Board-to-Board Mezzanine Connector for Tight Stack Heights
The Hirose DF12C-40DS-0.5V(81) is a 40-position, 2-row receptacle with center strip contacts on a 0.020" (0.50mm) pitch. The connector body sits 0.106" (2.70mm) above the board, and the same part supports three mated stacking heights — 3.5mm, 4mm, and 5mm — depending on which mating header you pair it with. That flexibility means one receptacle on the BOM can serve multiple board-spacing variants in the same assembly. It packs 40 signal lines into a compact footprint, but it also demands a PCB fab capable of routing between those pads — standard 0.5mm pitch design rules apply.
This is an SMT receptacle — it reflows onto the top side of one board. The mating half is a DF12 series header (the pin side) that sits on the opposing board. The three supported mated stacking heights (3.5mm, 4mm, 5mm) come from choosing the corresponding header height variant. The center strip contact arrangement means the mating interface is a row of flat contacts along the centerline of the connector body, not along the edges — this keeps the overall width narrow for dense layouts.
Sourcing the DF12C-40DS-0.5V(81) Now
Because this part is obsolete, the procurement path is the independent surplus and broker channel.