Don't let the 0.50mm pitch fool you — this is a high-I/O mezzanine workhorse
The JST 100R-JMDSS-G-1-TF is the 100-position member of the JMD series, a dual-row receptacle with center strip contacts on 0.020" (0.50mm) pitch. The 100 contacts are laid out in two rows, giving you a compact, high-I/O interface for mezzanine stacking applications where board real estate is the constraint, not the z-height. The solder retention feature — integral hold-down tabs on the SMT package — prevents the connector from lifting during reflow and adds shear resistance once the board is populated. Mated stacking heights of 4.5mm, 5mm, and 6mm give the board layout engineer flexibility to match the overall assembly height without changing the connector footprint.
The 100R-JMDSS-G-1-TF sits at the top of the JMD series position range. The only sibling worth comparing is the 80R-JMDSS-G-1-TF: same 0.020" (0.50mm) pitch, same 0.122" (3.10mm) height above board, same dual-row layout, same gold contacts and solder retention. The difference is 100 circuits against 80. If your BOM calls for 80 I/O lines, the 80-position variant saves board space and cost. If you need the full 100, this is the one — there is no 120-position option in the series, so this is the maximum density point.