Copper Pour Discussion

edited March 17 in PCBs
This discussion was created from comments split from: Faster Copper Pour.

Comments

  • Hi Iliya,

    I think I found an issue with the copper pour. The capacitor on the right is supposed to be connected to GND on pin 2, and Vdd on pin 1. The hatched plane is supposed to be a ground plane, but it bridges both, so it'd end up shorting 24V to ground.

    I set the exclusion gap to be 30 mils, but pin 1 on the capacitor on the left shows a keepout much smaller than this.

  • edited March 12

    Doesn't that require that I add internal layers? And the trial version Electra autorouter only supports up to 2 layers. Prior to the recent changes I was using the copper pour function without a problem for the past 9 months or so.

  • Iliya,

    I think Ggavari is saying that the copper pour is CREATING the short..

    Look at the capacitor on the RIGHT in his example.. The pour is connecting to both the TOP and BOTTOM pad..

    I can clearly see that the TOP pad is GND and the bottom pad looks like it connects to a net call V??? so the pour should not connect to it unless his schematic somehow has V?? connected to GND.

    Regards,

    Mick

  • Can someone else please check the "remove unconnected islands" is working properly? My current design removes most of the connected copper when I select this checkbox. Suspect there is a setting issue rather than a bug.

  • @bigmik said:
    Iliya,

    I think Ggavari is saying that the copper pour is CREATING the short..

    Look at the capacitor on the RIGHT in his example.. The pour is connecting to both the TOP and BOTTOM pad..

    I can clearly see that the TOP pad is GND and the bottom pad looks like it connects to a net call V??? so the pour should not connect to it unless his schematic somehow has V?? connected to GND.

    Regards,

    Mick

    Hi Mick, yes that is correct. The bottom pad is connected to Vdd, and the copper pour is bridging Vdd and GND.

  • @Rixen said:
    Can someone else please check the "remove unconnected islands" is working properly? My current design removes most of the connected copper when I select this checkbox. Suspect there is a setting issue rather than a bug.

    Hi Rixen, I've submitted this bug twice and mentioned it here in the forums, but haven't heard anything regarding it. I'm getting the same behavior; the check box ends up keeping only the unconnected islands, when it should be doing the reverse. There was a workaround if I remember correctly. I played around with filling the pour and changing the keepout and was able to reproduce it. Unfortunately, I have since forgotten the workaround. :\

  • Hi Guys,
    I use the, Keep Out, see attached, hope this helps.
    Jan

  • Hi Jan, that is an alternate solution, but that would mean I'd have to create keepouts on every pad that's not part of the pour.

  • edited March 17

    Here is a comparison of the same project, one saved before the recent changes, one saved after the recent changes. Prior to the changes, the copper pour avoided all pads that weren't part of its net.

    With the recent changes, the copper pour connects to pretty much every pad on the IC. I haven't been able to find a rhyme or reason why it chooses some but not others.

  • I have been having the opposite problem- my pads connected to GND net would not connect to the pour. On sub-picking each pad I found the "connection" field was blank. Editing this field to GND fixed the issue.

    The strange thing is they were connected to GND in schematic, showed the correct net lines and no DRC error with the manually routed GND tracks.

    Try sub-picking the pads to check their connection.

    Does the DRC indicate any error with the erroneous pour connections?

  • It looks like somehow, all of the pads were placed on the ground net. Not sure why that happened, I certainly didn't do it....

    The DRC gives the errors that you mentioned.

  • @System said:
    This discussion was created from comments split from: Faster Copper Pour.

    Thanks!

  • I checked another project of mine; something I hadn't opened since the recent updates. And same thing, all the pads connected to ground are no longer part of the ground net...

  • Hi Ggavari1,

    Not saying there isn’t an issue but I find this usually occurs if the GND net is highlighted and delete is pressed instead of right click and in route (segment/track etc)

    Mik

  • Test schematic:

    Test PCB, both resistors show correct connections. Mouse hover shows connections on net GND and net +12:

    PCB with pour properties displayed. Pour set to have thermal reliefs to GND:

    Properties of pad shows no signal:

  • When posting it's always a good idea to add a project or part so people can reproduce things; otherwise it's very difficult or even impossible to help.

    Iliya Kovac is the developer of AutoTRAX DEX

  • Project attached, similar test to above. I manually changed R1 pad to connect to signal gnd and it produces a thermal relief connection. the other pad on R2 does not, despite being attached to net gnd..

  • Hi Rixen,

    I do not know why but when you SUB PICK the top pad and look at the properties you will see the PAD is not assigned to AGND, despite a hover over telling you that it is.

    The bottom pad IS assigned to AGND.

    I would assume the two resistors were both placed at the same time so I don't know why or how this changed as linking them to AGND on the schematic should have assigned both pads to be connected to AGND.

    Mik

  • I manually changed the bottom pad, which is why it's connected. By default the pads don't connect otherwise- on any library component I've used so far.

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