WO2025249152A1 - Capteur de gaz - Google Patents

Capteur de gaz

Info

Publication number
WO2025249152A1
WO2025249152A1 PCT/JP2025/017429 JP2025017429W WO2025249152A1 WO 2025249152 A1 WO2025249152 A1 WO 2025249152A1 JP 2025017429 W JP2025017429 W JP 2025017429W WO 2025249152 A1 WO2025249152 A1 WO 2025249152A1
Authority
WO
WIPO (PCT)
Prior art keywords
wall
hole
gas sensor
flow path
substrate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/JP2025/017429
Other languages
English (en)
Japanese (ja)
Inventor
和 ▲高▼木
良平 濱▲崎▼
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Murata Manufacturing Co Ltd
Original Assignee
Murata Manufacturing Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Murata Manufacturing Co Ltd filed Critical Murata Manufacturing Co Ltd
Publication of WO2025249152A1 publication Critical patent/WO2025249152A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/18—Investigating or analyzing materials by the use of thermal means by investigating thermal conductivity
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
    • G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
    • G01N27/14—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature
    • G01N27/18—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature caused by changes in the thermal conductivity of a surrounding material to be tested
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
    • G01N27/22—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance

Definitions

  • This disclosure relates to a gas sensor that detects gas concentration.
  • Gas sensors detect gas concentrations by, for example, utilizing differences in thermal conductivity depending on the gas concentration. For example, gas sensors detect the concentration of a gas based on the amount of change in resistance of a detection element caused by differences in the amount of heat dissipated into the atmosphere from the detection element heated by the gas. Examples of gas sensors are disclosed in Patent Documents 1 and 2.
  • the detection element is located on an extension of the intake hole. Therefore, gas concentration detection by the detection element is easily affected by gas that has entered the interior through the intake hole, which may result in a decrease in detection accuracy.
  • an expansion chamber is provided between the intake hole and the measurement chamber in which the detection element is located. Gas that enters through the intake hole flows into the measurement chamber via the expansion chamber.
  • the expansion chamber expands the gas communication path, which can slow down the speed of gas that enters the interior through the intake hole. This can reduce fluctuations in gas flow rate.
  • the detection element is located on an extension line from the intake hole through the expansion chamber.
  • gas concentration detection by the detection element is easily affected by gas that has entered the gas sensor, which may result in a deterioration in detection accuracy.
  • the provision of an expansion chamber that is roughly the same shape and size as the measurement chamber results in an increased size of the gas sensor.
  • the object of the present disclosure is to solve the above-mentioned problems by providing a gas sensor that can suppress a decrease in gas concentration detection accuracy while suppressing an increase in size.
  • a gas sensor includes: A substrate; a detection element supported by the substrate and having a detection portion; an inner wall supported by the substrate and surrounding the detection unit when viewed along an orthogonal direction orthogonal to a support surface on which the substrate supports the detection element; an outer wall supported by the substrate and surrounding the inner wall when viewed along the orthogonal direction; a lid portion supported by the inner wall and the outer wall, which closes a detection chamber in which the detection unit is provided, which is a space inside the inner wall when viewed along the orthogonal direction, and which closes a flow path which is a space between the inner wall and the outer wall when viewed along the orthogonal direction;
  • the outer wall is At least one first outer hole penetrating in a first direction so as to communicate the outside of the outer wall with the flow path; at least one second outer hole provided on the opposite side of the detection chamber from the first outer hole in the first direction and penetrating the outer wall in the first direction to communicate the outside of the outer wall with the flow path;
  • This disclosure provides a gas sensor that can suppress an increase in size while suppressing a decrease in gas concentration detection accuracy.
  • FIG. 1 is a schematic perspective view of a gas sensor according to a first embodiment of the present disclosure.
  • FIG. 2 is a schematic perspective view of a portion of the gas sensor according to the first embodiment of the present disclosure, with a lid portion removed.
  • FIG. 10 is a schematic perspective view of a gas sensor according to a second embodiment of the present disclosure.
  • FIG. 11 is a schematic plan view of a portion of a gas sensor according to a third embodiment of the present disclosure, with a lid portion removed.
  • FIG. 10 is a schematic plan view of a portion of a gas sensor according to a fourth embodiment of the present disclosure, with a lid portion removed.
  • FIG. 11 is a schematic plan view of a portion of a gas sensor according to a fifth embodiment of the present disclosure, with a lid portion removed.
  • FIG. 13 is a schematic plan view of a portion of a gas sensor according to a sixth embodiment of the present disclosure, with a lid portion removed.
  • FIG. 13 is a schematic plan view of a portion of a gas sensor according to a seventh embodiment of the present disclosure, with a lid portion removed.
  • FIG. 13 is a schematic plan view of a portion of a gas sensor according to an eighth embodiment of the present disclosure, with a lid portion removed.
  • FIG. 13 is a schematic perspective view of a gas sensor according to a ninth embodiment of the present disclosure, with a lid portion removed.
  • FIG. 23 is a schematic plan view of a portion of a gas sensor according to a tenth embodiment of the present disclosure, excluding a lid portion.
  • FIG. 23 is a schematic perspective view of a portion of a gas sensor according to an eleventh embodiment of the present disclosure, with a lid portion removed.
  • the X direction is an example of a first direction
  • the Y direction is an example of a second direction
  • the Z direction is an example of an orthogonal direction.
  • FIG. 1 is a schematic perspective view of a gas sensor according to a first embodiment of the present disclosure
  • Fig. 2 is a schematic perspective view of a portion of the gas sensor according to the first embodiment of the present disclosure, excluding a lid portion.
  • the gas sensor 10 shown in Figures 1 and 2 is for detecting gas concentrations.
  • the gas sensor 10 is of a thermal conduction type.
  • the gas sensor 10 is not limited to a thermal conduction type, and may be of other types such as a capacitance type.
  • the gas sensor 10 can be used in a variety of technical fields.
  • the gas sensor 10 may be installed indoors to detect the gas concentration therein, or may be used to control the internal combustion engine of an automobile or the like.
  • the gas sensor 10 includes a substrate 20, a detection element 30, a circuit element 40, an inner wall 50, an outer wall 60, and a lid portion 70.
  • the substrate 20 has a rectangular parallelepiped shape that is thin in the Z direction. That is, in the first embodiment, the substrate 20 has a rectangular shape when viewed in a plan view along the Z direction.
  • the shape of the substrate 20 is not limited to a rectangular parallelepiped shape (a shape that is rectangular when viewed along the Z direction).
  • the substrate 20 may have a polygonal shape other than a rectangular shape when viewed along the Z direction.
  • the substrate 20 is a rigid substrate made of glass epoxy, ceramic, or the like, but is not limited to this.
  • the substrate 20 may be a lead frame.
  • the detection element 30 is supported on the support surface 20A of the substrate 20.
  • the support surface 20A is one of a pair of main surfaces, front and back, of the substrate 20, and faces in the Z direction.
  • the detection element 30 is a thermal conduction element that detects gas concentration by utilizing differences in thermal conductivity depending on the gas concentration.
  • the detection element 30 has a detection unit 31.
  • the detection unit 31 is exposed to the outside of the detection element 30. As a result, the detection unit 31 is exposed to the detection chamber 11, which will be described later.
  • the amount of heat dissipated from the detection unit 31 to the detection chamber 11 changes depending on the thermal conductivity depending on the concentration of the gas, causing the temperature of the detection unit 31 to change. This changes the resistance value of the detection unit 31.
  • the gas concentration can be detected based on the amount of change in the resistance value of the detection unit 31.
  • the gas concentration value may be calculated in the detection element 30, or outside the detection element 30, for example, in a circuit element 40, which will be described later.
  • the detection element 30 may also be an element that detects gas concentration using a method other than thermal conduction, such as capacitance.
  • the circuit element 40 is supported on the support surface 20A of the substrate 20.
  • the circuit element 40 is an element having wired logic that cannot be reprogrammed.
  • the circuit element 40 is an element having an application specific integrated circuit (ASIC).
  • ASIC application specific integrated circuit
  • the circuit element 40 is not limited to an element having wired logic that cannot be reprogrammed.
  • the circuit element 40 may have an arithmetic unit that works in cooperation with software to achieve a specified function.
  • the detection element 30 and the circuit element 40 are electrically connected to each other.
  • the detection element 30 is electrically connected to the substrate 20 via a bonding wire 32.
  • the circuit element 40 is electrically connected to the substrate 20 via a bonding wire 41.
  • the bonding wires 32 and 41 are electrically connected to each other via a conductive wiring pattern (not shown) formed on the substrate 20.
  • a signal corresponding to the gas concentration detected by the detection element 30 is transmitted from the detection element 30 to the circuit element 40.
  • the signal corresponding to the gas concentration may represent the gas concentration, or may represent something other than the gas concentration (for example, the resistance value of the detection unit 31).
  • the detection element 30 and circuit element 40 may be electrically connected to the substrate 20 by means other than bonding wires.
  • the detection element 30 and circuit element 40 may be mounted on the substrate 20 by flip chip mounting.
  • the detection element 30 and circuit element 40 are electrically connected to the substrate 20 by solder.
  • the detection element 30 and circuit element 40 may also be electrically connected directly without going through the substrate 20.
  • the circuit element 40 includes a signal processing circuit (not shown) that processes the signal corresponding to the gas concentration output from the detection element 30.
  • the circuit element 40 includes a converter, a filter, a temperature sensor, a processor, memory, etc.
  • the converter converts the voltage signal output from the detection element 30 into a digital signal.
  • the filter filters the digital signal from the converter.
  • the temperature sensor detects the temperature.
  • the processor corrects the filtered digital signal based on the temperature detected by the temperature sensor.
  • the memory stores correction coefficients and the like used when correcting the digital signal using the detected temperature.
  • the signal processed by the circuit element 40 is output to the outside of the gas sensor 10 via an external connection terminal (not shown) provided on the substrate 20.
  • the detection element 30 and the circuit element 40 are each directly supported by the substrate 20.
  • the detection element 30 and the circuit element 40 may also be indirectly supported by the substrate 20.
  • the circuit element 40 may be supported by the substrate 20, and the detection element 30 may be supported by the circuit element 40.
  • the detection element 30 may be indirectly supported by the substrate 20 via the circuit element 40.
  • the detection element 30 may be supported by the substrate 20, and the circuit element 40 may be supported by the detection element 30.
  • the circuit element 40 may be indirectly supported by the substrate 20 via the detection element 30.
  • the circuit element 40 is supported by a portion of the detection element 30 other than the detection portion 31.
  • the circuit element 40 may be supported on a surface different from the support surface 20A, for example, on the back side of the substrate 20 opposite the support surface 20A.
  • the gas sensor 10 may not be equipped with the circuit element 40. In this case, a signal corresponding to the gas concentration output from the gas sensor 10 is input to a circuit element provided outside the gas sensor 10.
  • the circuit element processes the input signal as described above.
  • the inner wall 50 is supported by the support surface 20A of the substrate 20. When viewed along the Z direction, which is perpendicular to the support surface 20A, the inner wall 50 surrounds the detection element 30 and the circuit element 40. When viewed along the Z direction, the space surrounded by the inner wall 50 is the detection chamber 11. The detection element 30 and the circuit element 40 are provided in the detection chamber 11.
  • the inner wall 50 is rectangular when viewed along the Z direction.
  • the inner wall 50 has a first wall 51, a second wall 52, and third walls 53 and 54.
  • the first wall 51, the second wall 52, and the third walls 53 and 54 correspond to the sides of the rectangle.
  • the first wall 51 and the second wall 52 extend along the Y direction and face each other in the X direction.
  • the third walls 53 and 54 extend along the X direction and face each other in the Y direction.
  • the third wall 53 connects one end of the first wall 51 and the second wall 52 to each other in the Y direction.
  • the third wall 54 connects the other end of the first wall 51 and the second wall 52 to each other in the Y direction.
  • the third walls 53, 54 have at least one inner hole 50A.
  • the third walls 53, 54 have a total of two inner holes 50A.
  • the number of inner holes 50A may be other than two.
  • the first wall 51 and the second wall 52 do not have an inner hole 50A.
  • the inner hole 50A has at least one one-side hole 50Aa provided in the third wall 53 and at least one other-side hole 50Ab provided in the third wall 54.
  • the number of one-side holes 50Aa may be other than one, and the number of other-side holes 50Ab may be other than one.
  • the one-side hole 50Aa and the other-side hole 50Ab sandwich the detection unit 31 of the detection element 30 in the Y direction.
  • the one-side hole 50Aa is located on one side of the detection unit 31 in the Y direction
  • the other-side hole 50Ab is located on the other side of the detection unit 31 in the Y direction.
  • the inner hole 50A penetrates the third walls 53, 54 in the Y direction. More specifically, the one side hole 50Aa penetrates the third wall 53 in the Y direction, and the other side hole 50Ab penetrates the third wall 54 in the Y direction. This allows the flow path 12 and the detection chamber 11 to communicate via the inner hole 50A (i.e., the one side hole 50Aa and the other side hole 50Ab).
  • the inner hole 50A may be provided in only one of the third walls 53, 54.
  • the third wall 53 may have one one-side hole 50Aa, while the third wall 54 may not have an other-side hole 50Ab.
  • the third wall 54 may have three other-side holes 50Ab, while the third wall 53 may not have a one-side hole 50Aa.
  • the outer wall 60 is supported on the support surface 20A of the substrate 20. When viewed along the Z direction, the outer wall 60 surrounds the inner wall 50. When viewed along the Z direction, the space between the inner wall 50 and the outer wall 60 is the flow path 12.
  • the outer wall 60 has at least one first outer hole 60A and at least one second outer hole 60B.
  • the outer wall 60 has two first outer holes 60A and two second outer holes 60B.
  • the number of first outer holes 60A may be other than two
  • the number of second outer holes 60B may be other than two.
  • the first outer hole 60A and the second outer hole 60B sandwich the detection chamber 11 in the X direction.
  • the second outer hole 60B is located on the opposite side of the detection chamber 11 from the first outer hole 60A in the X direction.
  • the first outer hole 60A and the second outer hole 60B penetrate the outer wall 60 in the X direction.
  • the direction in which the first outer hole 60A and the second outer hole 60B penetrate the outer wall 60 is different from the direction in which the inner hole 50A penetrates the inner wall 50.
  • the outside of the outer wall 60 in other words, the outside of the gas sensor 10) and the flow path 12 are connected via the first outer hole 60A and the second outer hole 60B.
  • the first outer hole 60A faces the first wall 51 in the X direction.
  • the second outer hole 60B faces the second wall 52 in the X direction.
  • each of the first outer hole 60A and the second outer hole 60B faces in the X direction a wall of the inner wall 50 that does not have an inner hole 50A.
  • the lid portion 70 is supported by the inner wall 50 and the outer wall 60. As a result, the lid portion 70 closes the detection chamber 11 and the flow path 12.
  • the detection chamber 11 is a space defined by the support surface 20A of the substrate 20, the inner wall 50, and the lid portion 70.
  • the flow path 12 is a space defined by the support surface 20A of the substrate 20, the inner wall 50, the outer wall 60, and the lid portion 70.
  • Insulating materials are preferred as materials for the inner wall 50, outer wall 60, and lid portion 70.
  • the inner wall 50, outer wall 60, and lid portion 70 are made of a hard resin such as a thermosetting resin, but they may also be made of a material other than a hard resin.
  • a portion of the gas traveling along the flow path 12 enters the detection chamber 11 through one of the one side hole 50Aa and the other side hole 50Ab, and is released from the detection chamber 11 into the flow path 12 through the other of the one side hole 50Aa and the other side hole 50Ab.
  • Whether the gas enters the detection chamber 11 through the one side hole 50Aa or the other side hole 50Ab depends on the angle at which the gas sensor 10 is positioned relative to the direction of gas flow, the dimensional accuracy of the flow path 12 in the gas sensor 10, and other factors.
  • Gas released from the detection chamber 11 into the flow path 12 travels through the flow path 12 toward the second outer hole 60B and is released to the outside of the gas sensor 10 through the second outer hole 60B.
  • the inner hole 50A is penetrated in a different direction from the first outer hole 60A and the second outer hole 60B.
  • gas that flows into the flow path 12 from at least one of the first outer hole 60A and the second outer hole 60B changes direction before reaching the detection unit 31 provided in the detection chamber 11 via the inner hole 50A.
  • the gas speed decreases, which makes it possible to reduce fluctuations in the flow rate and direction of the gas entering the detection chamber 11. This reduces the effect of these fluctuations on the detection unit 31, and prevents a decrease in the detection accuracy of the detection unit 31.
  • the outer wall 60 surrounds the inner wall 50 when viewed along the Z direction, and the gap between the outer wall 60 and the inner wall 50 forms a flow path 12 through which gas passes. This prevents the gas sensor 10 from becoming too large.
  • gas can be introduced into the detection chamber 11 through one of the one side hole 50Aa and the other side hole 50Ab, and can be discharged from the detection chamber 11 through the other of the one side hole 50Aa and the other side hole 50Ab. This reduces the accumulation of gas in the detection chamber 11.
  • the first wall 51 and the second wall 52 prevent the gas that has flowed into the flow path 12 from the first outer hole 60A and the second outer hole 60B from reaching the detection unit 31 in a straight line. This reduces the effect of fluctuations in the flow rate and direction of the gas on the detection unit 31, thereby preventing a decrease in the detection accuracy of the detection unit 31.
  • At least one of the inner wall 50 and the outer wall 60 and the lid 70 may contain a metal material such as aluminum.
  • at least one of the inner wall 50 and the outer wall 60 and the lid 70 may be made of a metal instead of an insulating material.
  • a metal film may be attached to the outer surfaces of the outer wall 60 and the lid 70 that face the outside of the gas sensor 10.
  • the inner wall 50, the outer wall 60, and the lid 70 may be made of a mixture of a metal material and another type of material such as a resin.
  • the inner wall 50, the outer wall 60, and the lid portion 70 can function as an electromagnetic shield. This improves the resistance of the detection element 30 to electrostatic discharge (ESD).
  • the substrate 20, the inner wall 50, and the outer wall 60 are separate members.
  • the substrate 20, the inner wall 50, and the outer wall 60 may be integrally formed.
  • the substrate 20 including the inner wall 50 and the outer wall 60 is formed in multiple layers, and the detection chamber 11 and the flow path 12 are formed by photolithography, polishing, or the like.
  • the inner wall 50 and outer wall 60 are integrally formed with the substrate 20. This improves the stress resistance of the gas sensor 10 compared to a configuration in which the inner wall 50 and outer wall 60 are separate members from the substrate 20.
  • the manufacturing process for the gas sensor 10 does not require the step of attaching the inner wall 50 and outer wall 60 to the substrate 20.
  • the elimination of this step has a significant effect in simplifying the manufacturing process.
  • Second Embodiment 3 is a schematic perspective view of a gas sensor according to a second embodiment of the present disclosure.
  • the gas sensor 10A according to the second embodiment differs from the gas sensor 10 according to the first embodiment in that a cover hole 70A is provided. The differences from the first embodiment will be described below.
  • the lid portion 70 has at least one lid hole 70A.
  • the lid portion 70 has four lid holes 70A, but the number of lid holes 70A is not limited to four.
  • Each lid hole 70A penetrates the lid portion 70 in the Z direction and connects the outside of the gas sensor 10A to the flow path 12.
  • Each lid hole 70A is located at a vertex of the flow path 12, which extends along the sides of a rectangle when viewed in the Z direction. Note that the position of each lid hole 70A is not limited to the position shown in FIG. 3.
  • the outside of the gas sensor 10A is connected to the flow path 12 by the cover hole 70A in addition to the first outer hole 60A and the second outer hole 60B. This improves the ability to replace gas between the outside of the gas sensor 10A and the flow path 12.
  • the gas sensor 10A it is desirable to position the gas sensor 10A so that any one of the first outer hole 60A, the second outer hole 60B, and the lid hole 70A faces upstream in the direction of gas flow.
  • the gas sensor 10 in the case of a configuration such as the gas sensor 10 of the first embodiment, which does not have the lid hole 70A, it is desirable to position the gas sensor 10 so that any one of the first outer hole 60A and the second outer hole 60B faces upstream in the direction of gas flow.
  • the presence of the lid hole 70A increases the number of desirable positions for the gas sensor 10A compared to the gas sensor 10 of the first embodiment. In other words, according to the second embodiment, it is possible to increase the flexibility in the positioning of the gas sensor 10A.
  • Third Embodiment 4 is a schematic plan view of a portion of a gas sensor according to a third embodiment of the present disclosure, excluding a lid portion.
  • the gas sensor 10B according to the third embodiment differs from the gas sensor 10 according to the first embodiment in that it includes a substrate hole 20B. The differences from the first embodiment will be described below.
  • the substrate 20 has at least one substrate hole 20B.
  • the substrate 20 has three substrate holes 20B, but the number of substrate holes 20B is not limited to three.
  • Each substrate hole 20B penetrates the substrate 20 in the Z direction and connects the outside of the gas sensor 10B to the detection chamber 11.
  • Each substrate hole 20B is located at one of the three corners of the rectangular detection chamber 11 when viewed along the Z direction. Note that the position of each substrate hole 20B is not limited to the position shown in FIG. 4.
  • the interior of the detection chamber 11 is connected to the outside of the gas sensor 10B by the substrate hole 20B in addition to the inner hole 50A. This makes it possible to easily release gas that has entered the detection chamber 11 from the inner hole 50A to the outside of the gas sensor 10B.
  • the substrate 20 is supported on the device on which the gas sensor 10B is installed. Therefore, even if the gas sensor 10B is configured with a substrate hole 20B, the inflow of gas from outside the gas sensor 10B into the detection chamber 11 through the substrate hole 20B, i.e., the inflow of gas into the detection chamber 11 without passing through the flow path 12, is kept to a minimum.
  • Fourth Embodiment 5 is a schematic plan view of a portion of a gas sensor according to a fourth embodiment of the present disclosure, excluding a lid portion.
  • the gas sensor 10C according to the fourth embodiment differs from the gas sensor 10 according to the first embodiment in that it further includes a filter film 80. The differences from the first embodiment will be described below.
  • a filter membrane 80 is attached to the outer wall 60.
  • the filter membrane 80 blocks the first outer hole 60A and the second outer hole 60B.
  • the filter membrane 80 limits the substances that can pass through the first outer hole 60A and the second outer hole 60B to those smaller than a certain size.
  • the filter membrane 80 may be a mesh membrane, or a semipermeable membrane that blocks the passage of liquids while allowing the passage of gases.
  • the filter membrane 80 is attached to the outer surface of the outer wall 60, but the filter membrane 80 may also be attached to the inner surface of the outer wall 60 (in other words, the surface of the outer wall 60 facing the inner wall 50).
  • the gas sensor 10C includes a filter membrane 80 that blocks the first outer hole 60A and a filter membrane 80 that blocks the second outer hole 60B, but it may also include only one of the filter membrane 80 that blocks the first outer hole 60A and the filter membrane 80 that blocks the second outer hole 60B. In other words, both the first outer hole 60A and the second outer hole 60B may be blocked by the filter membrane 80, or only one of the first outer hole 60A and the second outer hole 60B may be blocked by the filter membrane 80.
  • the filter membrane 80 can reduce the intrusion of foreign matter other than the gas into the flow path 12 from the outside of the gas sensor 10C via the first outer hole 60A and the second outer hole 60B.
  • Fifth Embodiment 6 is a schematic plan view of a portion of a gas sensor according to a fifth embodiment of the present disclosure, excluding a lid portion.
  • the gas sensor 10D according to the fifth embodiment differs from the gas sensor 10 according to the first embodiment in that the flow path 12 includes an expanded path 12A. The differences from the first embodiment will be described below.
  • the flow path 12 has an enlarged path 12A in which the cross-sectional area of the flow path 12 increases as it approaches the inner hole 50A.
  • the enlarged path 12A is provided in the portion of the flow path 12 that extends along the X direction, but this is not limited to this.
  • the enlarged path 12A may be provided throughout the entire flow path 12, including the portion of the flow path 12 that extends along the Y direction.
  • the cross-sectional area of the flow path 12 is the area of a cross section perpendicular to the direction in which the flow path 12 extends.
  • the cross-sectional area of the expansion path 12A is the area of the YZ cross section of the expansion path 12A.
  • the third wall 53 and the third wall 54 each have inclined surfaces 53A and 54A that slope in the Y direction as they approach the inner hole 50A along the X direction.
  • the cross-sectional area of the expansion path 12A increases as they approach the inner hole 50A.
  • the configuration for realizing the expansion path 12A is not limited to the inclined surfaces 53A and 54A.
  • the outer wall 60 may have an inclined inner surface.
  • the surfaces of the inner wall 50 and the outer wall 60 facing the expansion path 12A may be stepped, so that the cross-sectional area of the expansion path 12A increases in stages as it approaches the inner hole 50A.
  • the speed of gas entering the flow path 12 from outside the gas sensor 10D decreases as it passes through the enlarged path 12A and approaches the inner bore 50A. This reduces the speed of gas entering the detection chamber 11 via the inner bore 50A. As a result, the effect of fluctuations in the gas flow rate on the detection unit 31 can be reduced, thereby preventing a decrease in the detection accuracy of the detection unit 31.
  • Sixth Embodiment 7 is a schematic plan view of a portion of a gas sensor according to a sixth embodiment of the present disclosure, excluding a lid portion.
  • the gas sensor 10E according to the sixth embodiment differs from the gas sensor 10 according to the first embodiment in that the flow path 12 includes a narrowed path 12B. The differences from the first embodiment will be described below.
  • the flow path 12 has a narrowing path 12B in which the cross-sectional area of the flow path 12 decreases as it approaches the inner hole 50A.
  • the narrowing path 12B is provided in a portion of the flow path 12 that extends along the X direction, but this is not limited to this.
  • the cross-sectional area of the flow path 12 is the area of a cross section perpendicular to the direction in which the flow path 12 extends.
  • the third wall 53 and the third wall 54 each have inclined surfaces 53B and 54B that slope in the Y direction as they approach the inner hole 50A along the X direction.
  • the cross-sectional area of the reduced passage 12B decreases as it approaches the inner hole 50A.
  • the configuration for realizing the reduced passage 12B is not limited to the inclined surfaces 53B and 54B.
  • the speed of gas that enters the flow path 12 from outside the gas sensor 10E increases as it passes through the narrowing path 12B and approaches the inner hole 50A.
  • the foreign object is transported at high speed along the flow path 12.
  • Seventh Embodiment 8 is a schematic plan view of a portion of a gas sensor according to a seventh embodiment of the present disclosure, excluding a lid portion.
  • the gas sensor 10F according to the seventh embodiment differs from the gas sensor 10 according to the first embodiment in that the corners of the inner wall 50 that defines the detection chamber 11 are curved. The differences from the first embodiment will be described below.
  • the surface 50B of the inner wall 50 that defines the detection chamber 11 is a rectangle.
  • the four vertices of the rectangle formed by the surface 50B are the four boundary portions 50Ba between two adjacent walls among the first wall 51, the second wall 52, the third wall 53, and the third wall 54.
  • the four boundary portions 50Ba are the boundary portion between the first wall 51 and the third wall 53, the boundary portion between the first wall 51 and the third wall 54, the boundary portion between the second wall 52 and the third wall 53, and the boundary portion between the second wall 52 and the third wall 54.
  • all of the four boundary portions 50Ba are curved surfaces. Note that only a portion of the four boundary portions 50Ba may be curved surfaces. In other words, at least one of the boundary portion between the first wall 51 and the third walls 53, 54 and the boundary portion between the second wall 52 and the third walls 53, 54 is a curved surface.
  • the corners of the inner wall 50 and outer wall 60 that define the flow path 12 are not curved. However, the corners of the inner wall 50 that define the flow path 12 may be curved, or the corners of the outer wall 60 that define the flow path 12 may be curved.
  • the four boundary portions 50Ba mentioned above of the surfaces of the inner wall 50 that define the detection chamber 11 were bent rather than curved, there is a risk that the gas flowing into the detection chamber 11 would become turbulent near the bent portions.
  • at least one of the boundary portions 50Ba between the first wall 51 and the third wall 53 and the boundary portions 50Ba between the second wall 52 and the third walls 53, 54 is a curved surface. This makes it possible to reduce the turbulence.
  • Eighth Embodiment 9 is a schematic plan view of a portion of the gas sensor according to the eighth embodiment of the present disclosure, excluding the lid portion.
  • the gas sensor 10G according to the eighth embodiment differs from the gas sensor 10 according to the first embodiment in that a rib or a groove is provided in the flow path 12. The differences from the first embodiment will be described below.
  • the gas sensor 10G has ribs 91A and 91B protruding from the support surface 20A of the substrate 20.
  • the ribs 91A are provided along the direction in which the flow path 12 extends. In the configuration shown in FIG. 9, the ribs 91A are provided around the entire circumference of the flow path 12, but they may also be provided around part of the flow path 12. The ribs 91A only need to extend along the flow path 12 from at least one of the first outer hole 60A and the second outer hole 60B to the inner hole 50A. For example, the ribs 91A may extend along the flow path 12 from the first outer hole 60A to the inner hole 50A of the flow path 12, but may not be provided between the second outer hole 60B and the inner hole 50A of the flow path 12.
  • the gas sensor 10G has two ribs 91A.
  • the two ribs 91A are spaced apart in the width direction of the flow path 12. Note that the number of ribs 91A is not limited to two.
  • the width direction of the flow path 12 is perpendicular to the direction in which the flow path 12 extends and perpendicular to the Z direction.
  • Rib 91B is provided in the inner hole 50A. Rib 91B is provided contiguous with rib 91A. Rib 91B extends from the flow path 12 toward the detection chamber 11 in the direction through the inner hole 50A (the Y direction in Figure 9).
  • the gas sensor 10G has one rib 91B.
  • the gas sensor 10G may have multiple ribs 91B.
  • the multiple ribs 91B are spaced apart in a direction perpendicular to the penetration direction of the inner hole 50A.
  • gas sensor 10G may have grooves 92A and 92B recessed from support surface 20A of substrate 20.
  • groove 92A is provided along the direction in which flow path 12 extends, and extends along flow path 12 from at least one of first outer hole 60A and second outer hole 60B to inner hole 50A.
  • groove 92B is provided contiguous to groove 92A in inner hole 50A, and extends from flow path 12 toward detection chamber 11 in the direction through inner hole 50A.
  • the ribs 91A, 91B and grooves 92A, 92B are provided on the substrate 20, but this is not limited to this.
  • the ribs 91A, 91B and grooves 92A, 92B may also be provided on the inner wall 50, the outer wall 60, or the lid portion 70.
  • the ribs 91A and grooves 92A can make the direction of gas flow in the flow path 12 closer to a constant direction. In other words, the gas flow in the flow path 12 can be rectified.
  • the ribs 91B and grooves 92B make it possible to keep the gas flow direction in the inner hole 50A close to a constant direction. This allows the gas rectified in the flow path 12 to be guided to the detection chamber 11 via the inner hole 50A while remaining in a rectified state.
  • Ninth Embodiment 10 is a schematic perspective view of a portion of a gas sensor according to a ninth embodiment of the present disclosure, excluding a lid portion.
  • the gas sensor 10H according to the ninth embodiment differs from the gas sensor 10 according to the first embodiment in that the inner wall 50 is supported by the detection element 30. The differences from the first embodiment will be described below.
  • the inner wall 50 is supported by the detection element 30. That is, in the ninth embodiment, the inner wall 50 is supported by the substrate 20 via the detection element 30. In other words, the inner wall 50 is indirectly supported by the substrate 20. On the other hand, in the first embodiment, the inner wall 50 is directly supported by the substrate 20.
  • the detection chamber 11 is a space defined by the detection element 30, the inner wall 50, and the lid portion 70. Note that in the ninth embodiment, the inner wall 50 surrounds the detection portion 31 when viewed along the Z direction, and therefore the detection portion 31 is located in the detection chamber 11.
  • the gas sensor 10H shown in FIG. 10 may also include a circuit element 40.
  • the circuit element 40 may be supported, for example, by the detection element 30, or may be supported on the back side of the substrate 20 opposite the support surface 20A.
  • the area of the gas sensor 10H when viewed along the Z direction can be reduced compared to a configuration in which the inner wall 50 and the detection element 30 are individually supported by the substrate 20.
  • the gas sensor 10H can be made smaller.
  • the gap can function as an internal hole that connects the flow path 12 and the detection chamber 11. This improves the exchange of gas between the inside and outside of the detection chamber 11.
  • Tenth Embodiment 11 is a schematic plan view of a portion of a gas sensor according to a tenth embodiment of the present disclosure, excluding a lid portion.
  • the gas sensor 10I according to the tenth embodiment differs from the gas sensor 10 according to the first embodiment in that the circuit element 40 forms part of the inner wall 50 and defines the inner hole 50A. The differences from the first embodiment will be described below.
  • the circuit element 40 forms part of the inner wall 50 and defines the inner hole 50A.
  • the circuit element 40 forms part of the third wall 53.
  • the third wall 53 has two one-side holes 50Aa.
  • the circuit element 40 defines the two one-side holes 50Aa.
  • the circuit element 40 forms part of the inner wall 50.
  • the entire circuit element 40 is located in the detection chamber 11, and the area of the gas sensor 10I when viewed along the Z direction can be made smaller than in a configuration in which the circuit element 40 is not part of the inner wall 50. In other words, the gas sensor 10I can be made smaller.
  • the circuit element 40 partitions the inner hole 50A, making it easy to make the inner hole 50A larger. This improves the ability to replace gas between the inside and outside of the detection chamber 11.
  • Eleventh Embodiment 12 is a schematic perspective view of a portion of a gas sensor according to an eleventh embodiment of the present disclosure, with a cover portion removed.
  • the gas sensor 10J according to the eleventh embodiment differs from the gas sensor 10 according to the first embodiment in that the gas sensor 10J includes a cover portion. The differences from the first embodiment will be described below.
  • the gas sensor 10J includes a covering portion 25.
  • the covering portion 25 is provided on the support surface 20A of the substrate 20.
  • the covering portion 25 is made of an insulating material.
  • the covering portion 25 may be made of a hard resin such as a thermosetting resin, or may be made of a material other than a hard resin.
  • the covering portion 25 may be made of the same material as the inner wall 50, outer wall 60, and lid portion 70, or may be made of a different material.
  • the covering portion 25 may be made of resin, and the lid portion 70 may be made of a material other than resin, such as metal.
  • the covering portion 25 may be integrally formed with the inner wall 50 and the outer wall 60.
  • the covering portion 25 may be a separate member from the inner wall 50 and the outer wall 60.
  • the inner wall 50 and the outer wall 60 may be supported by the support surface 20A, and the covering portion 25 may be provided on a portion of the support surface 20A where the inner wall 50 and the outer wall 60 are not provided.
  • the covering portion 25 may be supported by the support surface 20A, and the inner wall 50 and the outer wall 60 may be supported by the covering portion 25.
  • the inner wall 50 and the outer wall 60 may be supported on the substrate 20 via the covering portion 25.
  • the coating 25 covers the bonding wires 32 and 41.
  • the bonding wires 32 and 41 are an example of a connection portion.
  • the covering portion 25 may cover a portion of the detection element 30.
  • the covering portion 25 covers the entire detection element 30 except for the detection portion 31. In other words, the detection portion 31 is exposed to the detection chamber 11.
  • the covering portion 25 may cover at least a portion of the circuit element 40.
  • the circuit element 40 has a temperature sensor 42, and the covering portion 25 covers the circuit element 40 except for the temperature sensor 42. In other words, the temperature sensor 42 is exposed to the detection chamber 11.
  • the bonding wires 32, 41 are covered with the covering portion 25. This protects the bonding wires 32, 41 from foreign matter such as water droplets.
  • the gas sensor described above can also be expressed as follows:
  • a gas sensor includes: A substrate; a detection element supported by the substrate and having a detection portion; an inner wall supported by the substrate and surrounding the detection unit when viewed along an orthogonal direction orthogonal to a support surface on which the substrate supports the detection element; an outer wall supported by the substrate and surrounding the inner wall when viewed along the orthogonal direction; a lid portion supported by the inner wall and the outer wall, which closes a detection chamber in which the detection unit is provided, which is a space inside the inner wall when viewed along the orthogonal direction, and which closes a flow path which is a space between the inner wall and the outer wall when viewed along the orthogonal direction;
  • the outer wall is At least one first outer hole penetrating in a first direction so as to communicate the outside of the outer wall with the flow path; at least one second outer hole provided on the opposite side of the detection chamber from the first outer hole in the first direction and penetrating the outer wall in the first direction to communicate the outside of the outer wall with the flow path;
  • the inner hole is at least one one-side hole located on one side of the detection unit in the second direction;
  • the sensor may have at least one other-side hole located on the other side of the detection portion in the second direction.
  • the inner wall is a first wall that does not have the inner hole and faces the first outer hole in the first direction; a second wall that does not have the inner hole and faces the second outer hole in the first direction; a third wall connecting the first wall and the second wall and having the inner hole.
  • At least one of a boundary between the first wall and the third wall and a boundary between the second wall and the third wall may be a curved surface.
  • the lid may further include at least one lid hole that connects the outside of the gas sensor with the flow path.
  • the substrate may further include at least one substrate hole that communicates the outside of the gas sensor with the detection chamber.
  • the device may further include a filter membrane that closes an opening of at least one of the first outer hole and the second outer hole.
  • the flow path may have an expanding path in which the cross-sectional area of the flow path increases toward the inner hole.
  • the flow path may have a narrowing path in which the cross-sectional area of the flow path decreases toward the inner hole.
  • the fluid passage may further include a rib or a groove provided in the fluid passage and extending along the fluid passage from at least one of the first outer hole and the second outer hole to the inner hole.
  • the rib or groove may be provided in the inner hole in addition to the flow path, or may extend continuously from the flow path toward the detection chamber along the inner hole.
  • the inner wall may be supported by the detection element.
  • At least one of the inner wall and the outer wall and the lid portion may include a metal material.
  • the device may further include a circuit element supported by the substrate, The circuit element may constitute a part of the inner wall and define the inner hole.
  • the inner wall and the outer wall may be integral with the substrate.
  • any one of the gas sensors (1) to (15) is a connection portion that electrically connects the detection element and the substrate;
  • the connector may further include a covering portion supported by the substrate and covering the connection portion.

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Abstract

Ce capteur de gaz comprend : un substrat ; un élément de détection qui est supporté par le substrat et comporte une unité de détection ; une paroi intérieure qui est supportée par le substrat et entoure l'unité de détection ; une paroi extérieure qui est supportée par le substrat et entoure la paroi intérieure ; et une partie couvercle qui est supportée par la paroi intérieure et la paroi extérieure, ferme une chambre de détection qui est un espace à l'intérieur de la paroi intérieure dans lequel l'unité de détection est disposée, et ferme un trajet d'écoulement qui est un espace entre la paroi intérieure et la paroi extérieure. La paroi extérieure a un premier trou extérieur pénétrant dans une première direction de façon à faire communiquer le côté extérieur de la paroi extérieure et le trajet d'écoulement, et un second trou extérieur disposé du côté opposé au premier trou extérieur par rapport à la chambre de détection dans la première direction et pénétrant dans la première direction de façon à faire communiquer le côté extérieur de la paroi extérieure et le trajet d'écoulement. La paroi intérieure comporte un trou intérieur pénétrant dans une seconde direction de façon à faire communiquer le trajet d'écoulement et la chambre de détection, la seconde direction croisant la première direction.
PCT/JP2025/017429 2024-05-30 2025-05-13 Capteur de gaz Pending WO2025249152A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2024-088034 2024-05-30
JP2024088034 2024-05-30

Publications (1)

Publication Number Publication Date
WO2025249152A1 true WO2025249152A1 (fr) 2025-12-04

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PCT/JP2025/017429 Pending WO2025249152A1 (fr) 2024-05-30 2025-05-13 Capteur de gaz

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WO (1) WO2025249152A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002236105A (ja) * 2000-11-23 2002-08-23 Robert Bosch Gmbh ガス測定センサ
JP2006242776A (ja) * 2005-03-03 2006-09-14 Denso Corp センサ装置
JP2007017452A (ja) * 2001-02-28 2007-01-25 Denso Corp ガスセンサ
US20150075257A1 (en) * 2013-09-16 2015-03-19 Lg Innotek Co., Ltd. Gas sensor package
JP2017049011A (ja) * 2015-08-31 2017-03-09 日立オートモティブシステムズ株式会社 気体センサ装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002236105A (ja) * 2000-11-23 2002-08-23 Robert Bosch Gmbh ガス測定センサ
JP2007017452A (ja) * 2001-02-28 2007-01-25 Denso Corp ガスセンサ
JP2006242776A (ja) * 2005-03-03 2006-09-14 Denso Corp センサ装置
US20150075257A1 (en) * 2013-09-16 2015-03-19 Lg Innotek Co., Ltd. Gas sensor package
JP2017049011A (ja) * 2015-08-31 2017-03-09 日立オートモティブシステムズ株式会社 気体センサ装置

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