Effect of Temperature on the Chip Soldering Process with AuGa0.03 Alloy Solder

In this study, soldering is conducted between a chip and a CLCC-3 shell base with a sheet-like AuGa0.03 alloy solder as the encapsulating material. X-ray images of chip soldering samples, XRD diffraction analysis of the joints, SEM images reflecting the microstructures of the joints, and EDS of the cross sections of the chip soldering samples show that with gradually increasing soldering temperature, the phase composition is not affected, and all the joint structures are an Au + Si eutectic structure; the Au-Si eutectic reaction occurs during the soldering process. No deposition of meta-stable phases, such as Au7Si, Au5Si, or Au3S, is found. A soldering temperature of 420 degrees C can reduce the negative impacts of secondary cap welding soldering on the joint and improve the structure and mechanical properties of the joint.