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Author Topic: thoughts on this strange PCB/gerber file format  (Read 1618 times)
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Typically, PCB manufacturers seem to ask for 7 or so gerber files of the following formats:
pcbname.GTL (top layer), pcbname.GBL (bottom layer), pcbname.GTS (solder stop mask top), pcbname.GBS (solder stop mask bottom), pcbname.GTO (silk, top), pcbname.GBO (silk, bottom), pcbname.TXT (NC drill)

However, I am trying to learn to create a PCB modeling it on a simple evaluation board from the Texas instruments website, so I downloaded the zip file of gerbers they provided... So I have gerber files in these file formats (note the file extensions):
pcbname.TOP (top layer), pcbname.BOT (bottom layer), pcbname.TMK (top solder mask), pcbname.BMK (bottom solder mask), pcbname.BRD (board outline), pcbname.TSK (text top layer), pcbname.NCD (NC drill file, plated), pcbname.FAB

Question:
Assuming it's even necessary, how can I convert gerber files of the lower file extension formats into gerber files of the upper formats above, so I can send them to the pcb manufacturer?

SOLVED:
While the file extensions (as above) are different depending on the program used to create them, the files correspond to each other and contain the exact same information, as far as sending a PCB design out.
« Last Edit: October 23, 2011, 12:58:15 pm by johansson_81 » Logged

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The formats are the same, it is only the names that are different. There is no standard file extension for Gerber files (e.g., .AVI means video) so different CAD programs just make up their own.

It is sufficient just to rename the files (though unnecessary):

rename pcbname.TOP pcbname.GTL
rename pcbname.BOT pcbname.GBL

etc.

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RuggedCircuits, glad to hear that, thank you.

In that case, while the rest are fine, there are two mismatches I spotted in the two varieties:
pcbname.GTO (silk, top), pcbname.GBO (silk, bottom)
VERSUS
pcbname.BRD (board outline), pcbname.TSK (text top layer), pcbname.FAB

Any idea how the two silk layers would match to the files in the lower format?
one of them I can take a guess: GTO(silk top) = PSK (text top layer)
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Most likely the .TSK file and the .GTO file are the same in purpose. Also, it is quite possible the TI files have no silkscreen on the bottom layer hence there is no file provided.

As there is no standard for Gerber file extensions, there is also no standard as to what files are sent to a PCB manufacturer. The TI files, for example, come with a .BRD board outline, but this is not always a requirement and it is a file you don't seem to have from Eagle (though you can easily generate it by modifying the CAM file to generate an output based on the Dimension layer).

Same with the .FAB file...who knows what is in it? Various fabrication information that is optional and could also be communicated with a text file perhaps.

You can view the Gerber files yourself using a previewer such as GC-Prevue, ViewMate, or gerbv (my favorite) under Linux/Mac OS X. Then you can see what is in them and match them up with what you expect.

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Great, I'll try Viewmate and maybe view separate layers if that's possible on that software, as our university computers already have Viewmate, I believe.

Thanks again for the detailed answer.
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