High-throughput transient thermal interface testing method using time-domain thermal response

In the field of thermal interface testing, the one-dimensional (1D) reference bar method has been the most popular and trusted among many available techniques. However, this steady-state method has several drawbacks, including low test speed and inability to capture dynamic response. In this paper, we report a high-throughput transient method that can be used in concert with the traditional 1D reference bar setup without hardware modifications. Instead of waiting for steady-state conditions, the method requires only an arbitrary segment of the transient thermal response in the time domain. The transient thermal model and data fitting algorithm are presented. Radiation heat loss and temperature-dependent thermophysical properties are incorporated in the model to improve high-temperature accuracy. The measurement uncertainty is quantified numerically, and the criteria for choosing the input segment are discussed. The effects of the TIM (thermal interface material) heat capacity are also investigated, and reveal that in most practical cases, the measurement result is not sensitive to the heat capacity of the TIM. In the end, we demonstrate this method on a commercial TIM sample over a wide temperature range (room temperature to 400 °C) and show that the results are comparable to those obtained from a steady-state method but with drastically reduced testing time.