Eagle and Gerber Files (easier!)

Monday, February 6th, 2006

I’ve been doing a little more experimentation with EAGLE and the included .cam files. I found that these should be more than sufficient for my needs (two-layer PCB, top and bottom soldermask, top and bottom solder stop and top silkscreen.) I just processed the ger274x.cam and the excellon.cam job files, uploaded my design to FreeDFM and they recognized all of the file contents. FreeDFM will analyze your design and correct or suggest fixes before you submit it for production.

To run these .cam job files:

  1. open up your .brd file, then
  2. from the menu: File -> CAM Proecessor (a new window will popup)
  3. from the menu: Select File -> Open -> Job…
  4. EAGLE should already be showing the contents of the ./cam directory under the main directory where EAGLE is installed, if not, navigate to it. Choose the gerb274x.cam file
  5. (Click through the tabs and make sure “mirrored” is not checked! I made the mistake of submitting the files with the top layers as normal and the bottom layers as “mirrored” and the boards came back wrong.
  6. Click on the Process Job button
  7. from the menu: Select File -> Open -> Job…
  8. Choose the excellon.cam file (make sure “mirrored” is not checked)
  9. Click on the Process Job button

List of files created from the two jobs:

  • combined3.plc – top silkscreen
  • combined3.cmp – component side copper (top side)
  • combined3.sol – solder side traces (bottom side)
  • combined3.stc – top soldermask
  • combined3.sts – bottom soldermask
  • combined3.gpi – Photoplotter info file
  • combined3.drd – NC drill file
  • combined3.dri – Drill station info file

You should download GC Prevue from www.graphicode.com. This is for Windows only. After you install, run the program and from the menu “import” all of the files that you generated above. You should see all the layers and the drill holes in the right place. (One way to make sure that your top and bottom layers are correct is to write text on the top and bottom traces layer…this way you know your GERBER files are right when you see the top layer text as normal, but the bottom layer text as reversed)

Here’s an article about the history of the Gerber PCB making process and the file format.

Eagle and Gerber Files

Tuesday, January 31st, 2006

Addendum:
We submitted the files to pcbexpress and they said that the .drl file was not the NC drill file. I had to run the excellon.cam job file to generate the .drd file.

Recently I had to use Eagle to adjust a colleague’s PCB layout. To install it on a Mac, first download and install X11. Next download Eagle from cadsoft and uncompress the file. You should now see a directory. Inside, there’s a readme.txt file that tells you to run a bunch of commands in the terminal so that you can use the ‘install’ script that’s in the directory…but immediately following these commands it says:

NOTE: the installation procedure described here is not mandatory.
You can just extract the TGZ archive to any location of your choice
and use it there directly. All the ‘install’ script does is to copy
the program and man-page to the default location and set up a
symbolic link to the executable in /usr/bin/eagle.

So, just copy the directory to your /Applications directory and you should be set.

Now (drumroll), in order to run Eagle you first have to start the X11 server. After X11 is up and running, double-click on the ‘eagle’ file in the ./bin directory in Eagle’s main directory. That’s it.

After creating your schematic and pcb layout, you need to generate the appropriate files to submit to a PCB manufacturer. Most of these places will require Gerber files. I’m submitting my designs to PCBexpress and I found these easy to follow directions on their site…to generate Gerber files from Eagle, download these .cam job files and follow these instructions.
These .cam files will generate the appropriate Gerber files for you to submit. For a two layer PCB (traces on top and bottom), you’ll use E1.cam or E2.cam. Here are the files that are commonly generated with the .cam files downloaded from pcbexpress:

.bot – bottom traces
.top – top traces
.bsk – bottom silkscreen
.slk – top silkscreen
.smb – bottom solder mask
.smt – top solder mask
.drl – drill tool file

Happy PCB designing! There’s something satisfying about laying out component and solving the puzzle of connecting them together without crossing wires. :)