The Hirose BM24-40DS/2-0.35V(53) is a 42-position socket with center strip contacts from the BM24 series — a mezzanine board-to-board interconnect family built for dense, low-profile stacking.
Position Count — 40 Signal Plus 2 Power
The 42 positions break down as 40 signal contacts plus 2 power contacts.
This socket mates with the BM24-40DP/2-0.35V(53) header, which carries outer shroud contacts and a 0.026" (0.65mm) height. The combined mated stack height is 0.8mm — the header sits lower, and the socket's 0.031" (0.80mm) profile sets the total z-height between boards. The 0.35mm pitch means the header and socket must align within a tight tolerance during board assembly; the solder retention pads on both halves help keep the parts registered through reflow.