Quantum mechanics

Engineering

Multiphysics

Heat transfer

Materials science

Chromatography

Layer (electronics)

Thermal conductivity

Thermal resistance

Interfacial thermal resistance

Omega

Heat flux

Chemical engineering

Substrate (aquarium)

Parylene

Geology

Oceanography

Physical chemistry

Polymer

Thermodynamics

Physics

Finite element method

Nanotechnology

Thermal

Thin film

Conductivity

Composite material

Analytical Chemistry (journal)

Contact resistance

Thermal contact conductance

Chemistry

Thermal conduction

Journal of Thermal Analysis and Calorimetry

Parylene has attracted a great interest in the last years because of its potential use in many fields. Among all kinds of parylene, parylene C seems the most interesting one for a large range of applications. In this paper, we are interested in its thermal properties, and in particular the thermal conductivity of thin films. This later is determined by the so-called three-omega method. This technique makes use of a thin conducting strip, in contact with the material under test. The metal wire serves both as a heat source for applying a heat flux and a sensitive thermometer for measuring the surface temperature. The thermal conductivity of parylene C films of different thicknesses (210, 440 and 760 nm) deposited by CVD process on borosilicate substrates is investigated. It is demonstrated that the effective thermal conductivity increases as a function of the thickness of thin film (81.20 × 10−3, 88.37 × 10−3 and 92.81 × 10−3 W m−1 K−1 are measured, respectively). This effect is produced by the phonon scattering boundary at the interface between substrate/film and film/heater. To highlight the presence of contact thermal resistances and to estimate their value, a numerical approach, based on a finite element method using the software COMSOL® Multiphysics, is also proposed. This study shows that the main part (97%) of the interfacial thermal resistance is due to the contact between the parylene C film and the substrate.

Thermal conductivity and interfacial effect of parylene C thin film using the 3-omega method