Experimental and numerical simulation of mechanical behavior of micro-scale SAC305 solder joint based on joint height

• Published in: Welding in the world 2020-12, Vol.64 (12), p.2101-2108
• Main Authors: Yin, Limeng, Zuo, Cunguo, Zhang, Zhongwen, Wang, Gang, Yao, Zongxiang, Su, Zilong, Fang, Naiwen
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Computer simulation; Copper; Copper wire; Electronic packaging; Failure mechanisms; Finite element method; Lead free; Materials Science; Mathematical models; Mechanical properties; Metallic Materials; Research Paper; Shear forces; Shear strength; Shear stress; Soldered joints; Solders; Solid Mechanics; Tensile strength; Theoretical and Applied Mechanics; Tin base alloys
• ISSN: 0043-2288; 1878-6669
• DOI: 10.1007/s40194-020-00985-1

Lead-free “copper wire/Sn-3.0Ag-0.5Cu (SAC305) solder/copper wire” sandwich-structured micro-scale solder joints with a constant diameter ( d  = 400 μm) and various heights (125, 225, and 325 μm) were adopted to carried out the mechanical behavior research. Experimentally, quasi-static shear and tensile experiments were conducted by using a precision dynamic mechanics analyzer (DMA Q800). Then, the micro-scale solder joint model was built to simulate shear and tensile behavior of solder joints using the finite element analysis software ABAQUS. The experimental results show that, when the solder joint diameter is fixed, the smaller the joint height is, the stronger the shear strength and tensile strength. Under the same test conditions (225 μm), the shear strength of micro-scale solder joints of the same size is lower than the tensile strength, which indicates that the service environment of electronic packaging interconnection solder joints under shear stress is more severe. In addition, the micro-scale solder joints fracture at the interface of the solder joint and copper wire under shear force, but in the middle of the solder joint under tensile force. Different fracture failure mechanisms are found by observing the cross sections under different stress states.