Abstract: The present invention provides a thermal flow meter 300 which reduces a stress applied from a fixing portion 3721, which is used to hold and fix a circuit package 400 with respect to a housing 302, to the circuit package 400 and has high reliability. In the thermal flow meter of the invention, the circuit package 400 embedded with a flow rate measurement circuit is formed through a first resin molding process, the fixing portion 3721 is formed along with the housing 302 through a second resin molding process, and the circuit package 400 is enveloped by the fixing portion 3721, whereby the circuit package 400 is held by and fixed to the housing 302. In order to reduce the influence of a stress, generated based on a temperature change of the fixing portion 3721, on the circuit package 400, the fixing portion 3721 is constituted of a thick portion 4714 and a thin portion 4710.

Abstract: Provided is a thermal flow meter to improve the measurement accuracy of a temperature detector provided in a thermal flow meter. The thermal flow meter includes a bypass passage through which a measurement target gas 30 flowing through a main passage flows, and a circuit package 400 which includes a measurement circuit for measuring a flow rate of the measurement target gas 30 flowing through the bypass passage and a temperature detecting portion 452 for detecting a temperature of the measurement target gas. The circuit package 400 includes a circuit package body which is molded by a resin to internally envelope the measurement circuit and a protrusion 424 molded by the resin. The temperature detecting portion 452 is provided in the leading end portion of the protrusion 424, and at least the leading end portion of the protrusion protrudes to the outside from a housing 302.

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

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: To obtain a thermal flow meter capable of alleviating stress in an axial direction that acts on a lead according to a temperature difference between a proximal end side and a leading end portion side of a measuring portion. An air flow sensing portion 300 according to the present 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 via a heat transfer surface, and the thermal flow meter includes a circuit package 400 in which the air flow sensing portion 602 and a lead 514 are sealed by a first resin molding process and a housing 302 forming a part of the bypass passage and fixing the circuit package 400 by a second resin molding process.

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

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: A technique capable of suppressing performance variation of every flow sensor and achieving performance improvement is provided. For example, in an arbitrary cross-sectional surface in parallel to a moving direction of a gas flowing on an exposed flow detecting unit FDU which is formed in a semiconductor chip CHP1, a sealing body is released from the lower mold BM by thrusting up, from a lower mold BM, an ejection pin EJPN arranged in an outer region of the semiconductor chip CHP1 so as not to overlap with the semiconductor chip CHP1 arranged in the vicinity of the center part. Thus, according to the first embodiment, the deformation applied to the sealing body at the time of mold releasing can be smaller than that in a case in which the sealing body is released from the lower mold BM by arranging the ejection pin EJPN in a region overlapping with the semiconductor chip CHP1.

Abstract: A thermal flow meter has a bypass passage for taking in and flowing measurement target gas flowing in a main passage, a circuit package having an air flow measurement circuit for measuring an air flow by carrying out heat transfer in relation to the measurement target gas flowing in the bypass passage, and a temperature detecting portion. A case is provided with an external terminal outputting electric signals indicating the air flow and the temperature of the measurement target gas and supports the circuit package. Resin contains the air flow measurement circuit and the temperature detecting portion. The temperature detecting portion has a protrusion which protrudes out of a circuit package main body, and the protrusion is formed into a shape which is thicker in its root than in its leading end portion and its neck portion is narrower little by little toward the leading end.

Abstract: An objective of the present invention is, in a thermal flow meter having a structure including a resin portion formed in the vicinity of a diaphragm structural portion using a mold, to prevent destruction of the diaphragm structural portion at the time of pressing the mold, in a method of manufacturing the thermal flow meter, including: supporting a gas flow measurement element 200 on support members 102b and 111, the gas flow measurement element 200 including a cavity portion 202 surrounded by a substrate inclined portion 202a inclined to a substrate surface, a diaphragm 201 that covers the cavity portion, and an electrical resistive element formed in the diaphragm 201; and covering the gas flow measurement element 200 and the support members 102b and 111 with the resin portion 104 formed with the mold, to set the mold 14 such that an acting portion of pressure force by the mold that molds the resin portion 104 is positioned outside the substrate inclined portion 202a in the entire periphery of the diaphragm

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: An objective of the present invention is, in a thermal flowmeter having a structure including a resin portion formed in the vicinity of a diaphragm structural portion using a mold, to prevent destruction of the diaphragm structural portion at the time of pressing the mold, in a method of manufacturing the thermal flow meter, including: supporting a gas flow measurement element 200 on support members 102b and 111, the gas flow measurement element 200 including a cavity portion 202 surrounded by a substrate inclined portion 202a inclined to a substrate surface, a diaphragm 201 that covers the cavity portion, and an electrical resistive element formed in the diaphragm 201; and covering the gas flow measurement element 200 and the support members 102b and 111 with the resin portion 104 formed with the mold, to set the mold 14 such that an acting portion of pressure force by the mold that molds the resin portion 104 is positioned outside the substrate inclined portion 202a in the entire periphery of the diaphragm

Abstract: Technology capable of suppressing performance variation for each flow sensor and enhancing the performance is provided. According to a flow sensor of an embodiment, a local cavity CAV is provided on an upper surface SUR (MR) of a resin MR to generate an eddying current in a counterclockwise direction, so that an advancing direction of gas (air) that collided to an exposed side surface of a semiconductor chip CHP1 can be changed to an eddying direction instead of a direction toward an upper side of the semiconductor chip CHP1 differing by 90 degrees. Therefore, according to the flow sensor of the embodiment, the flow of the gas (air) at an upper side of the flow sensing unit FDU can be stably made smooth without being disturbed, whereby a flow sensing accuracy in the flow sensing unit FDU can be enhanced.

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).