Mechanical layer convention, does it exist?

[EPTech]

Hi all,


Does there exist some kind of concensus in the use of mechanical layers. I have searched for this many times and I hope that some of my collegues here can point me in the right direction.
In Altium I found a lot of inconsistancies in libraries when it comes to mechanical layer usage and I do not know which ones to correct.
I have found a description at ninedotsconnect. Is this a good reference?

Greetings,
Pascal.

[T3sl4co1l]

Nope. Use house standard.

In Altium, layers are easily changed in libraries or PCBs, so it's not a big deal updating stock, old or outside libraries as needed.

For example I use, I think it's the default from Altium stock libraries: Mech 1 centroid mark, Mech 13 3D info (models and outlines), Mech 15 courtyards.  Paired with Mech 3, 14 and 16 respectively, for top/bottom pairs.

Have also often merged Mech 1 into Mech 15 so 15 has both centroids and courtyards.  Have seen multiple kinds of outlines (body, pins, etc.) and courtyards on other layers, as well as labels and such.  PCB templates, might have sheet graphics on a layer or two, sometimes including different title blocks for different drawings (fab, assembly top/bottom).

Other tools, might have only a few layers, of specific purpose.  Eagle is kind of this way, I think.  Ultiboard has a few spare mech layers, which can be used for drawings.  That sort of thing.

Now that Altium's been expanded to ludicrous layers (as of... AD18, 19?), there's no worry about running out...  Plus you can rename the layers how ever you like.  Which I find a bit annoying as they still show up as "Mech-N" but you can't query them by number, you need to remember the actual exact (case-insensitive) name to do a query on...

Tim