Board-Stacking Design Fit
The Hirose DF40C-70DS-0.4V(51) is a 70-position, 2-row receptacle with center strip contacts from the DF40 series, designed for board-to-board mezzanine stacking. Its defining dimensions are the 0.016" (0.40mm) pitch and a mated stacking height of 1.5mm — the tight pitch packs 70 signal lines into a compact footprint, while the 1.5mm stack height sets the board spacing in a portable or handheld assembly where z-height is at a premium.
Mating and Board Layout
The 0.40mm pitch demands precise PCB land pattern alignment; the recommended footprint is available in the Hirose product drawing. The SMT pads are laid out in a dual-row staggered pattern to maintain signal integrity through the mezzanine connection.