HEAT-TYPE FLOW METER

摘要

Provided is a compact thermal type flowmeter that can perform a partial thermal treatment on a sensor element portion without affecting other elements and can improve the reliability of a sensor element while improving the sensitivity of the sensor element. A thermal type flowmeter includes a hollow portion which is formed in a semiconductor substrate, a thin film portion which is formed by insulating films provided to cover the hollow portion and, a heating resistor body and a temperature-measuring resistor body which are formed between the insulating films. In a method for manufacturing the thermal type flowmeter, a thermal treatment is performed to grow a crystal grain size of the heating resistor body and a crystal grain size of the temperature-measuring resistor body by heating the thin film portion after forming the thin film portion.