A numerical study on the theoretical accuracy of film thermal conductivity using transient plane source method

The thermal conductivity of film specimen is different with bulk materials and lack of standard reference materials, and few study of the measurement accuracy of film thermal conductivity has been reported. A numerical study is conducted to analyze the theoretical accuracy of film thermal conductivity introduced by the assumption of transient plane source method. In the data reduction from the measurement results, it is difficult to determine the calculation area and thickness due to the non-ideal 1D heat conduction generated in the film and the heat element has a certain thickness. The simulation found that if the thermal resistance of the film to be measured is comparable or higher than that of the sensor insulation layer, the accuracy of determining the film thermal conductivity would be very high. The theoretical accuracy of transient plane source method can be as small as ±6% after some modification.