| 摘要 |
<p>PURPOSE:To keep sensitivity and a response speed over a long period of time, by supplying a current to a burning-off resistor layer when suspended particles are adhered to a flow rate detecting resistor layer and a substrate to burn off or separate the suspended particles. CONSTITUTION:A flow rate detecting resistor layer 62 composed of a platinum pattern layer and a burning-off resistor layer 62' for burning off a contaminant such as suspended particles are provided on a substrate 61. The resistor layers 62, 62 are covered with separate passivation films 63, 63'. When the suspended particles are adhered to the substrate 61 on the upstream side thereof, by supplying a current to the burning-off resistor layer 62' to heat the upstream side, for example, to 400-800 deg.C, the adhered suspended particles are burnt off or separated. Since the passivation film 63 is separated from the passivation film 63', even when a crack is generated in the passivation film 63' by thermal shock due to the supply of a current to the burning-off resistor layer 62', the passivation film 63 covering the flow rate detecting resistor layer 62 receives no effect thereof.</p> |
