How to connect ground plane to via using Eagle?

[Ipanema]

Hi,

Can anyone show me how to automatically connect a via to a ground plane show in this picture?

FYI, I'm planning to make a two layer PCM1798 DAC board using eagle. The top layer will be use for signal routing and the bottom layer as ground plane. All my top layer ground will be connected to the bottom ground plane using via. I try to create a ground plane by using the "polygon" function to draw a box around the circuit and the press "ratsnest" to fill up the polygon. I got the ground plane made this way, where it leave some space between the ground plane and pad/via. But I would like the ground plane to connect to my via, just like the picture shows below, while make no connection to the pad. Pls enlight me.

Happy DIY!

Thanks.

[singa]

Hi,
If you have used the integrated schematic capture and converted it to pcb layout i don't see a problem.BTW the evaluation version allows all this up to 3 by 4 inches limit.Anything bigger you have to do it manually.I have not used eagle for some time but I suspect you are doing it manually so just use draw a line/trace and just connect the via to the ground plane.

[heater]

I'm a bit rusty with this and don't have time to play with it just now. But the trick is to change the name of your ground plan polygon to be the same as the ground signal that you want to connect to. So if your ground signal is "GND" make the polygon name "GND". You can name the ground signal in the original schematic or in the board layout. Then ratsnest will flood the polygon and connect it to any traces, pads and vias on the same side.

Now the connection created by ratsnest will be 100% solid to just a thin cross hair. "thermal relief" I think it is called. See dialog "tools->drc->suppy" and check/uncheck the generate "thermals for vias" check box and set parameters there.

Hope that helps.

[heater]

Of course having named your polygon the same as the GND signal (or which ever) you will no longer be able to see the tracks on the polygon side after a ratsnest. They all get merged into the polygon. If you really want to see where they are just "unroute" the polygon. Then perhaps redraw the board to get them back again.

BUT in general I don't think you should route the GND signals on the polygon side of the board. So just unroute them all and leave them as yellow connections. ratsnet will then automatically connect them to the ground plane polygone for you. magic hey!

[Ipanema]

Thanks guys for your help. It works wonderfully.

Have a nice day!

[pinkmouse]

Originally posted by heater
So just unroute them all and leave them as yellow connections.

"ripup GND" is the quickest way.