Board-to-board mezzanine header for tight stacking
The Hirose DF12(3.0)-20DP-0.5V(80) is a 20-position, dual-row header with outer shroud contacts from the DF12 series, designed for parallel board stacking at a fixed 3mm mated gap.
Pitch and stacking height — the two numbers that decide fit
Two dimensions lock in the mechanical fit. The 0.50mm pitch sets the pad layout on both boards — the footprint is non-negotiable; any replacement must match that centreline spacing exactly. If your enclosure or mezzanine card cage was designed for that gap, a taller or shorter header won't fit without reworking the standoffs or card guides.
Mounting and board retention
The board guide aligns the header during reflow and takes the shear load when the mating half is inserted — keeps the solder joints from taking the full insertion force.