Eagle drillfile/gerber creation

[skrodahl]

Hi, I hope somebody will help me out here.

When creating drillfile and gerbers from Eagle, which (if any) gerbers should be mirrored/rotated?

I read in another post in this forum "Beware of CAM mirroring" but without any further explanation. A few days of searching the Internet has not revealed how to do this. The Eagle documentation just says run gerb274x.cam, and nothing more.

If I use gerb274x.cam in Eagle, the solder side gerbers are mirrored by default, causing complete misalignment when viewed in gerbv.

Gerbv won't display .drd-files correctly, so I have no idea if it should be mirrored or not.

I messed around with these settings until they aligned correctly in gerbv, and sent them off for production. The copper was the wrong way (what should be inwards to the board was outwards), and my silkscreen ended up on the copper side. Understandably I don't like this to happen again, so I'm hoping you will are kind enough to help me get it right.

Thank you very much.

-skrodahl

[BWRX]

Even if the layers are mirrored any reasonably competent board house will see that and can mirror them using whatever software they use to view the gerber files. Even so, I'll post more on how to do it correctly when I get home from work.

[BWRX]

After opening the gerb274x.cam file, click the in the CAM processor window click the solder side tab and just uncheck the box next to mirror. Do the same for the solder stop mask tab. Process the job and then view the results in your gerber file viewer. The layers should line up that way. They were the last time I did that and checked them in gerbtool (part of the orcad toolsuite).

[skrodahl]

Originally posted by BWRX
After opening the gerb274x.cam file, click the in the CAM processor window click the solder side tab and just uncheck the box next to mirror. Do the same for the solder stop mask tab. Process the job and then view the results in your gerber file viewer. The layers should line up that way. They were the last time I did that and checked them in gerbtool (part of the orcad toolsuite).

Thanks for the replies I've gotten so far.

Just to make sure I'm reading this reply correctly:
Are you saying that none of the gerbers should be mirrored?

-skrodahl

[marce]

Hi Skrodahl,
None of the gerbers should be mirrored.
Generaly the standard convention for providing gerbers is:-
Viewed from the top layer, usualy as they are designed on the ECAD system.
Preferably alligned, if not some reference points on each layer to allow easy allignment by the fabricator.
Instructions , minimum indicating the stack up, ie which gerber layer is the top, which is the bottom layer (for multilayer the inner layers stack up info). Required copper weight. Surface finish etc. The more info you supply the less guess work involved when the gerbers are put through the front end system.
RS-274X for gerbers and Excellon II for drill data. (Excellon II is the drilling equivilent of RS-274x, it has an emebdded drill table at the begining of the file, cuts out translating drill table errors.)

One of the reasons for not mirroring is that when the actual photo tools are created from the gerbers, they are created so that the emulsion layer (the actual image) is always face down to the copper, this avoids the image expanding as it passes through the film. Not so critical with wider tracks and gaps but every little helps. And most fabrication houses will be geared up to process data this way so it makes thier job easier and helps reduce errors.
Hope this helps.
Marc