TE 5177985-1 — 40-Position Free Height (FH) Mezzanine Receptacle
The receptacle is surface-mount terminated and includes an integrated board guide to assist alignment during assembly. Typical use is stacking parallel PCBs at mated heights between 5 mm and 8 mm, common in compact telecom, networking, and server modules where signal density and board spacing are both constrained.
0.80 mm Pitch and Stack Height Range
The 0.80 mm pitch is the tightest standard in the Free Height family — the sibling 1-120532-2 runs at 1.00 mm pitch and carries 84 positions in a plug form factor. For the 5177985-1, the 40 positions at 0.80 mm pitch give a compact board footprint that still leaves room for two signal traces between pads on a typical PCB. Confirm the plug's stack height code against your board spacing before ordering.
This is a standard-duty plating grade — adequate for the moderate mating cycle counts typical of production board stacking and field replacement, but not specced for high-cycle hot-swap or corrosive environments. The gold layer prevents oxidation on the contact interface during the shelf life of unassembled boards.
No official cross-reference or second-source is on record; the 1-120532-2 is a different pitch and position count and is not a functional substitute. Stock both halves of the mating pair when you order — the receptacle alone is an orphan without its FH plug.