I am thinking of using some Hirose DF40 PCB stacking connectors to stack together a bunch of PCBs. Each pair of PCBs would be connected by two connectors for mechanical stability.
These connectors do not have locating pins, so they rely entirely on the self-alignment effect during reflow to pull them into the correct position. Now, I can imagine that these connectors, being 0.4mm pitch, will self align pretty accurately in the X axis, but surely not so well in the Y axis.
This might not be a problem if only one connector was being used, but two connectors have to be lined up fairly accurately between the two PCBs. How well will they self align in the Y axis?
Does anyone have any experience with similar connectors in a similar situation?