A mated pair measures 0.465 high. Instead, many of today's high-speed connectors descend from the DIN connector. The DIN connector provides a maximum of 96 contacts arranged in three rows on a 0.100-in. grid. Before engineers became concerned with signal integrity, they evaluated connectors and backplanes against mechanical criteria. Density, their only real concern, meant simply adding more rows to two-piece connector designs.
Signals still have to get into tightly spaced connector pins.
So staggered pins are common in high-density connectors. Signal modules contain either 72 or 144 contacts. For free information. EDN is a registered trademark of Reed Properties Inc, used under license.