I am trying to use vias on a fill to connect copper in Altium, but I keep getting unrouted net constraint errors. I have the following: enter image description here

The red square and blue rectangle (which extends fully underneath the red square) are fills on the top and bottom layers, respectively. Why would I get an unrouted net constraint here?

  • \$\begingroup\$ What are the actual errors? \$\endgroup\$ Mar 30, 2018 at 0:59
  • \$\begingroup\$ Un-Routed Net Constraint: Net 5V Between Via (45.2mm,49mm) from Top Layer to Bottom Layer And Via (45.2mm,49.5mm) from Top Layer to Bottom Layer \$\endgroup\$ Mar 30, 2018 at 1:04
  • \$\begingroup\$ I have also tried adding a trace directly between all of the vias, and it did not resolve it. \$\endgroup\$ Mar 30, 2018 at 1:04
  • \$\begingroup\$ Are you sure there isn't something funny going on like another via underneath the ones that are showing? Maybe delete the vias and replace them. \$\endgroup\$ Mar 30, 2018 at 1:14
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    \$\begingroup\$ Are you sure you are re-running the design rule check every time you make a change? The DRC error markers will not go away automatically when you fix the error, you need to run the DRC again to get rid of them. \$\endgroup\$
    – DerStrom8
    Mar 30, 2018 at 11:25

2 Answers 2


In my experience, Altium gets mixed up when vias are close together. When it says there is an un-routed net from via to via, try moving the vias farther apart (or make them smaller).
You can also get more info about what Altium is thinking by going to Design -> Rules... and then select Electrical - Un-routed Net - UnroutedNet. In that dialog box, uncheck the option for "Check for incomplete connections." If that makes your errors go away, then it tells you that your vias are close enough that Altium thinks they should be connected together, but somehow doesn't understand that the polygon fill is making the connection. Don't know why... seems like a bug to me.


I don't think fills count as actual copper nets, or if they do it's pretty buggy. You need to actually draw a polygon pour in order for it to work to connect components. Also, to state the obvious, the polygons need to have the same net as the objects they're supposed to be connecting. The net is set in the polygon properties.

  • \$\begingroup\$ Just replaced the fills with polygon pours and it did not correct the issue. \$\endgroup\$ Mar 30, 2018 at 0:15
  • \$\begingroup\$ And you're sure you set the net of the polygon? The net is not set automatically, you have to manually open the polygon properties (double-click on it) and set it in the dropdown \$\endgroup\$
    – DerStrom8
    Mar 30, 2018 at 10:48
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    \$\begingroup\$ @BillyKalfus And don't forget to run the DRC again after changing from a fill to a polygon. The error markers will not go away automatically \$\endgroup\$
    – DerStrom8
    Mar 30, 2018 at 11:29
  • \$\begingroup\$ I did set the net of the polygon. And yes, I cleared error markers and reran DRC every time I made a change \$\endgroup\$ Mar 30, 2018 at 15:25
  • \$\begingroup\$ @BillyKalfus Please show screenshots of your polygon properties window and your via properties window \$\endgroup\$
    – DerStrom8
    Mar 30, 2018 at 15:48

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