The Hirose BM28B0.6-30DS/2-0.35V(51) is a 30-position receptacle with center strip contacts, part of the BM28 series. It's the board-side half of a board-to-board mezzanine connection, designed to mate with a matching BM28 header at a fixed 0.6mm stack height. The 0.35mm pitch and 0.6mm mated height put this squarely in ultra-thin portable device territory — think smartphone mainboards, wearable PCBs, or compact camera modules where every tenth of a millimeter of z-height is budgeted. The gold-plated contacts and dual-row layout give it a signal-density advantage for high-pin-count interconnects in a small footprint. Solder retention features on the body hold the part steady during reflow — no extra fixturing needed on the SMT line.
Pitch and Footprint — The Tight Squeeze
At 0.35mm pitch, this connector demands a fine-line PCB process. The trace-and-space rules for routing out of the footprint need to match the 0.35mm centerline — standard 0.5mm pitch design rules won't clear. The 30 positions in two rows keep the board-edge footprint compact, but the breakout vias need careful placement to avoid necking down the traces.
Stack Height and Z-Height Budget
The mated stack height is 0.6mm, and the receptacle alone sits 0.024" (0.61mm) above the board. That means the total z-height from the bottom of the header's PCB to the top of the receptacle's body is about 1.2mm — tight enough that a 1.0mm-thick PCB plus a 0.6mm stack leaves almost no room for a stiffener or shield can above the connector. Plan the enclosure clearance accordingly.
RoHS compliant.
Comparing the 30-Position Variant
The BM28B0.6-30DS/2-0.35V(53) shares the same 30 positions, 0.35mm pitch, 0.6mm stack height, and gold plating — the only difference is the packaging suffix, which affects reel vs cut-tape quantity. For a prototype run or a low-volume BOM, the (51) variant in Cut Tape is the one to order; the (53) ships in Tape & Reel for automated assembly. No footprint or electrical difference between them. The 34-position siblings (BM28B0.6-34DS/2-0.35V(51) and (53)) add four more signal lines at the same pitch and stack height — same footprint length extension, same routing rules. If the BOM calls for 34 circuits, the 30-position part won't fit the header.