Board-to-Board Mezzanine Receptacle for Tight Stack Heights
The Hirose DF40HC(3.0)-44DS-0.4V(51) is a 44-position receptacle from the DF40 series of board-to-board mezzanine connectors. It uses a 0.40 mm pitch and mates to a corresponding DF40 header to create a 3 mm stack height between parallel PCBs. The connector uses gold-plated center strip contacts in a 2-row layout, and the "HC" designation in the part number indicates the 3 mm stacking height variant.
The 0.40 mm pitch and 3 mm mated stack height define the board-to-board spacing. The 2-row center strip contacts keep the signal return path short.
Mating Connector and SMT Soldering
The connector is surface-mount only, and the gold-plated contacts are suited for reflow soldering. The 0.40 mm pitch means the solder paste stencil aperture and reflow profile need to be dialed in for fine-pitch SMT; standard 0.5 mm pitch profiles may bridge adjacent pads.