4 Layer Gerber Generation

On 03/23/2011 08:35 PM, rybarnes wrote:

Hi,

 

I'm working on a 4 layer mixed signal board. I'm  working on generating gerbers but it seems to not be working correctly. This could just be my ignorance, but I want to make sure I get this right.

 

My layers are stacked up as such right now:

Signals

Digital Ground

Supply

Signals

 

When I generate my gerbers, I run into no problems. When I go to view the gerbers of the internal layers, I'm expecting to see planes with isolation around vias that should not be connected to that layer. However, I'm only seeing filled in pads and vias. I'm always confused when interpreting gerbers, but that certainly doesn't seem right to me.

 

I'm confused with what I'm looking at, as it isn't what I am anticipating, so it may be correct, I just want some reassuarnce.

 

Thanks!

 

If you use a supply layer type then the output is negative. What yous

see on the Digital Ground and Supply are missing copper.

If you change the supply layer to a normal layer and then put down named

polygon(s) covering the layer. Name the ploygon the net name you want

the plane to be. The gerbers should then all be positive.

Paul R.

On 03/23/2011 08:35 PM, rybarnes wrote:

Hi,

 

I'm working on a 4 layer mixed signal board. I'm  working on generating gerbers but it seems to not be working correctly. This could just be my ignorance, but I want to make sure I get this right.

 

My layers are stacked up as such right now:

Signals

Digital Ground

Supply

Signals

 

When I generate my gerbers, I run into no problems. When I go to view the gerbers of the internal layers, I'm expecting to see planes with isolation around vias that should not be connected to that layer. However, I'm only seeing filled in pads and vias. I'm always confused when interpreting gerbers, but that certainly doesn't seem right to me.

 

I'm confused with what I'm looking at, as it isn't what I am anticipating, so it may be correct, I just want some reassuarnce.

 

Thanks!

 

If you use a supply layer type then the output is negative. What yous

see on the Digital Ground and Supply are missing copper.

If you change the supply layer to a normal layer and then put down named

polygon(s) covering the layer. Name the ploygon the net name you want

the plane to be. The gerbers should then all be positive.

Paul R.

"Paul Romanyszyn" <pgr@arcelectronicsinc.com> wrote in message

news:imefgc$od7$1@cheetah.cadsoft.de...

On 03/23/2011 08:35 PM, rybarnes wrote:

>> Hi,

>>

>> I'm working on a 4 layer mixed signal board. I'm  working on generating

>> gerbers but it seems to not be working correctly. This could just be my

>> ignorance, but I want to make sure I get this right.

>>

>> My layers are stacked up as such right now:

>> Signals

>> Digital Ground

>> Supply

>> Signals

>>

>> When I generate my gerbers, I run into no problems. When I go to view the

>> gerbers of the internal layers, I'm expecting to see planes with

>> isolation around vias that should not be connected to that layer.

>> However, I'm only seeing filled in pads and vias. I'm always confused

>> when interpreting gerbers, but that certainly doesn't seem right to me.

>>

>> I'm confused with what I'm looking at, as it isn't what I am

>> anticipating, so it may be correct, I just want some reassuarnce.

>>

>> Thanks!

>>

If you use a supply layer type then the output is negative. What yous see

on the Digital Ground and Supply are missing copper.

 

If you change the supply layer to a normal layer and then put down named

polygon(s) covering the layer. Name the ploygon the net name you want the

plane to be. The gerbers should then all be positive.

Paul R.

You should include a text file in your Gerbers with your contact information

as well as a description of the layer files:

xxxxx.001    Layer 1 Signal Layer

xxxxx.002    Layer 2 Supply Layer

xxxxx.003    Layer 3 Supply Layer

xxxxx.004    Layer 4 Signal Layer

'Supply Layer'  would be interpeted as a negative layer.

If you change that to positve in eagle, you should note it the description

file for the board house.

eg:  xxxxx.003    Layer 3 Signal Layer

The board house does not care about the function of the Layer.

It helps to avoid confusion and you will get boards made the way you want

them to be.

Cheers

"Martin" <martin_rid@verizon.net> wrote in message

news:imgcgp$ti7$1@cheetah.cadsoft.de...

You should include a text file in your Gerbers with your contact

information as well as a description of the layer files:

 

xxxxx.001    Layer 1 Signal Layer

xxxxx.002    Layer 2 Supply Layer

xxxxx.003    Layer 3 Supply Layer

xxxxx.004    Layer 4 Signal Layer

 

'Supply Layer'  would be interpeted as a negative layer.

If you change that to positve in eagle, you should note it the description

file for the board house.

eg:  xxxxx.003    Layer 3 Signal Layer

 

The board house does not care about the function of the Layer.

 

It helps to avoid confusion and you will get boards made the way you want

them to be.

Afaik, gerber has instructions to tell the layer is negative, but Eagle

doesn't use them?

Morten Leikvoll wrote on Fri, 25 March 2011 04:34

Afaik, gerber has instructions to tell the layer is negative, but Eagle

doesn't use them?

I don't know, but I have never had a board house misinterpret a gerber file

from Eagle or even ask about positive/negative.  I know Eagle does

sometimes produce negative gerber files, because I've seen that in the

gerber viewer when I do a quick check of the files before sending them

out.

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