What This 0.40mm-Pitch Header Is For
The Hirose DF40TC-10DP-0.4V(51) is a 10-position, 2-row header from the DF40T series, using a 0.016" (0.40mm) pitch and outer shroud contacts. It's designed for board-to-FPC (flexible printed circuit) interconnects where the mated stack height sits at 0.045" (1.14mm) above the board — a common z-height for ultra-thin devices like smartphone display links, camera modules, and compact sensor boards. The gold-plated contacts (1.97µin finish) handle signal-level current, and the SMT termination with solder retention features keeps the part aligned during reflow.
If your board-to-board gap is larger, the DF40T series also offers variants with taller standoffs; the (51) suffix in the order code denotes this specific 1.14mm height version.