JST JMD 40-Position Receptacle — 0.50mm Pitch, SMT, Gold Contacts
The JST 40R-JMDSS-G-1-TF(S)(LF)(SN) is a 40-circuit receptacle from the JMD series, designed as the board-mount half of a board-to-board stacking interconnect. The surface-mount termination and solder retention features suit it for reflow assembly in automated production lines. Typical use is as the lower board receptacle in a mezzanine stack, mating with the JMD series header to achieve mated heights of 4.5mm, 5mm, or 6mm — the height is selected by choosing the matching header variant.
Pitch and Stack Height — What They Mean for Board Layout
It drives the PCB footprint: each pad sits on 0.50mm centres, which limits trace escape width between pads to roughly 0.20mm on the inner layers. The mated stacking heights of 4.5mm, 5mm, and 6mm are set by the header side — this receptacle is the same height regardless, so the designer picks the header that gives the required z-height clearance above the top board. The 40 positions match a 40-signal BOM line; if your circuit count is 40, this is the one.
Solder Retention and Surface Mount Termination
The surface-mount termination means no through-hole soldering — the connector sits entirely on the board surface, which frees up the opposite side for other components. This is a standard SMT assembly process: paste, place, reflow.