Heavy Copper PCB
Up to 12 oz copper — carry real current.
Heavy copper PCBs from 3 oz to 12 oz for EV battery systems, industrial BMS, inverters and high-current motor control. Low resistance, high thermal mass, long duty cycles.
- Copper weight
- 3 – 12 oz
- Finished
- 100 – 420 µm
- Max voltage
- 600 V
- Continuous
- 250 A
Where Heavy Copper Ships
Applications
Why Heavy Copper
Where 1 oz just won’t cut it
- High current density — single trace carries 100+ A
- Low resistance — less I²R heating, higher efficiency
- Higher thermal mass — absorbs transient spikes
- Combined signal + power on one board
- Smaller system footprint — fewer bus bars
- Extended product life under thermal cycling
Heavy Copper Capability
Certified fabrication range
| Copper | |
| Copper weight | 3 oz – 12 oz (finished) |
|---|---|
| Finished thickness | 100 – 420 µm |
| Min trace / space (4 oz) | 10 mil / 12 mil |
| Min trace / space (12 oz) | 20 mil / 25 mil |
| Stack-up | |
| Layer count | 1 – 14 layers |
| Mixed-weight builds | Heavy outer + standard inner |
| Max board size | 500 × 600 mm |
| Thickness | 1.6 – 6.4 mm |
| Electrical | |
| Max continuous current | Up to 340 A (12 oz) |
| Breakdown voltage | ≥ 3,000 V |
| Compliance | |
| Flammability | UL 94 V-0 |
| Compliance | RoHS · REACH · IPC-2152 |
| Finish | |
| Options | HASL · ENIG · Immersion Ag · Hard Gold |
Frequently Asked Questions
Heavy copper PCB FAQ
01How do I know what copper weight I need?
Start with IPC-2152 for current capacity vs. trace width. We’ll run the calculation for you on quote — just send the target continuous current, ambient temp and max allowed temperature rise.
02Can you mix heavy copper with standard signal layers?
Yes — hybrid builds are common. Typical stack: 6 oz outer power planes + 1 oz inner signal. We optimize lamination profile to avoid resin starvation around thick copper.
03What’s the minimum trace for 12 oz copper?
We recommend 20 mil / 25 mil for 12 oz. Tighter spacing increases yield risk because the thicker copper over-etches unevenly.
04Lead time for heavy copper?
4 oz: 7–10 business days. 6 oz: 10–14 days. 8–12 oz: 14–21 days. The extra time covers controlled etch cycles and lamination.
Ready when you are
Send your Gerber & BOM — get a quote in 24 hours.
NDA available · Free DFM review · Senior engineer response.