The Hirose DF9B-31P-1V(69) is a 31-position, dual-row header with center strip contacts, part of the DF9 series of board-to-board connectors. It uses a 0.039" (1.00mm) pitch and surface-mount termination, with gold-plated contacts at 8.00µin thickness.
The mating receptacle must match this pitch exactly — the DF9B-31S-1V(69) is the correct partner. The 4.3mm mated stack height is a fixed value, not adjustable; the designer must verify that the enclosure gap and the opposing board's component height clear this dimension. The dual-row layout gives 31 positions in a compact footprint, but the narrow pitch means the board layout engineer should check for adequate clearance between adjacent traces, especially if routing between the pads.
Gold vs Tin — Which Plating for Your Duty
For builds that require field-service reconnection or higher reliability over time, the gold-plated (69) version is the right call. The DF9-31P-1V(69) adds a board guide feature for alignment during assembly, while the DF9B version relies on solder retention alone — a difference in how the part self-aligns on the board before reflow.