Gerber files -- all over the place

extensions as they're required by the PC house?

Yes. Match the layer descriptions from your PC house to the purpose of each of your RS-274-X files. Include a short text file showing the names and purpose of each of your files. Share all the info you can with them. See this, from my favorite PCB house for example:

Proof each of your re-titled files using a Gerber Viewer like 'Gerbv' before you press the 'send' button. Correct any unintended offset and scaling issues before the files go to the vendor.

HTH!

--Winston

Ok thanks -- so renaming the file extension is ok too?

For example my file is project.gb0 (bottom layer copper), project.gb1 (top layer copper).

The PC house wants --

projectcopper1.gtl

projectcopper2.gbl

Obviously, the t is for top and the b is for bottom.

tensions as they're required by the PC house?

- I have another PCB program that uses .gbr on everything, then a drill.drl= ?

drill.txt

It's confusing because Gerber files are kind of dumb, they're just a bunch of coordinates in ASCII text format. A related but different format is used for drilling. Way back when computers were new and exciting, their numerical nature (as opposed to analog) caused some things to be called "numerically controlled", NC. So that's your NC drill. Sometimes people will call it a "tape" because guess what? Back then, they used punched paper tape to hold the numerical data. Of course, no one does THAT anymore, but why is a movie captured on a cell phone called "taping"? :)

So because gerber files are dumb, YOU need to be smart, or at least very clear. Since they're just a bunch of coordinates, there's nothing special *in* the Gerber file that indentifies it specifically as being top layer copper or bottom silkscreen, for example.

So you either rename the files *OR* supply a seperate ASCII text file explaining the mapping to the vendor. Since the vendore is the guy building the board, and he's probably used to a particular way of doing things, to ensure success, you have to work with him and work it out.

On your CAD tool, there should be a way to determine the name of each gerber output file.

Next time, it's best to have all this crap set up clearly from the start. Have a in-house standard naming convention for your CAD tool.

Also, I hope you followed their manufacturability guidelines and didn't use 4 mil lines everywhere just because you could, even though you could have used 10 mil tracks. And make very sure you understand how they want the bottom layer data. Usually you DON'T mirror the gerbers, but you DO write in reverse on the bottom layers!

Put targets on your layout, and use plenty of text notes to make sure everything is crytstal clear.

Did you indentify each layer in text outside the PCB area on your design?

layer copper).

The Gerber format itself, AFAIK, does not specify how the filename base or extension should be constructed. That said, there are some de facto standards that have arisen.

lists some of the common ones. Sounds like your board house prefers the Protel style, which is indeed quite widely recognized.

It's often helpful if the filename base includes the layer description, e.g., MyProject_TopSilkScreen.gto, MyProject_TopCopper.gtl, etc., and also include a ReadMe.txt that matches names to layers. More information is generally better than too little...

Some online board houses will also accept your files as a zipped bundle and then as you online to specify which file goes where in the stack.

--
Rich Webb     Norfolk, VA

layer copper).

You can use any filename and extension on your Gerber file. It's just a text file, human readable. If it makes your board house happy, rename to their convention. Easy to write a batch file to do the renaming.

It sounds to me that:

gtl is top copper layer gbl is bottom copper layer

bt0 and gb0 could be solder masks gts and gbs could be silkscreens

(possibly the other way around)

drill.txt is the drill file, not viewable in all Gerber file viewers, sometimes it has the .drl extension

--
 - Don Klipstein (don@donklipstein.com)

PADS defaults to this:

Directory of C:\2\GERBERS

07/25/2011 12:56 PM . 07/25/2011 12:56 PM .. 12/08/2009 12:04 PM 113,690 art001.pho 12/08/2009 12:04 PM 2,025 art001.rep 12/08/2009 12:04 PM 37,622 art003.pho 12/08/2009 12:04 PM 861 art003.rep 12/08/2009 12:04 PM 891,615 art004.pho 12/08/2009 12:04 PM 823 art004.rep 12/08/2009 12:04 PM 1,872,331 art005.pho 12/08/2009 12:04 PM 823 art005.rep 12/08/2009 12:04 PM 30,668 art006.pho 12/08/2009 12:04 PM 861 art006.rep 12/08/2009 12:04 PM 1,080,482 art007.pho 12/08/2009 12:04 PM 823 art007.rep 12/08/2009 12:04 PM 89,879 art008.pho 12/08/2009 12:04 PM 1,372 art008.rep 12/08/2009 12:03 PM 811,123 dd001024.pho 12/08/2009 12:03 PM 351 dd001024.rep 12/08/2009 12:03 PM 17,304 drl001.drl 12/08/2009 12:03 PM 20,359 drl001.lst 12/08/2009 12:03 PM 587 drl001.rep 12/08/2009 12:04 PM 27,756 pgp002.pho 12/08/2009 12:04 PM 1,103 pgp002.rep 12/08/2009 12:04 PM 76,971 sm001021.pho 12/08/2009 12:04 PM 1,599 sm001021.rep 12/08/2009 12:04 PM 34,088 sm008028.pho 12/08/2009 12:04 PM 1,064 sm008028.rep 12/08/2009 12:04 PM 200,734 ssb008029.pho 12/08/2009 12:04 PM 351 ssb008029.rep 12/08/2009 12:04 PM 269,337 sst001026.pho 12/08/2009 12:04 PM 431 sst001026.rep 30 File(s) 5,587,033 bytes 2 Dir(s) 26,160,336,896 bytes free

I don't think any board house has ever complained.

John

extensions as they're required by the PC house?

have another PCB program that uses .gbr on everything, then a drill.drl?

drill.txt

I know what you mean about the names being all over the place.

I just label my gerber extensions so they make sense to me, in English... Silkscreen-top, sm-top, layer1-Top, layer2-Bot etc.

These PCB companies seem to get it right most the time by themselves. Usually you will put text on the copper layers saying component side top, and bottom solder side or something like that.

That's about all I can do since the gerber file is usually going to be read by a Chinese person anyway.

A textual description of the filenames in the drill drawing is also a good idea.

boB

extensions as they're required by the PC house?

Crikey! what a lot of work.

I use a fab that takes my composite .PCB file and separates it themselves, and if I were faced with that lot I'd go hunt for a fab that took native files from the PCB program you use.

The less post-design work you need to do to massage your design into fab-consumable format, the less chance of messing it up. KISS.

xtensions as they're required by the PC house?

-- I have another PCB program that uses .gbr on everything, then a drill.dr= l?

drill.txt

"Right reading" was the term I came across many years ago. So, you'd put reverse text on the bottom layer, because somehow registration marks don't seem to mean much to those viewing the "human readable" output.

Never laid out a board using crepe tape and donuts, did you?

Jim

extensions as they're required by the PC house?

Nah. This is one of those things that sounds like a lot of work but goes very quickly and easily. It's almost more trouble to describe the process than to just do it. :)

Gerber has always worked great for me, from a number of different PCB editors.

My experience runs a little counter to that. I caught a vendor placing features on a board that I had clearly decided against. Then I caught a layer misalignment of > 1 cm in two directions. Checking is good.

--Winston

Yup. Two layers. Several chips. It worked too. Dayum. I never want to *that* again. :)

--Winston

What about back in the mid 1980's and before?

My father did PCB fab back then, and did PCB layouts with tapes and donuts. At 4x or 5x or whatever scale works we4ll here ...

Next step was to put the large-size drafting page with tape/donuts on a large light table, to be photographed with a "large format" camera - an old-fashioned beast with bellows between the lens and the the film.

Next, the film gets placed on top of a photo-resist-coated copper-clad board. Then, irradiate from a cluster of "blacklight" fluorescent lamps with peak wavelength around 360 nm.

After that, dunk the boards in a solvent that removes other-than traces, donuts, etc. , then dunk the boards in etchant.

Only thing remaining to do then is to drill the holes - which a "good drill tech" can do 50 per minute with the proper tool. I like to think I can do 57 per minute, but I "got that far" just as this was being obsoleted by PCB manufacturing processes that did not need a human drilling holes, also by surface-mount technology obsoleting need for most of the donuts and the holes in them.

Nest step was "stuff-and-solder". After that, clean the flux from the boards if they were "wave-soldered". I got work back around 1986 doing that, but more recently that is done more by machines than by humans.

--
 - Don Klipstein (don@donklipstein.com)

Certainly did, Jim. In fact I probably still have some tape and pads in the back of the workshop even now.

With that modern software stuff it's a long-gone memory. But there's no need to make the job not only harder than it has to be but also more likely to introduce errors.

extensions as they're required by the PC house?

First time I send work to a new fab (*) I ask for the layer separations - which is done by CAM350 or similar software - to be emailed back to me for checking, to make sure their system and my .PCB files are on the same page. Thereafter I send the .PCB file with a reasonable expectation that it will come out right. So far it has.

(*) It's not that I change fabs at all often. But if I get jerked around - as I was by CustomPCB - I'm not hanging around. I'm there to get a product, not a life experience. Have been with pcbcart for over three years, no glitches whatsoever.

My first photolith project was ca. 1979 and it wasn't nearly that nice. It was 1:1 so any um 'imperfections' were easy to see in the copper. I thought my local Bishop Graphics store was a wonderland!

There was a company in my area that had four expensive 'stat cams'. They'd do a photo-reduction and/or reversal for a few dollars. I was a customer for PCB and front panel artwork. The shrunk artwork always looked so much more *professional* than the source drawing!

It pains me to realize those great machines probably got tossed into a landfill a decade ago.

The 'Po-boy' version was heated ferric chloride in a pyrex tray, as you know. Yellow Fingers!

Off-center holes still make me cringe. I made plenty of them.

At Xerox we had our very own wave solder machine. It was a 'production' unit we used before assembly was shipped off to China.

All dinosaurs! Clomp your right forepaw!

--Winston

(...)

I see that they accept Eagle *.brd files directly. That is a terrific feature!

--Winston

extensions as they're required by the PC house?

I'm not a big fan of sending out live design files, when derivative files will work (ie. send out gerbers rather than .MAX files, or PDFs rather than .DOCX or .INDD files). It hides information and and gives you more control.

It tends to move some of the potential mess-ups to someone else's area of responsibility. Going through the extra steps of generating gerbers and doing DRCs by another program, checking netlists manually, etc. adds a lot to the confidence level, IMHO.