Optimization of the Temperature Sensor Position for MEMS Gas Flow Meters

摘要

A bulk micromachined structure for a thermal type gas flow meter is proposed. It is considered as the thermal type device and consists of a micro heater and two temperature sensors situated at both sides of the heating element. The sensor works on the bases of displacement of temperature profile around the heating element with the gas flow. The heater and the temperature sensors are assumed to be situated on a stacked (SiO2 / Si3N4) thermally isolated membrane. The effect of the distance of the temperature sensor from the heating element on the output signal is investigated using Ansys/Flotran software. The simulation results for a specified device provide the optimum distance between the central heating element and two sensing elements in the range of 200um.