Thermoreflectance by Pulsed Light Heating

Thermoreflectance by Pulsed Light Heating

The Method for the Determination of Thermal DiffusivityThermal diffusivity (a with the unit mm2/s) is a material-specific property for characterizing unsteady heat conduction. This value describes how quickly a material reacts to a change in temperature.Thermal Diffusivity in the Thickness Range of Nanometer With the significant progress in the design of electronic devices and the associated need for an efficient thermal management, accurate Thermal DiffusivityThermal diffusivity (a with the unit mm2/s) is a material-specific property for characterizing unsteady heat conduction. This value describes how quickly a material reacts to a change in temperature.thermal diffusivity / Thermal ConductivityThermal conductivity (λ with the unit W/(m•K)) describes the transport of energy – in the form of heat – through a body of mass as the result of a temperature gradient (see fig. 1). According to the second law of thermodynamics, heat always flows in the direction of the lower temperature.thermal conductivity measurements in the nanometer range are more than ever crucial. The National Institute of Advanced Industrial Science and Technology (AIST), Japan, already responded to industrial requirements with the development of a “pulsed light heating ThermoreflectanceThermoreflectance is a method for determining the thermal diffusivity and thermal conductivity of thin films with thicknesses in the nanometer range.thermoreflectance method” in the early 90’s. PicoTherm Corporation was established in 2008 with the launch of a nano-second ThermoreflectanceThermoreflectance is a method for determining the thermal diffusivity and thermal conductivity of thin films with thicknesses in the nanometer range.thermoreflectance apparatus “NanoTR” and a pico-second ThermoreflectanceThermoreflectance is a method for determining the thermal diffusivity and thermal conductivity of thin films with thicknesses in the nanometer range.thermoreflectance apparatus “PicoTR”, which allows for absolute measurements of the Thermal DiffusivityThermal diffusivity (a with the unit mm2/s) is a material-specific property for characterizing unsteady heat conduction. This value describes how quickly a material reacts to a change in temperature.thermal diffusivity of thin films in a thickness range of several 10 μm down into the nanometer range. In October 2020, PicoTherm joined the NETZSCH Group as a subsidiary of NETZSCH Japan. In combination with our LFA systems, NETZSCH can now offer the solution for thin films in the nanometer range up to bulk materials in the range of mm.

Principle of NanoTR NanoTR’s state-of-the-art signal processing technology allows high speed measurements. With this thermoreflectance apparatus, a laser pulse of 1-ns pulse width is periodically (20 μs) irradiated to the sample. The resulting temper- ature response is applied to a CW laser (probe laser). Excellent s/n ratio can be attained by high speed integration of repetitive signals. It can be easily switched between the RF and FF configura- tions though the software for a wide variety of samples. NanoTR is in accordance with JIS R 1689, JIS R 1690, and SI traceable by the thin film standard of thermal diffusivity (CRM5810-a), supplied from AIST.

Principle of PicoTR

With picosecond thermoreflec- tance analyzer PicoTR, laser pulses (pump laser) of 0.5-ps pulse width are applied to the sample with the time period of 50 ns. The temper- ature response is detected with the probe laser. PicoTR allows for easy switching between RF and FF modes by the user. PicoTR is in accordance with JIS R 1689, JIS R 1690