        "text": "The board-specific rise 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 rise includes a 15 % margin for the model's measured disagreement with published data: it is 1.15 times the model's rise."
      },
      {
        "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 rise is computed at the ambient entered: it sets the air’s properties, the radiation and the copper’s resistivity, so a hotter ambient gives a somewhat larger rise."
      },
      {
        "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 rise 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 rise is the one to use there."
      }
    ],
    "validRange": {
      "status": "inside",
      "bounds": {
        "current": {
          "min": 0,
          "max": null,
          "unit": "A"
        },
        "traceWidth": {
          "min": 0.1,
          "max": null,
          "unit": "mm"
        },
        "copperWeight": {
          "min": 0.5,
          "max": null,
          "unit": "oz"
        },
        "ambientTemp": {
          "min": null,
          "max": null,
          "unit": "°C"
        },
        "traceLength": {
          "min": 1,
          "max": null,
          "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"
        },
        "isExternal": {
          "min": 0,
          "max": 1,
          "unit": ""
        },
        "laminate": {
          "min": 0,
          "max": 3,
          "unit": ""
        },
        "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 rise is within −5.7 % to +7.3 % of 12 chart readings, and 18 % low at 10 °C and 700 sq mil",
        "worstCaseError": 0.18,
        "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 rise is within −5.7 % to +7.3 % of 12 chart readings, and 18 % low at 10 °C and 700 sq mil",
          "worstCaseError": 0.18,
          "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": 3,
      "traceWidth": 2,
      "copperWeight": 1,
      "ambientTemp": 25,
      "traceLength": 100,
      "boardThickness": 1.6,
      "planeDistance": 0,
      "planeCopperWeight": 0.5,
      "isExternal": 1,
      "laminate": 0,
      "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"
    }
  ]
}

テキストとして送られた入力。計上はされていません。

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

1 分あたりのリクエストが多すぎます。Retry-After 付き。

同じ入力で計算ツールのページを開くPCB トレースの温度上昇、この値で