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Looking for pcb manufacturer who can create pcbs with copper buss bars

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I'm wanting to investigate PCB's that are created with inbuilt bus bars for carrying very high currenets ( >300A ). ( its low voltage, for a spot welder )...

Does anyone have any suggestions of a manufacturer of such things?

PCBway can do copper up to 13oz (0.45mm) but that gets expensive fast.  A better way might be getting thicker copper or brass sheet machined to shape (etch, mill, laser, waterjet - many options) and solder/rivet/bolt that to your PCB.

You probably don't need the thickness of copper you think you do.
For a 300A spot welder PCB track heating isn't really a big issue since the duty cycle is usually really low.
You just need to be sure you're not going to lose too many volts/mV across the PCB. But you can use a higher input voltage to counter that.
I have a 6 layer 3oz pcb that can do 12V 150A for 30sec and the fets get a little warm but the PCB tracks carry 150A do not.
I reckon my PCB could do 300A for 1 second with no problems.

You will need a way to get this 300A into the PCB and out of the PCB.  I use press fit M6 terminals for 150A and they are rated to 250A i think.
But they make them for higher current too. And since you're only doing pulses you could probably use a terminal rated lower than 300A anyway.
Google image search "press fit pcb terminal" to see what i mean.

You need to spec the holes as press-fit with the pcb fab and provide them the info from the datasheet so they know the tolerances.
Then you need an arbor press to push them in and maybe a steel backing plate with holes cut out of it so it can sit flat and provide a surface to push against.  You can push them in with a vice for a one-off project if you can find a good way to push safety on the back of the PCB, but a $100 arbor press is way better.
Alternatively you can just have lots of sticking vias between layers in a location where you solder some thick wire directly to the PCB.
But that is annoying if you have to do lots of them. You need a very high wattage iron.

I'd likely use SMT Mount Terminals,  ( theres a good selection of them )..  I have vapour phase soldering, and its perfect for this kind of thing.
8oz-12oz copper may well be enough.

As far as I know, the bus bars are not a part of the PCB manufacturing process, but they are just parts that are placed on footprints.

And you can buy some standard models bus bars, have them custom made, or just solder some extra thick copper wire to the PCB.


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