Mechanicals - vscore and breakoff tabs


How do I define a v-score (i.e. a straight line score on both top and bottom such that can easily break off a piece of PCB). If can’t be done from within Upverter, what other ways are there to get this into correct file so taken care of while milling rest of PCB?
(I work on MacOS and have access to Linux)

I have a very small triangular daughter card (used to raise 3 SMT components off the main PCB) and would like to manufacture it simultaneously with the main PCB. I have been advised that for such a small board (8mm shortest side) it will be harder to break
off if I use break-off tabs.

Also, anyone know best way to communicate breakoff tab location to manufacturer. I defined an Upverter component “Breakoff tab zone” and placed it with holes centered
on board outline. Upverter complaining each of the 5 holes violates “hole to edge” constraint.


Hi @erik6677,

There is not a way to mark them in Upverter, but I will take a look around and see if I can find out what you need to tell your manufacturer.


So my understanding is that you put the line on a second mechanical layer and name it vscore.

There is no way to do that in Upverter right now, but I think you can add an internal copper layer, and only have the line on it that you want cut, then rename the inner layer files “mechanical.vscore”. You will have to check with your manufacturer when you have the files made to make sure they will work with it. In theory it should work.

Let me know how it goes, I am hoping that your manufacturer will get it done!


Thanks -will try it out.



I am also trying to add v-score.
Why can we only add internal layers? Why can’t we add mechanical layers? It could be very bad if they accidentally created a copper layer out of a mechanical layer.
Also, why can’t we add text on mechanical or notes layer?
It seems especially odd that the notes layer does not support any text.


You should be very careful when adding this fake copper layer to not get an unexpected board result.

I agree, the notes layer in particular should have a way to add text note in the PCB and Schematic, not only in the issues tab on the right hand side. I will add this to the TODO list.


In the end we used a mouse tab instead of a v-score:

  • several manufacturers can only handle vertical and horizontal v-scores and they
    must be for the length of the board
  • some manufacturers have ordering options for what angle to use for the v-scores,
    which influences min component distances to board edge
  • several manufacturers require large distances (>=3mm) from edge to closest component.

Instead we defined two mechanical layer board outlines and based on OSH Park published capabilities used a 1mm score width. They have a good blogpost
on defining slots:


Thanks for the update, glad to hear you got it sorted out!