The Hirose FX11LA-120P/12-SV(92) is a 120-position header from the FX11 series, designed as a board-to-board mezzanine interconnect. It uses a 0.50mm pitch and a 2mm mated stack height, placing it in the high-density, low-profile segment of parallel board stacking. The outer shroud contacts with gold plating at 4.00µin suit signal-level duty where repeated mating cycles are moderate — think portable electronics, handheld instruments, or any assembly where board spacing is tight and position count is high. The ground plate and board guide features help align the connector during SMT placement and provide a low-impedance return path, which matters for signal integrity in dense digital designs.
Board Layout and Assembly Considerations
The 1.90mm height above board is the standoff after soldering — the mating receptacle sits on the opposing board at the same height, giving a total 2mm stack between PCBs. The board guide eases alignment during manual or automated mating, and the ground plate ties to the board ground plane through multiple solder tabs, which helps control EMI in high-speed designs. The 0.50mm pitch demands careful PCB layout — trace routing between pads is tight, and a four-layer board with buried vias is typical for fanning out 120 signals.
The closest sibling in the FX11 series is the FX11LA-100P/10-SV(92), which shares the same 0.50mm pitch, 1.90mm height above board, and 2mm stack height but carries 100 positions instead of 120. The 140-position variant FX11LA-140P-SV(22) exists for even higher density, but note it lacks the ground plate feature present on the 120- and 100-position versions, which may matter for EMI performance.