Board-to-Board Mezzanine Header for Tight Stack-Up
The Hirose DF12(4.0)-40DP-0.5V(86) is a 40-position, dual-row header from the DF12 series, designed for parallel board stacking at a 4mm mated height.
At 0.50mm pitch, the trace routing between pads is tight — you'll need controlled impedance design if running high-speed signals. The 40 positions in 2 rows give you 20 per row, which keeps the connector length manageable for a 0.50mm pitch part. The 4mm stacking height is the fixed z-axis gap between the two PCBs; your enclosure and component heights on the bottom board must clear that envelope.
Obsolete — Sourcing the DF12(4.0)-40DP-0.5V(86) Now
No direct replacement is listed in the DF12 series with the same 4mm stacking height and 40-position count at 0.50mm pitch. For a BOM that needs this exact fit, the only channel is the surplus and broker market — we source traceable, date-coded stock against an RFQ.