Hello SerchMX,
Thanks for your reply. Mini-ATX, which is mainly a 15x15cm in size, would be too large for our cause.
What I'm looking for is about 70mm x 50mm in size that can directly be soldered on a carrier board from its all 4 sides. No edge connectors or board-to-board connectors.
I don't think there is a standard for that. I have come across with these kind of SOMs, but not one with an i.MX6 processor.
If those companies you mentioned have built a something similar, we might be interested in them.