The Hirose BM28B0.6-30DP/2-0.35V(51) is a 30-position, 2-row header from the BM28 series, designed for board-to-board mezzanine stacking at a tight 0.6mm mated height. Gold contact finish with 1.97µin thickness covers the mating surface, adequate for the limited number of mate/unmate cycles typical in a one-time assembly or field-replaceable module.
Stacking Height and Board Layout
The 0.6mm mated stacking height is the defining dimension for this connector — it sets the gap between parallel PCBs in a mezzanine stack. At 0.35mm pitch, the board-level routing needs fine trace and space geometries; expect to use microvias and controlled impedance if signals run at high edge rates. The 0.018" (0.46mm) height above board after soldering keeps the profile low, so components on the underside of the top board must be accounted for in the keep-out zone.
Contact Finish and Mating Duty
This connector is intended for applications where the boards are stacked once (or a handful of times during test and assembly) and then left mated for the product life. The outer shroud contacts provide alignment and some strain relief, but the gold flash means the contact resistance is stable for the first few mates only.