High density electrical connector with lead-in device

An electrical connector for being mounted on a mother board, comprising:

• an insulative housing defining a plurality of channels;
• a plurality of circuit boards partially received in the channels;
• and
• a spacer including a plurality of wafers defining a plurality of tunnels between every two adjacent wafers for receiving corresponding circuit boards, each wafer having a body portion, a plurality of terminals retained in the body portion and conductively contacting with signal traces formed on a corresponding circuit board, and a grounding bus covering on the body portion and having a plurality of grounding tabs for conductively contacting with grounding traces formed on the circuit board;
• wherein
• at least one grounding tab of the wafer forms a smooth slope portion at an upper end thereof for facilitating insertion of the circuit board;
• wherein the plurality of wafers are side-by-side arranged;
• wherein the body portion of each wafer defines in one side surface thereof a plurality of passageways for receiving the terminals and a plurality of slots for receiving corresponding grounding tabs of the grounding bus;
• wherein the grounding bus has a body plate covering another side surface of the body portion of each wafer, a flange vertically extending from an upper edge of the body plate and covering a top face of the body portion of each wafer, and a plurality of grounding tails depending from a lower edge of the body plate for insertion into corresponding through holes of the mother board;
• wherein the grounding tabs extend from the flange and are received in corresponding slots of the body portion;
• wherein the smooth slope portion of the grounding tab is adjacent to the flange;
• wherein the grounding bus forms a chamfered portion at a common boundary portion between the flange and the body plate of the grounding bus for facilitating insertion of a corresponding circuit board;
• wherein each terminal and each grounding tab respectively forms a contact point and a protrusion for conductively contacting with a corresponding signal trace and a corresponding grounding trace of the circuit board, respectively;
• wherein a pair of posts extend from opposite ends of the body portion in opposite directions;
• further comprising a fastening device attached to the housing for retaining the spacer and the circuit board to the housing;
• wherein the fastening device has a body wall and a pair of latch arms extending from the body wall;
• wherein each latch arm forms a latch projection, and wherein the housing defines a recessed cavity latching with the latch projection.