Copy clearance created by tracks in polygon to other layer polygons - Page 1
Forum section: electronics / general

author: AlfBaz
author_rank: Super Contributor
timestamp: November 10, 2020, 04:57:42 am
content: I have a 4 layer stackup with no plane layers. Instead I use polygon pours on all layersOn 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?

author: Pseudobyte
author_rank: Frequent Contributor
timestamp: November 10, 2020, 01:55:06 pm
content: 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 padsOption 2: add multilayer pour cutouts to your footprintsOption 3: do it manually

author: AlfBaz
author_rank: Super Contributor
timestamp: November 10, 2020, 09:49:00 pm
content: Quote from: Pseudobyte on November 10, 2020, 01:55:06 pmThat might do it if instead of pad you can do it for a netclass which is what I would needQuoteInteresting but not really viable for what I'm doingQuoteWhat I'm unfortunately doingIf I come up with any alternatives I'll post hereThanks

author: AlfBaz
author_rank: Super Contributor
timestamp: November 13, 2020, 01:23:40 am
content: 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/viasIt'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 showsThe 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 primitivesThe structure has now been converted into a copper primitive, we double click it and change it to another layer. Here its the bottom layerDouble 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 thisNow 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 cutoutAt 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 layersIf you already have polygons on each layer they should now have their cutouts otherwise add your polygons nowWe now have have polygon clearance on all layers for the copper on one layer

author: Pseudobyte
author_rank: Frequent Contributor
timestamp: November 13, 2020, 02:02:12 pm
content: Neat ill keep that one in the back pocket.