First time here, so please be patient if I do something wrong that is unique to this forum.
I am asking about creating a hat for a Raspberry Pi 4 that does not need header pins. I have a gap in my stack of hats that can hold the board I need, and I have seen sold products by Pimoroni and Sparkfun that are called shims that slot onto the Raspberry Pi header.
I don’t know if there is a layout for this type of connector already (I doubt it), but I’ll say this: there’s no way that a friction-fit (non-soldered) connection is going to be reliable. You need spring contacts to allow for board movement and tolerances. If you don’t mind soldering it, then it’s a pretty easy design, although a horizontal mount is going to require a very small diameter router bit, which might limit your PCB manufacturing choices.
What would you recommend for this then? I don’t mind soldering it, but I do want some flexibility early on when testing. I really do not want to put another header pin set on it (stacking header block) as it would become really tall for no real reason