The Hirose DF40C-90DP-0.4V(51) is a 90-position plug with outer shroud contacts from the DF40 series of board-to-board mezzanine connectors. Its 0.016" (0.40mm) pitch and dual-row layout pack 90 circuits into a compact footprint, making it suitable for high-density interconnects in portable electronics, cameras, and handheld devices where board real estate is tight. The plug mates with the matching DF40C-90DS-0.4V(51) receptacle, and the six available mated stacking heights — 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, and 4mm — give the designer flexibility to set the board gap for component clearance or airflow.
The 0.40mm pitch drives the PCB footprint — expect fine-line routing and possibly blind vias to escape the inner rows. The gold contact finish at 2.00µin (0.051µm) provides corrosion resistance for repeated mating cycles typical in production test or field-replaceable modules; if your application demands thousands of cycles, consider a thicker plating variant in the DF40 family.
Mating and Stack Height Selection
This plug mates with the DF40C-90DS-0.4V(51) receptacle. The mated stack height is determined by the combination of plug and receptacle heights; the DF40C-90DP-0.4V(51) itself has a height above board of 0.045" (1.14mm). The six listed stacking heights (1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm) cover a range of board-to-board gaps from ultra-low-profile to moderate clearance. Confirm the receptacle height and the total stack height against your enclosure z-height budget before layout.