I needed a way to attach a Pi Zero to the back of a High Quality Camera in order to use it as a webcam, doc cam, or whatever. There is enough clearance on the camera and Pi sides to accommodate the components that protrude out of the back side of the boards.

I originally intended to use heat-set inserts, but I found that 2.5mm screws thread really well into the holes. Your mileage may vary depending on your printer.