Mezzanine Stacking Receptacle for Tight Z-Height Budgets
The Hirose DF40HC(2.5)-20DS-0.4V(51) is a 20-position, dual-row receptacle from the DF40 series, designed for board-to-board mezzanine stacking with a fixed mated height of 2.5mm. The 0.016" (0.40mm) pitch packs 20 positions into a compact footprint, making it a fit for space-constrained portable electronics, handheld devices, and internal module interconnects where the PCB stack height is tight. Gold-plated contacts with 2.00µin (0.051µm) finish on the mating surface handle the low-cycle mating typical of a one-time assembly — the plating is adequate for the few mate-unmate events during manufacturing and rework, not for repeated field service.
20 vs 50 vs 60 Positions — Same Footprint Class, Different Circuit Count
The DF40HC(2.5)-20DS-0.4V(51) shares the same 0.016" (0.40mm) pitch, 2.5mm stacking height, and dual-row layout with the DF40HC(2.5)-50DS-0.4V(51) and DF40HC(2.5)-60DS-0.4V(51). The difference is purely the position count — 20 circuits vs 50 circuits vs 60 circuits — which means the board footprint length scales with the number of positions while the z-height and pitch remain identical.
Termination is surface mount — the contacts are reflow-soldered to the PCB pads. The 0.40mm pitch demands a precise solder paste stencil and a controlled reflow profile; the narrow pitch means the board layout must maintain tight tolerance on pad position and trace routing to avoid shorts.