Abstract: Thermal flow measuring device and method for the manufacture of a thermal flow measuring device with a spacer having a first cavity for accommodating a resistance thermometer, wherein the spacer has at least a first planar area, which faces the first cavity, and a second cavity, through which the resistance thermometer can be pressed by means of a hold-down onto the first planar area of the spacer.

Abstract: A thermal liquid flow sensor and method of forming same. The sensor has a substrate and one or more sensing elements, disposed on the substrate, for sensing a property of a liquid. The liquid flow sensor, which can be for example a microsensor having a microbrick® structure, has a hydrophilic layer which is disposed on the substrate and covers the sensing element(s). The hydrophilic layer is preferably formed from a spin on glass material, such as for example a silicate or phosphosilicate. A silicon nitride layer can be disposed on the sensing element(s) and interpose the substrate and the hydrophilic layer. The silicon nitride layer can be oxidized, for example, by means of plasma oxidation or oxygen ion implantation so to form the hydrophilic layer thereon. A variety of other hydrophilic compounds can be utilized to form the hydrophilic layer such as, gold, palladium and diamond like carbon.

Abstract: A thermal-type fluid flow sensor is provided to measure an air flow rate flowing through an air intake passage.

Abstract: The present invention is generally related to a novel micromachining thermal mass flow sensor and, more particularly, to a device incorporated with high strength and robust characteristics, which therefore is capable of operating under harsh environments. The new disclosed sensor is made of essential material which can provide robust physical structure and superior thermal properties to support the flow measuring operation. The invented thermal mass flow sensor is featuring with the advantages of micro-fabricated devices in terms of compact size, low power consumption, high accuracy and repeatability, wide dynamic range and easiness for mass production, which could avoid the drawbacks of fragility and vulnerability.

Abstract: The current invention generally relates to Micro Electro Mechanical Systems (MEMS) thermal mass flow sensors for measuring the flow rate of a flowing fluid (gas/liquid) and the methods of manufacturing on single crystal silicon wafers. The said mass flow sensors have self-cleaning capability that is achieved via the modulation of the cavity of which the sensing elements locate on the top of the cavity that is made of a silicon nitride film; alternatively the sensing elements are fabricated on top of a binary silicon nitride/conductive polycrystalline silicon film under which is a porous silicon layer selective formed in a silicon substrate. Using polycrystalline silicon or the sensing elements as electrodes, an acoustic wave can be generated across the porous silicon layer which is also used for the thermal isolation of the sensing elements.

Abstract: A method for measuring an air mass flow flowing in a main flow direction, and a hot-film air mass meter by which the method is able to be realized. The method and the hot-film air mass meter are especially suitable for use in the induction tract of an internal combustion engine. The hot-film air mass meter includes a sensor chip having a chip surface across which an air mass flow is able to flow. The chip surface in turn has a measuring surface, the measuring surface including a central hot-film air mass meter circuit having at least one central heating element and at least two temperature sensors. The method is implemented so that the at least one central heating element is periodically heated using a frequency ?. With the aid of at least two temperature sensors, at least two measuring signals are detected. The measuring signals and/or at least one differential signal of the at least two measuring signals are modulated using the frequency ?.

Abstract: Although flow detection accuracy deterioration due to a subject fluid inflow into a gap between a sensor device and an engaging portion is prevented by an underflow inhibitor, the underflow inhibitor overflow to a sensor device surface results in the subject fluid turbulence, causing a flow element output fluctuation risk. One solution is a configuration comprising a sensor device made of a planar semiconductor material with a heating element and an intake air temperature detection element formed thereon, a support member containing an engaging portion the sensor device is engaged to, which is placed at a passage the subject fluid circulates and underflow inhibitor being filled into a void between the sensor device and the support member to prevent the subject fluid from flowing into the void, and a pooling portion being placed to prevent the under flow inhibitor from overflowing out of the void.

Abstract: A fluid sensing system and method for sensing properties of a flowing fluid. The system and method entail a microfluidic device having a micromachined tube supported above a substrate, a tube passage within a freestanding portion of the tube, an inlet and outlet in fluidic communication with the tube passage and an exterior of the microfluidic device, elements for vibrating the freestanding portion of the tube, and elements for sensing movement of the freestanding portion of the tube so as to measure the vibration frequency and/or deflection of the freestanding portion and produce therefrom at least one output corresponding to a property of a fluid flowing through the tube passage. The system and method further entail placing the microfluidic device in a flowing fluid so that a fraction of the fluid enters the tube passage, and processing the output of the device to compute a property of the fluid.

Abstract: A device is provided for measuring the velocity of flow of a fluid in a respiration system and includes a first thermal sensor element (5) provided with a controllable heating element (50) and a second thermal sensor element (6). The thermal sensor elements (5, 6) are arranged at spaced locations from one another at a path of flow, so that a thermal signal generated by the first sensor element (5) with the heating element (50) is transmitted to the second sensor element (6), and the second sensor element (6) is designed to detect the thermal signal from the fluid flow. The second sensor element (6) is connected to the first sensor element (5) via feedback (12) which triggers another thermal signal. A controlling and analyzing device (13, 15) is connected to the sensor elements (5, 6) to start the generation of a first thermal signal and to read and analyze the signal frequency as an indicator of the velocity of flow.

Abstract: The present invention provides a highly-sensitive thermal-type flow-rate sensor with enhanced reliability. Provided is a thermal-type flow-rate sensor including: a passage into which a measurement-target fluid is introduced; and a sensor element which is provided in the passage and which measures the flow rate of the measurement-target fluid. The sensor element 1 includes: a semiconductor substrate; a hollow portion formed in the semiconductor substrate; and a heating resistor formed on an electric insulating film above the hollow portion. The sensor element measures the flow rate of the measurement-target fluid by radiating heat from the heating resistor to the measurement-target fluid.

Abstract: This invention relates to hot film shear stress sensors and their fabrication. We describe a hot film shear stress sensor comprising a silicon substrate supporting a membrane having a cavity underneath, said membrane bearing a film of metal and having electrical contacts for heating said film, and wherein said membrane comprises a silicon oxide membrane, where in said metal comprises aluminium or tungsten, and wherein said membrane has a protective layer of a silicon-based material over said film of metal. In preferred embodiments the sensor is fabricated by a CMOS process and the metal comprises aluminium or tungsten.

Abstract: This invention discloses a mass flow sensor manufactured by applying the micro-electromechanical system (MEMS) process to provide a new and improved mass flow sensor that is a self-calibrated in a time-of-flight manner with configuration to measure the flow velocity directly. The self-calibration of a mass flow rate sensor is achieved by providing an electric pulse to a heater in the flow and determining a temperature variations of the fluid. The method further includes a step of measuring a temperature variation by a temperature sensor disposed at a short distance from the heater. The method further includes a step of correlating the temperature variation measured at the temperature sensor with the temperature variation of the heater to determine a time delay and a corresponding flow velocity.

Abstract: A method of making a plurality of flow sensors is provided, each flow sensor having a substrate with a sensing element and flow channel aligned over the sensing element. The sensing element senses at least one property of a fluid. The flow channel is aligned by one or more guide elements formed in an alignment layer. The flow channel across the sensing area is accurately and precisely aligned due to the guide elements provided at the wafer-level, facilitating reliable, low-cost, and consistent results among multiple flow sensors. The flow sensor is adapted for use in harsh environments.

Abstract: To reduce power consumption by a thermal flowmeter while good flow-rate detection sensitivity is maintained, it is only necessary to reduce power consumption by a heat resistor under predetermined conditions. Specifically, provided that a width Wh of the heat resistor is between 100 micrometers and 400 micrometers inclusive (100?Wh?400), it is only necessary that a relationship among the length Lh of the heat resistor, a temperature increase ?Th for the heat resistor, and a maximum permissible power Phmax to be supplied to the heat resistor be set so as to satisfy a formula 1.4??Th·Lh/Ph max?2.8 in order to maintain good flow-rate detection sensitivity. Accordingly, the length of the heat resistor and the temperature increase in the heat resistor are set so that the maximum power consumption can be reduced within a range in which the formula is satisfied.

Abstract: A mass flow sensor is manufactured by a process of carrying out a micro-machining process on an N or lightly doped P-type silicon substrate with orientation <100>. This mass flow sensor comprises a central thin-film heater and a pair of thin-film heat sensing elements, and a thermally isolated membrane for supporting the heater and the sensors out of contact with the substrate base. The mass flow sensor is arranged for integration on a same silicon substrate to form a one-dimensional or two-dimensional array in order to expand the dynamic measurement range. For each sensor, the thermally isolated membrane is formed by a process that includes a step of first depositing dielectric thin-film layers over the substrate and then performing a backside etching process on a bulk silicon with TMAH or KOH or carrying out a dry plasma etch until the bottom dielectric thin-film layer is exposed.

Abstract: A flow sensor may be formed of a sensor chip in which a flow rate detecting section is formed on an electric insulating film applied to cover at least a part of a concave portion formed on an upper surface of a substrate and may also include a flow path forming member which is provided on the sensor chip and has a flow path of a fluid flowing through the flow rate detecting section formed therein.

Abstract: A mass flow sensor is supported on an N or P-type silicon substrate with orientation <100>. This mass flow sensor comprises a central thin-film heater and a pair of thin-film heat sensing elements, and a thermally isolated membrane for supporting the heater and the sensors out of contact with the substrate base. The mass flow sensor is arranged for integration on a same silicon substrate to form a one-dimensional or two-dimensional array in order to expand the dynamic measurement range.

Abstract: A thermal type flow sensor measures a flow rate of a fluid by means of a heat resistive element having a temperature dependency. The sensor is comprised of: plural heat resistive elements used for a flow rate measurement; and a driver circuit for controlling a current applied to these heat resistive elements to cause their heating. The driver circuit is configured to sense a resistance change of a lower-temperature side heat resistive element among the plural heat resistive elements and to control the current to be applied to the plural heat resistive elements in accordance with a sensed value of the lower-resistance's variation.

Abstract: A heater chip (4) as a heat generation element is secured to the surface on the periphery of piping (2). Further, a temperature sensor chip couple (6) is placed on the surface on the periphery of the piping (2), along the direction of flow of fluid flowing in the piping (2). One (6a) of the sensor chips in the couple is placed on the upstream side of the heater chip (4) and the other (6b) is placed on the downstream side of the heater chip (4). The heater chip (4) and the temperature sensor chips (6a, 6b) are formed in a chip type. The temperature sensor chips (6a, 6b) as the pair are placed at positions spaced by the same distance from the heater chip (4).

Abstract: A flow sensor element and a method for self-cleaning of the flow sensor element are provided, in which a temperature-measuring element and a heating element are arranged on a carrier element, and these elements can form a multiple-part ceramic component. The temperature-measuring element has a platinum thin-film resistor on a ceramic substrate for the temperature measurement and is heated with an additional platinum thin-film resistor. A measurement device, in particular an anemometric measurement device of a flow sensor, contains film resistors mounted in at least one opening of a cover or a hollow body. Two of the film resistors have resistance values differing by one to three orders of magnitude. The anemometric measurement device has a temperature sensor and a heat output sensor set in a carrier element. The temperature sensor has a temperature-measuring resistor and a heat conductor, as platinum thin-film or thick-film resistors, on a ceramic substrate.

Abstract: A thermal fluid flow sensor having a diaphragm structure body configured by an insulating film formed by stacking a film having compressive stress and a film having tensile stress on the top and bottom of a temperature-measuring resistive element and a heater resistive element which are processed by microprocessing is provided. The insulating film at a lower layer of the heater resistive element, a temperature-measuring resistive element for heater resistive element, upstream temperature-measuring resistive elements, and downstream temperature-measuring resistive elements, has films having compressive stress (a first insulating film, a third insulating film, and a fifth insulating film) and films having tensile stress (a second insulating film and a fourth insulating film) being alternately arranged, and two layers or more of the films having tensile stress are arranged.

Abstract: A thermal-type fluid flow sensor technology for measuring more precisely the temperature of the heater for an improved sensibility of detecting flow measurements. The thermal-type fluid flow sensor for measuring the air flow rate includes a heating resistive element formed on the semiconductor substrate through a first insulating layer, temperature-measuring resistive elements for heating resistive element for measuring the temperature of the heating resistive element, upstream and downstream temperature-measuring resistive elements for detecting the temperature of air on the upstream side and the downstream side of the air heated by the heating resistive element, and an air temperature measuring resistive element for measuring the temperature of the air heated by the heating resistive element, and at least the temperature-measuring resistive element for the heating resistive element is disposed in the upper layer or lower layer of the heating resistive element.

Abstract: Conventional thermal flow measurement devices lack consideration for automobiles in severe environments. A detection element of the thermal flow measurement device according to the present invention is structured by the provision of a planar substrate made of a material having good thermal conductivity, such as silicon or ceramic, with a thin-walled portion (diaphragm). On the surface of the thin-walled portion, the detection element comprises a heat element as a heater heated to a temperature being different to a predetermined extent from the temperature of the air flow to be measured, temperature-detecting resistors as temperature-detecting means on both sides of the heat element, wiring portions formed of electrical conductors that draw signal lines from the heat element and the temperature-detecting resistors and that have a melting point of 2000° C. or higher, and pads.

Abstract: According to a flow measuring device, first ranges formed by a first plurality of resistors form a single continuous value range on a flow direction coordinate axis. Thus, the first plurality of resistors is limited from being thermally insulated from one another in the flow direction, and thereby detectivity is improved. Also, second ranges formed by a second plurality of resistors form an other single continuous value range on a longitudinal direction coordinate axis. The other continuous value range includes a position that corresponds to a half length of a heating element in a longitudinal direction. As a result, detection difference is obtained at the position, at which a temperature is most optimally detected, and thereby detectivity is further improved.

Abstract: To provide a flowmeter producing stable measurement results and coincidentally achieving miniaturization, a bent portion is provided in a flow path located between an inlet port of fluids to the flowmeter and a second flow path at which a sensor detecting a flow rate is positioned, thus forming at a sensor an almost uniform flow-velocity distribution in cross-section of the fluids and a reproducible and constant flow-velocity distribution.

Abstract: A package is configured by stacking a flat board whereupon a rectangular hole for storing a sensor chip is formed, a flat board whereupon a hole section to be a package inner channel for introducing a measurement target gas into the sensor chip is formed, and a flat board whereupon hole sections which communicate with the package inner channel as an inlet and an outlet of the measurement target gas on the same end surface of the package are formed.

Abstract: In a structure in which peripheral part of a diaphragm section of an electrical insulating film is covered with a protective film made of an organic material, the resistor wire on the diaphragm section crosses the peripheral part of the diaphragm section. At a place where a narrow wire of a resistance temperature detector and the like crosses the peripheral part of the diaphragm section, the protective film is thinner than the other part, and the dust impact resistance is reduced. At a place where a heating resistor wire connected to a heating resistor body or resistance temperature detector wires connected to resistance temperature detector bodies cross a periphery of the diaphragm section, a film component protruding from an electrical insulating film is arranged side by side with the heating resistor wire or the resistance temperature detector wires.

Abstract: In a gas flowmeter in which a rod and a sensor element are formed as a single body, for preventing heat of the sensor element from flowing into a sensor probe through a substrate (rod) so as to suppress considerable power consumption, and for obtaining a necessary response speed with respect to a flow rate of gas to be measured or a change in temperature, the gas column (rod) is made of an insulating material on a center axis of the sensing probe and is formed with a conductor pattern on its surface, and the sensing probe connects the sensor element disposed in a pipe through which the gas to be measured flows and a harness terminal through the conductor on the surface of the rod, so as to measure a gas flow rate by using the sensing prove.

Abstract: A thermal-type fluid flow sensor technology for measuring more precisely the temperature of the heater for an improved sensibility of detecting flow measurements. The thermal-type fluid flow sensor for measuring the air flow rate includes a heating resistive element formed on the semiconductor substrate through a first insulating layer, temperature-measuring resistive elements for heating resistive element for measuring the temperature of the heating resistive element, upstream and downstream temperature-measuring resistive elements for detecting the temperature of air on the upstream side and the downstream side of the air heated by the heating resistive element, and an air temperature measuring resistive element for measuring the temperature of the air heated by the heating resistive element, and at least the temperature-measuring resistive element for the heating resistive element is disposed in the upper layer or lower layer of the heating resistive element.

Abstract: A method and a sensor for detecting a component, in particular H2, in a gaseous fluid containing multiple components. A measuring chamber, which accommodates a heatable measuring element, is implemented in a sensor. The measuring chamber is heated.

Abstract: A measurement device, particularly an anemometric measurement device, is provided for mounting in an exhaust-gas pipe, particularly an exhaust-gas recirculation pipe. The device includes a ceramic carrier embedded in an injection-molded housing made of plastic, with at least one film resistor mounted on the ceramic carrier on an end opposite the embedding. Electrical connections lead out from the film resistor to the embedded end of the ceramic carrier, and the electrical connections are passed through the injection molding, sealed and mounted within the injection-molded part. Additional components can be used for the sealing and mounting.

Abstract: According to one embodiment, a first capacitive element may be provided and associated with a surface where a fouling layer is to be detected. A second capacitive element may also be provided, and a capacitance between the first and second capacitive elements may be used to detect formation of the fouling layer. According to another embodiment, a thermal device is provided proximate to a surface where a fouling layer is to be detected. A detector (e.g., a thermometer or vibration detector) may detect a condition associated with the surface, and formation of the fouling layer may be determined based at least in part on the condition.

Abstract: A flow rate sensor has a problem that a resistance value of a heat generating resistor itself varies and sensor characteristics are changed during use of the sensor for a long term. Also, the temperature of the heat generating resistor must be adjusted on a circuit substrate with a resistance constituting one side of a fixed temperature difference control circuit, and this has been one of factors pushing up the production cost. All resistances used for fixed temperature difference control are formed on the same substrate as temperature sensitive resistors of the same material. This enables all the resistances for the fixed temperature difference control to be exposed to the same environmental conditions. Hence, even when the resistances change over time, the changes over time occur substantially at the same tendency. Since the resistances for the fixed temperature difference control change over time essentially at the same rate, a resulting output error is very small.

Abstract: A flow rate/liquid type detecting method for detecting the flow rate of a fluid and, at the same time, detecting any one of or both the type of the fluid and the concentration of the fluid, characterized in that, by using a flow rate/liquid type detecting apparatus comprising: a main passage through which a fluid to be detected flows, an auxiliary passage branched from the main passage, and a flow rate/liquid type detecting sensor device provided in the auxiliary passage, is provided, and in conducting any one of or both the detection of the type of the fluid and the detection of the concentration of the fluid, the auxiliary passage opening/closing valve is closed, and the fluid is allowed to temporarily stay within the flow rate/liquid type detecting sensor device to conduct any one of or both the detection of the liquid type and the detection of the concentration, and in detecting the flow rate of the fluid detected, the auxiliary passage opening/closing valve is opened to allow the fluid to flow into the f

Abstract: In the thermal type flowmeter for measuring the flow rate by a measuring element with an exothermic resistor and a temperature measuring resistor being shaped in the side of the surface of a substrate, a facing wall facing the surface of the measuring element is arranged, cantilever plate parts protruding from the facing wall toward the measuring element side are arranged, a gap is provided between the tip of the cantilever plate parts and the measuring element, and the cantilever plate parts are extended from the upper stream to the down stream of the measuring element.

Abstract: A sensor includes: a silicon substrate having a hollow portion, which is arranged on a backside of the substrate; an insulation film disposed on a front side of the substrate and covering the hollow portion; a heater disposed on the insulation film, made of a semiconductor layer, and configured to generate heat; and an anti-stripping film for protecting the insulation film from being removed from the silicon substrate. The silicon substrate, the insulation film and the. semiconductor layer provide a SOI substrate. The hollow portion has a sidewall and a bottom. The anti-stripping film covers at least a boundary between the sidewall and the bottom of the hollow portion.

Abstract: A thermal flow sensor is equipped with a self-test unit that monitors the device and generates a fault signal in the presence of a malfunction. The self-test unit can e.g. monitor the integrity of a membrane carrying the heater and temperature sensors, or it can monitor various operational parameters of the device, thereby increasing the safety of the device.

Abstract: In a flow quantity measuring device, each of upstream side and downstream side sensing resistors, which are placed on an upstream side and a downstream side, respectively, of a heating resistor, includes resistor elements, each of which forms a folded path. The folded path has a generally constant width along an entire extent thereof and is returned at each of first and second longitudinal end edges of a sensing area. The heating resistor forms a folded path, which has a generally constant width along an entire extent thereof and is returned at the second longitudinal end edge of the heat generating area. First and second ends of the folded path of the heating resistor projects beyond the first longitudinal end edge of the sensing area on a first side of the flow quantity measuring device.

Abstract: A semiconductor device includes: a semiconductor substrate; a flow sensor having a first heater for detecting a flow rate of fluid; and a humidity sensor for detecting a humidity of the fluid. The flow sensor and the humidity sensor are disposed on the semiconductor substrate. The flow sensor is disposed around the humidity sensor. The humidity sensor is disposed on an upstream side of the first heater. Since the device includes the humidity sensor, moisture in the fluid is compensated so that detection accuracy of the flow rate is improved.

Abstract: A method for measuring an air mass flow flowing in a main flow direction, and a hot-film air mass meter by which the method is able to be realized. The method and the hot-film air mass meter are especially suitable for use in the induction tract of an internal combustion engine. The hot-film air mass meter includes a sensor chip having a chip surface across which an air mass flow is able to flow. The chip surface in turn has a measuring surface, the measuring surface including a central hot-film air mass meter circuit having at least one central heating element and at least two temperature sensors. The method is implemented so that the at least one central heating element is periodically heated using a frequency ?. With the aid of at least two temperature sensors, at least two measuring signals are detected. The measuring signals and/or at least one differential signal of the at least two measuring signals are modulated using the frequency ?.

Abstract: A humidity sensor system and method include a ceramic substrate upon which a heater can be printed. A humidity sensor can be mounted above and in contact with the heater, or the heater can be mounted one side of the substrate and the humidity sensor on the opposite side of the substrate, such that the heater heats the humidity sensor, raising its temperature above the dew point of the ambient air such that moisture does not condense on the humidity sensor, thereby preventing the humidity sensor performance from being affected. The heater can be configured as a resistive heater, and the humidity sensor can be configured from one or more humidity-sensing die. A thin film platinum RTD (Resistance Temperature Detector) component can be printed upon the substrate in association with the humidity sensor.

Abstract: A flowmeter including a system chip with a silicon substrate provided on a carrier, in an opening whereof at least one silicon flow tube is provided for transporting a medium whose flow rate is to be measured, the tube having two ends that issue via a wall of the opening into channels coated with silicon nitride in the silicon substrate, wherein the flow tube forms part of a Coriolis flow sensor and/or a thermal flow sensor, and wherein the channels are preferably in communication through the carrier with connection lines to the external world.

Abstract: A thermal air flowmeter having excellent temperature characteristics and improved measurement accuracy. The thermal air flowmeter includes a temperature sensor disposed in a casing of the air flowmeter, a computing unit for correcting a flow rate detection voltage from a measuring element by using the temperature sensor, and a heating temperature control disposed in a temperature control circuit for performing temperature control of a heating resistor to vary a temperature rise of the heating resistor relative to an air temperature depending on the air temperature. Flow rate detection errors of the thermal air flowmeter caused by an overall temperature change and a temperature change on an intake passage wall surface can be corrected simultaneously and a thermal air flowmeter having superior measurement accuracy can be realized.

Abstract: A thermal-type fluid flow sensor comprises a heating resistor formed on a thin film of a substrate, and plural thermal sensitive resistors configuring a bridge circuit. The thermal sensitive resistors are disposed on the thin film of the substrate so as to be located on an adjacent upstream side and an adjacent downstream side of the heating resistor in a stream direction of fluid to be measured. Resistor traces for the thermal sensitive resistors are formed so that the respective thermal sensitive resistors exhibit substantially equal changes in resistance with each other to distortion caused in the thin film.

Abstract: There is a need for providing a flow sensor with metal film resistor that improves detection sensitivity using a metal film for a resistance heat detector and a resistance temperature detector. The flow sensor with metal film resistor is structured to form a resistance heat detector, a resistance temperature detector for resistance heat detector for measuring temperature of the resistance heat detector, an upstream resistance temperature detector, a downstream resistance temperature detector, and an air resistance temperature detector on a silicon substrate. Plural floating-island insulators are provided for the resistance heat detector and within wiring thereof.

Abstract: A measurement device, in particular anemometric measurement device of a flow sensor, contains film resistors in one or more opening(s) of a cover or a hollow body. The film resistors are fastened according to the invention in the opening(s). Two film resistors differ with respect to their resistance by one to three orders of magnitude. In an anemometric measurement device of a flow sensor according to the invention, a temperature sensor and a heating capacity sensor are placed in a carrier element. The temperature sensor has a temperature-measuring resistor and a heat conductor as platinum thin-film or thick-film resistors on a ceramic substrate. For self-cleaning of an anemometric measurement device of a flow sensor, in which a temperature-measuring element and a heating element are placed in a carrier element, the temperature-measuring element has a platinum thin-film resistor on a ceramic substrate for temperature measurement and is heated with an additional platinum thin-film resistor.

Abstract: The coupling capacitance of the wiring portions of a thermal type flow rate measuring apparatus is reduced so as to prevent a drop in the response characteristics. A detection element of the thermal type flow rate measuring apparatus includes a planar substrate made of silicon, ceramic, or the like, in which a diaphragm is formed. On the surface of the diaphragm, there are disposed a heat-generating resistor as a heat-generating element that is heated to a predetermined temperature difference from the temperature of air flow to be measured, a heat-generating element temperature-detecting resistor for detecting the temperature of the heat-generating resistor, and temperature-detecting resistors disposed on both sides of the heat-generating resistor. The detection element also includes wiring portions which have connecting terminals electrically connected to the heat-generating resistor and a wiring pattern electrically connected with the surface of the planar substrate.

Abstract: A MEMS flow sensor has a flow channel that avoids wire bond pads and ancillary circuit elements. A fluid can move from the bottom of the sensor substrate, though an inlet hole, over a sensing element on the top of the substrate, and then through an outlet hole. The inlet hole and the outlet hole can pass from the substrate top to the substrate bottom. A top cap can be fixed to the top of the substrate such that it covers the sensing element, the inlet hole, and the outlet hole. The top cap constrains the flow channel and keeps fluid, either gaseous or liquid, from exiting the channel and contacting the wire bond pads or ancillary circuit elements.

Abstract: A thermal anemometer or mass flow meter typically having temperature and flow velocity sensor elements is provided in which a thin film temperature sensor is used in the heated sensor of the fluid velocity sensor element of the system. At least one thin-film RTD sensor is held within a spacer or interface member and the spacer, optionally, received within a housing. The thermal anemometer is preferably constructed to offer sufficient precision and accuracy in its design to be suitable for sensitive scientific and industrial applications. This goal is achieved while using cost effective parts by employing a construction approach in which the spacer and RTD sensor(s) is secured in place by solder, braze or another compound flowed into place while inserting the spacer and/or sensor(s).

Abstract: A MEMS based flow sensor is disclosed which generally incorporate isolation between a sensing structure and the sensed media. An internal flow channel can be configured by attaching a backing structure with flow openings to the back of the sensing structure. The sensing structure can be composed of a insulating layer with heating element and a dual sensing element which comprises of resistive thin films positioned in a Wheatstone bridge configuration over a backside cavity. The dual sensing element and its associated wirebonds can be isolated from the sensing media by directing the fluid through the internal flow channel. The completed sensing structure can be over packaged with standard processes such as epoxies and seals.