Effect Of Ga₂O₃ On The Structure And Properties Of Sn-Ag-Cu Solder

The rapid development of the electronic packaging industry has put forward greater requirements for electronic packaging interconnection materials.In order to meet the development needs of the packaging industry,it is necessary to study new lead-free solders so as to improve the performance of lead-free solders.In this study,Sn-3.0Ag-0.5Cu was used as the substrate and Ga₂O₃ nanoparticles with different contents were applied to perform nano-composite solder.The two were uniformly mixed with mechanical mixing method.The solder joints were prepared by reflow soldering process,and then subjected to high-temperature thermal aging treatment for different aging times.At this time,30 groups of solder joints with 6 different contents and 5 different high-temperature thermal aging times were formed.After that,various dimensional performance tests were conducted on these solder joints with different measurements,including melting characteristics,wetting properties,microhardness,shear properties,and electrical properties,and the results were analyzed.The addition of nano Ga₂O₃ particles to Sn-3.0Ag-0.5Cu can significantly improve the wettability of the solder.In the range of 0-1.2wt%addition amount in this group of the study,the wetting angle in the range of 0.4%to 0.8%is relatively small,and the amount of change is relatively small.as the addition amount of Ga₂O₃ reaches 0.8%,the maximum value of decrease is obtained,and compared to the bared solder,the wetting angle is reduced by 68.8%;Through SEM analysis,it was found that nano Ga₂O₃can inhibit the growth of IMC layers to some extent,but not completely linearly,however it follows a trend of first decreasing and then increasing.At 0.4%to 0.8%,relatively excellent inhibition effect is obtained.Based on analysis and fitting,the diffusion mechanism was obtained,and the minimum diffusion coefficient was obtained at 0.4wt%which is 3.44×10^-16m²/s,Nanometer Ga₂O₃ can reduce the grain size of the Cu₆Sn₅ layerafter researched the IMC grains,there is a linear relationship between grains and^0.31.As a small size hard material,nanometer Ga₂O₃ can significantly improve the microhardness of the nano-composite solder under the coupling effect of fine grain strengthening and dispersion strengthening,but after isothermal aging treatment,the microhardness will also be reduced to a certain extent;The addition of nano Ga₂O₃ can increase the shear strength,mainly through two mechanisms:dislocation stacking and dislocation bypass.The highest shear strength is obtained at 0.4%,while increasing the amount of nano Ga₂O₃ will cause agglomeration and reduce the optimization rate;Adding nano Ga₂O₃ to Sn-3.0Ag-0.5Cu can lead to a decrease in resistivity due to the coupling effect of dispersion strengthening and fine grain strengthening;In summary,the addition of nano Ga₂O₃ to Sn-3.0Ag-0.5Cu can improve the performance of the solder in multiple dimensions,it can be obtained that the optimal addition amount in the range of 0.4%to 0.8%.