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I am attempting to create a PCB hatch footprint as used on calculators etc with a rubber keypad switch.

I can create a hatched area without any issues: Interlocking fingers used for round PCB push button

Which is clearly lovely.

If you look, you'll see that the two ends of the pads are 1 and 2, as per the round pads at the top and the bottom of the footprint.

However, when I try an use it in my PCB layout, Altium complains that the traces are shorted around pad 1, as all the traces are labeled as GND (the net attached to pin 2). I have redrawn this multiple times in multiple ways to try and ensure that the traces are as you would expect.

Is there a way in Alitum to force a set of traces to connect to a pin? Is there a way to check which pin the trace is connected to? What simple thing have I stupidly managed to miss?

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  • \$\begingroup\$ Ah. I have now found this question: electronics.stackexchange.com/questions/195412/… which seems to be the same issue, but doesn't have an answer. Also, it is a couple of years old, and Altium does have a new version out every year to so, I'm using Altium 17, which is two versions up from the newest that question could be using. \$\endgroup\$ – Puffafish Jun 6 '17 at 12:19
  • \$\begingroup\$ Do you have a Sch file with Pad1 and Pad2 connected to GND net? \$\endgroup\$ – ammar.cma Jun 6 '17 at 15:03
  • \$\begingroup\$ @ammar.cma no, the schematic connects PAD1 or GND and PAD2 to a different net off an IC. \$\endgroup\$ – Puffafish Jun 6 '17 at 15:28
  • \$\begingroup\$ The way I see it, is that you can make a pour and make this pattern which will remove the errors. \$\endgroup\$ – ammar.cma Jun 6 '17 at 15:30
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    \$\begingroup\$ Are you sure you want pads 1 & 2 to be through-hole? \$\endgroup\$ – DerStrom8 Jun 6 '17 at 16:24
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Start with "top layer" pads named 1 and 2, instead of through-hole pads like you have now. The way your display settings are, it also looks like your through-holes are non-plated which would cause further problems obviously, given that it breaks up the traces.

Once those pads are placed, simply draw nets connected to the pads. These nets should have "no net" properties.

It should look something like this: enter image description here

One final thought, you'll want to make sure that you've drawn soldermask all over the part where the carbon pill will be pressed, otherwise your button won't work. It's hard to tell if you are missing this or just not drawing that layer.

I've also attached a .PcbLib with just an Abatek silicone membrane footprint in there that you can copy and modify if that helps you. Dropbox link to switch footprint.

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