Footprint editor - view more routable layers

[Anonymous]

Happy Wednesday!

I can't seem to figure out how to view the 'routable' layers in Eagle's footprint editor.

I can only see the Top and Bottom layers, but I want to access Route2 and Route15.  Here's a picture:

Any ideas on how to access the other layers?

Thank you!

[one-of-the-robs]

I'm not sure you can in the footprint editor, because it's not really useful or appropriate. You're defining the footprint of a component which is affixed to the board. It's either a leaded component, in which case you have PTH pads and perhaps extra holes, or it's SMD, in which case it needs pads on either top or bottom (and perhaps some non-PTH locating holes). You can't solder it to the inner layers, so it doesn't really make sense to define inner layer copper for it.

So what is your unusual use case that you think you need this for?

[Anonymous]

Thanks for your reply @one-of-the-robs 

In this case, I am making a footprint for a clik-mate connector.  The datasheet specifies a milling/slot of 0.3mm wide in the SMD pad which basically acts as a slotted via for the pad.  So in each layer, I want to have a 'pad' that a signal line can connect to.  

If nothing else, I am modifying this footprint that came from an old version of Eagle (i.e. 4 pin connector footprint to a 2 pin footprint).  Since these internal layer pads existed in the old footprint, I can not delete them in my new/smaller/modified footprint because I can not view these internal layers in the footprint editor.  The phantom Route2 and Route15 smd pads do not appear in the footprint editor, but do appear in the board editor..

I hope that makes sense.

[one-of-the-robs · Accepted solution]

Ah, yes, I see.

Prompted by your post, I fired up V5.12 and find that the package editor does, indeed, allow you to pick layers 2 & 15 on that version.

It has to be said, Eagle currently does not handle PTH slots very well. I believe it's on the list.

[Anonymous]

No worries, I can re-make the footprint instead of modifying this old one.  I was just looking to learn more aspects of Eagle if it were possible.

Thank you for helping out with this!

[charlie_didear]

@Anonymous ,
After much hair-pulling, I figured out how to view more routable layers in the footprint editor.  I had the same use case as you - needing to define a custom PTH slot and have internal layer pads (not only does this let me connect traces to the pads on the internal layers, it keeps EAGLE from auto-pouring copper from other signals over the slot!).  I also could have sworn seeing the option to edit internal layers in a footprint editor before, and this was in EAGLE 9.x.x.

Then, for some inexplicable reason, I noticed that one of my libraries had layers 1-3 and 14-16 available, but I was working on an eight layer board and needed layers 4 and 13 also.  Since EAGLE files are in XML format, I decided to open up the .lbr file in a text editor.

Toward the top of the file, I saw these lines of code:

"<layers>
<layer number="1" name="Top" color="12" fill="1" visible="no" active="yes"/>
<layer number="2" name="Route2" color="1" fill="3" visible="no" active="yes"/>
<layer number="3" name="Route3" color="4" fill="3" visible="no" active="yes"/>
<layer number="4" name="Route4" color="1" fill="4" visible="yes" active="no"/>

[and so on]"

I made sure my library file was not open in EAGLE, then I changed the <layer> tags for 4 and 13 from  'active="no"' to 'active="yes" and then opened up the library, and sure enough, I was able to now define polygons in layers 4 and 13!  The footprint works as expected.  I also discovered that placing a PTH in the center of a polygon pour on a routable layer causes EAGLE to consider that polygon as part of that pad.  Similar to arbitrary SMD shapes, but for PTH pads...only problem is now I have pads and drills in the middle of my slots, which end up getting exported to the Gerbers, annoying, and possibly confusing.

This is definitely a workaround Autodesk implementing arbitrary pad (PTH) shapes for PTH slots, which hopefully will happen soon.

Charlie

[aholtzma]

Thank for you posting this! I too had a library with the inner layers enabled and no idea how to replicate it on other libaries. 

[aholtzma]

BTW another use for this feature is to draw cutout polygons on inner layers to make antipads for RF applications.