The Hirose DF40GL-44DP-0.4V(58) is a 44-position, 2-row header with outer shroud contacts from the DF40GL series, designed for board-to-board mezzanine stacking at a 1.5mm mated height. The 0.40mm pitch and 1.14mm height above board make it a fit for compact portable electronics — think smartphones, tablets, or wearable modules where every tenth of a millimeter of z-height is allocated before the enclosure closes.
The mated stacking height of 1.5mm is the single dimension that decides whether this connector works in your assembly. That 1.5mm is the gap between the two PCBs when the header mates with its matching DF40GL receptacle — the board thicknesses plus the component keep-outs on both sides must fit inside that envelope. The 0.40mm pitch means traces between pads are tight; a 4-layer board with microvias is typical for routing all 44 lines out from under the connector footprint. Gold contacts at 1.97µin thickness handle the 50-odd mating cycles a consumer device sees in its life without fretting corrosion.
Mating and Series Compatibility
This header mates with the DF40GL series receptacle — the DF40GL-44DS-0.4V(58) is the direct mating half, also 44 positions, same 0.40mm pitch, same gold plating thickness. The outer shroud contacts on the header align with the center strip contacts on the receptacle; the shield on the header body mates with the receptacle's shield to complete the EMI enclosure. No other DF40GL variant at 44 positions is a mate — the (58) suffix on both parts signals the same packaging and plating specification.