The Hirose DF12NB(3.0)-40DS-0.5V(51) is a 40-position, 0.50 mm pitch board-to-board receptacle from the DF12 series. Gold-plated contacts at 8.00 µ" are standard for signal-level interconnect in controlled environments like consumer electronics, handheld devices, and internal module-to-mainboard links.
The 3 mm Stack Height Is the Fixed Dimension
The mated stacking height is specified at 3 mm — not a range, not adjustable. That means the mating header must also be a DF12NB(3.0) variant with the same (3.0) suffix to achieve the correct board-to-board spacing.
Gold Plating for Signal-Duty Mating Cycles
The 8.00 µ" gold finish on the contacts is a signal-grade plating. It handles the moderate mating cycle counts typical of a mezzanine interconnect in a product that sees assembly and occasional field service — think a display module or a sensor board that gets swapped out. It is not specified for high-wear applications like frequent hot-swap or corrosive industrial environments, where thicker gold or a different contact system would be called for.
Solder Retention for SMT Reliability
The solder retention feature is a practical detail for an SMT connector at this pitch. The tabs on the connector body hold it in place on the board during the reflow process and add mechanical resistance to the shear force that a mated cable or board can apply. Without them, a 40-position, 0.50 mm pitch connector is vulnerable to lifted pads if the assembly sees vibration or handling stress.