Board-to-Board Header Selection Note
The Amphenol FCI 68405-128HLF is a 28-position, dual-row unshrouded header in the BERGSTIK II series, on the standard 0.100" (2.54mm) pitch that defines the board footprint for this class of interconnect.
Pitch first — the 0.100" (2.54mm) row and column spacing is the legacy 0.100-inch grid that matches the vast installed base of BergStik-compatible receptacles and breakout boards. The 28 positions, all loaded, mean the BOM line must call for exactly 28 circuits; no depopulated rows to manage. Right-angle mounting places the pin tails 0.095" (2.41mm) long below the insulator — verify the board thickness and through-hole plating depth to ensure the solder fillet forms correctly.