Abstract: A method of inhibiting a formation of palladium-nickel-tin (Pd—Ni—Sn) intermetallic in solder joints is described as follows. Firstly, a solder alloy is provided. Then, at least one of a trace of copper and a trace of zinc is doped into the solder alloy. Afterward, the solder alloy is disposed on the Pd-bearing surface finish, such as a Pd/Ni bi-layer or a Au/Pd/Ni tri-layer. Next, the solder alloy is soldered with the surface finish as solder joints. During the soldering, the Cu and Zn will incorporate into the soldering reaction, forming copper-palladium-nickel-tin intermetallic and zinc-palladium-nickel-tin intermetallic, replacing the Pd—Ni—Sn respectively. Consequently, the addition of Cu and/or Zn into solders will inhibit the undesirable Pd—Ni—Sn intermetallic to form in the solder joints.