Cu-foam sheets with the thicknesses of 0.15 mm and 0.5 mm were utilized as strengthening structure to improve the performances of the Sn3.0Ag0.5Cu (SAC305)/Cu solder joints. The ultrasonic-assisted soldering was applied to manufacture the solder joints. The effects of Cu-foam and ultrasound-assisted soldering time on microstructure and mechanical property of solder joints were researched. Experimental results showed that excellent metallurgical bonding was generated between the copper substrate and the Cu-foam/SAC305 composite solder layer. The average thickness of interfacial intermetallic compound (IMC) layer decreased with the increase of ultrasonically soldering time, and a thinner interfacial IMC layer was found in the joints with ultrasonic treatment in narrow channels. With the ultrasonic soldering time prolonged, the Cu₆Sn₅ grains became more refined. Some round-shape Cu₆Sn₅ grains were transformed into hexagonal prismatic with the increase of the ultrasonic soldering time. The shear test was conducted for the solder joints under different soldering conditions. It was found that the shear strength of the Cu-foam/SAC305 composite solder joints were higher than that of SAC305 solder joints. The grain refinement caused by ultrasonic cavitation significantly improved the shear strength of the solder joints. Besides, the fracture behavior of solder joints without ultrasonic vibration was classified to be ductile-brittle mixed type while that with ultrasonic vibration was changed to be ductile type.

利用厚度为0.15mm和0.5mm的Cu泡沫板作为加强结构，以改善Sn3.0Ag0.5Cu（SAC305）/ Cu焊点的性能。超声辅助焊接被用于制造焊点。研究了泡沫铜和超声辅助焊接时间对焊点组织和力学性能的影响。实验结果表明，在铜基板和Cu-foam / SAC305复合焊料层之间产生了优异的冶金结合。随着超声焊接时间的增加，界面金属间化合物（IMC）层的平均厚度减小，并且在狭窄通道中采用超声波处理的接头中发现界面IMC层更薄。随着超声波焊接时间的延长，铜₆ Sn ₅晶粒变得更细。随着超声焊接时间的增加，一些圆形的Cu ₆ Sn ₅晶粒转变为六角棱柱形。在不同的焊接条件下对焊点进行了剪切测试。结果表明，Cu-foam / SAC305复合焊点的剪切强度高于SAC305焊点的剪切强度。超声空化引起的晶粒细化显着提高了焊点的剪切强度。另外，将没有超声波振动的焊点的断裂行为分类为延性-脆性混合型，将具有超声波振动的焊点的断裂行为改变为延性型。