Electrical – Altium – Defining top or bottom layers as a plane layer

altiumpcbpcb-designpcb-layers

I have four layer PCB stack up but wish to use the bottom layer as a 'plane' layer instead of a signal layer. Is it possible to configure Altium like this through layer stackup manager?

  • L1 Top – Signal
  • L2 Mid – Plane
  • L3 Mid – Signal
  • L4 Bottom – Plane

I can use multiple polygons but for my design a negative plane definition with splits would be easier to work with.

Best Answer

This is possible, when in PCB mode press d then k you can then edit the layers as such but you would change the lower layer to an internal plane

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You don't specifically need to change the lower layer to an internal plane, a better way is to use fills or polygon planes for the lower layer and keep its definition as a signal layer. This is more appropriate to keep the power planes on one layer (and that way you can have multiple) whereas a internal plane can only have one net attached to it (although you can break these up with a 'negative' trace), much better to use planes.

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