The solder materials used in this work are commercial Sn3.0Ag0.5Cu (SAC) solder ball and Sn58Bi solder paste. The soldering substrates are Cu pads with the diameter of 460 μm on printed circuit board (PCB). Firstly, SAC balls with diameter of 300 μm were soldered onto the Cu pads by a heating platform at 260 °C for 80 s. The soldered samples were put into anhydrous ethanol and cleaned for 10 min by ultrasonic. Secondly, SnBi solder paste was dispensed onto the soldered SAC joints by Create-PSD solder paste dispenser. The samples were soldered at 160 °C for 80 s and formed the solder joints with superposition structure. The manufacturing process and schematic diagram of this