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Questions relating to designing PCBs
By CJnis
#178563
I cant seem to find anything on this. How does one calculate the current a pcb can handle like in the case of the below power board? I know there are trace width calculators but in this case im looking for the current of the whole pcb can handle which is basically just one big power and ground plane.

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By Ross Robotics
#178565
The only way I know of is to find a datasheet for it. The designer or distributor should have that info. Buy the looks of it, it should handle at least a few amps..
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By Ross Robotics
#178587
The board designer would know how thick the PCB and the amount of the copper pour.
By CJnis
#178591
The board im designing is double sided 2oz copper (top power plane ,bottom gnd plane) but im not sure how i would calculate the copper pour to tell the current capability . Its not like a square copper board . Its a intriquete shape with components and other traces on it. Is there a calculator or equation to tell you this?
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By Ross Robotics
#178593
No, you just go by the thinnest area. So your max rating would be from the smallest section in a trace..
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By languer
#178980
I suggest you search for "ipc current capacity chart". The people at Ultracad have some cool tools for this. But honestly every PCB designer in the industry has at least a copy or reference to the IPC tables.
By InactiveUser001
#179019
Get the PCB Toolkit from Saturn PCB, its a lot more upto date than Ultracads old one (no longer free ISTR)and certainly more than the old graphs that give you an approx value.
It's free - you will not regret it.

By the looks of that board, it will easily carry more current than any quadcopter can take (unless its a full sized one).
By monkeyxpress
#179910
Think about the first principles. The copper area on the PCB is just a resistive heater, and this heat needs to be removed or the board will literally fry. You want to keep the surface temp below around 60degC (I think from memory).

The track width calculators just assume a thermal conductivity from the surface of the board into the air (and through the fibreglass if it is an intermediate layer) and tells you the amount of heat energy the track can produce before it gets too hot.

You could do your own calculation, but given the board shape, I would just plug a rectangle the average width and path length between terminals into a track calculator and this will give you a baseline. To be honest, I doubt you'll have any issues because the huge bits of copper wire soldered directly to the board are going to soak away most of the heat anyway.

Only caveat is if you do have narrow sections for any appreciable length (say narrow section length is equal to the narrow section width) this may then become a localised heating point.