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Rats nest on all GND connections, despite existing GND plane

split63

I have completely routed a small board manually.  The only "opens", as indicated by the Rats nest lines, are all the GND connections.  I have a negative inner GND plane and each connection has a through-hole via, so why are the GND nets not finding the plane?  Is there some command that must be issued to cause the vias to find the plane?

 Thanks,

 

P.S. Under SETUP -CROSS-SECTION, it lists TOP, GND, Layer 3 and Bottom.   On the Visibility Tab, Under view, it lists Film: Top, Film Layer 2, Film Layer 3, Film bottom.    Not sure if the two should match

 

  • oldmouldy

    Way too little information to form an accurate reply but, I guess the product is PCB Editor, which version? Let's assume 16.x, set the plane to +ve artwork, ensure that it has a dynamic copper shape on it and that this shape is connected to the correct net, THEN you should see full contact vias and thermals on through holes, assuming "default" settings, and you might start to get somewhere.

  • split63

     Sorry About that:

    Allegro PCB editor 16.01

     

    oldmouldy said:
    set the plane to +ve artwork
    Where is this performed?

     

    oldmouldy said:
    ensure that it has a dynamic copper shape on it and that this shape is connected to the correct net
      Where is this checked at?

  • KenM

    to set the net name of the shape -

     in the menu select shape - select shape or void.  select the shape on the gnd layer, right click (rmb), assign net.  you can pick something with that net or go to the options tab and type it or find it.

     

    i don't know what +VE ARTWORK is.

  • BillZ

    Hi

    I think the problem maybe the fact you are using negative planes. Try chaning to positive planes. If your padstack is not built correctly you could have problems with negative plane connections. Also in the help is a section on best practices working with shapes.

    Regards,

    BillZ

    EMA Design Automation

  • steve

    To change to positive planes go to the layer stackup (setup - cross section) and next to your gnd plane there is a check box for negative artwork. If this is checked you have a negative plane so uncheck it to make it positive).

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