Trying to have both GND and VCC pours for a 4-layer PCB

Anonymous — Fri, 27 Apr 2018 00:32:48 GMT

Hello, I am trying to make a 4-layer board, consisting of a top layer, bottom layer, a ground layer, and VCC layer (The names of the GND and VCC layers are arbitrary). I hope that I am correct in assuming this, but I was thinking that if I make a VCC layer, all components that connect to VCC will simply route to this layer automatically. If this is correctly implemented, I should not see any routing lines for VCC. However, when I run the autorouter, I am still seeing VCC routing connections running across the TOP and BOTTOM layers, which seems to indicate the components are not correctly connecting to the VCC layer. I would like your help, and I have included some images to explain my current configuration.

I have created each layer (as seen in the visible layers window), and for VCC and GND I have made polygons which cover the entire board.

For the VCC polygon I have the following settings:I would kindly appreciate your help! I'd be happy to include any additional information.

I am running the freemium educational version v9 of Eagle.

Re: Trying to have both GND and VCC pours for a 4-layer PCB

C.Nicks — Fri, 27 Apr 2018 18:42:29 GMT

Hi Nicholas,
I've never used the auto router, but what I would suggest is pre-routing the power connections with vias.

Start a route at the component and then drop a via. The via will be considered connected as long as it's within the polygon pour. I think then the auto router will stop attempting to place vcc routes since they will already be connected.

Personally I tend to re-route most of the power connections in my boards this way, even if I haven't created the polygons yet. I'll place the components, put a gnd s via next to the pad, then do a route straight to a via. Later in the process I will put in the power and gnd polygons for them to connect to.

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Trying to have both GND and VCC pours for a 4-layer PCB

Re: Trying to have both GND and VCC pours for a 4-layer PCB