| 摘要 |
<p>PURPOSE:To achieve a reduction in drifting along with a higher stability of power consumption when a drive current of an exothermic resistor by using for the exothermic resistor a material with a resistance temperature coefficient thereof smaller than that of the material of a resistance thermometer bulb. CONSTITUTION:A thermal oxidation film 4 is formed on a silicon substrate 8 to check damage in a plasma etching and a ground dielectric layer 5 thereon. Then, a Pt thin film made by a sputtering method undergoes a patterning to form an exothermic resistor 3 on the dielectric layer 5. An Ni thin film made by a sputtering method undergoes a patterning to form an upstream side resistance thermometer bulb 1 and a downstream side resistance thermometer bulb 2 separately. Thereafter, an embossing is performed by plasma etching from the rear of the substrate 8 to form a hollow part at a specified dimension. Thus, the use of the material with a resistance temperature coefficient smaller than that of the material of the resistance thermometer bulb for the exothermic resistor enables the prevention of a change in the power consumption as caused by a change in the temperature of a fluid without lowering a sensor output with respect to a flow rate.</p> |
