No error reported on via in vrestrict (layer43) polygon !

Question

Hi,

On some package I add a vRestric (layer 43) polygon because I want to be sure that there will be no via (or holes) in this area.

But it seems that when I put a via in the area, there is no DRC error or warning !!!!

How can I activate this checking ???? (I hope it's possible !)

I already activate the 'Check restrict' in 'Misc' tab in the DRC setting.

Guillaume Barrey

autodeskguest · Accepted Answer

Guillaume barrey[1

wrote on Wed, 05 November 2014 02:52]No body have a clue ?

EAGLE won't give you an error if a via is placed in a rectangle or other

shape on that layer. All it does is restrict the auto-router from placing

a via in that layer.

Of course that is silly and really negates the point of the layer.

CadSoft should change this, or at least give an option for the vrestrict

layer to actually create an error if a via is within that area. That is

what any rational person would think it does and it's actually a needed

function.

From the help for the RECT command

If used in the layers tRestrict, bRestrict, or vRestrict, the RECT command

defines restricted areas for the Autorouter.

This isn't 100% true. For tRestrict and bRestrict it will also create DRC

errors if there is copper in those areas. But vRestrict works differently.

This is a bug and should be fixed.

In addition, there is probably more nuanced control that is needed for

blind and buried vias. If you're trying to make sure that a via wouldn't

short to the bottom of a connector (for instance) then it's OK if you have

a via in that location as long as it doesn't come out to the surface.

And while we're at it, being able to identify a restrict area on an inner

layer is often needed as well. For instance, under the antenna of an RF

module. Some nuance here because you'd want to put that into the footprint

of a part to cover all layers but not all boards have all layers. So that

needs to be considered.

So in general, I'd like to see a lot more improvement in the restrict

methodology. But yes, at a bare minimum vRestrict should give DRC errors

when a via is placed in that area.

James.

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James Morrison ~~~ Stratford Digital

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