# how to include ground plate in two layers PCB

**URL:** <https://community.sparkfun.com/t/how-to-include-ground-plate-in-two-layers-pcb/15873>\
**Category:** PCB Design\
**Created:** [May 23, 2010, 8:22am UTC](https://community.sparkfun.com/t/how-to-include-ground-plate-in-two-layers-pcb/15873 "2010-05-23T08:22:58Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![natanel](https://avatars.discourse-cdn.com/v4/letter/n/e99b99/32.png) [@natanel](https://community.sparkfun.com/u/natanel)\
**Post date:** [May 23, 2010, 8:22am UTC](https://community.sparkfun.com/t/how-to-include-ground-plate-in-two-layers-pcb/15873/1 "2010-05-23T08:22:58Z")

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Hi

how in eagle I can dedicate as much of the bottom layer as possible to a groundplane.

so it will look like what brendan0powers did in his project

any automatic tool?

thanks

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**Author:** ![trialex](https://avatars.discourse-cdn.com/v4/letter/t/ea666f/32.png) [@trialex](https://community.sparkfun.com/u/trialex)\
**Post date:** [May 23, 2010, 8:35am UTC](https://community.sparkfun.com/t/how-to-include-ground-plate-in-two-layers-pcb/15873/2 "2010-05-23T08:35:46Z")

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Do you mean besides the “poly” tool?

You use it by selecting the ground layer, then either clicking the polygon tool or typing “poly GND” (substitute whatever your gnd traces are called, then just draw a rectangle around your whole board. If it doesn’t appear straight away, click the ratsnets button.

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<div class="post-metadata">

**Author:** ![natanel](https://avatars.discourse-cdn.com/v4/letter/n/e99b99/32.png) [@natanel](https://community.sparkfun.com/u/natanel)\
**Post date:** [May 23, 2010, 8:54am UTC](https://community.sparkfun.com/t/how-to-include-ground-plate-in-two-layers-pcb/15873/3 "2010-05-23T08:54:02Z")

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thanks

but now my entire bottom layer is ground

which erased all bottom wire

also now the auto wire is only using the top layer

how I can tell the auto wire to use bottom layer for wiring like in the picture?

thanks

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<div class="post-metadata">

**Author:** ![natanel](https://avatars.discourse-cdn.com/v4/letter/n/e99b99/32.png) [@natanel](https://community.sparkfun.com/u/natanel)\
**Post date:** [May 23, 2010, 1:34pm UTC](https://community.sparkfun.com/t/how-to-include-ground-plate-in-two-layers-pcb/15873/4 "2010-05-23T13:34:53Z")

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ok found it

it is poly and not rect

thanks

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<div class="post-metadata">

**Author:** ![natanel](https://avatars.discourse-cdn.com/v4/letter/n/e99b99/32.png) [@natanel](https://community.sparkfun.com/u/natanel)\
**Post date:** [May 24, 2010, 8:52am UTC](https://community.sparkfun.com/t/how-to-include-ground-plate-in-two-layers-pcb/15873/5 "2010-05-24T08:52:15Z")

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another question

in 2 layers PCB is it better ok to have both layer as poly ground (wire running inside them)

or only bottom layer as poly GND (like the picture)

thanks

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<div class="post-metadata">

**Author:** ![analogon](https://avatars.discourse-cdn.com/v4/letter/a/46a35a/32.png) [@analogon](https://community.sparkfun.com/u/analogon)\
**Post date:** [May 24, 2010, 3:41pm UTC](https://community.sparkfun.com/t/how-to-include-ground-plate-in-two-layers-pcb/15873/6 "2010-05-24T15:41:25Z")

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> in 2 layers PCB is it better ok to have both layer as poly ground (wire running inside them)
> 
> or only bottom layer as poly GND (like the picture)

Simple answer is both. I assume that "wire running inside them" refers to the traces that are not connected to the ground planes.

It may not be necessary at all, but it won’t hurt. It could help. If you really want to keep grounds solid, you might be able to add grounded vias between the layers to really parallel the grounding. I set the spacings to keep my ground plane 0.020 away from traces. That is not some general rule. I wanted some clearance.

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<div class="post-metadata">

**Author:** ![natanel](https://avatars.discourse-cdn.com/v4/letter/n/e99b99/32.png) [@natanel](https://community.sparkfun.com/u/natanel)\
**Post date:** [May 24, 2010, 6:18pm UTC](https://community.sparkfun.com/t/how-to-include-ground-plate-in-two-layers-pcb/15873/7 "2010-05-24T18:18:37Z")

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thanks all you really helping