THERMAL-TYPE AIR FLOW SENSOR

摘要

PROBLEM TO BE SOLVED: To provide a highly reliable thermal-type air flow sensor with little characteristic change even in a severe environment such as an engine room. SOLUTION: A semiconductor sensor element has a measurement portion including a temperature sensing resistance element formed on a semiconductor substrate and a heating resistance element formed on a thin walled part of the semiconductor substrate. The sensor element is formed in a recessed part of a recessed laminate substrate in such a manner that the measurement portion of the sensor element is substantially flush with a surface of the laminate substrate. A circuit for controlling the sensor is mounted on a substrate other than the laminate substrate. The laminate substrate mounted with the sensor element is electrically connected to the substrate mounted with the control circuit.