Abstract: To improve measurement accuracy of a thermal flow meter. The present invention provides a thermal flow meter, in which a protrusion 356 having an orifice surface 503 and a recovery surface 505 is provided on a wall surface 501 of a bypass passage, an intersection line 506 between the orifice surface 503 and the wall surface 501 is arranged in an upstream side from an upstream side end 401 of a circuit package 400, an intersection line 507 between the recovery surface 505 and the wall surface 501 is arranged in a downstream side from a downstream side end 402 of the circuit package 400, and an apex 504 of the protrusion 356 is arranged in a downstream side from a heat transfer surface of an air flow sensing portion 602 and in an upstream side from the downstream side end 402 of the circuit package 400.

Abstract: In order to provide a thermal-type flowmeter highly accurate, with high reliability, and simple in construction, while being available at a lower price, a thermal-type flowmeter as proposed includes a sub-path that takes in a fluid under measurement; a sensor element that measures a flow-rate of the fluid under measurement in the sub-path; a temperature detection element that detects a temperature of the fluid under measurement; a drive circuit that controls a heating temperature of the sensor element; and a protection circuit that protects the drive circuit from noise, a cavity being formed on a substrate of the sensor element, an exothermic resistor being provided on a thin-film part on the cavity through the intermediary of an electrically insulating film, and a flow rate being detected on the basis of temperature distribution in the thin-film part.

Abstract: The present invention is to improve measurement accuracy of a thermal flow meter. In a thermal flow meter of the invention, a circuit package 400 includes a processing unit 604 in which a passage 605 and a circuit are disposed. An air flow sensing portion 602 is disposed in the passage 605. A fixing portion 372 is integrally formed with and fixed to the circuit package 400 and forms a bypass passage. The passage 605 of the circuit package 400 is arranged inside the bypass passage. In the bypass passage, a storage portion 384 having a concave portion 383 is formed to face the fixing portion 372. At least a part of the leading end 401 of the circuit package 400 is contained in the concave portion 383 of the storage portion 384.

Abstract: An airflow measuring apparatus includes a sub-passage that takes in part of flow of fluid flowing through an intake pipe, a sensor element disposed in the sub-passage to measure the flow of fluid, a circuit part converting the flow of fluid detected by the sensor element into an electric signal, a connector part connected to the circuit part to output a signal externally, and a casing supporting the sensor element and the circuit part. The sensor element is disposed in the intake pipe, and includes a cavity disposed at a semiconductor substrate and a diaphragm including a thin film part that covers the cavity. The sensor element on a lead frame has surfaces that are mold-packaged with resin so that the diaphragm and part of the lead frame are exposed. One hole is disposed at the lead frame for communication between the cavity and exterior.

Abstract: In order to provide a thermal flow meter capable of preventing adherence of contaminants to an air flow sensing portion, the thermal flow meter (300) of the invention includes a bypass passage for flowing a measurement target gas (30) received from a main passage (124) and an air flow sensing portion (602) for measuring a flow rate of the measurement target gas (30) by performing heat transfer with the measurement target gas (30) flowing through the bypass passage through a heat transfer surface (437). The air flow sensing portion (602) is provided to be exposed to an exposed surface (402) arranged along a flow direction of the measurement target gas (30) inside the bypass passage is embedded, the mount support surface (402) has a stage (407) formed to surround a periphery of the air flow sensing portion (602), and an inner portion surrounded by the stage protrudes more than an outer portion of the stage.

Abstract: In order to provide a method of manufacturing a thermal type flowmeter that is capable of reducing deformation of a semiconductor chip, which is caused by molding, a method of manufacturing a thermal type flowmeter is provided that includes a circuit package of a resin-molded semiconductor chip. The method includes resin-molding the semiconductor chip in a state in which a mold is pressed against a heat transfer surface that is provided on a surface of the semiconductor chip and a pressed surface that is set on the surface of the semiconductor chip at a position separate from the heat transfer surface.

Abstract: An object of the present invention is to provide a thermal-type air flow meter with a high measurement accuracy by reducing influence of a thermal stress generated in a resistor in an LSI while securing a high positioning accuracy flow rate detection unit.

Abstract: Provided is a welding structure which enables external visual checks and has improved stability of bonding properties at a laser weld between a cover and a housing of this flow sensor. This flow sensor is provided with a housing, a cover, a circuit chamber sealed between these and housing electronic components or wiring, and a subpassage through which the fluid flows that is to be sensed, and is characterized in that at least the part near the gate section of the cover that transmits the laser is thinner than the other parts that transmit the laser.

Abstract: Provided are a laser-welded structure and a laser welding method for a cover and a housing ensuring high reliability and suppressing changes in characteristics due to burrs protruding into a subpassage of the flow sensor. To this end, this flow sensor is provided with a housing, a cover, a circuit chamber sealed between these and housing electronic components or wiring, and a subpassage through which the fluid flows that is to be sensed, and is characterized in that there are projections provided on both ends of the joining section of the cover where the housing and the cover are laser-welded, and the height of the projection on the subpassage side is greater than the height of the projection on the side opposite of the subpassage.

Abstract: Provided is a low-cost flow sensor which improves productivity while maintaining high quality and high reliability. This flow sensor is provided with a housing, a cover, a circuit chamber sealed between these and housing electronic components or wiring, and a subpassage through which the fluid flows that is to be detected, and is characterized in that the welding width of a first welded portion forming the circuit chamber is greater than the welding width of a part of the second welded portion forming the subpassage unit.

Abstract: Technique of suppressing performance variations for each flow sensor is provided. In a flow sensor FS1 of the present invention, apart of a semiconductor chip CHP1 is configured to be covered with resin (MR) in a state in which a flow sensing unit (FDU) formed on a semiconductor chip CHP1 is exposed. Since an upper surface SUR(MR) of the resin (MR) is higher than an upper surface SUR(CHP) of the semiconductor chip (CHP1) by sealing the resin (MR) on a part of the upper surface SUR(CHP) of the semiconductor chip CHP1 in a direction parallel to an air flow direction, the air flow around the flow sensing unit (FDU) can be stabilized. Further, interface peeling between the semiconductor chip (CHP1) and the resin (MR) can be prevented by an increase of contact area between the semiconductor chip (CHP1) and the resin (MR).

Abstract: Technique of suppressing performance variations for each flow sensor is provided. In a flow sensor FS1 of the present invention, a part of a semiconductor chip CHP1 is configured to be covered with resin (MR) in a state in which a flow sensing unit (FDU) formed on a semiconductor chip CHP1 is exposed. Since an upper surface SUR(MR) of the resin (MR) is higher than an upper surface SUR(CHP) of the semiconductor chip (CHP1) by sealing the resin (MR) on a part of the upper surface SUR(CHP) of the semiconductor chip CHP1 in a direction parallel to an air flow direction, the air flow around the flow sensing unit (FDU) can be stabilized. Further, interface peeling between the semiconductor chip (CHP1) and the resin (MR) can be prevented by an increase of contact area between the semiconductor chip (CHP1) and the resin (MR).

Abstract: It is an object of the present invention to improve a measurement accuracy of a thermal flow meter. A circuit package 401 is such that a measurement surface 430 and a backside of measurement surface 431 of a rear surface thereof are located in a bypass passage, and the bypass passage is configured to allow a measurement target gas 30 to flow upon dividing the measurement target gas 30 into a flow path 386 at a side of the 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.

Abstract: In order to provide a thermal flow meter (300) for improving workability of a flow rate measurement device having a temperature measurement function for the measurement target gas (30) and measurement accuracy for measuring a temperature, the thermal flow meter is structured such that a flow rate measurement circuit package (400) having a protrusion (424) for measuring a gas temperature is formed through resin molding, an inlet port (343) opened to the upstream side of the measurement target gas (30) is formed, a protrusion (424) is arranged inside the inlet port, an inlet port (344) and an outlet port (345) are formed in the front and rear covers (303 and 304) along the protrusion (424), and the measurement target gas (30) received from the inlet port (343) flows along the protrusion (424). Since the measurement target gas (30) subjected to the measurement flows along the protrusion (424), it is possible to reduce influence of the heat from other heat resources and improve measurement accuracy.

Abstract: An LED lighting device of embodiment comprising an LED light source which generates an ultraviolet light or a visible light, an axisymmetric transparent member which is provided over the light source and which is transparent to visible light, and an axisymmetric light scattering member disposed in the transparent member apart from the light source. A distance of closest approach L2 between the light source and the light scattering member, and an area C of a light emitting surface of the light source satisfy the settled relation. A length L1 of the light scattering member, and an absorption coefficient ? (1/mm) of the light scattering member satisfy the settled relation. A diameter d1 of the bottom surface of the light scattering member, the distance of closest approach L2, and a refractive index n of the transparent member satisfy the settled relation.

Abstract: The present invention is to improve measurement accuracy of a thermal flow meter. In a thermal flow meter of the invention, a circuit package 400 includes a processing unit 604 in which a passage 605 and a circuit are disposed. An air flow sensing portion 602 is disposed in the passage 605. A fixing portion 372 is integrally formed with and fixed to the circuit package 400 and forms a bypass passage. The passage 605 of the circuit package 400 is arranged inside the bypass passage. In the bypass passage, a storage portion 384 having a concave portion 383 is formed to face the fixing portion 372. At least a part of the leading end 401 of the circuit package 400 is contained in the concave portion 383 of the storage portion 384.

Abstract: The present invention provides a thermal flow meter which can suppress a degradation of measurement accuracy caused by deformation of a diaphragm and a stained rear surface thereof even in a case where a gap is provided in order to form the diaphragm in an air flow sensing element. The present invention relates to a thermal flow meter 300 which includes a bypass passage through which a measurement target gas 30 received from a main passage 124 flows, and an air flow sensing element which measures a flow rate of the measurement target gas 30 by performing heat transfer with the measurement target gas 30 flowing through the bypass passage. The thermal flow meter 300 includes at least a circuit package 400 which contains the air flow sensing element 602. A gap 674 is formed in a rear surface of the air flow sensing element 602 to form a diaphragm 672 in an air flow sensing area 437 of the air flow sensing element 602, and the gap 674 becomes a sealed space reduced in pressure compared to an atmospheric pressure.

Abstract: Provided is a thermal flow meter that can be prevented from being eroded due to adhesion of water or like to a cut end portion of the lead exposed from the mold resin of the circuit package. A thermal flow meter 300 of the present invention is a thermal flow meter having a circuit package 400 formed by mounting a detection element 518 on leads 544 and 545 supported by a support frame 512, sealing with a mold resin, and cutting off the support frame 512, wherein cut end portions 544a and 545a of the leads 544 and 545 exposed from the mold resin of the circuit package 400 by cutting off the support frame 512 is covered by a covering portion 371.

Abstract: In order to provide a thermal-type flowmeter highly accurate, with high reliability, and simple in construction, while being available at a lower price, a thermal-type flowmeter as proposed includes a sub-path that takes in a fluid under measurement; a sensor element that measures a flow-rate of the fluid under measurement in the sub-path; a temperature detection element that detects a temperature of the fluid under measurement; a drive circuit that controls a heating temperature of the sensor element; and a protection circuit that protects the drive circuit from noise, a cavity being formed on a substrate of the sensor element, an exothermic resistor being provided on a thin-film part on the cavity through the intermediary of an electrically insulating film, and a flow rate being detected on the basis of temperature distribution in the thin-film part.

Abstract: The invention provides a thermal flow meter which can precisely sense the measurement target gas even in the case that the resin housing and the cover are welded by the laser. The invention is a thermal flow meter (300) having a bypass passage for flowing measurement target gas (30) which is taken from a main passage (124), and an air flow sensing portion (602) for measuring a flow rate of the measurement target gas (30) by carrying out heat transfer in relation to the measurement target gas (30) which flows in the bypass passage. A concave trench (741) is formed in such a manner that a part of an interface (792) between an end face of a bypass passage forming wall (390) including a weld portion (792) and a rear face of a cover (303) is positioned in a wall surface of the concave trench (741).