Incorrect orientation of components in Footprint Position File (KiCad)

Question

I am using a PCB(A) factory where they have an online system where you can get a preview of your PCBA once you upload your files. As part of the process, I have to upload the Gerbers, the Bill of Materials (BOM) and the component placement list (or footprint position file, as it's called in KiCad).

The last one is generated through the PCB Layout editor from the File --> Fabrication Outputs --> Footprint Position (.pos) File menu and contains the orientation of the components among other information.

The issue is that the orientation of most of the components is incorrect, according to the factory's preview system. Of course it doesn't matter that much for resistors and capacitors, but as you can imagine I have to manually rotate all the rest, everytime I place a new order or do a small change.

Am I doing something wrong or is there a convention for the KiCad footprints (e.g. pin 1 has to face at a certain corner always) that I am missing?

Answer 1

A big problem with position files is that there is more than one standard for the so called zero orientation of footprints. The official library uses zero orientation standard A from IPC-7x51. Simplified this means pin 1 is always at the top left corner.

There are other standards. For example the orientation B from the same standard that places pin one on the bottom left corner.

A more detailed explanation can be found here https://blogs.mentor.com/tom-hausherr/blog/2011/01/14/pcb-design-perfection-starts-in-the-cad-library-part-10/

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The situation is even worse regarding component orientation inside the tape. Typically it is however the responsibility of the board house to map the PCB zero orientation to the tape and then the machine zero orientation (tapes can be fed from different sides relative to the PCB orientation inside the machine)