Thermal Characterization of a Multilayer Material Through the Flash Method

The extension of the heat pulse method, commonly used for the measurement of the diffusivity of homogeneous isotropic materials, to the characterization of multiplayer structures that can be found in electronic boards, for example, is examined. Both models and experimental estimations of thermophysical property measurement are presented for the diffusivity in the thickness direction, for interface contact resistance (glue) characterization, and for deposits on substrates. A strong emphasis is placed on sensitivity analysis and the type of thermal parameter that can be reached in practice for a given experiment. Estimation of the in-plane thermal diffusivity of possible anisotropic flat-plate samples through a nonhomogeneous pulse excitation and infrared camera measurements are presented.