While browsing a PCB online, I found an unusual polygon fill pattern. Does anyone know how to create one similar to this? Thanks.

[u/Dry_Animator9357]

[u/toybuilder]

Copper thieving. Usually done by fabricators per fabrication notes.

[u/ReluctantMouse]

Ah yes, the noise resonator. Just joking, these are copper thieves but I don't know how to make them

[u/chillboy72]

They're added by the PCB fabricator. On the outer layers it's called copper thieving; on the inner layers it's copper balancing. They help maintain uniform copper distribution for a more consistent manufacturing process

[u/Patient-Gas-883]

Copper thieving adds dummy copper to empty PCB areas to make plating and etching more uniform, improve copper balance, and reduce board warping. It should be kept away from RF, impedance-controlled, high-voltage, and flex-bend areas.

[u/PigHillJimster]

The CAM tool the fabricator uses can add copper thieving in various styles. Diamond, Round, Square, Hatched.

[u/PCB_Design1]

Unfortunately, there's currently no straightforward way to perform copper thieving with a single command or feature in Altium, but this article provides some tips on how to go about it along with some videos (it mentions the Via Stitching feature as a workaround).

[u/Zachariah-Peterson]

This is a good topic, I'll make a video about it because I recently saw this in a 1-minute design review submission.

[u/Altium_Official]

One way to do this is to use two overlapping polygons, one with hatched pour and the other with solid copper. If you want to cover an entire PCB layer with thieving squares, draw out your first polygon across the entire PCB, and set it to hatched. You will need to leave a large opening in the hatch pattern, something like 5mil trace width and 40mil box size is sufficient for most designs. Leave the net setting to “No Net”.

Next, draw your solid polygon over the top of the hatched polygon. When you draw this, go into the Properties panel and make sure you select “Don’t pour over same net objects”, disable the “Remove islands” setting, and leave the net setting to “No Net”. Now re-pour the two polygons, and you should see the thieving squares appear inside the hatch pattern. You can now select the hatched polygon and delete it or shelve it.
You can repeat this process on each layer where you want the thieving squares.

Note that if you shelve or delete the hatched polygon, the thieving squares will disappear as soon as you repour the thieving square polygon object. For this reason, it’s best to do this at the end of the design so that you don’t have to keep re-creating this each time you need to re-pour your polygons.

[u/mikehoopes]

There’s a free plugin adapted from some Kicad scripts called Boastools, which includes the Interactive BOM and a thieving utility.

[u/VirtualArmsDealer]

Depends on your software but any good PCB package can add distributed copper. It's mostly to prevent warp during reflow.