The Hirose DF40TC(4.0)-40DS-0.4V(51) is a 40-position receptacle from the DF40T series, designed for board-to-board mezzanine stacking. It uses center strip contacts on a 0.016" (0.40mm) pitch in a dual-row layout, with a mated stacking height of 4mm. The connector is surface-mount and comes in Tape & Reel packaging, with pick-and-place and solder retention features for automated assembly.
The 0.40mm pitch is the tightest constraint for the board layout engineer — it forces finer trace widths and tighter via escape routing compared to a 0.50mm or 0.80mm pitch part. The dual-row arrangement at this pitch means the footprint is narrow, but the routing channels between pads are tight — expect to use micro-vias or blind vias to escape the inner rows.
SMT Assembly and Packaging
The connector is packaged in Tape & Reel (TR), which is the standard feed for high-speed pick-and-place lines. No manual handling or tray loading is needed — it feeds straight off the reel. Confirm the feeder pocket pitch on your placement machine can handle the 0.40mm pitch component body width.