Fracture toughness measurement of thin films on compliant substrate using controlled buckling test
Date of Issue2007
School of Materials Science and Engineering
Thin films and multilayered structures are increasingly used in the industry. One of the important mechanical properties of these thin layers is the fracture toughness, which may be quite different from the known value of the bulk sample due to microstructural difference. In the design towards device flexibility and scratch resistance, for example, fracture toughness is an important parameter of consideration. This work presents a testing scheme using controlled buckling experiment to determine the fracture toughness of brittle thin films prepared on compliant substrates. When the film is under tension, steady-state channelling cracks form in parallel to each other. Critical fracture strain can be calculated by the measuring the displacement of the buckled plate. The fracture toughness can then be obtained with the help of finite element calculation. When the substrate experiences plastic deformation, the energy release rate is increased by the degree of plasticity. Fracture toughness measurement of two types of thin film Cu–Sn intermetallic compounds has been given to illustrate the merits of such a test scheme.
DRNTU::Engineering::Materials::Microelectronics and semiconductor materials::Thin films
Thin solid films
© 2006 Elsevier. This is the author created version of a work that has been peer reviewed and accepted for publication by Thin Solid Films, Elsevier. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1016/j.tsf.2006.01.044].