The Hirose DF12A-40DS-0.5V(81) is a 40-position receptacle from the DF12 series, designed for board-to-board mezzanine stacking. A built-in board guide helps align the receptacle with its matching header during assembly, reducing the risk of stubbing the pins on the plastic housing.
Stack Height Range and Board Spacing
This receptacle supports three mated stack heights: 3.5 mm, 4 mm, and 5 mm. The height above the board for the receptacle alone is 2.70 mm. The stack height is set by the mating header variant, not by this part — so the engineer selects the header that gives the required z-gap between the two PCBs.
The DF12A-40DS-0.5V(81) is officially obsolete. There is no listed direct replacement from Hirose in the evidence. No pin-compatible equivalent from another manufacturer is on record.