Electrical connector system

An electrical connector system comprising:

• a circuit card assembly including a host circuit board, a socket connector mounted to the host circuit board, and a guide rail extending along the host circuit board, the host circuit board having a contact array of circuit board contacts on an upper surface of the host circuit board, the socket connector having a socket substrate having an upper contact array of upper contacts and a lower contact array of lower contacts electrically connected to corresponding upper contacts, the upper contacts having mating interfaces being accessible from above the socket connector and being coplanar, the lower contacts being electrically connected to corresponding circuit board contacts, the guide rail having a guide feature including a guide rib extending from the guide rail, the guide rail having a module actuator separate from the guide feature;
• a pluggable module including a module body having a top and a bottom extending between a front and a rear, the module body having a longitudinally extending guide feature including a channel receiving the guide rib and operatively engaging the guide rail to guide mating of the module body with the guide rail in a module mating direction parallel to the upper surface of the host circuit board, the module body having a window at the bottom proximate to the rear, the pluggable module including a module circuit board held by the module body, the module circuit board having a mating edge between an upper surface and a lower surface, the module circuit board having a module contact array of module contacts at the lower surface proximate to the mating edge aligned with the window with the module contacts exposed from below the module body for mating with corresponding upper contacts of the circuit card assembly, the pluggable module including an actuation feature at an exterior of the module body at the top of the module body separate from the guide feature, the actuation feature engaging the module actuator of the circuit card assembly, the actuation feature and the module actuator interfacing each other to force mating of the module contacts with the upper contacts of the circuit card assembly in a contact mating direction transverse to the module mating direction;
• and
• a lifter spring forward of the socket connector on the upper surface of the host circuit board, the lifter spring being compressible and imparting a spring bias on the pluggable module in a lifting direction to lift the pluggable module upward, wherein the guide rib is shifted vertically upward within the channel when the lifter spring lifts the pluggable module upward to move the pluggable module upward away from the host circuit board as the pluggable module is plugged into the socket connector and passes over the lifter spring prior to the actuation feature engaging the module actuator;
• wherein the module actuator forces the pluggable module to move downward against the spring bias of the lifter spring to mate the module contacts of the pluggable module with the upper contacts, wherein the guide rib is shifted vertically downward within the channel when the module actuator moves the pluggable module in the contact mating direction;
• and
• wherein the channel includes an upper wall and a lower wall extending along a linear path along an entirety of the channel between a front and a rear of the channel, the guide rib being movable vertically within the channel between the upper wall and the lower wall in the lifting direction and the contact mating direction, wherein the channel extends substantially along an entire length of the module body and the guide rib extends substantially along an entire length of the guide rail, wherein the guide rib is located entirely within the channel between the front and the rear of the channel in the final mated position of the module contact array and the upper contact array of upper contacts of the socket substrate.