Author Topic: Copy clearance created by tracks in polygon to other layer polygons  (Read 1806 times)

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Offline AlfBazTopic starter

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I have a 4 layer stackup with no plane layers. Instead I use polygon pours on all layers
On the top layer I place tracks, footprints and pads/vias and the polygon pour automagically creates openings around these objects.
On the other layers I want to create the exact same openings but without any tracks, pads or vias. Is this possible without having to painstakingly create polygon cutouts?
 

Offline Pseudobyte

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Re: Copy clearance created by tracks in polygon to other layer polygons
« Reply #1 on: November 10, 2020, 01:55:06 pm »
There is no way to compute electrical clearance between copper layers, for obvious reasons Altium doesn't let you do this (it would fundamentally change the drc)

Option 1: write a script that adds polygon pour cutouts to your pads
Option 2: add multilayer pour cutouts to your footprints
Option 3: do it manually
“They Don’t Think It Be Like It Is, But It Do”
 

Offline AlfBazTopic starter

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Re: Copy clearance created by tracks in polygon to other layer polygons
« Reply #2 on: November 10, 2020, 09:49:00 pm »
There is no way to compute electrical clearance between copper layers, for obvious reasons Altium doesn't let you do this (it would fundamentally change the drc)

Option 1: write a script that adds polygon pour cutouts to your pads
That might do it if instead of pad you can do it for a netclass which is what I would need
Quote
Option 2: add multilayer pour cutouts to your footprints
Interesting but not really viable for what I'm doing
Quote
Option 3: do it manually
What I'm unfortunately doing

If I come up with any alternatives I'll post here

Thanks
 

Offline AlfBazTopic starter

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Re: Copy clearance created by tracks in polygon to other layer polygons
« Reply #3 on: November 13, 2020, 01:23:40 am »
OK, I've found a way that's not adaptive but cuts out having to create cutouts manually.
By not adaptive I mean that any changes made to the circuit copper requiring multilayer clearance after this is done wont propagate down unless additions are multilayer objects such as through hole pads/vias

It's a rather convoluted process but the result is more accurate than the tracing things manually, especially if the outline is more complex than this example shows

The traces and pads below are not a real circuit and are just for this example.



We then add our polygon pour to the layer containing the traces and adjust its properties/clearances to suite. In this instance we are working on the top layer.



We now explode the polygon to free primitives



The structure has now been converted into a copper primitive, we double click it and change it to another layer. Here its the bottom layer



Double click it again and in the properties we change its Kind from "Copper" to "Polygon Cutout"



We now place a polygon on the bottom layer over this cutout and we end up with this



Now we select this polygon, right click and select "Explode Selected Polygons To Free Primitives"
Each copper primitive is independent now so we select the ones we want as clearance and convert those in the properties->Kind from copper to polygon cutout
At this stage we can clean up by deleting the the first cutout and the copper regions we don't want.



Turn off single layer mode, switch to the layer containing the original traces, select the cutouts from the bottom layer, copy using some reference point on your current layer and paste as many times as you need.
Then transfer the copies to the required layers
If you already have polygons on each layer they should now have their cutouts otherwise add your polygons now

We now have have polygon clearance on all layers for the copper on one layer


« Last Edit: November 13, 2020, 01:34:21 am by AlfBaz »
 
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Offline Pseudobyte

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Re: Copy clearance created by tracks in polygon to other layer polygons
« Reply #4 on: November 13, 2020, 02:02:12 pm »
Neat ill keep that one in the back pocket.
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