Initiation and propagation of microcracks in Cu thin films on flexible substrates through the thickness direction during a cyclic bending test

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 708; pp. 60 - 67
• Main Authors: Bag, Atanu, Choi, Shi-Hoon
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 21-12-2017; Elsevier BV
• Subjects: Bend tests; Bending; Bending test; Copper; Crack initiation; Crack propagation; Electron backscatter diffraction; Electron backscatter diffraction (EBSD); Focused ion beam (FIB); Grain boundaries; Intergranular fracture; Ion beams; Microcracks; Substrates; Thickness; Thin film; Thin films; Twin boundaries; Grain boundaries; Focused ion beam (FIB); Thin film; Bending test; Electron backscatter diffraction (EBSD)
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2017.09.079

The initiation and propagation of microcracks in the copper thin film on flexible polyimide substrates was examined through the thickness direction following cyclic bending test using a focused ion beam (FIB) and electron backscatter diffraction (EBSD) technique. The EBSD observations of the cross-sectional plane clearly indicated that intergranular fracture was predominant during the initiation and propagation of microcracks. During the cyclic bending testing, through the thickness direction microcracks were propagated mostly along the high-angle grain boundaries (HAGBs) that separated the neighboring grains with a high Schmid factor (SF), instead of at the twin boundaries (TBs).