| 摘要 |
<p>PURPOSE:To obtain stable output characteristics and to eliminate a fear of breakage by providing a flow rate detecting circuit conductor on the surface of an insulating layer formed on the surface of a substrate, and removing a part of the substrate corresponding to the rear side of the flow rate detecting circuit conductor. CONSTITUTION:An insulating layer 3 is formed on the surface of a substrate 1, and moreover flow rate detecting circuit conductors 5, 6, 7 are formed on the surface of the insulating layer 3. An insulating film 4 is formed on the surface of the insulating layer 3 in a manner to cover the conductors 5, 6, 7. An insulating film 9 is provided at the lower face of the substrate 1. As the substrate 1 is partially removed at the rear side of the conductors 5, 6, 7, an opening 2 is defined to expose the insulating layer 3 to the rear side. Further, a communicating groove 8 is formed at one side face of the substrate 1 so that the opening 2 communicates with the outside. Since a part of the insulating layer 9 where the conductors 5, 6, 7 are provided is thermally insulated from the substrate 1, the flow velocity can be detected from the temperature difference of the conductors 5, 6, 7. Moreover, since there is no opening at the surface of the sensor, the flow velocity can be detected with high accuracy without the disturbance of the flow.</p> |
