A printed circuit board assembly, comprising: a semiconductor package; and a print circuit board, in the following also referred to as PCB; wherein the semiconductor package comprises: a base comprising an upper surface and a lower surface that is opposite to the upper surface; a radio-frequency, in the following also referred to as RF, structure embedded near the upper surface of the base; an integrated circuit, in the following also referred to as IC, die mounted on the lower surface of the base in a flip-chip manner so that a backside of the IC die is available for heat dissipation; a plurality of conductive structures (118, 120) disposed on the lower surface of the base and arranged around the IC die; and a metal thermal interface layer comprising a backside metal layer that is in direct contact with the backside of the IC die, and a solder paste conformally printed on the backside metal layer; and wherein the PCB comprises: an upper surface directly facing the lower surface of the base; a plurality of thermal vias within the PCB; a heat spreading structure mounted onto a lower surface of the PCB, wherein the heat spreading structure is in thermal contact with the plurality of thermal vias; characterized in that the PCB further comprises an array of conductive thermal pads on the upper surface of the PCB; wherein the plurality of thermal vias is under the array of conductive thermal pads; wherein the semiconductor package is mounted on the array of conductive thermal pads; wherein the solder paste is in direct contact with the array of conductive thermal pads; and wherein the array of conductive thermal pads comprises slits between the thermal pads and the slits are filled with the solder paste. a semiconductor package; and a print circuit board, in the following also referred to as PCB; wherein the semiconductor package comprises: a base comprising an upper surface and a lower surface that is opposite to the upper surface; a radio-frequency, in the following also referred to as RF, structure embedded near the upper surface of the base; an integrated circuit, in the following also referred to as IC, die mounted on the lower surface of the base in a flip-chip manner so that a backside of the IC die is available for heat dissipation; a plurality of conductive structures (118, 120) disposed on the lower surface of the base and arranged around the IC die; and a metal thermal interface layer comprising a backside metal layer that is in direct contact with the backside of the IC die, and a solder paste conformally printed on the backside metal layer; and a base comprising an upper surface and a lower surface that is opposite to the upper surface; a radio-frequency, in the following also referred to as RF, structure embedded near the upper surface of the base; an integrated circuit, in the following also referred to as IC, die mounted on the lower surface of the base in a flip-chip manner so that a backside of the IC die is available for heat dissipation; a plurality of conductive structures (118, 120) disposed on the lower surface of the base and arranged around the IC die; and a metal thermal interface layer comprising a backside metal layer that is in direct contact with the backside of the IC die, and a solder paste conformally printed on the backside metal layer; and wherein the PCB comprises: an upper surface directly facing the lower surface of the base; a plurality of thermal vias within the PCB; a heat spreading structure mounted onto a lower surface of the PCB, wherein the heat spreading structure is in thermal contact with the plurality of thermal vias; characterized in that the PCB further comprises an array of conductive thermal pads on the upper surface of the PCB; wherein the plurality of thermal vias is under the array of conductive thermal pads; wherein the semiconductor package is mounted on the array of conductive thermal pads; wherein the solder paste is in direct contact with the array of conductive thermal pads; and wherein the array of conductive thermal pads comprises slits between the thermal pads and the slits are filled with the solder paste. an upper surface directly facing the lower surface of the base; a plurality of thermal vias within the PCB; a heat spreading structure mounted onto a lower surface of the PCB, wherein the heat spreading structure is in thermal contact with the plurality of thermal vias; characterized in that the PCB further comprises an array of conductive thermal pads on the upper surface of the PCB; wherein the plurality of thermal vias is under the array of conductive thermal pads; wherein the semiconductor package is mounted on the array of conductive thermal pads; wherein the solder paste is in direct contact with the array of conductive thermal pads; and wherein the array of conductive thermal pads comprises slits between the thermal pads and the slits are filled with the solder paste. the PCB further comprises an array of conductive thermal pads on the upper surface of the PCB; wherein the plurality of thermal vias is under the array of conductive thermal pads; wherein the semiconductor package is mounted on the array of conductive thermal pads; wherein the solder paste is in direct contact with the array of conductive thermal pads; and wherein the array of conductive thermal pads comprises slits between the thermal pads and the slits are filled with the solder paste.