Microstructure of Cu/Sn/Cu Micro-solder Joints after Interfacial Reaction [Cu/Sn/Cu微焊点界面反应的微观组织]

作者：Liu L.; Wei G.^*; Wei J.

来源：Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys, 2019, 39(9): 1033-1036.

DOI：10.15980/j.tzzz.2019.09.028

• Cu/Sn/Cu Micro-solder Joint
• EBSD
• Grain Orientation
• Interface Reaction
• Microstructure

The interfacial reaction of Cu/Sn/Cu micro-solder joints aged for 0 h (post-weld state) and 400 h at 110 ℃ was investigated by means of electron backscatter diffraction (EBSD). The results show that the microstructure of Cu/Sn/Cu micro-solder joint after interfacial reaction is composed of Cu6Sn5, Cu3Sn and beta-Sn. After 400 h isothermal aging, a large amount of beta-Sn is consumed. The morphology of Cu6Sn5 is changed from scallop-like to polygon-like, and Cu3Sn still keep long strip-like structure. For orientation, the preferred orientation of Cu6Sn5 (0001) surface is present after 400 h isothermal aging and <0001> crystal direction is parallel to RD direction. The interfacial type of Cu6Sn5 after 400 h aging was analyzed. The orientation difference angle is about 53°, 45°, 36°, presenting large angle grain boundaries. The analysis of microstructure and grain orientation shows that isothermal aging has a little effect on the orientation of microstructures morphology of solder joints, however it will affect greatly the transformation and growth of microstructures.

• 单位
  华南理工大学