| 摘要 |
PROBLEM TO BE SOLVED: To provide a thermal type air flowmeter in which measurement accuracy is improved.SOLUTION: The thermal type air flowmeter has: a sensor chip 4 for measuring the flow rate of a fluid to be measured that is disposed in a sub-passage and having a cavity part 28 formed in a semiconductor substrate and a diaphragm 27 formed so as to cover the cavity part 28; a circuit part 3 for converting the flow rate of the fluid detected by the sensor chip 4 into an electric signal; a plate 2 on which the sensor chip 4 is mounted, the plate 2 having a groove (air passage) 13 used for connection to an atmospheric air; and a lead frame 1 on which the plate 2 is mounted. The sensor chip 4, as well as the plate 2 and the lead frame 1, are molded with resin so that a portion of the diaphragm 27 of the sensor chip 4 is exposed, the principal plane of the plate 2 being silicon of a plane (100), the longitudinal direction of the groove (air passage) 13 formed in the plate 2 being a plane <100>.SELECTED DRAWING: Figure 1 |
