0.40mm Pitch, 20-Position, SMT Header — DF37 Series
The Hirose DF37B-20DP-0.4V(75) is a 20-position header from the DF37 series of fine-pitch board-to-board connectors. The connector sits 0.030" (0.75mm) above the board surface and achieves a mated stack height of 0.98mm with its matching receptacle — a tight z-budget for compact handheld or wearable electronics.
SMT Mounting with Solder Retention
Surface-mount termination on a 0.40mm pitch demands precise stencil and placement alignment — the Solder Retention feature adds mechanical hold-downs that keep the header seated during reflow, reducing the risk of skew or tombstoning. The dual-row footprint routes traces between pads at this pitch; a typical PCB design uses micro-vias or blind vias to break out the inner rows.
Plating Grade and Mating Cycles
The (75) suffix variant carries 4.00µin (0.100µm) gold on the contacts, compared to the (53) variant's 2.00µin (0.051µm) gold. The thicker plating on this version supports more mating cycles — relevant if the connector sees field-service disconnect or test-stand use. For a one-time assembly in a sealed consumer device, the thinner plating may suffice; for a module that gets swapped or reworked, the (75) variant is the safer choice.