Electric connector assembly

An electric connector assembly comprises a first electric connector installed on a first circuit board and a second electric connector installed on a second circuit board and embedded with the first electric connector in the vertical direction, and the first electric connector comprises a first insulation body and two rows of first conductive terminals fixedly held on the first insulation body; the first insulating body is provided with a first base and a tongue part; the second electric connector comprises a second insulating body and two rows of second conductive terminals fixedly held on the second insulating body; the second insulating body is provided with a second base, a pair of longitudinal side walls and a pair of end walls, and the pair of side walls and the pair of end walls enclose a slot for the tongue part to insert; each first conductive terminal is provided with a first plate-shaped contact surface which is embedded and fixed on the butt joint surface of the tongue part and a first welding par