Efficient solution of inverse thermal problem via parametric model order reduction

In this paper we present a novel approach to determine material thermal properties of thin film materials. As a test case we have chosen silicon nitride employed in a micro-hotplate structure. We use ANSYS to build a three-dimensional finite element (FE) model of the test structure, which considers heat conduction and convection effects. It is further parameterized and subjected to parametric model order reduction (pMOR). The parameters of the reduced model are the unknown material thermal properties and the heat transfer coefficient, which are automatically adjusted within the optimization loop, so that the simulation results of the model are in agreement with the transient temperature measurements. The use of parameterized reduced order models within the optimization iterations speeds up the transient solution time by several orders of magnitude, while retaining almost the same precision as the full FE model.