| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a thermal-type air flow-rate sensor that has less signal noise and reduces costs when measuring the flow rate of air. SOLUTION: A thermal-type air flow-rate sensor 1 has a semiconductor sensor element 2 that has a measurement site containing a temperature-sensing resistor 3 and a heat generation resistor 4 being formed on a semiconductor substrate and a cavity being provided on the semiconductor substrate, respectively, a control circuit 11 that supplies heating current to the heat generation resistor 4 so that the temperature of the heat generation resistor 4 becomes higher by a specific temperature than that of the temperature-sensing resistor 3 and obtains an air flow-rate signal indicating the flow rate of air, and a terminal 10c that outputs the air flow-rate signal to an external part. The semiconductor sensor element 2 and the control circuit 11 are supported while the cavity is being blocked by terminal material that forms the terminal 10c, thus reducing the signal noise of the sensor by blocking, decreasing the number of parts by forming, for example, a blockade body and a support in one piece, and lowering costs.</p> |
