Why we can't Design for Odd number of Layer???

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Hello all,
As I see that PCB manufacturers are manufacturing PCBs in an even number of layers like 2,4,6 etc., But why we can't manufacture PCB in the ODD number of layer??
Are there any technical reasons??


Thank you.

[qdrives]

It is an efficiency reason.
They start with cores. Both sides have copper - so two layers.
Add multiple cores together with prepreg in between -> n*2.
Or use multiple press cycles (sequential lamination), add one layer to the top and one to the bottom, again +2 layers.
You can make a three layer board, but it is just a four layer board where one of the layers is completely stripped of copper.

Perhaps these will help:

https://www.eurocircuits.com/Making-a-PCB-PCB-Manufacture-step-by-step/

https://www.youtube.com/watch?v=67WhV0EDqCA

https://www.polarinstruments.com/support/stackup/AP537.html

[robertferanec]

I think, if you really want, they can do ODD, just as qdrives said, it may not be efficient (also, I am not sure about parameters of that kind of PCB e.g. maybe it will be bending?). The best is to watch the videos which qdrives attached to understand how the process works.