Abstract: A flow sensor includes a semiconductor, an electric control circuit, a lead frame, and a spacer. The spacer is disposed in a clearance between the lead frame and the semiconductor device on an opposite side from a joint portion of the semiconductor device with the lead frame on a side of the electric control circuit across the diaphragm disposed therebetween. A surface of the electric control circuit and a part of a surface of the semiconductor device is covered with resin while the air flow sensing unit is exposed. At the joint portion, the semiconductor device is attached to the lead frame via an adhesive.

Abstract: A thermal airflow sensor includes a sensor element, a bonding wire, a resin, and a protective film. The sensor element has a thin-wall portion. The thin-wall portion has a heating resistor. The bonding wire is electrically connected to the sensor element. The resin covers the bonding wire. The protective film is formed on a surface of the sensor element so that the heating resistor is exposed. The protective film has at least a slit between the resin and the thin-wall portion.

Abstract: The present invention provides a thermal flow rate measurement device that is capable of highly accurate correction of the temperature of an intake gas flow rate using a two-dimensional correction map that stores a correction value in association with temperature and intake gas flow rate.

Abstract: A flow sensor includes a semiconductor, an electric control circuit, a lead frame, and a spacer. The spacer is disposed in a clearance between the lead frame and the semiconductor device on an opposite side from a joint portion of the semiconductor device with the lead frame on a side of the electric control circuit across the diaphragm disposed therebetween. A surface of the electric control circuit and a part of a surface of the semiconductor device is covered with resin while the air flow sensing unit is exposed. At the joint portion, the semiconductor device is attached to the lead frame via an adhesive.

Abstract: The present invention has been made to improve measurement accuracy of a thermal flow meter. In the thermal flow meter according to the invention, a circuit package (400) that measures a flow rate is molded in a first resin molding process. In a second resin molding process, a housing (302) having an inlet trench (351), a bypass passage trench on frontside (332), an outlet trench (353), and the like are formed through resin molding, and an outer circumferential surface of the circuit package (400) produced in the first resin molding process is enveloped by a resin in the second resin molding process to fix the circuit package (400) to the housing (302).

Abstract: A flow sensor structure seals the surface of an electric control circuit and part of a semiconductor device via a manufacturing method that prevents occurrence of flash or chip crack when clamping the semiconductor device via a mold. The flow sensor structure includes a semiconductor device having an air flow sensing unit and a diaphragm, and a board or lead frame having an electric control circuit for controlling the semiconductor device, wherein a surface of the electric control circuit and part of a surface of the semiconductor device is covered with resin while having the air flow sensing unit portion exposed. The flow sensor structure may include surfaces of a resin mold, a board or a pre-mold component surrounding the semiconductor device that are continuously not in contact with three walls of the semiconductor device orthogonal to a side on which the air flow sensing unit portion is disposed.

Abstract: The present invention has been made to improve measurement accuracy of a thermal flow meter. In the thermal flow meter according to the invention, a circuit package (400) that measures a flow rate is molded in a first resin molding process. In a second resin molding process, a housing (302) having an inlet trench (351), a bypass passage trench on frontside (332), an outlet trench (353), and the like are formed through resin molding, and an outer circumferential surface of the circuit package (400) produced in the first resin molding process is enveloped by a resin in the second resin molding process to fix the circuit package (400) to the housing (302).

Abstract: In order to provide a flow measuring device high in thermal responsiveness, the flow measuring device includes a temperature detecting element 2 for temperature detection, and a conductive metal lead frame 3 that supports and fixes the temperature detecting element. Of the metal lead frame, a part of the metal lead frame mounted with the temperature detecting element has a portion which is thinner than the thickness of the other metal lead frame or narrower than the width of the other metal lead frame.

Abstract: The present invention has been made to improve measurement accuracy of a thermal flow meter. In the thermal flow meter according to the invention, a circuit package (400) that measures a flow rate is molded in a first resin molding process. In a second resin molding process, a housing (302) having an inlet trench (351), a bypass passage trench on frontside (332), an outlet trench (353), and the like are formed through resin molding, and an outer circumferential surface of the circuit package (400) produced in the first resin molding process is enveloped by a resin in the second resin molding process to fix the circuit package (400) to the housing (302).

Abstract: A thermal flowmeter circuit package having a side of a measurement surface 430 of the circuit package and a flow path 387 at a side of the backside of measurement surface 431 of a rear surface of the measurement surface 430, and an inflow-side end surface of the circuit package for dividing the measurement target gas 30 has different shapes at the side of the measurement surface and at the side of the backside of measurement surface. The inflow-side end surface of the circuit package for dividing the measurement target gas 30 is formed with a reference line 700 dividing the measurement target gas 30, and an end surface 701a at the side of the measurement surface with respect to the reference line and an end surface 701b at the side of the backside of measurement surface with respect to the reference line are formed to be asymmetrical.

Abstract: In configurations in which a circuit element is connected in parallel with a resistor, it is difficult to detect a break in the two wires. A thermal flow meter includes a heating element and a temperature controlling bridge circuit that is formed of a plurality of resistors and controls the temperature of the heating element. The thermal flow meter includes: a circuit element connected in parallel with at least one resistor configuring the temperature controlling bridge circuit through two wires drawn from both ends of the resistor; a voltage detection circuit that detects that the magnitude of voltage produced between the two wires has become smaller than a first predetermined value; and a fault signal output circuit that, when it is detected at the voltage detection circuit that the. magnitude of the voltage has become smaller than the first predetermined value, outputs a signal indicating a fault.

Abstract: The present invention provides a thermal flow rate measurement device that is capable of highly accurate correction of the temperature of an intake gas flow rate using a two-dimensional correction map that stores a correction value in association with temperature and intake gas flow rate.

Abstract: Provided is a thermal flow meter to improve the measurement accuracy of a temperature detector. The thermal flow meter includes a bypass passage through which a measurement target gas flowing through a main passage flows, and a circuit package which includes a measurement circuit for measuring a flow rate of the measurement target gas flowing through the bypass passage and a temperature detecting portion for detecting a temperature of the measurement target gas. The circuit package includes a circuit package body which is molded by a resin to internally envelope the measurement circuit and a protrusion molded by the resin. The temperature detecting portion is provided in the leading end portion of the protrusion, and at least the leading end portion of the protrusion protrudes to the outside from a housing.

Abstract: A thermal-type flowmeter includes a chip package. The chip package is formed through encapsulation with a resin of a sensor element, a drive circuit, a metal lead frame adapted to have mounted thereon the sensor element and the drive circuit, and a temperature detecting element. The chip package has an exposed structure in which a surface of the sensor element having the diaphragm is exposed. The temperature detecting element is mounted on the lead frame via an electrically conductive member.

Abstract: To obtain a thermal flow meter capable of providing thermal insulation without degrading responsiveness of a temperature detection element.

Abstract: A thermal airflow sensor includes a sensor element, a bonding wire, a resin, and a protective film. The sensor element has a thin-wall portion. The thin-wall portion has a heating resistor. The bonding wire is electrically connected to the sensor element. The resin covers the bonding wire. The protective film is formed on a surface of the sensor element so that the heating resistor is exposed. The protective film has at least a slit between the resin and the thin-wall portion.

Abstract: The present invention has been made to improve measurement accuracy of a thermal flow meter. In the thermal flow meter according to the invention, a circuit package (400) that measures a flow rate is molded in a first resin molding process. In a second resin molding process, a housing (302) having an inlet trench (351), a bypass passage trench on frontside (332), an outlet trench (353), and the like are formed through resin molding, and an outer circumferential surface of the circuit package (400) produced in the first resin molding process is enveloped by a resin in the second resin molding process to fix the circuit package (400) to the housing (302).

Abstract: A thermal airflow sensor includes a semiconductor device, a protective film a bonding wire, and a resin. The resin covers over a part of the semiconductor device so that the bonding wire is covered with the resin and the region including a thin-wall portion is exposed. The protective film is not covered with the resin and has an outer peripheral edge located outside the thin-wall portion.

Abstract: The present invention has been made to improve measurement accuracy of a thermal flow meter. In the thermal flow meter according to the invention, a circuit package (400) that measures a flow rate is molded in a first resin molding process. In a second resin molding process, a housing (302) having an inlet trench (351), a bypass passage trench on frontside (332), an outlet trench (353), and the like are formed through resin molding, and an outer circumferential surface of the circuit package (400) produced in the first resin molding process is enveloped by a resin in the second resin molding process to fix the circuit package (400) to the housing (302).

Abstract: A thermal flow meter capable of measuring flow rates of a gas flowing in a forward direction and a backward direction with a high degree of accuracy is provided. A thermal flow meter 300 according to the present invention includes a bypass passage configured to retrieve and flow a measurement target gas 30 received from a main passage 124 and a flow rate measurement circuit 601 configured to measure a flow rate by performing heat transfer with the measurement target gas flowing in the bypass passage.