In the fabrication process of thermo-resistive sensors, the dynamic response of a sensor is a very important feature to be noted. The dynamic characterization of a sensor reflects his electric performance when submitted to power variations. By measuring these power variations, it is possible to evaluate some of the sensor's thermoelectric properties, and so optimize its physic configuration in the fabrication process and its subsequent use in specific applications. In this paper, the influence of the micromachined thermo-resistive sensors substrate in the determination of its thermal time constant is evaluated. © 2005 IEEE.3 16471651Bentley, J. P., Temperature sensor characteristics and measurement design, J. Phys. E: Sci Instum, 17, pp. 430-439. 1984Okamoto, K., A digital anemometer (1994) IEEE Transactions on Instrumentation and Measurement, 43 (2), pp. 116-120. , AprFujita, H., A thermistor anemometer for low-flow-rate measurement (1995) IEEE Transactions on Instrumentation and Measurement, 44 (3), pp. 779-782. , JunMochizuki, K., Watanabe, K., A linear resistance-to-frequency converter (1995) Instrumentation and Measurement Technology Conference, pp. 339-343. , IEEEMullins, M.A., Potential for a smart sensor based on an integrated silicon anemometer (1995) Sensor and Actuators A, 46-47, pp. 342-348Lerne, C.A., Malcovanti, P., Baltes, H., Oversample interface for IC sensor with minimized analog content (1995) IEEE Transactions on Instrumentation and Measurement, 44 (3), pp. 647-651. , JunKohl, F., A micromachined flow sensor for liquid and gaseous fluids (1994) Sensors and Actuators A, 41-42, pp. 293-299Stankovic, D., Zlatanovic, M., A versatile computer controlled measuring system for recording voltage-current characteristics of various resistance sensors (1994) Sensors and Actuators A, 41-42, pp. 612-616Kaliyugavaradan, A linear resistance-to-time converter with high resolution (2000) IEEE Transactions on Instrumentation and Measurement, 42 (5), pp. 952-956Yankov, I.Y., Gigov, C.I., Yankov, E.A., Linear Temperature-to-Time Period converter using Standard Thermistors (1990) Meas. Sci Technol, (1), pp. 1168-1171Oliveira, A., Freire, R.C.S., Deep, G.S., An Anemometer with PWM Excitation, IECON'95 (1995) Orlando, FLA, pp. 893-897. , Nov, EEUU, ppFreire, R.C.S,. Deep, G.S.Lobo, P.C.Oliveira, A. dynamic response of a feedback fhermoresistive electrical substitution pyranometer, Journal of Solar Energy Engineering, 120, pp. 126-130, May 1998Freire, R.C.S., Deep, G.S., Error in the thermoresistive sensor-based feedback measurement configuration due to DC amplifier offset voltage (1999) IEEE Transactions on Instrumentation and Measurement, 48 (1), pp. 50-54Freire, R.C.S., Experimental determination of time constant of a thermoresistive sensor (1994) IEEE Instrumentation and Measurement Technology Conference, pp. 1279-1281Zubel, I., Barycka, I., Silicon anisotropic etching in alkaline solutions I. The geometric description of figures developed under etching Si(100) in various solutions (1998) Sensors and Actuators A, 70, pp. 250-259Manea, E., Muller, R., Popescu, A., Some particular aspects of the thin membrane by boron diffusion processes (1999) Sensors and Actuators A, 74, pp. 91-94Deep, G.S., Oliveira, A., Freire, R.C.S., França, M.B.M., Thermodynamic modeling of a thermoresistive sensor using electrical power step (1999) International Conference on Electronics, Circuits and Systems, Pafos. International Conference on Electronics, Circuits and Systems, 3, pp. 1301-1304. , IEEEFreire, Deep, G.S.Lobo, P.C. Experimental determination of time constant of a thermoresistive sensor. IEEE Instrumentation and Measurement Technology Conference, 1994, Hamamatsu. IMTC'94: 1994. pp. 1279-1281