| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a thermal flow sensor improved in reliability at a low cost. <P>SOLUTION: The thermal flow sensor improved in reliability at a low cost capable of inhibiting the adhesion of buoyant particle such as carbon particle caused by the thermal immigration effect is constituted such that on the semiconductor substrate provided with a cavity, at least a heating resistor is formed via an insulation film at the proximity of the center of the cavity, the temperature of the heating resistor (Th) is controlled for keeping higher than the temperature of the medium (Ta) by a constant temperature (ΔTh=Th-Ta), and relation between the proximate distance (Ws) from the heater edge of the upstream side of the air flow to the up stream side edge of the electric insulation film on the cavity and the constant temperature (ΔTh) satisfies the following relation:ΔTh/Ws≤800 (°C/mm). <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
