The paper covers a useful and practical method for users of power semiconductor devices to derive dynamic thermal models of discrete semiconductor packages. Derivation is based on transient thermal impedance responses measured experimentally or deduced from semiconductor manufacturer data-sheets. Such dynamic thermal models are required for electro-thermal simulation of power electronic circuits corresponding to short power pulse excitations. Indeed in such excitations, the main transient phenomena occur inside the semiconductor die. Contrarily to classical thermal models based on simple resistor/capacitor cells, the proposed model is a behavioral thermal model based on the finite element modeling of the semiconductor chip. It takes into account the main thermal temperature-related non-linearities of package layers. The derived thermal models offer an excellent trade-off between accuracy, efficiency and CPU-cost. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.