Formation mechanism and reliability of Cu_6Sn_5 textures formed in-between liquid Sn and (111)/(001) Cu single crystals

摘要

Formation mechanism and reliability of the Cu_6Sn_5 textures formed in-between the liquid SnCu_(0.7) solder and (111)/(001) Cu single crystals were studied in this paper. Regular arrays of the roof-type Cu_6Sn_5 grains with the fixed intersecting angles were generated on both types of Cu single crystals after soldering at 250°C for 1 min. The formation mechanism of these Cu_6Sn_5 roofs was confirmed to be a hexagonal-rod-type growth mode due to morphology and orientation analyses. In addition, based on the shear tests of the actual solder joints, the Cu_6Sn_5 textures formed on (111)/(001) Cu single crystals were affirmed to be ideally suitable for use as the reliable interfacial connection layers to resist shear failures in electronic packaging.