51-Position Board-to-Board Header at 1.00mm Pitch
The Hirose DF9-51P-1V(69) is a 51-position, dual-row header with center strip contacts, designed for parallel board-to-board stacking at a fixed 4.3mm mated height. The 0.039" (1.00mm) pitch packs 51 circuits into a compact footprint — typical for tight mezzanine layouts in portable electronics, handheld instruments, and embedded modules where board real estate is at a premium. Surface-mount termination with integrated board guides and solder retention features helps align the part during reflow and holds it in place against the shear forces of cable or mating connector strain.
The 1.00mm pitch also sets the routing channel width between pads: at this density, a single trace between pads is standard, but two traces between rows requires a finer line-width capability. The solder retention features add a mechanical anchor to the SMT pads, which matters when the assembly sees vibration or repeated board separation.