Board-to-Board Mezzanine Fit
The Molex 5055502420 is a 24-position receptacle from the SlimStack 505550 series, designed for parallel board stacking. The 0.65 mm height above board and 0.8 mm mated stack height set the z-axis clearance between the two PCBs — a dimension you need to lock before the layout is final. Gold contact finish at 4.00 µ" is a light flash. It handles the moderate mating cycles of a mezzanine link — think a few dozen board separations over the product life — but it won't survive the repeated connect-disconnect duty of a field-service cable interface. The solder retention feature adds a mechanical anchor on the SMT pads. During reflow, it keeps the part from shifting as the solder paste wets; in service, it resists shear forces from the mating header or from board flex. For a 0.40 mm pitch part, that extra hold matters — the narrow pads don't have much grip on their own.