0.40mm Pitch, 0.80mm Stack — the Board-Level Fit
The Hirose BM20B(0.8)-30DS-0.4V(53) is a 30-position receptacle from the BM20 series, built for dense board-to-board mezzanine stacking. The 0.016" (0.40mm) pitch and 0.031" (0.80mm) mated height define the tightest envelope in this class — the 0.8mm stacking height means the two PCBs sit nearly flush, which drives the component clearance on the underside of the top board. Gold-plated center strip contacts handle signal duty; the dual-row layout packs 30 circuits into a footprint that fits inside a thumbprint.
Solder Retention for Vibration Resistance
The connector includes solder retention features — small metal tabs on the sides that reflow to the PCB pads. These take shear and peel stress off the signal contacts during handling or low-level vibration, which matters when the mated pair is inside a portable device or an enclosure subject to shipping shock. Surface-mount termination with gold contacts keeps contact resistance stable through the reflow cycle.
The BM20 series offers the same 0.40mm pitch and 0.80mm stacking height across multiple position counts. The 30-position BM20B(0.8)-30DS-0.4V(53) sits between the 24-position BM20B(0.8)-24DS-0.4V(53) and the 34-position BM20B(0.8)-34DS-0.4V(53), with a 40-position variant also available.
No official second-source cross-reference exists, but the BM20 series is a Hirose proprietary footprint — the mating header is a Hirose BM20 series plug with matching 0.40mm pitch and 0.8mm stacking height.