THERMAL SIMULATION OF A MICROMACHINED THERMOPILE-BASED THIN-FILM GAS-FLOW SENSOR

FEM calculations of a thermal gas flow sensor based on thermopiles mad e of thin films of Bi0.87Sb0.13 as n-type material and Sb as p-type ma terial are presented. The results of thermal simulations concerning th e response of the signal voltage to variations of the now velocity at constant gas temperature as well as to variations of the gas temperatu re at constant now velocity are compared with experimental data. The g ood agreement between calculated and experimental results confirms the proposed two-dimensional thermal model. The design as a classical del ta-T-type now sensor did not result in a complete suppression of the i nfluence of gas temperature variations to the sensor response. (C) 199 8 Published by Elsevier Science Ltd. All rights reserved.