Move all traces/components between layers on 4-layer board

[Anonymous]

Hi,

I have a 4-layer board with components and traces on layers 1 and 2.  Is it possible to move all the content of layer 1 to layer 4 and 2 to 3?  Obviously without losing all the routing!

[jorge_garcia]

Hi @Anonymous,

I hope you're doing well. Your best bet is the cmd-change-swap-layer.ulp that comes with EAGLE. It allows you to move objects from one layer to another.

This ULP hasn't been touched in a while so there is a chance it might not work, please let me know if that happens.

Best Regards,

[Anonymous]

Thanks for ULP suggestion.  I did try it and it did move the traces, but not the components.  Possibly something I was doing wrong.  Not sure.  I actually changed my approach for the layout after that and then didn't need the ULP, so didn't get any further with it.

[one-of-the-robs]

Moving traces between layers is one thing but moving components... well...

There are only two layers on which a component can be placed - the top (layer 1) and the bottom (layer 16) - and they're not actually the layers that the component occupies (the xPlace, xOrigins, xNames, xValues and xDocu are all involved). Now, consider, if you move an SMD IC from the top to the bottom, you're now fitting it from the other side. You have mirrored it. This is why the tool that moves components between top and bottom is the "mirror" tool. Because you've mirrored it, all the pins are on the opposite sides. Your routing is now completely broken.

So, while Jorge's suggestion of the ULP does the layer changing you asked for, it can't sensibly do it for components because it's not sensible to try doing so. If you want to literally swap the whole circuit onto the other side, accounting for the mirroring of all the bits, your best bet is to flip the whole circuit. You can do that by grouping the whole circuit and applying the "mirror" tool to the group.

[Anonymous]

Ah yes, I think essentially what I was after was a more complex Mirror tool.  So I was planning on doing all my routing on the top 2 layers. The components on the top layer and linking traces on the second layer.  Then I wanted to select the entire design and copy and paste it.  Then flip the duplicated design so that the components were on the bottom layer and linking traces on the third layer.

Basically a way of stacking multiples of the same 2-layer design on 1 4-layer board.

Unfortunately I was restricted to full vias and there were a lot of them!  So had to abandon this idea, as they would have collided on both sides of the board.

Thanks for the help though. Paul