Clarification on 4 layer arrangement

Hello there,

I’m using KiCad to lay out a 4 layer board for the first time. I just want to check that the 4 copper layers are arranged in the order that I assume that they are, before proceeding.

The 4 layers are listed in the drop-down menu as:

  • F.Cu
  • Inner2.Cu
  • Inner1.Cu
  • B.Cu

I assume that this would be the same order that they would be stacked as on the PCB? In other words, starting with the “top” of the board the layers in order would be F.Cu, then Inner2.Cu, then Inner1.Cu, and finally B.Cu on the bottom?

Thanks,
Jon

Honestly, this is more of a thing to work out with your PCB manufacturer. You will be given an option to tell them which gerber files correspond to which manufactured layer. There isn’t really a universal layer numbering that people follow, it’s just important to understand everyone’s convention.

That being said, I haven’t tried doing blind or buried vias (where the layer ordering would matter inside KiCad). If you’re just doing standard vias, it won’t affect your net connectivity either way.

As mbarlow states, you’ll want to check with your manufacturer to confirm the layer stackup if the order is critical.

That said, the canonical standard is to treat the Top copper as layer 1, then Internal planes in ascending order, then the bottom layer. So, it should get fabbed like this.

Top/Front Layer
Inner1
Inner2
Bottom layer

Thanks for your help guys.