β-Sn increased in the solder bulks after soldering while the hardness and elastic modulus showed a decrease trend. Another effective way to improve the properties of SnBi solder joint is to modify the surface finish or composition of substrate. The common surface finishes include organic solderability preservative (OSP), electroless nickel-immersion gold (ENIG), and electroless nickel-electroless palladium-immersion gold (ENEPIG) [7]. Besides, Wang et al. [8] obtained Sn–Ag–Cu surface finish with the thickness of 5 μm on Cu. This surface finish was found to be helpful to inhibit the growth of interfacial IMC layer during isothermal aging. Hu et al. [9] and Zou et al. [10] added trace amounts of Ag, Al, Sn or Zn elements into Cu substrate, and found the interfacial Bi embrittlement in SnBi/Cu was restrained. Meanwhile, the void at the interface was eliminated. This study aimed to suppress the interfacial brittleness of SnBi solder joint by structure and soldering process design. Therefore, solder joint with SnBi/SnAgCu/Cu superposition structure was proposed. The microstructure and shear behavior of this type of solder joint was investigated in comparison with SnBi/Cu and SnAgCu/Cu