- Published: Thursday, 12 July 2018
- Written by Jon Chandler
- Hits: 834
Circuit boards are wonderfully cheap to had made (even with the "president's ill-conceived tariffs). Having custom circuit boards made is really open to everybody. But there are a lot of steps between finishing a circuit board design and having it ready to send to a fab house. I've developed a piece of software to make the process a little easier.
When the board design is finsihed, Gerber files must be generated. A file is required for each layer of the circuit board. Top and bottom copper - 2 layers. That doesn't seem so difficult. Actually, your board layout's CAM processor generates many more layers: the silkscreen layers showing the labeling of the board, the soldermask layers, paste layers if you're having a stencil made, the Excellon drill file, various layers showing routing and Vscores. The list gets pretty long.
The pcb fabricators like each of these layers to be the board name plus a particular extension for each. I like to include a readme text file listing the board parameters, including the name of the file for each layer. This gets pretty tedious! I have created the Gerber File Readme Generator to make this process a breeze. Enter in a few parameters, click a few boxes, and the file is written to disk. A very tedious task is done in a few seconds.
[Link to program at end of article]
The main screen is shown below. If you click the [file name] button at the upper left, the program will search for Eagle BRD files and allow you to click one to set the name. In the file selector box, you may choose to view Eagle BRD files, Gerber file names (a few common extensions are included) or all files. The file name, minus extension will be entered into the program. Alternatively, you may just type the file name (no extension needed).
Enter the board size in the next box. This is a free-form entry box, and doesn't check against the board files. Include the units, 100mm x 47mm for example.
The number of layers should be entered into the next box. Since I only make 2 layer boards, I didn't set the program up for more.
Click the appropriate check boxes under the Notes section and click the additional options on the left side of the screen and the program will make a pretty good guess at what layers you'll want to include. File extensions are pretty consistent among Chinese fabricators and are becoming increasrly common across the boardReview the checked layers on the right, add any notes and you're ready to click [Write File] at the bottom of the screen to write the file. Well, almost ready....
If this is the first time you're used the program, you'll need to set up your name, contact and shipping information. Click the gear symbol at the upper right of the screen to open the screen for this information. Once you've saved it, there's no need to enter it each time.
The resulting Readme file is shown below. It can be edited in Notepad if needed. Otherwise, create a ZIP file and copy the needed Gerber and Excellon files into it, along with the Readme file and you're ready to order boards.
A couple comments. I didn't include an option for Vscore. This allows you to score a straight line across the circuit board material so that smaller boards may be snapped apart. Vscoring leaves a rough edge instead of a smooth routed edge, and must run across the full board.
One of the options is "Board Outline Included on All Layers" - I include the outline of the board on all of the Gerber layers just to prevent confusion. It only needs to be on one of the layers rather than all of the layers, but doing so can (and has) resulted in delays when the fabricator overlooked the one layer where I had the outline and put a hold on the job until it was clarified.
This program was written in Visual Basic 6. Newer versions of Windows may require a file, comdlg32.ocx, be installed. I've included this file with the program file. Search the web on how to install it in your version of Windows. Gerber File Generator will run from any folder without any installation being required. Unzip and put all of the files in the same directory.
This is a link to my shared Dropbox file. I believe it will work. If not, please send me a message.
The site is not allowing me to upload the file.