Hirose BM24-20DS/2-0.35V(53) — 0.35 mm Pitch Mezzanine Socket with Power Pair
The Hirose BM24-20DS/2-0.35V(53) is a 22-position socket with center strip contacts from the BM24 series, designed for board-to-board mezzanine stacking at a fixed mated height of 0.80 mm. Its defining feature is the 0.014" (0.35 mm) pitch, which packs 20 signal contacts and 2 additional power contacts into a compact two-row footprint — the power pair handles higher current duty while the signal rows manage fine-pitch routing.
Position Count and the Power Pair
The BM24-20DS/2-0.35V(53) carries 22 positions total, broken out as 20 signal contacts plus 2 dedicated power contacts. That power pair is sized for a higher current path than the signal lines — useful for distributing board-level power in a mezzanine stack without routing it through the fine-pitch signal array. The two-row layout keeps the connector narrow, matching the 0.35 mm pitch for dense PCB routing.
0.80 mm Mated Stack Height — Fixed Mezzanine Spacing
The mated stack height is 0.80 mm, set by the connector's 0.031" (0.80 mm) height above board. This is a fixed-height mezzanine interconnect — the board-to-board gap is non-negotiable, so the mating header must match this exact height. The low profile suits tight enclosures where z-axis clearance is at a premium.
Mating Half and SMT Termination
This socket mates with the BM24-20DP/2-0.35V(53) header, which has a 0.65 mm height above board — the difference gives the 0.80 mm mated stack. The gold contact finish on both halves ensures consistent contact resistance over multiple mate-unmate cycles.
The BM24-20DS/2-0.35V(53) sits between the 26-position BM24-24DS/2-0.35V(53) and the 32-position BM24-30DS/2-0.35V(53) in the same series. All three share the 0.35 mm pitch, 0.80 mm mated height, gold contacts, and SMT termination. The choice comes down to circuit count: 22 positions (20+2) vs 26 (24+2) vs 32 (30+2). Pick the one that matches your BOM's signal and power line count.