JP2008209243A - In-vehicle electronic device, in-vehicle physical quantity measuring instrument and thermal air flow meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a physical quantity measuring instrument not corroded by a corrosive gas as air flow sensors, pressure sensors, temperature sensors, oxygen concentration sensors, or the like, placed in the intake pipe or exhaust pipe of an internal combustion engine is subjected to various kinds of corrosive gases. <P>SOLUTION: A copper-made mesh, honeycomb or porous substance for removing sulfur gas is employed as sensors including the temperature sensor, a flow rate measuring device, the pressure sensor, the oxygen concentration sensor, or the like, incorporated in the intake pipe and the exhaust pipe, whereby the corrosion of a wire consisting mainly of Ag can be prevented, marked improvements in reliability can be expected, and a low-cost and high corrosion-resistant product can be obtained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a device that detects the flow rate, pressure, temperature, and oxygen amount of an internal combustion engine, and relates to an air flow rate measurement device that measures the amount of air taken into the internal combustion engine, for example.

In an intake pipe and an exhaust pipe of an internal combustion engine such as an automobile, devices for measuring physical quantities such as a flow sensor, a pressure sensor, a temperature sensor, and an oxygen concentration sensor for properly controlling the operation of the internal combustion engine are installed. These physical quantity measuring devices are composed of a sensor for measuring a physical quantity, a drive circuit that drives the sensor, amplifies the sensor signal, and transmits the sensor signal to a control device, and an input / output circuit. These physical quantity sensors are assumed to be used under severe environmental conditions such as high temperature, low sound, and humidity. The drive circuit and input / output circuit are bonded to the case member made of resin, etc., and the case member upper surface is bonded to the cover. It has a sealing structure. As the adhesive, a silicone adhesive is often used. The drive circuit and the input / output circuit are composed of a ceramic circuit board and electronic components mounted thereon. The wiring material used for the circuit board is pure silver (Ag) or silver palladium (Ag-Pt) conductor mainly composed of silver to reduce the size and cost of the circuit board from the conventional Ag-Pd conductor. There are many examples to do. Since pure Ag and Ag-Pt conductors have a relatively low resistivity, the wiring can be miniaturized and suitable for miniaturization, but the corrosion resistance is lower than that of conventional Ag-Pd conductors. Environments exposed to physical quantity measuring devices used in internal combustion engines such as automobiles are sulfur gas (S ₈ etc.), sulfur oxide gas (SOx), hydrogen sulfide gas (H ₂ S), nitrogen oxide gas (NOx). , Hydrocarbon gas (HC) and chlorine gas (Cl ₂ ) exist. Among these, the Ag conductor is corroded by SOx, H ₂ S, particularly sulfur gas. A glass coating is applied on the Ag conductor material to prevent corrosion. However, since glass has pinholes, it cannot be completely prevented from corrosion.

Japanese Patent Laid-Open No. 2001-12987 JP-A-6-22373

  The above prior art has a sealing structure in which a resin case is bonded with an adhesive, but the silicone adhesive has physical properties that allow gas to permeate itself. When corrosive gas exists outside, the corrosive gas permeates the silicone adhesive and enters the case. A glass coating is applied on the conductor material for corrosion protection, but there is a pinhole in the glass coating. For this reason, the Ag wiring material corrodes through the glass-coated pinhole by the corrosive gas entering the case. The Ag wiring material may be disconnected due to the progress of corrosion, and there was anxiety about its reliability.

  By the way, in air conditioners and air purifiers, a deodorizing filter consisting of a ceramic fiber paper honeycomb carrying cuprous oxide and a solid acid is used to remove the four major odors (hydrogen sulfide, mercaptan, ammonia, and amine). Has been. Since air conditioners and air purifiers are intended to remove bad odors in the intake air from the outside, a deodorizing filter is provided at the intake port.

  Air flow sensors, pressure sensors, temperature sensors, and oxygen concentration sensors installed in an intake pipe or exhaust pipe of an internal combustion engine are exposed to corrosive gas released from rubber. The corrosive gas has a low concentration because it is diluted with the intake air during operation, but becomes a high concentration because air stays after stopping. Therefore, air flow sensors, pressure sensors, temperature sensors, and oxygen concentration sensors installed in the intake pipe or exhaust pipe of an internal combustion engine diffuse not only from the intake pipe but also from the exhaust pipe as in air conditioners and air purifiers. Will be exposed to sulfur gas. This is a point that is greatly different from the structure of an air conditioner or an air purifier, and causes a corrosion failure due to sulfur gas in sensors of an internal combustion engine.

  As described above, the air flow rate sensor, pressure sensor, temperature sensor, and oxygen concentration sensor installed in the intake pipe or exhaust pipe of the internal combustion engine are exposed to various corrosive gases, and thus are not corroded by the corrosive gas. It is a problem to provide a physical quantity measuring device.

  The present invention includes a flow rate measurement pipe installed in a conduit through which a fluid to be measured flows, a physical quantity measurement passage structure inserted from the outside into the flow measurement pipe, a sensor and a drive circuit board installed in the physical quantity measurement passage structure. In the physical quantity measuring device and the thermal air flow meter as described above, a copper mesh (wire grid) or a honeycomb body (plate grid) is provided on the measured fluid inlet side and outlet side of the physical quantity measuring tube. Thereby, corrosion of wiring mainly composed of Ag can be prevented, and a significant improvement in reliability can be expected.

The present invention also provides a flow rate measurement tube installed in a conduit through which a fluid to be measured flows, a physical quantity measurement passage structure inserted from the outside into the flow rate measurement tube, a sensor and a drive circuit board installed in the physical quantity measurement passage structure. In the physical quantity measuring device and the thermal air flow meter comprising the above, a copper mesh (wire lattice) or a honeycomb body (plate lattice) is provided on the measured fluid inlet side and outlet side of the measurement passage structure.
The present invention also provides a flow rate measurement tube installed in a conduit through which a fluid to be measured flows, a physical quantity measurement passage structure inserted from the outside into the flow rate measurement tube, a sensor and a drive circuit board installed in the physical quantity measurement passage structure. In the physical quantity measuring device and the thermal air flow meter, the periphery of the insertion portion of the flow rate measurement passage structure is covered with a copper mesh (wire lattice).

By providing copper mesh (wire grid) or honeycomb body (plate grid) or porous structure on the inlet and outlet sides of the fluid to be measured, corrosive gas such as sulfur gas, sulfur compound gas SOx, H ₂ S, etc. Can be removed. Thereby, a highly reliable physical quantity measuring device can be provided.

In addition, a mesh (wire grid) or honeycomb body (sheet grid) or porous structure in which the copper surface is previously sulfided in a sulfur gas environment, a mesh (wire grid) or honeycomb body (sulfurized copper surface to which oil has been previously adhered) ( By using a plate lattice) or a porous structure, it is possible to more stably remove corrosive gases such as sulfur gas, sulfur compound gas SOx, and H ₂ S.

  Reliability can be improved by simply providing a copper mesh (wire lattice) and a honeycomb body (plate lattice) on the inlet and outlet sides of a conventional physical quantity measuring tube.

  Embodiments of the present invention will be described below in order to clarify the present invention more specifically. However, the present invention is not limited by the description of such embodiments.

  First, referring to FIG. 4 showing a typical cross-sectional structure of the in-vehicle electronic device shown in FIG. 3 and a corrosive environment to which these in-vehicle electronic devices are exposed, the structure, use environment and problems of the in-vehicle electronic device will be described. In-vehicle electronic devices are roughly classified into sensors, fuel control devices for control units, and ignition control devices for igniters and coils. The sensor detects physical quantities such as intake air flow rate, air temperature, atmospheric pressure, boost pressure, etc., and the control unit receives the sensor signal and controls the combustion state in the cylinder. The igniter and coil are inside the cylinder. It has a function to control the ignition timing. What is common in the structure of these in-vehicle electronic devices is that each has an electronic drive circuit 1 or an electronic control circuit, and is bonded and fixed to a metal base 2 on which the electronic drive circuit 1 or the electronic control circuit is installed. In many cases, the electronic drive circuit 1 or the case 3 for storing the electronic control circuit is bonded and sealed 4 to the base 2, and the upper surface is covered with a cover 5. The electronic drive circuit 1 or the electronic control circuit is formed by printing and firing circuit conductor wiring 8 and resistance on the surface of a ceramic substrate 7 formed of an inorganic material such as ceramic, and further on the surface a capacitor, diode, semiconductor A hybrid IC substrate 9 mounted with an integrated circuit is mounted. In order to promote heat dissipation from the hybrid IC substrate 9, the hybrid IC substrate 9 is bonded and fixed to the metal base 2 with a silicone adhesive. Since the metal base 2 serves as a heat sink for heat dissipation, a metal having a high thermal conductivity, particularly aluminum, is often used. The case 3 that stores the hybrid IC substrate 9 and the cover 5 that covers the upper surface have a shape integrated with a connector that is an input / output signal interface of the electronic drive circuit 1. A structure in which a terminal 11 made of a conductive member that transmits an electrical signal is inserted into the resin forming the case 3 is insert-molded. Here, the sensor for detecting the physical quantity such as the intake air temperature, the intake air flow rate, the boost pressure has a structure in which the sensing element 10 is installed outside or in the case opening, and is electrically connected via the electronic drive circuit 1 and the terminal 11. Connected.

  Here, the case 3 made mainly of resin and the base 2 made mainly of metal are adhesively sealed 4 with an adhesive having viscoelasticity such as a silicone adhesive because the linear expansion coefficients of both are greatly different. There are many. In many cases, the case 3 and the cover 5 are sealed with an epoxy adhesive if they are the same member, and a silicone adhesive if they are different members. In this state, after adjusting the output characteristics and the like of the sensor, silicone gel 22 is injected into the case 3 as a protective film of the hybrid IC substrate 9 and covered with the cover 5 on the upper surface of the case 3. It has a structure in which the adhesive seal 6 is used.

  Many of the on-vehicle electronic devices described above are characterized in that bonding is employed at many structural locations for bonding between structural components, and silicone adhesive is often used. However, silicone adhesives have disadvantages due to the unique properties of silicone resins. The atmosphere inside the engine room of the vehicle on which the in-vehicle electronic device is mounted is that the combustion gas from the engine blows back, the unburned gas returns, and the sulfur oxide gas SOx, the nitrogen oxide gas NOx, and the hydrocarbon HC stay. Exposed to. In addition, the interior of the engine room is in a state where products such as rubber ducts containing sulfur, hoses 26, and the like, which are often arranged in engine components, are gathered, and the internal temperature of the engine exceeds 100 ° C for some in-vehicle electronic devices. Reach. In this state, corrosive gases 14 such as sulfur gas and sulfur compounds are released from the product group vulcanized with sulfur such as the rubber duct and the hose 26. In some cases, a composite gas state is formed in which combustion gas is blown back, unburned gas return gas, and hydrocarbon are mixed in addition to the above-described sulfur gas. Therefore, unless an in-vehicle electronic device that is resistant to these corrosive gases is manufactured, there is a possibility that it can be a product with low reliability. In these in-vehicle electronic devices, the conductor wiring 8 formed on the ceramic substrate 7 of many electronic drive circuits 1 is often formed of Ag or an Ag alloy, and the inside of the case 3 is corrosive gas, particularly sulfur gas. When the corrosive gas 14 such as sulfur-based compound enters, the conductor wiring portion of the Ag, Ag alloy which is the conductor wiring 8 is sulfided, and the conductor wiring 8 of the electronic driving circuit 1 is finally disconnected, and the electron There is a possibility that the drive circuit 1 will not operate.

  Silicone adhesives used in many in-vehicle electronic devices have a high gas permeability. Accordingly, as described above, when the in-vehicle electronic device is exposed to the environment of corrosive gas, the corrosive gas 14 such as sulfur gas or sulfur-based compound permeates from the adhesive sealing portion 4 of the silicone adhesive, and the case 3 Invade inside. A glass coating is applied on the conductor material for corrosion protection, but since there is a pinhole in the glass, the electronic driving circuit 1 passes through the glass-coated pinhole by the corrosive gas that has entered the case. There is a problem that the conductor wiring 8 formed of Ag or Ag alloy formed on the surface is corroded by sulfide.

  The in-vehicle electronic device according to the present invention has an anti-sulfurization structure in which a copper mesh and porous structure highly reactive with sulfur gas are formed around a conductor wiring formed of Ag or an Ag alloy formed on the surface of the electronic drive circuit 1. The conductor wiring formed by Ag or Ag alloy can be cut off from the corrosive gas.

  Hereinafter, a copper mesh (wire lattice), a honeycomb body (plate lattice) or a porous structure for suppressing corrosion of conductor wiring formed of Ag or an Ag alloy according to the present invention will be described.

  Since there are a large number of in-vehicle electronic devices and it is difficult to explain them all here, the cross-sectional structure represented by the thermal flow meter for measuring the intake air flow shown in FIG. Examples of the present invention will be described. FIG. 2 is a structural diagram showing the structure of the thermal flow meter of the present invention.

The thermal flow meter is a sensor that measures intake air that has been rapidly spread in the market in recent years. The heating resistor 15 of the thermal flow meter 17 using the heating resistor 15 and the temperature sensitive resistor 16 is controlled at a constant temperature so as to be always kept at a constant temperature difference from the temperature sensitive resistor 16 for measuring the air temperature. The circuit 18 is controlled at a constant temperature and is constantly heated. Since the heat generating resistor 15 is installed in the air flow, the surface portion of the heat generating resistor 15 that radiates heat to the air flow becomes a heat radiating surface, that is, a heat transfer surface. The amount of heat lost to the air flow by this heat transfer is converted into an electrical signal to measure the air flow rate. The overall configuration of the body 19 that holds the thermal flow meter 17 while introducing the intake air is the heating resistor 15, the temperature sensitive resistor 16, the intake air temperature in the sub-passage 20 into which a part of the total flow rate flows. A sensor 21 is arranged. The resistor element and the constant temperature control circuit 18 have a structure for transmitting an electrical signal through the terminal 11 by a conductive member embedded in the case. In the thermal flow meter 17 described above, a base for diffusing self-heating of a power device such as a power transistor serves as a structural base. This base is often made of a metal material having high thermal conductivity, such as aluminum. A conductor wiring and a resistor are formed on the surface of the base 2 by printing on the surface of the ceramic substrate, and a hybrid IC substrate on which a semiconductor integrated circuit, a capacitor, a diode and the like are mounted is bonded with a silicone adhesive. Further, a case 3 in which a connector as an interface part for storing a hybrid IC substrate and transmitting a sensor signal to the outside or supplying a circuit driving power from the outside is formed on the base 2 with a silicone adhesive. Stop 4 In this state, after adjusting the output characteristics of the sensor, silicone gel was injected into the case as a protective film for the hybrid IC substrate, covered with a cover on the upper surface of the case, and sealed with silicone adhesive, epoxy adhesive, etc. It has a structure.

Here, as described above, the silicone adhesive employed for bonding many members to each other has a high gas permeability, and when in a corrosive environment, the adhesive seal portion permeates the inside of the case, The components mounted on the hybrid IC substrate and the conductor wiring are corroded, and eventually a disconnection failure is caused. In addition to SOx, NOx, and H ₂ S, which are exhaust gases, sulfur gas released from rubber used in intake pipes and exhaust pipes installed upstream and downstream of the body 19 that holds the air flow meter corrodes. It becomes a factor. If the Ag conductor wiring of the air flow meter is not brought into contact with these corrosive gases, corrosion of the Ag conductor wiring can be prevented. Therefore, by providing copper meshes 50a and 50b that are highly reactive with sulfur gas on the upstream and downstream end surfaces of the body 19 that holds the air flow meter connected to the rubber duct, a thermal flow rate that has high corrosion resistance reliability. This makes it possible to manufacture in-vehicle electronic devices including the total 17. When the copper mesh is corroded, the corrosive gas that has diffused is captured by the copper mesh. Thereby, since Ag wiring does not contact with corrosive gas, corrosion can be prevented. At the same time, the mesh installation has the effect of rectifying the air flow and contributes to improving the measurement accuracy of the air flow rate.

  The inventors have found that the amount of corrosion of silver can be remarkably reduced by installing a copper mesh 50 between the sulfur source and silver. Copper, like silver, is a metal that is easily corroded in a sulfur gas environment, and a copper mesh having an area sufficient to absorb corrosive gas is provided.

Furthermore, it has been found that sulfur gas can be stably captured by previously forming sulfide on the surface of copper. In a high-humidity environment assumed for automobiles, oxidation is prioritized when copper is compared with oxidation. This is because the standard production energy of CuO (ΔGf ° = −128.12 kJ / mol) or Cu ₂ O is lower than the standard production energy of Cu ₂ S (ΔGf ° = −86.20 kJ / mol). It is. Once copper oxide is formed on the copper surface, the copper oxide is dense and stable, and the sulfur gas hardly diffuses in the oxide film, so the sulfidation rate decreases. Therefore, it is effective to suppress the formation of oxides by previously forming sulfides. Moreover, forming copper oxide on the copper surface is also effective in suppressing the formation of an oxide film.

  Furthermore, it has been found that sulfur gas can be stably trapped by preliminarily attaching oil to the copper surface. The oil layer on the copper surface suppresses the ingress of water in a high humidity environment assumed in automobiles, while facilitating the entry of sulfur gas that is soluble in oil. Therefore, attaching oil to the surface of copper in advance has an effect of suppressing oxidation of copper and an effect of promoting sulfurization of copper.

  Another embodiment of the present invention will be described. FIG. 5 is a cross-sectional structure of the thermal flow meter of the present invention, and FIG. 6 is a structural diagram showing the structure of the thermal air flow meter of the present invention. In this embodiment, a copper mesh 50 is provided at the inlet and outlet of the air flow meter sub-passage 20. In the said invention, the copper mesh 50 highly reactive with sulfur gas is provided in the upstream and downstream end surface of the body 19 holding the air flowmeter connected with the rubber duct 26. Since sulfur gas other than that released from rubber and diffusing into the sub-passage is captured by the copper mesh, the sulfur gas capture efficiency may be low. On the other hand, in the present embodiment, only the sulfur gas that diffuses into the sub-passage involved in the corrosion failure of the Ag conductor wiring is captured, so that the sulfur gas can be captured efficiently. In order to efficiently capture sulfur gas as in this embodiment, the entire thermal flow meter 17 is covered with a copper mesh as shown in the cross-sectional structure of FIG. 7 and the structure of the thermal air flow meter of FIG. Good.

  In the said invention, it described about the mesh made from copper. A plurality of meshes may be laminated in order to secure a sufficient area for absorbing the corrosive gas. A honeycomb body having a large surface area may be used. Furthermore, a structure in which the surface area of a copper mesh or honeycomb body is expanded by etching or the like is also effective.

  Copper mesh, honeycomb body, and porous body for removing sulfur gas of the present invention are used for various sensors such as temperature sensor, flow rate measuring device, pressure sensor, oxygen concentration sensor, etc. mounted on the intake pipe and exhaust pipe. By doing so, it is possible to obtain a low price and high corrosion resistance product.

  In addition to a physical quantity measuring device attached to an intake pipe and an exhaust pipe of an internal combustion engine, the present invention can be applied to a flow rate sensor, a pressure sensor, and a temperature sensor that detect the flow rate of EGR gas.

Sectional drawing which shows the flow volume measuring apparatus by this invention (Example 1). FIG. 1 is a structural diagram showing a flow rate measuring device according to the present invention (Example 1). A typical cross-sectional structure of an in-vehicle electronic device. Corrosive environment to which on-vehicle electronic devices are exposed. Sectional drawing which shows the flow volume measuring apparatus by this invention (Example 2). FIG. 6 is a structural diagram showing a flow rate measuring device according to the present invention (Example 2). Sectional drawing which shows the flow volume measuring apparatus by this invention (Example 2). FIG. 6 is a structural diagram showing a flow rate measuring device according to the present invention (Example 2).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic drive circuit 2 Base 3 Case 4 Bonding sealing part 5 of base and case Cover 6 Bonding sealing part of cover and case 7 Ceramic substrate 8 Conductor wiring 9 Hybrid IC substrate 10 Sensing element 11 Terminal 12 Bonding wire 13 Combustion gas, NOx such as unburned gas and hydrocarbon, corrosive gas of HC 14 Corrosive gas such as sulfur gas and sulfur compounds 15 Heating resistor 16 Temperature sensitive resistor 17 Thermal flow meter 18 Constant temperature control circuit 19 Body 20 Sub Passage 21 Intake air temperature sensor 22 Silicone gel 26 Rubber duct, hose 50 Copper mesh (wire grid) or honeycomb (plate grid)

Claims (14)

In an in-vehicle electronic device having an electronic component in which an electronic circuit is formed, a case incorporating the electronic component, a cover that covers the open surface of the case, the electronic component is disposed in the case,
An in-vehicle electronic device characterized in that an electronic component is covered with a copper mesh or a honeycomb body. The in-vehicle electronic device according to claim 1,
An in-vehicle electronic device characterized in that an electronic component is covered with a mesh or honeycomb body in which a sulfide film is previously formed on a copper surface. The in-vehicle electronic device according to claim 1,
An in-vehicle electronic device characterized in that an electronic component is covered with a mesh or honeycomb body in which an oil layer is previously formed on a copper surface. In a physical quantity measuring instrument comprising a measuring pipe installed in a conduit through which a fluid to be measured flows, a physical quantity measuring passage structure inserted from the outside into the measuring pipe, a sensor and a drive circuit board installed in the physical quantity measuring passage structure,
A physical quantity measuring instrument characterized by covering the periphery of the insertion portion of the flow rate measuring passage structure with a copper mesh or a honeycomb body. In a physical quantity meter comprising a measurement pipe installed in a conduit through which a fluid to be measured flows, a physical quantity measurement passage structure installed in the measurement pipe, a sensor and a sensor drive circuit board installed in the physical quantity measurement passage structure,
A physical quantity measuring instrument, wherein a copper mesh or a honeycomb body is provided on an inlet side surface or an outlet side surface of a fluid to be measured of the measuring tube. In a physical quantity meter comprising a measurement pipe installed in a conduit through which a fluid to be measured flows, a physical quantity measurement passage structure installed in the measurement pipe, a sensor and a sensor drive circuit board installed in the physical quantity measurement passage structure,
A physical quantity measuring instrument comprising a copper mesh or a honeycomb body provided on the measured fluid inlet side or outlet side of the measurement passage structure. In the physical-quantity measuring instrument in any one of Claims 4-6,
The said copper is a copper by which the sulfide film was previously formed on the copper surface, The physical quantity meter characterized by the above-mentioned. In the physical-quantity measuring instrument in any one of Claims 4-6,
The said copper is a copper with the oil layer previously formed in the copper surface, The physical quantity meter characterized by the above-mentioned. A measurement tube installed in a conduit through which a fluid to be measured flows, a flow measurement passage structure inserted from the outside into the measurement tube, a heating resistor and a temperature sensing resistor installed in the flow measurement passage structure, and the heating resistor In a thermal flow meter that measures the intake air flow rate, which has an electronic circuit that controls the body and the temperature sensitive resistor,
A thermal air flow meter characterized in that the air flow meter is covered with a copper mesh or a honeycomb body. A measurement tube installed in a conduit through which a fluid to be measured flows, a flow measurement passage structure inserted from the outside into the measurement tube, a heating resistor and a temperature sensing resistor installed in the flow measurement passage structure, and the heating resistor In a thermal flow meter that measures the intake air flow rate, which has an electronic circuit that controls the body and the temperature sensitive resistor,
A thermal air flow meter characterized in that a copper mesh or a honeycomb body is provided on the measured fluid inlet side or outlet side of the flow rate measuring tube. A measurement tube installed in a conduit through which a fluid to be measured flows, a flow measurement passage structure inserted from the outside into the measurement tube, a heating resistor and a temperature sensing resistor installed in the flow measurement passage structure, and the heating resistor In a thermal flow meter that measures the intake air flow rate, which has an electronic circuit that controls the body and the temperature sensitive resistor,
A thermal air flow meter characterized in that a copper mesh or a honeycomb body is provided on the measured fluid inlet side or outlet side of the measurement passage structure. The thermal air flow meter according to any one of claims 9 to 11,
The said copper is copper by which the sulfide film was previously formed on the copper surface, The thermal type air flowmeter characterized by the above-mentioned. The thermal air flow meter according to any one of claims 9 to 11,
The said copper is copper by which the oil layer was previously formed on the copper surface, The thermal type air flowmeter characterized by the above-mentioned. A measurement pipe installed in a conduit through which the fluid to be measured flows, a physical quantity measurement passage structure installed in the measurement pipe and having a passage through which the fluid to be measured flows, and a sensor installed in a passage in the physical quantity measurement passage structure; In a physical quantity measuring instrument comprising a conductor wiring of Ag or an Ag alloy and an electronic component that controls the sensor,
A physical quantity measuring instrument comprising a copper member provided at either the measured fluid inlet or outlet of the measuring pipe or the measured fluid inlet or outlet of the physical quantity measuring passage structure.

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