Eagle: Mirror bottom layer for Gerber files?

[orthoefer]

Do board houses generally want the bottom layer for Gerber files mirrored or not? The Eagle CAM package automatically mirrors the bottom layer (solder side), and I am not sure if this is the thing to do. Any advice?

Converting to Gerber files seems archaic. Are there any GOOD board houses that accept the Eagle files without Gerber conversion?

[dsavitsk]

Originally posted by orthoefer
Do board houses generally want the bottom layer for Gerber files mirrored or not? The Eagle CAM package automatically mirrors the bottom layer (solder side), and I am not sure if this is the thing to do. Any advice?

I always unmirror it but really only so that it is easier to look at for me. I think that board houses should be fine with either so long as you tell them which it is.

[pinkmouse]

Yup, it's always worth putting some writing on each layer so that the guys at the board house can tell which way round everything goes.

[BWRX]

That's the whole point of Gerber files though, so they don't make any errors converting them for you and ending up having to redo your boards or possibly get bad press and bad karma.

Plus, their machines use the Gerber files and not the layout file. It's just all around easier for them and it won't change anytime soon. There are some board houses that accept layout files though, but the majority of them don't.

[poobah]

Agreed, Gerber is the very best way to convey the art. It is free from dithering and rounding errors that a raster approach can have (as opposed to Gerber's vector approach). Besides, there are zillion different file types for PCB CAD programs... a zillion+ are incompatible. Eagle is a cheesey program... be glad it's free and does Gerbers at all.

Also... don't mirror anything. Let the board house do all that. Send all layers registered to the same datum, all reading from the TOP of the board.