A sensor device for determining at least one parameter of a fluid medium flowing through a duct, e.g., an intake air mass flow of an internal combustion engine, includes: a sensor housing, e.g., a sensor plug that is placed or that can be placed into a flow tube, in which the duct is fashioned; and at least one sensor chip situated in the duct for determining the parameter of the fluid medium. The sensor chip has a sensor area. The sensor housing has an inlet into the duct that is oriented opposite a main direction of flow of the fluid medium, and has at least one outlet from the duct. The sensor area is covered at least partly by an electrically conductive layer.

A sensor device for determining at least one parameter of a fluid medium flowing through a duct, e.g., an intake air mass flow of an internal combustion engine, includes: a sensor housing, e.g., a sensor plug that is placed or that can be placed into a flow tube, in which the duct is fashioned; and at least one sensor chip situated in the duct for determining the parameter of the fluid medium. The sensor chip has a sensor area. The sensor housing has an inlet into the duct that is oriented opposite a main direction of flow of the fluid medium, and has at least one outlet from the duct. The sensor area is covered at least partly by an electrically conductive layer.

Thermal flow measuring device (1), especially for determining and/or monitoring the mass flow (Φ.sub.M) and/or the flow velocity (v.sub.F) of a flowable medium (3) through a pipeline (2), comprising at least three sensor elements (4a,4b,4c) and an electronics unit (9), wherein each of the at least three sensor elements (4a,4b,4c) is at least partially and/or at times in thermal contact with the medium (3), and includes a heatable temperature sensor (5a,5b,5c), and wherein the electronics unit (9) is embodied to heat each of the three sensor elements (4a,4b,4c) with a heating power (P1,P2,P3), to register their temperatures (T1,T2,T3), to heat at least two of the at least three sensor elements (4a,4b,4c) simultaneously, to ascertain the mass flow (Φ.sub.M) and/or the flow velocity (v.sub.F) of the medium (3), from a pairwise comparison of the temperatures (T1,T2,T3) and/or heating powers (P1,P2,P3) of the at least three sensor elements (4a,4b,4c) and/or at least one variable derived from at least one of the temperatures (T1,T2,T3) and/or heating powers (P1,P2,P3), to provide information concerning a change of the thermal resistance of at least one of the at least three sensor elements (4a,4b,4c), from a response to an abrupt change ΔP of the heating power supplied to at least one of the at least three sensor elements, to provide information concerning a change of the inner thermal resistance of the at least one sensor element, and in the case that a change of the inner and/or outer thermal resistance occurs in the case of at least one of the at least three sensor elements (4a,4b,4c), to perform a correction of the measured value for the mass flow (Φ.sub.M) and/or the flow velocity (v.sub.F) and/or to generate and to output a report concerning the state of the at least one sensor element mass flow (Φ.sub.M) and/or the flow velocity (v.sub.F).

Thermal flow measuring device (1), especially for determining and/or monitoring the mass flow (Φ.sub.M) and/or the flow velocity (v.sub.F) of a flowable medium (3) through a pipeline (2), comprising at least three sensor elements (4a,4b,4c) and an electronics unit (9), wherein each of the at least three sensor elements (4a,4b,4c) is at least partially and/or at times in thermal contact with the medium (3), and includes a heatable temperature sensor (5a,5b,5c), and wherein the electronics unit (9) is embodied to heat each of the three sensor elements (4a,4b,4c) with a heating power (P1,P2,P3), to register their temperatures (T1,T2,T3), to heat at least two of the at least three sensor elements (4a,4b,4c) simultaneously, to ascertain the mass flow (Φ.sub.M) and/or the flow velocity (v.sub.F) of the medium (3), from a pairwise comparison of the temperatures (T1,T2,T3) and/or heating powers (P1,P2,P3) of the at least three sensor elements (4a,4b,4c) and/or at least one variable derived from at least one of the temperatures (T1,T2,T3) and/or heating powers (P1,P2,P3), to provide information concerning a change of the thermal resistance of at least one of the at least three sensor elements (4a,4b,4c), from a response to an abrupt change ΔP of the heating power supplied to at least one of the at least three sensor elements, to provide information concerning a change of the inner thermal resistance of the at least one sensor element, and in the case that a change of the inner and/or outer thermal resistance occurs in the case of at least one of the at least three sensor elements (4a,4b,4c), to perform a correction of the measured value for the mass flow (Φ.sub.M) and/or the flow velocity (v.sub.F) and/or to generate and to output a report concerning the state of the at least one sensor element mass flow (Φ.sub.M) and/or the flow velocity (v.sub.F).

The purpose of the present invention is to provide a highly accurate and highly reliable physical quantity sensor wherein an error due to stress applied to a sensor element of the physical quantity sensor is reduced. This physical quantity sensor device is provided with: a hollow section formed in a Si substrate; an insulating film covering the hollow section; and a heating section formed in the insulating film. The sensor device is also provided with a detection element that detects the temperature of the insulating film above the hollow section, the detection element is provided with a first silicon element and a second silicon element, and the first silicon element and the second silicon element are doped with different impurities, respectively.

There is provided a thermal-type airflow meter that reduces the number of output signals of the sensor circuit and that can suppress the accuracy of flow rate detection from being deteriorated because due to a nonlinear sensor output characteristic and a response delay in the output signal, the output signal shifts toward the positive side or the negative side. A thermal-type airflow meter outputs one or both of a positive-side comparison signal that is at the positive side of a comparison threshold value and a negative-side comparison signal that is at the negative side of the comparison threshold value, outputs a coefficient multiplication signal obtained by multiplying an average signal acquired by averaging the comparison signal by an adjustment coefficient, and outputs, as a flow rate signal, a value obtained by applying the coefficient multiplication signal to increase correction or decrease correction of the amplitude increase signal.

Degradation of reliability of a thermal fluid flow sensor, caused by generation of a crack in an insulating film is prevented in the thermal fluid flow sensor including a detection section and a circuit section formed on the same substrate when stress adjustment is performed by forming a deep concave portion in an interlayer insulating film in the detection section and forming the insulating film having a tensile stress thereon. As a means thereof, stair-like step is provided in a side wall of a concave portion, formed in the interlayer insulating film on a diaphragm. Accordingly, each depth of a first concave portion and a second concave portion, which form the concave portion, is reduced, and coatability of the insulating film for the stress adjustment, which covers a side wall and a bottom face of the concave portion, is improved.

Degradation of reliability of a thermal fluid flow sensor, caused by generation of a crack in an insulating film is prevented in the thermal fluid flow sensor including a detection section and a circuit section formed on the same substrate when stress adjustment is performed by forming a deep concave portion in an interlayer insulating film in the detection section and forming the insulating film having a tensile stress thereon. As a means thereof, stair-like step is provided in a side wall of a concave portion, formed in the interlayer insulating film on a diaphragm. Accordingly, each depth of a first concave portion and a second concave portion, which form the concave portion, is reduced, and coatability of the insulating film for the stress adjustment, which covers a side wall and a bottom face of the concave portion, is improved.

Methods and apparatuses associated with an example flow sensing device are provided. In some examples, the flow sensing device may include a flow cap component and a sensor component. In some examples, the flow cap component may include a heating element disposed in a first layer of the flow cap component. In some examples, the sensor component may include at least one thermal sensing element disposed in a second layer of the sensor component. In some examples, the first layer and the second layer are noncoplanar. In some examples, the flow cap component may be bonded to a first surface of the sensor component to form a flow channel. In some examples, the first layer and the second layer may be noncoplanar and separated by the flow channel.

Methods and apparatuses associated with an example flow sensing device are provided. In some examples, the flow sensing device may include a flow cap component and a sensor component. In some examples, the flow cap component may include a heating element disposed in a first layer of the flow cap component. In some examples, the sensor component may include at least one thermal sensing element disposed in a second layer of the sensor component. In some examples, the first layer and the second layer are noncoplanar. In some examples, the flow cap component may be bonded to a first surface of the sensor component to form a flow channel. In some examples, the first layer and the second layer may be noncoplanar and separated by the flow channel.