70-Position Plug, 0.40mm Pitch — DF40 Series Mezzanine Interconnect
The Hirose DF40C-70DP-0.4V(51) is a 70-position plug with outer shroud contacts from the DF40 series, designed for board-to-board mezzanine stacking. The connector supports mated stacking heights from 1.5mm up to 4mm, giving you several z-height options for the same footprint. The contact finish is gold with a thickness of 2.00µin (0.051µm). That is a thin flash — enough for a stable connection in a few dozen mating cycles inside an assembled product, but not designed for frequent field reconnections. This plug is the male half of the DF40 mezzanine system. It mates with the corresponding DF40 receptacle. The base product number is DF40C.
Mated Stacking Heights and Board Spacing
The DF40C-70DP-0.4V(51) supports a range of mated stacking heights: 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, and 4mm. This is not a single fixed height — the actual stack height depends on which receptacle height variant you pair it with. The 0.045" (1.14mm) height above board for this plug is constant; the receptacle's height determines the final gap. If your board stack-up calls for a specific clearance, pick the receptacle that matches.