It uses a center strip contact arrangement on a 0.024" (0.60mm) pitch across two rows — a dense layout that keeps the board footprint tight while routing 140 signal lines. The receptacle is surface-mount, with a height above board of 0.089" (2.26mm), and supports mated stacking heights of 3mm and 4mm when paired with the matching FX8 series header. Gold contact finish handles the repeated mating cycles typical of production test or field-service boards.
The mated stacking heights of 3mm and 4mm give the board designer two z-height options with the same receptacle. That means one BOM line for the receptacle across two different card-to-card gaps — the header height determines the final stack. The 0.60mm pitch is tight enough that the PCB layout needs controlled impedance traces if running high-speed signals; the dual-row center strip arrangement keeps the signal return path short.
The gold contact finish and 0.60mm pitch match the listed series — confirm the mating header part number and the board-to-board stack height before committing the BOM line.
The FX8-140S-SV(23) shares the same 140-position count, 0.60mm pitch, gold finish, and 2.26mm height as the FX8-140S-SV(22) and FX8-140S-SV(21). The difference is packaging: the (23) suffix ships in Tape & Reel, the (22) in Cut Tape / Digi-Reel, and the (21) in Tube. For a high-volume pick-and-place line, Tape & Reel is the standard feed; for prototype or low-volume builds, the Cut Tape or Tube options avoid the reel minimum. The base FX8-140S-SV (no suffix) comes in Tray packaging. All four are electrically and mechanically identical — the choice is packaging logistics.