Gerber file is the standard format for PCB manufacturing, the common extension is .gbr. The designers can output the .gbr files from various software, such as Altium Designer, Allegro SPB, Orcad, Kicad, Eagle, and so on. In which, Allegro and Orcad belong to the same company Cadence, who is one of the leaders in the EDA industry.
The interfaces and operation methods of Allegro and Orcad are almost the same, the difference is that Allegro is to advanced design, while Orcad is to med & low ends design, limited but cheaper.
Next, follow me to export Gerber file from Allegro/Orcad step by step.
1. Before exporting the Gerber file, check the parameters of the drawing, the stack-up, the copper traces, and check the DRC report, which will help you to output Gerber file correctly.
1.1 Design Parameters
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The unit selected in the setup should be consistent with the unit set in Gerber, as well as the accuracy
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In order to guarantee WYSIWYG in Gerber, check the three boxes as shown
1.2 Copper Parameters
- Select "Shap" tab
- Click the button in the red rectangle, it will fill in/cut out the copper area automatically
- In the "Void Controls" tab, select "Gerber RS274X"
1.3 Stack-up Parameters
- Click "Setup Cross Section", as shown
- Check the stack-up parameters carefully
1.4 DRC Check
- Select "Display-Status",
- Click "Update DRC" to run DRC
- Click "Update to Smooth" to verify the setup errrors, if it is a gray botton, the copper parameters are correct
1.5 Darebase Check
- Click "Tools-Database Check"
- Check the three boxes as above, click "Check"
2. Folder and path of outputting Gerber file
- Select "Setup-User Preferences Editor"
- Select "Output_dir" in the red box on the left, then enter the name of the folder for exported Gerber file in the red box on the right
- Then select "Temp_file" in the left red box and enter the export path in the right input box
3. Gerber file output
- Select "manufacture-NC-NC Parameters",
- In the above figure, except for "format" and "output unit" should be adjusted according to the situations, the other parameters are kept as default. NC data (.txt) will be generated after clicking the close button
- Select "Manufacture-NC-Drill Customization", which will list all the drilling information currently used
- Click on the red box 1 in the above picture, allegro will automatically assign symbols to the holes on the current circuit board. Click on the red box 2, check all the drilling pads information. Click on the red box 3, the drilling information will be saved to the output Gerber file
- Select "Display-Color/Visibility", click the "Global Visibility Off" button in the upper right corner to close all layer displays
- Then open the OUTLINE layer alone
- "Manufacture-NC-Drill Legend", all are kept as default except for the boxes in the red rectangles
- Select "File-Viewlog" to check whether there are errors or warnings during generating the drilling data
- Execute "Manufacture-NC-NC Drill"
- Check the options in the three red boxes in the above figure, then click "Drill"
- Select "Manufacture-NC-NC Route", just click "Route" to generate the required milling file
- Select "Manufacture-Cross Section Chart", leave the setting default, then click "OK", the cross-section data will be hung on the mouse, you can place it on the appropriate location
- Select "Manufacture-Artwork", then select "Film Control" tab, check all the options in the red box 1 and click on the button in red box 2, which will generate the artwork file
- Come to "General Parameters" tab in the above figure, leave it as default
- In the "Film Control" tab, ensure there are 3 layers in each folder
- Then keep this window display while select "Display-Color/Visibility", please click "Global Visibility Off" to disappear the other layers and then display the outline layer manually, click "apply"
- Back to the "Film Control" tab, hover mouse upon any electrical layer, right-click, select "add", enter "outline" in the input line, "OK" then the displayed outline layer has already been added to the available films
- Similarly, turn off the display of all layers, open the display color manager, as shown, check "Pin" and "Via" in the Pastemask_Top layer, while "Pastemask_Top" box under "Package Geometry", then click "OK" to exit. Go back to the "Film Control" tab and create a new folder named "Past_Top"
- Again, create a new folder "Past_Bottom"
- Note that when creat "Sold_Top" and "Sold_Bottom" folders, one more step is needed, check "Soldermask_Top" and "Soldermask_Bottom" under "Board Geometry" directory in the color display manager
- Then create "Silk_Top" and "Silk_Bottom" folders in the same way, please check silkscreen layers in the color manager
- Add the drilling data in the same way as above
- Generate the capture range, select "Setup-Areas-Photoplot Outline", and draw a box that contains all the data
- Finally, select "Manufacture-Artwork", click "Select All", then "Create Artwork", the required Gerber file will get generated in the output folder
What design software do you use? Can you get the Gerber file easily? Please feel free to contact PS Electronics if you need assistance in your circuit board design or fabrication.
