IPC-2152 Temperature Rise Examples for Real Boards
Use IPC-2152 as a starting model, not a single final number. On real boards, a 3A outer-layer path may be comfortable around 60-80 mil on 1oz copper, while 6A to 10A power paths often need wide pours, 2oz copper, or both once you include vias, connector pads, ambient temperature, and voltage-drop limits.
أهم النقاط
- •Convert the current target into a full path review: trace, pour, vias, pads, and plane changes.
- •Real boards usually fail at short bottlenecks, not at the longest straight copper run.
- •Internal layers and sealed hot products need more copper than open-air prototypes.
- •Check voltage drop and manufacturable geometry together before release.
Example Matrix
| Scenario | Current | Stackup | Starting point |
|---|---|---|---|
| 24V relay board | 3A | 1oz outer | 60-80 mil |
| Industrial I/O card | 6A | 1oz outer | 140-180 mil |
| Motor control power path | 8A | 2oz outer | 100-140 mil + vias |
| Internal-layer distribution | 2-3A | 1oz inner | Wider than outer layer |
Release Checklist
- Review the narrowest copper, not only the longest trace.
- Check vias, pads, connector exits, and fuse footprints separately.
- Verify voltage drop and ambient temperature before release.
- Use related calculators and the linked standards comparison during DFM review.
Related Tools & Resources
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الأسئلة الشائعة السريعة
What is a practical IPC-2152 starting point for 3A on a real PCB?
On a short 1oz outer-layer path with reasonable airflow, 60-80 mil is a practical starting bracket for about 3A. Internal paths or pad bottlenecks may need much more width.
Why does my real board need more copper than the IPC-2152 calculator result?
The calculator usually evaluates an ideal copper section. Real products add connector bottlenecks, vias, local hot parts, higher ambient, solder-mask coverage, and voltage-drop limits.
Should I change width or copper weight first when temperature rise is too high?
Increase width first when board area allows it. Move to 2oz copper when the width becomes awkward or the path still runs too hot.
Does IPC-2152 solve via heating automatically?
No. A trace can be wide enough while a via array still overheats. Verify vias separately.
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