High current on circuit board

Discussion in 'General Electronics Chat' started by meckert1960, Mar 8, 2008.

  1. meckert1960

    Thread Starter New Member

    Jul 13, 2005
    Has anyone put 30Amps on a circuit board?
    I'm working on a controller board and looking to see the best way to make this work. Would duplicate plane shapes on top and bottom suffice?
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    The cross section of the foil would need to be about the same as that of #12 building wire. I just cheat and solder on some .250 solder wick or coax braid onto the foil for the current. Looks nasty for a professional pcb, tho...
  3. SgtWookie


    Jul 17, 2007
    30 Amps at what voltage? If it's low voltage (like 3.3 and 5v) you may benefit from dissecting an ATX form-factor PC power supply to see how they did it. Higher voltages, you'll be dealing with lots more power.

    Beenthere's idea of using solder-wick works. So does using really wide traces with 2oz or heavier copper on the boards. You can also solder on strips of flat copper stock, but the solder layer should be as thin as possible. For your power connections, use multiple small pins rather than few large pins.

    Remember that standard 63/37 tin/lead solder has about 5x the resistance that copper does. Resistance = heat. If you dissect the PC power supply, you'll see what I mean about spreading connections around.
  4. scubasteve_911

    Senior Member

    Dec 27, 2007
    It depends on your maximum acceptable temperature rise. If you're okay with a 35 degree rise and have 1oz PCB, then a 700+mil trace is in order. Just don't use soldermask over the traces and tack on some copper, whether it be wick, wire, or more foil. I have done this in the past with success :)


    check out the link

  5. John Luciani

    Active Member

    Apr 3, 2007
    One easy way is to use bus wire jumpers in parallel with or instead of a PCB trace.

    (* jcl *)