US Patent 7794259 Electrical connector assembly for miniaturization

An electrical connector assembly (100) for connecting memory modules (200) to a printed circuit board (PCB) (300), includes a first and second connectors (10, 20) respectively mounted on two opposite surfaces of the PCB. The first and second connectors each defines an insulative housing (11/21) and a plurality of contacts retained in the housing. Each of the housing defines a front face and an inserted slot (13/23) running through the front face along a longitudinal direction. Each of the contacts defines an elastic arm partly projecting into the inserted slot and a soldering leg connecting to the PCB. The housing of the first connector provides a cavity (172) at a bottom portion thereof. A part of the second connector projects beyond the top surface of the PCB, and the soldering legs of the second connector run through the opposite surfaces of the PCB and enter into the cavity.