3mm mezzanine stack – what it locks
The DF12NB(3.0)-20DP-0.5V(51): This is a 20-position, 2-row header from the Hirose DF12 series, pitched at 0.50mm and designed for a fixed 3mm mated stacking height between boards.
Solder retention and surface-mount fit
Surface-mount termination (SMT) with a 0.50mm pitch means the board footprint requires a fine-pitch solder paste stencil and controlled reflow profile; the solder retention pads help keep the part flat during reflow.
No single-vendor lock – the DF12 series is widely used and cross-shopped.
