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Richard Hammerl

Richard is an engineer with 16 years experience in EAGLE customer support and is waiting for your questions.

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e14 Contributor over 15 years ago

Hello Sir,
I am designing a 4 layered board in Eagle. My ground layer has 3 types of grounds namely GND,AGND,GND, which are supposed to be in the same layer GND.
one of my signal layer is $GND and so only my GND shows thermal vias on that layer while other (AGND,GND1) show isolated rings...plz help me with this poblem..
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Richard_H over 15 years ago in reply to e14 Contributor

Hello,

to realize three different GND signals within one layer, you have to use polygons in one of the inner signal layers. Please don't use a Supply layer (which has the a $ character at the beginning) because such a supply layer is displayed and plotted inverted and leads exactly one signal. The signal you specify with the supply layer's name.

So what you have to do is to use an inner layer and draw three different POLYGONs. Name the polygons the same as the signal they should belong to. And think about the polygon property "Rank" which determines the priority of the polygon. Additional help can be found in our FAQ:
http://www.cadsoftusa.com/training/faq/#17

Regards,
Richard
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e14 Contributor over 15 years ago in reply to Richard_H

Hello Sir,

It wa so kind of you to answer my query so quickly.

Sir, I did try out the polygon method. It does work but the main point is that it does not show thermal vias for any signal, may it be GND or VCC or 5V or any other.

My other colleages have designed a similar 4 layered board using PADS software. And the gerber viewer (we are using Gerbv) shows thermal pads for all the different types of grounds and powers that they have used, but it is not the case with Eagle..Please help me with this problem of mine..
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e14 Contributor over 15 years ago in reply to Richard_H

Hello,

Ok. Thank you for your help sir.

Tkhan
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Richard_H over 15 years ago in reply to e14 Contributor

Hi,

you can have inner layer with signal wires only or you can have inner layers with additional polygons. In terms of distortion, electromagnetic compliance, high speed designs and so on it can be helpful to use polygons. This depends on the project you are designing.

Regards,
Richard
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e14 Contributor over 15 years ago in reply to Richard_H

Hello Sir,

I meant if i route a signal in an inner layer and not draw polygon for that signal, will it affect the working of my PCB in any way??

Thank You,
Tkhan
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Richard_H over 15 years ago in reply to e14 Contributor

Hi,

I am not sure what you would like to ask. Could you please clarify?

Thank you
Richard
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Richard_H over 15 years ago in reply to e14 Contributor

Hi,

I am not sure what you would like to ask. Could you please clarify?

Thank you
Richard
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e14 Contributor over 15 years ago in reply to Richard_H

Hello,

Ok. Thank you for your help sir.

Tkhan
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Richard_H over 15 years ago in reply to e14 Contributor

Hi,

you can have inner layer with signal wires only or you can have inner layers with additional polygons. In terms of distortion, electromagnetic compliance, high speed designs and so on it can be helpful to use polygons. This depends on the project you are designing.

Regards,
Richard
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e14 Contributor over 15 years ago in reply to Richard_H

Hello Sir,

I meant if i route a signal in an inner layer and not draw polygon for that signal, will it affect the working of my PCB in any way??

Thank You,
Tkhan
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