Monolithic Integration of a Flexible Micro Thermal Flow Sensor

摘要

In this paper, a novel monolithically integrated flexible thermal flow sensor combining four resistors in a Wheatstone bridge including hot-film resistor, temperature-compensating resistor and two other balancing resistors on one chip is proposed in order to improve the system integration level and sensor performances, such as signal to noise ratio (SNR), power consumption and temperature compensation. Fabricating the sensor directly on a flexible polyimide printed circuit board (PCB) by incorporating printed circuit technique with micromachining sputter technique is adopted. A complete performance test on the flow sensor demonstrates its superiorities on power consumption, SNR and temperature drift, the error of which is eliminated from 43% to 8% over a range of ambient temperature (35–75°C).