I have a multilayer board I'm working with. To ease placement and routing, I created some layer pairs and two Layer Set (TOPSet, BottomSet) and then I clicked on hide/show button to assign meaningful layers to each set. That worked fine with Signal, Overlay, Paste & Solder layers but I have a problem with mechanical layer 1 and 13.

In my design ICs are placed on both sides of the PCB. This doesn't show well on 2D layout Mode (3D obviously works fine as there isn't any trasparency). Some components at the top have their "violet" box assigned to Mechanical Layer 1, some to Mechanical Layer 13. This is also true for bottoms components.

How can I fix this problem so each component has the correct mechanical layer assigned based on its side placement? This question is similar to this one, but I cannot figure out how to solve what colin explained in his last comment: Assigning mechanical layers in Altium

Exactly, how can I delete Layers Pair with components already placed? I receive an error (there are primitives in it). If I change that pair to have other layers associated, then I'm able to delete it but then what colin explained doesn't work for me.

Thank you!


1 Answer 1


You need to create a layer pair that links M1 to M13.

The procedure differs from which version of Altium you are using. I can provide instruction for Altium 18 but anything before that, you might have to look in the layer settings.

The easiest way to reorient the components, is from within the footprint lib, update PCB. I had something similar happen recently and my colleague showed me that trick.

  • \$\begingroup\$ Oh turns out the answer to that previous question was me too. \$\endgroup\$
    – efox29
    Dec 10, 2018 at 16:18
  • \$\begingroup\$ Nice, thank you! Can't upvote your comment, but it seems it solved my problem. Components in libraries I created have the wrong mechanical layer selected (13 instead of 1)... So it's a matter of correcting those libraries! Now, is there a way to fast update the PCB without the need to remove that component in schematic, update PCB, then CTRL+Z in schematic, than update again PCB? Sometimes I need to do these actions (for example if I update 3D Body in a component in a library), but it's so time consuming... ahah so, I'm definitevely in good hand! \$\endgroup\$
    – SashaLag
    Dec 10, 2018 at 18:36

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