Board-to-Board Mezzanine Header for Dense Parallel Stacking
The Hirose FX10A-80P/8-SV1(91) is an 80-position header from the FunctionMax™ FX10 series, designed for parallel board-to-board mezzanine connections where board spacing is tight and signal density is high. The connector is surface-mount, with gold-plated contacts (4.00µin thickness) that handle the moderate mating cycle count typical of a production board stack. A built-in ground plate runs through the connector body to manage return current and reduce EMI between the stacked boards.
The 0.50mm pitch packs 80 signal contacts into a footprint roughly 20mm long — that is 40 contacts per row. Routing that density on a standard two-layer board is tight; you will likely need four or more layers to fan out the traces between vias. The 5mm mated stack height is the dimension to design for: the receptacle's own height plus the header's 4.50mm above-board profile add up to the 5mm post-mate gap, so your mezzanine board spacing is fixed at 5mm. The ground plate gives you a low-inductance return path right at the connector, which helps keep signal integrity clean on high-speed lines without relying solely on board-layer stitching.