The Hirose BM28B0.6-40DP/2-0.35V(53) is a 40-position header from the BM28 series, designed for board-to-FPC interconnects where z-height is the tightest constraint. At a 0.014" (0.35mm) pitch across two rows, this connector targets high-density signal routing inside compact portable devices — think smartphone display links, camera module interfaces, or any assembly where the mated stack height is just 0.6 mm. The outer shroud contacts shield the signal pins during mate and provide the mechanical reference for the FPC alignment.
Pitch and Stack Height Drive the Board Layout
The 0.35 mm pitch is the dimension that governs the PCB footprint — it demands fine-line routing between pads and matches the corresponding FPC pad pitch. The 0.018" (0.46 mm) height above board keeps the connector profile low, and the 0.6 mm mated stacking height defines the gap between the main PCB and the FPC. That 0.6 mm is the number the mechanical designer works to for enclosure clearance.
Position Count vs the 36-Position Sibling
The BM28B0.6-36DP/2-0.35V(53) is the same pitch, same stacking height, same contact finish — the only difference is 36 positions instead of 40. No functional delta beyond the circuit count.