Anisotropic thermal expansion of Ni3Sn4, Ag3Sn, Cu3Sn, Cu6Sn5 and beta Sn

作者：Xian J W^*; Zeng G; Belyakov S A; Gu Q; Nogita K; Gourlay C M

来源：Intermetallics, 2017, 91: 50-64.

DOI：10.1016/j.intermet.2017.08.002

• Intermetallics
• Anisotropy
• Joining (soldering)
• Interfaces
• Diffraction (X-ray)
• Electron backscatter diffraction

The directional coefficient of thermal expansion (CTE) of intermetallics in electronic interconnections is a key thermophysical property that is required for microstructure-level modelling of solder joint reliability. Here, CTE ellipsoids are measured for key solder intermetallics using synchrotron x-ray diffraction (XRD). The role of the crystal structure used for refinement on the CTE shape and temperature dependence is investigated. The results are used to discuss the beta Sn-IMC orientation relationships (ORs) that minimise the in-plane CTE mismatch on IMC growth facets, which are measured with electron backscatter diffraction (EBSD) in solder joints on Cu and Ni substrates. The CTE mismatch in fully-intermetallic joints is discussed, and the relationship between the directional CTE of monoclinic and hexagonal polymorphs of Cu6Sn5 is explored.

• 出版日期2017-12