Next-generation display technologies use unique combinations of flexible organic materials and relatively rigid inorganic layers. Mechanical failure of a multilayer device is determined by its weakest component, requiring materials and processes to be finely tuned to maximize performance and reliability. Mechanical property mismatches combined with residual stresses between deposition layers, thermal stresses due to thermal expansion mismatches, and external stresses applied to the devices add to the complexity of materials development. In addition to mechanical failures, stresses within the active layers may lower the efficiency of the devise as it deforms.
Bruker has developed a comprehensive suite of nanomechanical testing techniques to quantitatively measure the mechanical and interfacial properties of LEDs and OLEDs. Nanoindentation is a rapid means of characterizing the nanomechanical properties (e.g. modulus, hardness, fracture toughness, creep, and stress relaxation) of thin films and substrates used in display manufacturing. Dynamic nanoindentation measurements allow localized viscoelastic property and phase transition measurements to be conducted. Additionally, nanoscratch testing enables quantitative interfacial adhesion measurements between thin film layers.