Hirose DF12B(3.5)-40DP-0.5V(86) — 0.50mm Pitch Mezzanine Header at 3.5mm Stack
The Hirose DF12B(3.5)-40DP-0.5V(86) is a 40-position, 2-row SMT header from the DF12 series of board-to-board mezzanine connectors. It uses a 0.020" (0.50mm) pitch and is designed for a mated stacking height of 3.5mm, making it a compact interconnect for parallel PCB stacking in space-constrained assemblies. The connector type is Header, Outer Shroud Contacts — the shroud protects the mating interface and guides alignment during board mating.
Solder Retention for Reflow Reliability
The retention tabs resist shear forces from the mating cable or board, preventing the connector from lifting off the pads during thermal cycling or mechanical shock.
Obsolete — Sourcing the Replacement
The DF12B(3.5)-40DP-0.5V(86) is marked Obsolete. Hirose has discontinued this exact order code. Confirm the mated stacking height and position count match the board layout before committing; the 3.5mm stack is specific to the DF12B(3.5) variant and may not be interchangeable with other DF12 stack heights.
The 0.50mm pitch drives the PCB footprint — the pad width and spacing are tight enough that a standard FR-4 board with 1 oz copper can route one trace between pads on the outer layers, but inner-layer breakout may require finer line widths or additional layers. The 3.5mm mated stack height sets the z-axis clearance between the two PCBs; the header's height above board is 0.110" (2.80mm), so the mating receptacle must add the remaining 0.7mm to reach the full stack. The 2-row layout with 40 positions means 20 contacts per row, which keeps the connector body length manageable — roughly 20mm — for a compact board edge or mezzanine layout.