TIM-Tester – Metal sheets with adhesive layer – Thermal conductivity and Thermal Impedance
The investigated sample consists of stacked metal sheets with an insulating adhesive layer in between. This sample configuration is used in the field of the electrification of cars. The aim of the measurement was to examine the influence of the contact pressure on the results.
The plot shows the thermal impedance in dependence of the thickness of the different stacked metal sheets. The measurement was performed at room temperature and 100 °C where each a contact pressure of 0.1 MPa and 1 MPa was applied to the sample. As usual, the thermal conductivity corresponds to the reciprocal of the slope of the linear fit and the contact resistance corresponds to the intersection with the y-axis. The results for the thermal conductivity and contact resistance are the following:
The thermal conductivity of the stacked metal sheets with an adhesive layer in between decreases from room temperature to 100 °C. From the results one also can see, that with a lower contact pressure higher thermal impedances are measured and also the thermal conductivity and contact resistance are higher. This means, that depending on the applied contact pressure and thus on the application, the thermal conductivity of the sample can vary. This variation can be related to the deformable adhesive layer between the metal sheets.