Board-to-Board Stacking with the DF40 Series
The Hirose DF40HC(3.5)-80DS-0.4V(51) is an 80-position receptacle from the DF40 series of mezzanine board-to-board connectors. It uses a 0.40mm pitch and a dual-row layout with center strip contacts, designed for parallel PCB stacking at a fixed mated height of 3.5mm.
The 0.40mm pitch packs 80 circuits into a narrow footprint, which means the board layout needs fine trace routing and via clearance. The receptacle is surface-mount only, so the solder paste stencil and reflow profile must be matched to the 0.40mm pitch to avoid bridging between adjacent contacts.
Position Count vs the 60-Position Sibling
The DF40HC(3.5)-80DS-0.4V(51) shares the same 0.40mm pitch, 3.5mm stack height, gold plating, and SMT termination as the 60-position DF40HC(3.5)-60DS-0.4V(51). If your BOM calls for 60 I/O lines, the 60-position variant saves board space and cost; if you need the full 80, this is the part. No other spec changes between the two.
Mating Half and Assembly
This receptacle mates with the corresponding DF40 series header that has the same 0.40mm pitch and 3.5mm stacking height specification. The header is also a surface-mount, center-strip-contact design. When ordering, match the header's position count to this receptacle's 80 positions. The gold flash on both halves is adequate for the few mating cycles a mezzanine connector sees in production — the contacts are not designed for repeated field disconnect.