Studies on thermal properties of a micro gas sensing element array with central single heater

Thermal properties of a sensor array (3 mm×5 mm in diaphragm dimension) with 12 sensing elements were optimized with a view to realizing the discrete operating temperature of each sensing element of the sensor array. This sensor array with single heater on a glass diaphragm over front-etched silicon bulk realizes a new concept of a sensor array: an array of sensor elements operated at different temperatures can yield more information than single element measurement. Thermal properties including temperature distribution over the sensing elements and cross sectional temperature profile of glass substrate were simulated by commercial finite element method (FEM) package. The proposed micro-sensor array could provide well-integrated array structure because it has only single heater at the center of the diaphragm and used two kinds of metal oxide layers with various operating temperatures.