Assembly files or Fabrication files are recommended for PCBA orders to assist the assembly team with component placement. If insufficient information is printed in the silkscreen, or the details are not clear on the PCB boards then the assembly files can help confirm component placement and orientation.
The order form has a designated area that requests these files but they are optional. Not providing them, however, may cause delays.
What is an assembly/fabrication file?
Information exported in assembly layers varies by PCB design software but typically we are looking for something like this:
PDF format is preferred and top and bottom sides are required if components need to be soldered on both sides.
How do I export the assembly files?
Here are some guidelines on how to export these files from some popular PCB design software:
Note: The component information exported in the different layers differs for every PCB design software and will also depend on the particular footprint’s design. Please ensure that vital information is included in the assembly file or the silkscreen, such as orientation markers, component designators, and part outlines if possible.
In Eagle, open the .brd file and click the Layer Settings button. In the new window, select the following layers:
- tPlace (21)
- tNames (25)
- tDocu (51)
These Eagle layers should include the assembly data for the top side.
Click OK and go to File -> Print or click the print button on the main toolbar. Change the options while viewing the preview so that the board fits on one page but is large enough to be read clearly.
Click OK and save the file.
Do the same for the bottom side if needed by selecting the following layers:
Package these with the pick and place files and upload them to the order form.
Open up the kicad_pcb document and go to File –> Print, or click the Print Board button on the toolbar.
In the new window, select the F.CrtYd and F.Fab layer checkboxes, then change the Page Print to Single page.
You can preview the result using the Preview button to make sure everything is clear. Then once all looks good, click Print and choose the print to PDF option and save it.
Do the same for the bottom side if necessary (select B.CrtYd and B.Fab) and then you will have your assembly files. Package these up in an archive file with the pick and place files and upload them to the order form.