Supplier For Large Coil

Does anyone know where I can buy a reasonably priced coil like this (ideally it would be a circle)?

It’s 4 layers and I found a flexible PCB company that could make it but they wanted over $1000 each. Some of the things that can’t change about the design are that it needs to be flat, and it needs the wide tracks. Most flex PCBs companies won’t make something that’s 22" diameter, and if I have to solder pieces together then I might as well keep making them myself.

Anyone know of a company that could build something like this at production runs of about 1000 per month?

I have not seen it done, but if I had to, I would post a RFQ on Aliexpress and let some Chinese companies bid on the task


How thick do you need the foil to be? How thick do you need the insulator between the layers? This looks like something a PCB manufacturer could do.


A word of warning: I would strongly suggest using a one-time throwaway E-mail address for this — I posted an RFQ on Alibaba once, and pretty much ruined my E-mail. The RFQ has long been forgotten, but my E-mail is apparently now on every Chinese company’s E-mail list and I get 4-6 spam E-mails per day.


Hello Everyone,
If you are looking for any kind of manufacturing work like pcb, pcba, wire harness, box build etc, then you can go through Finding Mfg . It is a Michigan USA based portal where you can connect with vendors directly and receive multiple quotations. The best part is it’s free to use for estimations. if have any doubt then mail to

Thank you

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Thanks, the biggest issue I am running into is that the PCB manufacturers that I’ve spoken with so far have not been able to make a flexible board this size. 1oz copper would be fine, and normal distances between layers would also be fine, but the overseas guys that I’ve talked to don’t seem to make things this large and usa based companies want 10x what I can build these for myself

  • Is 22" the nominal, or outer diameter?
  • What is the turn width/ how wide is the strip?
  • How critical is the layer spacing?
  • what are the min/max layer spacing?
  • what is the current density required
  • how flexible does it need to be/can it be?

I’m thinking non-pcb suppliers might be an option. If you can expand past PCB processes, a lot of options open up. As an example, if you don’t need high current density then metalized mylar can be die or CNC cut. You could do arcs slightly over 180 degrees and clamp the conductive faces with a clamp or use conductive tape.

You should be able to buy 24" square sheets of board material and have them laser cut, but that will result in a lot of waste and be very expensive in material terms. Cheaper board materials like phenolics might work for you. Laser cutting should be relatively cheap.

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Hi David,
I would suggest you check my portal Finding MFG and drop your inquiry there (there’s also an NDA in place if you so require).
We have several connects in the US as well as overseas markets.
Surely we can help you out in achieving your target prices on this project.

Is this for wireless power transfer, or can you shed light on why you have so wide layers?

So it is to for biological interactions with the magnetic field. The wide traces have a couple of benefits to the application.

The main benefit is that it keeps the magnetic field spread out near the traces, where if it was just magnet wire it would be many times stronger near the current carrying part of the coil as opposed to the center of the coil.

The other benefit is less effects from the skin effect when applying a pulse to the coil

Can you pretend to have a wide cross section by running multiple wires in parallel in that shape? I’m imagining a framework of spokes that hold the wires in place AND shorts them together appropriately. You could 3d print an adapter for a coil winder jig.

How do you join the pieces of copper?

What is the insulation material between the layers?

This doesn’t seem to lend itself well to planer FPC construction due to how the windings would need to be connected but it feels like it could be automated cleverly with a robot and tape cutter. 1k pcs per month is a decent volume to invest in something like that.

Yeah I could build a machine to do it as well. That may be the best option at the moment. I was mostly hoping it could be purchased somewhere to start out because that would make the investors happier haha but machine builds like that are fun!


I’ve tried something like this, and it works, but not quite as well. I think the loss of capacitance between layers plays a role