30-Position Mezzanine Receptacle at 0.40mm Pitch
The Hirose DF40TC(3.0)-30DS-0.4V(58) is a 30-position receptacle from the DF40T series, designed for board-to-board mezzanine stacking. It uses a 0.40mm pitch dual-row layout with center strip contacts, all gold-plated to 1.97µin.
What the 0.40mm Pitch and 3mm Stack Height Mean for Your Layout
The 0.40mm pitch is the tightest routing constraint on the board. It forces trace widths and spaces below 0.20mm on outer layers, which means a standard 1oz copper board with 0.18mm lines may work, but you will need a controlled impedance stack-up if any signals run above a few hundred MHz. The 3mm mated stack height is non-negotiable — the mating header must also be a DF40T-series part with the (3.0) suffix to achieve this height. If your board spacing is 3.5mm, you need the DF40TC(3.5)-30DS-0.4V(58) sibling instead. The gold plating at 1.97µin is thin — adequate for a few mating cycles during assembly and testing, but not for repeated field disconnect/reconnect. This connector is best treated as a semi-permanent board-to-board interconnect inside an enclosure that is not regularly opened.
SMT Assembly with Pick-and-Place and Solder Retention
The DF40TC(3.0)-30DS-0.4V(58) is a surface-mount receptacle with built-in pick-and-place vacuum pickup area and solder retention features.