I'm designing an high power H bridge inverter able to supply up to 100A sinusoidal current.

Is it possible to carry this current levels on a PCB? Eventually, can you suggest me the trace width and thickness?

I've also read about bus-bar. Is it preferable for my application?

Any suggestion are welcome.

Thank You.

 

hi,
I would suggest you consider a copper bus-bar for a 100Amp current.
What is the voltage rating for the 100A current, consider suitable spacing and isolation.

https://www.copper.org/applications/electrical/busbar/bus_table3.html

E

 

It is not practical to run 100A on PCB copper laminate.
You will need a trace width of about 100mm on 2oz copper.
Have you seen the size of #4-AWG copper cable?
That is the size of the bus-bar you need, about 5 x 5mm.

 

Although extreme weight PCB etching is possible (https://www.epectec.com/articles/heavy-copper-pcb-design.html), I also suggest a busbar approach.

This link will calculate to 6 0z copper (maybe more?, http://www.circuitcalculator.com/wordpress/2006/01/31/pcb-trace-width-calculator/ ). For 0.5 oz, it gives the outrageous width of 146 mm; for 6 oz, it gives 12.4 mm. I have used 25 mil (about 16 oz/ft^2, https://www.riversidesheetmetal.net/sheet-metal/gauge-and-weight-chart/ )copper buss bar to make such high current circuits. Of course, all of the logic was on ordinary PCB.

 

It is absolutely possible to route 100A in the PCB but it means you have to take some precautions to avoid overheating:
- thick traces without cutouts or bottle necks
- route on multiple layers with large vias connecting layers
- intelligent layout of components to minimize high current path distances

I have designed PCBs that go up to 200A but that is with at least four layers of 1oz+ copper.

 

I'm a beginner on PCB routing. Can you please provide me a design procedure to find the PCB trace width to carry a specific current and a specific thickness?

Is this online calculator reliable?

https://www.4pcb.com/trace-width-calculator.html

And as "Current" is the RMS or MAX value?

Really thank you,

Fabio.

 

The calculator to which I linked and the 4 PCB one give the same results. That only shows consistency, not reliability. I suspect one would need to build and test t determine that.

Current capability of a trace is a heat limitation. Therefore, use RMS.