Ultra-low-profile mezzanine receptacle for 0.6mm board stacking
The Hirose BM23FR0.6-50DS-0.35V(895) is a 50-position receptacle from the BM23 series, designed for board-to-board mezzanine connections where vertical space is at a premium. The mated stacking height of 0.6mm places it among the lowest-profile connectors available — this is the spec that decides the board gap, not just a number in a table. The 0.014" (0.35mm) pitch and dual-row layout pack 50 circuits into a footprint that fits tight routing corridors typical of handheld and wearable device PCBs. The solder retention feature adds mechanical anchoring to the SMT pads — without it, the narrow 0.35mm pitch leaves little copper area for adhesion, and board flex during handling can lift the outer contacts. This connector is used in applications like smartphone main-to-sub PCB interconnects, compact camera modules, and any assembly where the board stack height budget is measured in tenths of a millimeter.
Pitch and position count — what drives the footprint
At 0.014" (0.35mm) pitch with 50 positions across 2 rows, this receptacle demands a fine-pitch SMT footprint. The 0.35mm centerline spacing means the PCB land pattern requires tight tolerances — standard 0.5mm or 0.4mm pitch design rules won't clear the pads. The 0.024" (0.61mm) height above board means the component sits flush enough to allow airflow under the board in stacked assemblies, but the low clearance also makes visual inspection of solder joints difficult; X-ray or side-inspection camera is the usual call for process validation.
Comparing the 50-position to the 40- and 30-position siblings
The BM23FR0.6-50DS-0.35V(895) shares the same 0.014" (0.35mm) pitch, 0.024" (0.61mm) height above board, and 0.6mm mated stacking height with the 40-position BM23FR0.6-40DS-0.35V(895) and the 30-position BM23FR0.6-30DS-0.35V(51). If your BOM calls for 40 or 30 positions, the footprint length shrinks proportionally, but the pad pitch and land pattern geometry are identical, so a single PCB layout can accommodate any of the three by depopulating the outer pads.