Board-Stacking Interconnect for Dense Parallel Buses
The Hirose FX10A-140P/14-SV(71) is a 140-position, dual-row header from the FunctionMax™ FX10 series, designed for mezzanine board-stacking applications where signal density and a controlled impedance path matter. At a 0.020" (0.50mm) pitch, this connector packs 140 circuits into a compact footprint — typical for routing wide parallel data buses between processor and memory boards, or FPGA-to-transceiver mezzanines. The header mates with a matching FX10 receptacle to achieve a 4 mm mated stacking height, which sets the board-to-board gap. That 4 mm z-height is a common mezzanine standard — check your enclosure clearance and component keep-out zones before committing the footprint. The flash-grade gold is adequate for typical production and field-service cycles, but not specified for high-wear or corrosive conditions — if your build sees frequent reconnects or an unsealed industrial cabinet, consider a thicker-plate variant in the FX10 family. A built-in ground plate provides a low-inductance return path close to the signal pins, which helps contain loop area and reduce radiated emissions at high edge rates. The board guide eases alignment during blind mating — without it, the fine 0.50 mm pitch leaves little room for misregistration.
SMT Mounting and Board Retention
The 0.138" (3.50mm) height above board means the connector body sits low — helpful when the mezzanine card has tall components on the underside. Packaged in a tray, this variant is suited for manual placement or pick-and-place lines that handle tray-fed parts. If your line runs tape-and-reel exclusively, the sibling FX10A-140P/14-SV(91) is electrically identical and available in Tape & Reel, Cut Tape, and Digi-Reel packaging — same footprint, same stack height, same ground plate.
Comparing the 140-Position Siblings
The FX10A-140P/14-SV(91) shares every functional spec — 140 positions, 0.50 mm pitch, 4 mm stack height, gold plating, ground plate — but ships in Tape & Reel instead of tray. For a high-volume SMT line, the tape-and-reel packaging eliminates a tray-handling step and reduces feeder changeovers. The FX10A-140P/14-SV1(91) bumps the height above board to 0.177" (4.50mm), which changes the mated stack height — verify your board spacing if considering that variant. The FX10A-144P-SV(71) adds 4 positions (144 total) at the same 0.50 mm pitch and 0.138" (3.50mm) height, but omits the ground plate — a meaningful difference if your signal integrity plan relies on that return path. For a 144-circuit bus that can tolerate a slightly higher loop inductance, the 144-position part is a drop-in footprint match on the board edge.