Development of a self-packaged 2D MEMS thermal wind sensor for low power applications

作者：Zhu Yan qing^*; Chen Bei; Qin Ming; Huang Jian qiu; Huang Qing an

来源：Journal of Micromechanics and Microengineering, 2015, 25(8): 085011.

DOI：10.1088/0960-1317/25/8/085011

• thermal sensors
• flow sensor
• self-packaged
• low power
• high reliability

This article describes the design, fabrication, and testing of a self-packaged 2D thermal wind sensor. The sensor consists of four heaters and nine thermistors. A central thermistor senses the average heater temperature, whereas the other eight, which are distributed symmetrically around the heaters, measure the temperature differences between the upstream and downstream surface of the sensor. The sensor was realized on one side of a silicon-in-glass (SIG) substrate. Vertical silicon vias in the substrate ensure good thermal contact between the sensor and the airflow and the glass effectively isolates the heaters from the thermistors. The substrate was fabricated by using a glass reflow process, after which the sensor was realized by a lift-off process. The sensor's geometry was investigated with the help of simulations. These show that narrow heaters, moderate heater spacing, and thin substrates all improve the sensor's sensitivity. Finally, the sensor was tested and calibrated in a wind tunnel by using a linear interpolation algorithm. At a constant heating power of 24.5 mW, measurement results show that the sensor can detect airflow speeds of up to 25 m s(-1), with an accuracy of 0.1 m s(-1) at low speeds and 0.5 m s(-1) at high speeds. Airflow direction can be determined in a range of 360 degrees with an accuracy of +/- 6 degrees.

• 出版日期2015-8
• 单位东南大学