The Hirose BM23PF0.8-40DS-0.35V(51) is a 40-position receptacle with center strip contacts from the BM23 series, designed for board-to-board mezzanine stacking in space-constrained portable electronics. The 0.35mm pitch and 0.80mm mated stacking height let you squeeze a dense signal interconnect into a slim device stack — think smartphone mainboard-to-display, tablet battery-to-logic, or compact camera module interfaces where every tenth of a millimeter of Z-height is budgeted.
Pitch and Footprint — Routing Density at 0.35mm
At 0.35mm pitch, this connector demands a fine-line PCB footprint — standard 0.5mm-pitch routing rules don't apply. The dual-row layout packs 40 circuits into a narrow body, so the board designer needs controlled impedance traces and via-in-pad capability to escape the inner rows. The 0.80mm mated height means the connector sits low enough that components on the opposite board can clear it without a cutout, but tight enough that the solder paste volume and reflow profile have to be dialed in to avoid bridging between those 0.35mm-spaced pads.
For applications requiring thousands of cycles, a thicker gold layer would be specified; here the design assumes the connector is mated once at final assembly and stays that way.
Solder Retention and Surface Mount
The solder retention feature — metal tabs that reflow to pads on the board — adds mechanical hold beyond the signal pins alone. On a 0.35mm-pitch part, the signal pins are too fine to absorb shear or peel forces from cable strain or thermal expansion; the retention tabs take that load so the contacts don't lift during temperature cycling or handling. Surface mount only, no through-hole option — this part is built for automated pick-and-place assembly on a standard SMT line.