0.80mm Pitch, 40-Position SMT Receptacle for Board-to-Board Stacking
The Hirose FX6-40S-0.8SV(71) is a 40-position receptacle with center strip contacts, part of the FX6 series of fine-pitch board-to-board connectors.
Stack Height Options and Board Layout Fit
This receptacle supports three mated stacking heights — 5mm, 6mm, and 7mm — depending on which mating plug you pair it with. The 4.00mm board height on the receptacle side is fixed; the plug side determines the final stack. That flexibility means you can reuse the same receptacle across different board spacings in a product family, just swapping the plug height. The 0.80mm pitch gives enough routing space between pads for two traces per channel on a standard PCB, but the narrow pitch does limit current per contact — expect signal-level duty, not power delivery. The board guide feature is a molded alignment post that mates with a corresponding hole on the plug, taking shear stress off the solder joints during board assembly.
40 vs 50 Positions — Same Footprint Class
The FX6-40S-0.8SV(71) carries 40 positions. The FX6-50S-0.8SV(71) is the 50-position sibling at the same 0.80mm pitch and 4.00mm board height. Both use the same 0.80mm pitch and dual-row layout, so the footprint scales by adding contact pairs along the length — the 50-position version is physically longer. Choose the 40-position if your BOM calls for 40 circuits; the 50-position is there if you need the extra lines. No difference in plating, mounting, or packaging format between the two.