fig2 e a process of heating and reflow soldering is performed on the assembly unit 700 to fuse the first solders 230 of the flip chip packaging chip 292 with the second solders 130 of the flip chip packaging substrate 192 in the present embodiment the pre solders 160 are paste shaped solders which comprises a flux hence during the process of heating and reflow soldering the flux inside the pre solders 160 can vaporize into gas so that the first solders 230 the pre solders 160 and the second solders 130 can be melted and blended with each other to form fused solders 340 herein the fused solder 340 as a conductive medium can electrically connect the electrode pads 210 with the conductive pads 110 meanwhile during the process of heating and reflow soldering the resin adhesive layer 240 of the flip chip packaging chip 292 is also under high temperature so that the resin adhesive layer 240 can adhere with the solder mask 120 of the flip chip packaging substrate 192 besides the resin adhesive layer 240 can fill the space between the flip chip packaging chip 292 and the flip chip packaging substrate 192 in addition during the process of heating and reflow soldering a heavy component may be selectively placed on the semiconductor chip the heavy component can apply suitable stress on the semiconductor chip to ensure the resin adhesive layer 240 contacts and adheres with flip.