Wettability and Shear Strength of SAC305 Based Composite Solder with co-doping X (Ni or Al 2 O 3 ) and CNTs Reinforcements

Through the pre-mechanical mixing, and co-doping of two reinforcements (zero-dimensional nanoparticles Ni or Al2O3, and one-dimensional CNT) into SAC305 solder, different types of composite solders were fabricated in this study. In order to evaluate the strengthening effect and combined action of two reinforcements in these composite solders, the wetting angle on Cu substrate was measured. The microstructure of composite solder bumps formed after reflowing on PCB Cu pads was observed and the corresponding shear test was also conducted. From the experimental results, the addition of nanoparticles was found to play a leading role in composite solder’s wettability. In the Ni/CNT and Al2O3/CNT composite solder bumps, the IMC formation and morphology have been changed with the different mixing ratio and doping ratio of reinforcements. Particularly, the interfacial IMC thickness of Al2O3/CNT composite solder bumps shows a positive correlation with the CNT content. Meanwhile, the property of shearing resistance has been worsened by the addition of CNT in these Ni/CNT and Al2O3/CNT composite solder bumps. For the good-linked IMC/solder, the coated Ni-CNT composite solder has different performances in the tests.