JP2024018687A - detection device - Google Patents

Abstract

The present invention provides a detection device that can efficiently supply a fluid to be detected to a detection element. The detection device includes a first surface, a second surface opposite to the first surface, an inlet 15 through which a fluid is introduced, an outlet 16 through which the fluid is discharged, and the first surface. a groove 14 provided in a first region extending linearly from the inlet to the outlet, and in a second region other than the first region of the first surface, the first surface and the It includes a storage chamber 12 facing the second surface with a cavity in between, and detection elements 22a to 22d provided at positions facing the first region of the second surface. [Selection diagram] Figure 1

Description

The present invention relates to a detection device.

In a detection device that detects information regarding a fluid such as a gas (for example, a specific substance in the fluid), a detection device is known in which a detection element such as a sensor is provided in a storage chamber such as a chamber, and the gas to be detected is introduced into the storage chamber. (For example, Patent Document 1). It is known to provide a detection element in a flow path through which fluid flows (for example, Patent Document 2). It is known to branch a channel through which a fluid flows into two and provide a detection element in each of the two branched channels (for example, Patent Document 3).

Japanese Patent Application Publication No. 2012-112651 JP2008-82768A Japanese Patent Application Publication No. 2021-165730

In the method of introducing fluid into the storage chamber, a distribution occurs in the flux and flow velocity of the fluid within the storage chamber. Furthermore, it is difficult to efficiently supply fluid to the sensitive portion on the surface of the detection element. In the method of providing a detection element in a flow path, it is difficult to efficiently supply fluid to the sensitive part on the surface of the detection element.

The present invention has been made in view of the above problems, and an object of the present invention is to efficiently supply a fluid to be detected to a detection element.

The present invention includes a first surface, a second surface opposite to the first surface, an inlet through which a fluid is introduced, an outlet through which the fluid is discharged, and a first surface in a first region of the first surface. a groove extending linearly from the inlet to the outlet, the first surface and the second surface forming a cavity in a second region other than the first region of the first surface; The detection device includes storage chambers facing each other, and a detection element provided at a position facing the first region on the second surface.

In the above configuration, a plurality of the detection elements may be provided at positions facing the first region on the second surface.

In the above configuration, a cover may be provided on the second surface at a position facing the first region to cover another detection element or a sealing body for sealing another detection element. .

In the above configuration, a plurality of storage chambers, a plurality of introduction paths branching from one introduction path and connected to the introduction ports of the plurality of storage chambers, and a plurality of introduction paths branching from one discharge path and connecting the plurality of storage chambers. A plurality of discharge passages respectively connected to the discharge ports may be configured.

The above configuration includes an introduction path for introducing the fluid into the introduction port, and a discharge path for discharging the fluid from the discharge port, and the extending direction of the introduction path and the extending direction of the first region are formed. The angle can be configured to be 10 degrees or less.

In the above configuration, the distance between the first surface and the second surface in the second region of the storage chamber is equal to the distance between the second surface and a point farthest from the second surface in the first region. It can be configured such that the ratio is 0.1 times or more and 0.9 times or less.

In the above configuration, the width of the first region is 0.2 times or more and 5 times or less the distance between the part of the first region farthest from the second surface and the second surface. I can do it.

In the above configuration, a substrate may be provided on a mounting surface on which the detection element is mounted, and the second surface may be the mounting surface.

In the above configuration, the fluid may be a gas.

The above configuration may include a determination unit that determines the odor of the gas based on the output value of the detection element.

The present invention provides a housing having a lower surface, an upper surface opposite to the lower surface, and a side surface provided from the periphery of the upper surface toward the lower surface as an inner wall of a detection space, and a first sensing section on the upper surface. a first sensing element provided; and a first pad having an upper surface joined to the first sensing element and provided around the first sensing element and electrically connected to a first electrode of the first sensing element. and a first substrate provided on the bottom surface of the detection space, the casing being spaced apart from the first sensing section and provided on the top surface of the detection space so as to overlap with the first sensing section. a groove extending upward as a concave portion connecting one side and the other of the two opposing sides of the upper surface of the detection space; an introduction path connected to one end of the groove on a side side, provided in the housing outward from the one end of the groove, and into which fluid is introduced; and on the other side of the upper surface of the detection space; a discharge path connected to the other end of the groove, provided in the housing outward from the other end of the groove, and through which the fluid is discharged, and the detection space is located between the groove and the first a high back portion that is a space between the first substrate and a low back portion that is a space between the upper surface of the detection space and the first substrate that is continuously provided on the outside of both sides of the groove in the extending direction up to the side surface; A detection device has a back portion, and a boundary between the high back portion and the low back portion is located so as to sandwich the first detection element.

In the above configuration, the groove may be provided linearly, and the cross-sectional shape of the groove may be a part of an ellipse or a part of a circle.

In the above configuration, the second detection element has a second sensing element provided on the upper surface thereof, and the second detection element is connected to the upper surface of the second detection element, and the second detection element is provided around the second detection element. a second substrate having a second pad electrically connected to an electrode and provided on the lower surface of the detection space; the groove is spaced apart from the second sensitive section; It is possible to have a configuration that overlaps with the above.

In the above configuration, the first electrode and the first pad may be connected by a thin metal wire, and the thin metal wire may pass through a boundary between the high back portion and the low back portion.

According to the present invention, the fluid to be detected can be efficiently supplied to the detection element.

FIG. 1 is a perspective view of a detection device according to a first embodiment. FIG. 2 is a plan view of the detection device according to the first embodiment. 3(a) and 3(b) are a sectional view taken along the line AA and sectional view taken along the line BB in FIG. 2, respectively. 4(a) is a plan view of the substrate 20a in Example 1, and FIG. 4(b) is a sectional view taken along line AA in FIG. 4(a). FIGS. 5A and 5B are plan views showing gas flows in Comparative Example 1 and Example 1, respectively, in Simulation 1. FIGS. 6A and 6B are cross-sectional views showing the gas velocity of Comparative Example 2 and Example 1 in Simulation 2, respectively. 7(a) is a plan view of a detection device according to Example 2, and FIG. 7(b) is a sectional view taken along line AA in FIG. 7(a). FIGS. 8A and 8B are plan views showing gas flows in Comparative Example 3 and Example 2, respectively, in Simulation 3. 9(a) is a plan view of a detection device according to Example 3, and FIG. 9(b) is a sectional view taken along line AA in FIG. 9(a). FIG. 10 is a plan view showing the gas flow in Example 3 in Simulation 4. FIG. 11 is a plan view showing the gas flow in Modification 1 of Example 3 in Simulation 4. FIG. 12 is a block diagram of a detection device according to the fourth embodiment.

Examples will be described below with reference to the drawings.

FIG. 1 is a perspective view of a detection device according to a first embodiment. In FIG. 1, the housing 10, the substrates 20a to 20c, and the detection elements 22a to 22d are shown in solid lines, and the storage section 13, the groove 14, the introduction path 17, and the discharge path 18 are shown in broken lines. FIG. 2 is a plan view of the detection device according to the first embodiment. 3(a) and 3(b) are a sectional view taken along the line AA and sectional view taken along the line BB in FIG. 2, respectively. In FIG. 2, the storage chamber 12, the substrates 20a to 20c, and the detection elements 22a to 22d are shown in solid lines, and the groove 14, the inlet 15, the outlet 16, the inlet 17, and the outlet 18 are illustrated in broken lines. The extending direction of the groove 14 and the arrangement direction of the detection elements 22a to 22d are the X direction, the direction parallel to the upper surface 11 and the lower surface 21 and orthogonal to the X direction is the Y direction, and the normal direction of the upper surface 11 and the lower surface 21 is the X direction. shall be.

First, I will touch on the definition of grooves, which is a key point, and then I will touch on specific points. In the Kojien, a groove is defined as "a place where water is poured by digging into a long thin strip of ground", and the "ground" is the inner surface that forms the measurement space, and the groove is a place where this surface is left on both sides and a recess is formed. be. In other words, the groove has surfaces on both sides. As will be described later, a groove 14 is provided on the upper surface 11 in FIG. 3(b). The height from the upper surfaces 21a to 21c of the substrates 20a to 20c to the curved surface, which is the upper surface of the groove 14 in which the groove 14 is formed, is higher than the height from the upper surface 21a to 21c to the upper surface 11 other than the groove 14. Therefore, the portion from the upper surfaces 21a to 21c of the substrates 20a to 20c to the upper surface of the groove 14 is called a high back portion 27a (see FIG. 4(b)). The portion from the upper surfaces 21a to 21c of the substrates 20a to 20c to the upper surface 11 other than the groove 14 is called a low back portion 27b (see FIG. 4(b)).

Next, I will touch on a few points.
First point (about groove 14)
Substrates 20a to 20c on which sensor chips, which are detection elements 22a to 22d, are provided are provided in the storage section 13, and detection is performed by the upper surfaces 21a to 21b (lower surface 21 of the storage chamber 12), upper surface 11, and side surfaces of the substrates 20a to 20c. A storage room 12, which is a space, is configured. Note that the detection elements 22a to 22d may be provided directly on the substrate 24 instead of the structure in which the detection elements 22a to 22d are provided on the substrates 20a to 20c. In this case, electrodes are provided on the lower surface of the substrate 24, and the electrodes and the detection elements 22a to 22d are electrically connected via wiring within the substrate 24. The high back portion 27a is a portion from the top surface of the detection elements 22a to 22d to the top surface of the groove 14, and the low back portion 27b is a portion from the top surface of the detection elements 22a to 22d to the top surface 11.

A groove 14 is provided on the upper surface 11 of the storage section 13 or storage chamber 12 from the inlet 15 to the outlet 16 or from the inlet 15 to the front of the outlet 16. This "before the discharge port 16" includes, for example, in FIG. 1, the groove 14 does not need to be provided on the +X side of the detection element 22b. Since no other detection element is provided from the detection element 22b to the discharge port 16, the term "before the discharge port 16" is used. From the definition of the groove 14, as shown in FIG. 3(b), the upper surface 11 is provided on both sides (±Y side) of the groove 14 so as to be continuous with the open part of the groove 14.

FIG. 5(a) is a simulation of the gas flow when the grooves 14 are not provided, and FIG. 5(b) is a simulation of the gas flow when the grooves 14 are provided. As shown in FIG. 5(a), when the groove 14 is not provided, the gas entering the storage chamber 12 from the inlet 15 is released at the inlet 15, and therefore dissipates vertically (in the ±Y direction) on the plane of the paper. . However, by providing the grooves 14 as shown in FIG. 5(b), gas dissipation is suppressed. In other words, the gas is guided to the groove 14 and flows into a bundle along the groove 14 . Further, when the groove 14 passes over the sensitive portion 23 (see FIGS. 4(a) and 4(b)), gas is guided to the groove 14. Thereby, it is possible to uniformly pass the bundled gas over the sensitive parts 23 of the detection elements 22a to 22d.

Second point (relationship between inlet 15 and groove 14)
The shape of the introduction port 15 (shape in the YZ plane) is almost the same as the cross-sectional shape of the introduction path 17, and the upper half of the shape of the introduction port 15 (half on the +Z side) and the groove 14 connect to the introduction port 15. The cross-sectional shape of the groove 14 in is almost the same as that of the groove 14 in FIG. The same applies to the discharge port 16 and the discharge path 18. As a result, the inlet 15, the groove 14, and the outlet 16 continuously have the same cross-sectional shape from the inlet 15 to the groove 14 and from the groove 14 to the outlet 16.

For example, as shown in FIG. 3(a), a side wall of the casing 10 on the −X side in which the introduction path 17 is provided, and a top plate of the casing 10 having a thickness from the upper end (+Z end) of this side wall are provided. It is being Drill an opening from the -X side wall to the -X side wall so that a groove 14 is formed on the lower surface (upper surface 11) of the top plate, and the above-mentioned hole passes from the inlet path 17 through the groove 14 to the discharge path 18. It has a cross-sectional shape like this. When the introduction passage 17, the groove 14, and the discharge passage 18 are formed using a drill in this manner, cylindrical holes are formed as the introduction passage 17 and the discharge passage 18. The cross-sectional shape of the groove 14 is continuous with the +Z side half of the cross-sectional shapes of the introduction path 17 and the discharge path 18, and a dome-shaped groove 14 is formed. Note that the housing 10 may be formed by molding using a metal mold. In this case, the cross-sectional shapes of the introduction path 17, the groove 14, and the discharge path 18 may be other than circular, such as a polygonal shape. In this way, since the inner wall of the dome-shaped groove 14 and the inner wall of the introduction passage 17 are formed continuously, the introduced gas is prevented from turbulence and dissipation, and flows concentratedly into the groove 14. Become.

Third point (the storage chamber 12 is long and narrow, and the detection elements 22a to 22d are arranged in a line)
One of the points is to arrange a plurality of detection elements 22a to 22d in a line along the groove 14, as shown in FIGS. 1 to 3(b). For example, in FIG. 1, four detection elements 22a to 22d are lined up in a row from left to right (in the X direction). If these four detection elements 22a to 22d are arranged in two or more rows, the width of the storage chamber 12 (width in the Y direction) increases, and the gas introduced into the storage chamber 12 from the inlet 15 is dissipated. , unevenness occurs in the velocity distribution and concentration distribution of the gas guided into the groove 14, resulting in a decrease in detection accuracy. For example, when configuring two sets of four detection elements 22a to 22d, the storage chambers 12a and 12b formed in two rows are separated by the side wall of the casing 10, as shown in FIG. 9, which will be described later. For example, the configuration is such that the casings 10 in FIG. 1 are arranged in two rows, and each row has the points described here.

Fourth point (low back portions 27b on both sides of groove 14)
As shown in FIG. 6(b), which will be described later, the storage chamber 12 has a height of a first space in the shape of a cylinder cut in half, from the inlet 15 to the outlet 16, as shown in FIGS. 1 to 3(b). A back portion 27a is provided. On both sides of the groove 14 in the ±Y direction, a low back portion 27b, which is a second space having a substantially horizontal upper surface 11 and a lower surface 21, which is lower than the height from the upper surfaces 21a to 21c to the curved surface of the groove 14, is provided. ing. According to the simulation, due to the presence of the low back portion 27b, gas enters the low back portion 27b, and the first space and the second space in the vicinity thereof can be secured as a more uniform flow velocity space. This has the advantage that the entire substrates 20a to 20c can be covered as a uniform flow velocity space and a uniform concentration space. At the same time, when the detection elements 22a to 22d are connected by the bonding wire 28, as shown in FIG. The bonding wire 28 is passed near the. Thereby, the terminal end of the bonding wire 28 and the bonding wire 28 in the vicinity thereof can be located in the low back part 27b, the diameter (width W1) of the high back part 27a can be reduced, and the storage chamber 12 can be made smaller. .

As can be understood from the above description, the present invention is characterized by the internal space through which gas passes.
Specific examples will be described below.

As shown in FIGS. 1 to 3(b), the rectangular parallelepiped-shaped housing 10 includes an outer wall and an inner wall. The housing 10 has a lower surface 21, an upper surface 11 opposite to the lower surface 21, and three side surfaces provided from the periphery of the upper surface 11 toward the lower surface. have as. The four side surfaces are two long sides (±Y sides) of the four sides of the top surface 11, and two short sides (±X sides) where the inlet 15 and the discharge port 16 are provided. side) side). The space of the groove 14 recessed upward from the upper surface 11 (+Z side surface) is also referred to as the storage section 13. The housing 10 is made of resin or metal, for example. A substrate 24 is housed in the housing section 13, and it is sealed except for the inlet 15 and the outlet 16.

The board 24 functions as a motherboard and may be provided with wiring. Furthermore, components such as a power supply and a capacitor may be mounted to form a circuit. Substrates 20a to 20c are arranged on the substrate 24 in the X direction. That is, the upper surfaces 21a to 21c of the substrates 20a to 20c are arranged in one row, facing and parallel to the upper surface 11 of the housing 10. Wiring is provided on the substrates 20a to 20c. Further, components such as a power supply or a capacitor electrically connected to the wiring may be mounted on the substrates 20a to 20c. For example, these parts are provided on the lower surface side (-Z side) of the substrates 20a to 20c, and a circuit is formed by these parts. The substrate 24 and the substrates 20a to 20c may be electrically connected via leads. The substrate 24 and the substrates 20a to 20c may be separated from each other.

A detection element 22a is provided on the upper surface 21a of the substrate 20a, a detection element 22b is provided on the upper surface 21b of the substrate 20b, and detection elements 22c and 22d are provided on the upper surface 21c of the substrate 20c. The detection elements 22a to 22d are electrically connected to wiring on the substrates 20a to 20c. The substrates 20a to 20c are mounting substrates such as resin substrates or ceramic substrates. A single substrate may be used instead of the plurality of substrates 20a-20c.

By separately providing the substrates 20a to 20c, the detection elements 22a to 22d can be replaced individually. The detection elements 22a to 22d are sensors that measure the amount of electrical reaction caused by contact with fluid. This amount of reaction includes the capacitance, electrical resistance, current, voltage, resonance frequency, impedance, or other electrical changes of the detection elements 22a to 22d. By measuring these reaction amounts, it is possible to detect the temperature, humidity, flow rate, pressure difference of the fluid, the amount of a specific single or composite substance contained in the fluid, or information regarding other fluids (gases). For example, the detection elements 22a and 22b are sensors that detect a specific substance in gas, and the detection elements 22c and 22d are a temperature sensor and a humidity sensor, respectively. The detection elements 22a to 22d may be sensors that detect different substances in the gas.

The substrates 20a to 20c and the storage section 13 form a storage chamber 12 (detection space or measurement space) that stores the detection elements 22a to 22d. The storage chamber 12 has an upper surface 11 (first surface) and a lower surface 21 (second surface) that face each other. The upper surface 11 is the upper surface of the housing 10, and the lower surface 21 is formed from the upper surfaces 21a to 21c of the substrates 20a to 20c. The planar shape of the storage chamber 12 is, for example, rectangular. An introduction path 17 is provided on the side surface of the storage chamber 12 on the -X side, and the gas to be detected is introduced into the storage chamber 12. That is, the introduction path 17 is connected to one end of the groove 14 at one side (-X side) of the sides facing in the X direction of the upper surface 11 of the storage chamber 12, and is connected to the outside (- (X direction) inside the housing 10. A discharge path 18 is connected to the side surface of the storage chamber 12 on the +X side. That is, the discharge path 18 connects to the other end of the groove 14 at the other (+X side) side of the upper surface 11 of the storage chamber 12 facing in the X direction, and extends outward from the other end of the groove 14 ( +X direction) within the housing 10. The introduction port 15 is where the storage chamber 12 and the introduction path 17 come into contact. The location where the storage chamber 12 and the discharge path 18 come into contact is the discharge port 16. The upper surface 11 of the storage chamber 12 is provided with a groove 14 that connects one side and the other of the two opposite sides of the upper surface 11 in the X direction and extends as a concave portion recessed upward. ing. The groove 14 is provided extending linearly from the inlet 15 to the outlet 16. The cross-sectional shape of the groove 14 is semicircular. The cross-sectional shape of the groove 14 may be the upper half of a polygonal shape such as a rectangle or the upper half of an elliptical shape. The detection elements 22a to 22d are provided on the upper surfaces 21a to 21c facing the groove 14. That is, in plan view, at least a portion of each of the detection elements 22a to 22d overlaps with at least a portion of the groove 14.

Gas to be detected is introduced into the introduction path 17 . Gas is introduced into the storage chamber 12 from the inlet 15, and passes over the upper surfaces of the detection elements 22a to 22d along the groove 14 that serves as a gas guide. The gas is discharged from the discharge port 16 through the discharge passage 18 . Information regarding the gases detected by the detection elements 22a to 22d is calculated, for example, by a circuit provided on the substrate 24, and, for example, the type of substance in the gas or the odor of the gas is determined. For example, in the first embodiment, a gas such as air is used as the fluid, but the fluid may be a liquid.

4(a) is a plan view of the substrate 20a in Example 1, and FIG. 4(b) is a sectional view taken along line AA in FIG. 4(a). As shown in FIGS. 4(a) and 4(b), a substrate 20a is provided on the lower surface 21 of the storage chamber 12. A detection element 22a (first detection element) is bonded (fixed) to the upper surface 21a of the substrate 20a (first substrate). A sensing portion 23 (first sensing portion) and an electrode 28c (first electrode), which are sensitive films, are provided on the surface of the detection element 22a. A pad 28a (first pad) and a conductive pattern 28b (first conductive pattern) electrically connected to the pad 28a are provided around the detection element 22a on the upper surface 21a of the substrate 20a. The electrode 28c on the upper surface of the detection element 22a and the pad 28a on the upper surface 21a of the substrate 20a are electrically connected by a bonding wire 28 (first bonding wire). When a specific substance in the gas is adsorbed to the sensitive part 23, the resistance value or resonance frequency of the detection element 22a changes. The detection element 22a is, for example, a QCM (Quartz Crystal Microbalance) sensor, a SAW (Surface Acoustic Wave) sensor, a BAW (Bulk Acoustic Wave) sensor, etc., and the resonance frequency changes depending on the weight of a specific substance adsorbed to the sensitive part 23. It is a sensor that The detection element 22a may be a sensor whose resistance value changes when a specific substance in the gas is adsorbed to the sensitive part 23. The substances in the gas to be detected are, for example, organic compounds such as ethanol, acetone or toluene, or inorganic substances such as ammonia, nitrogen oxides, ozone or chlorine.

The region of the upper surface 11 of the storage chamber 12 in which the groove 14 is provided is a first region 25a, and the region of the upper surface 11 other than the first region 25a is a second region 25. The space between the groove 14 (first region 25a) and the substrate 20a is a high back portion 27a, and the region between the second region 25 and the substrate 20a is a low back portion 27b. The low back portions 27b are continuously provided outside the groove 14 on both sides in the X direction up to the side surfaces of the storage chamber 12. The storage chamber 12, which is a detection space, has a high back part 27a and a low back part 27b.

It is preferable that the groove 14 overlaps all of the sensitive section 23 in a plan view. The width W1 of the groove 14 (that is, the first region 25a) in the Y direction (the plane direction of the upper surface 11 and the direction perpendicular to the arrangement direction of the detection elements 22a to 22d) is equal to or larger than the width W3 of the sensitive part 23 in the Y direction. The width W1 of the groove 14 is preferably equal to or larger than the width W2 of the detection element 22a in the Y direction. In other words, the two boundaries between the high back portion 27a and the two low back portions 27b are located so as to sandwich the detection element 22a. Thereby, gas is efficiently supplied to the sensing section 23. The width W1 of the groove 14 is sufficiently smaller than the width W4 of the storage chamber 12 in the Y direction.

The height H1 from the bottom surface (top surface) of the groove 14 and the top surface 21a of the substrate 20a is the height H2 between the top surface 11 of the storage chamber 12 and the top surface 21a of the substrate 20a in the second region 25 corresponding to the low back portion 27b. It is about twice as large as the previous year. The height H2 is preferably such that the bonding wire 28 comes into contact with the upper surface 11 and does not deform. The height H3 of the detection element 22a is less than or equal to the height H2.

Similarly to the detection element 22a, the detection element 22b (second detection element) is provided with a sensing section 23 (second sensing section) and an electrode 28c (second electrode). Similarly to the substrate 20a, the substrate 20b (second substrate) is provided with a pad 28a (second pad) and a conductive pattern 28b (second conductive pattern). The electrode 28c and the pad 28a are electrically connected by a bonding wire 28 (second bonding wire). A groove 14 is provided in the upper surface 11 of the storage chamber 12 corresponding to the detection elements 22a and 22b.

Let me state it again. The detection element 22a mounted on the substrate 20a is a hexahedral chip type. For example, a bonding wire 28 (fine metal wire) is used for electrical connection. The bonding wire 28 passes through the boundary between the high back part 27a and the low back part 27b. In the bonding wire 28 on the left side (+Y side) of FIG. 4(b), the bonding wire 28 rises upward from the top surface of the detection element 22a, passes through the top 29 of the bonding wire 28, and connects to the pad on the top surface 21a of the substrate 20a. It's down to the left (outside).

Since a top portion 29 is formed on the bonding wire 28, the height H2 of the low back portion 27b is made slightly higher than this top portion 29. Further, by placing the top portion 29 inside the boundary between the groove 14 and the low back portion 27b, the low back portion 27b can be made lower. Moreover, a portion extending from an arbitrary position outside the top 29 of the bonding wire 28 to the terminal end of the bonding wire 28 connected to the pad 28a is provided in the low-back portion 27b. Therefore, the width W1 of the groove 14 can be narrowed. In other words, due to the presence of the low back portion 27b, the width W1 of the groove 14 can be narrowed, and the size of the housing 10 can also be reduced. Furthermore, since the width W1 of the groove 14 can be narrowed, there is an advantage that the gas concentration distribution becomes more uniform.

[Simulation 1]
Regarding Example 1 and Comparative Example 1, the gas flow inside the storage chamber 12 was simulated. Comparative Example 1 has the same structure as Example 1 except that the groove 14 is not provided. That is, Comparative Example 1 has a structure in which the tall portion 27a is not provided. In simulation 1, the height H1 of the groove 14 was 2 mm, the height H2 in the region 25 of the storage chamber 12 (that is, the height of the low back portion 27b) was 1 mm, and the width W1 of the groove 14 was 2 mm. The cross-sectional shape of the groove 14 is a semicircle.

FIGS. 5A and 5B are plan views showing gas flows in Comparative Example 1 and Example 1, respectively, in Simulation 1. In FIGS. 5(a) and 5(b), the line inside the storage chamber 12 indicates the gas flux 50. Where the flux 50 is dense, the flux density is high and the amount of gas flowing is large, and where the flux is sparse, the flux density is low and the amount of gas flowing is small. If the flux is dense or dense, a distribution occurs in the flux density, indicating that a distribution occurs in the amount of gas. Gas is introduced from the inlet 15 of the storage chamber 12 as shown by the arrow 52, and gas is discharged from the exhaust port 16 of the storage chamber 12 as shown by the arrow 53.

As shown in FIG. 5A, in Comparative Example 1, the flux 50 is distributed throughout the storage chamber 12, and the gas introduced from the inlet 15 diffuses and flows into the storage chamber 12. In the vicinity of the discharge port 16, the flux 50 swirls, and a distribution occurs in the flux 50. The flow velocity at position 51a is 0.5 to 1 m/s.

As shown in FIG. 5(b), in Example 1, the flux 50 in the portion corresponding to the groove 14 is dense, and the gas mainly flows near the groove 14. The gas velocity (flow velocity) at the position 51b of the groove 14 is 2 to 3 m/s, which is approximately twice the flow velocity of Comparative Example 1.

As described above, in Comparative Example 1, the gas diffuses into the storage chamber 12, so that the gas cannot be efficiently supplied to the detection elements 22a to 22d. As a result, the sensitivity of the detection elements 22a to 22d decreases, and the detected value fluctuates. Furthermore, since the flow velocity near the detection elements 22a to 22d is slow, the amount of gas supplied to the detection elements 22a to 22d is reduced. This reduces the sensitivity of the detection elements 22a to 22d. Further, when a vortex is generated in the flux 50, a distribution occurs in the flux 50, so that the amount of gas supplied to the detection elements 22a to 22d differs depending on the location where the detection elements 22a to 22d are provided. Therefore, variations in sensitivity occur among the detection elements 22a to 22d.

On the other hand, in Example 1, compared to Comparative Example 1, gas flows in the groove 14 in a concentrated manner, so gas is efficiently supplied to the detection elements 22a to 22d, and the sensitivity of the detection elements 22a to 22d is improved, resulting in a detection value fluctuations are also suppressed. Further, since the flow velocity near the groove 14 is high, the amount of gas supplied to the detection elements 22a to 22d increases, and the sensitivity of the detection elements 22a to 22d improves. Furthermore, no vortices are generated as in Comparative Example 1, and the distribution of flux 50 is uniform near the grooves 14. As a result, the same amount of gas is supplied to the detection elements 22a to 22d. Therefore, variations in sensitivity among the detection elements 22a to 22d can be suppressed. Further, in the portion where the flow rate is high, the gas concentration is high during the initial period (for example, 3 to 4 seconds) when the gas is introduced. Utilizing this, the sensitivity of the detection elements 22a to 22d can be improved.

[Simulation 2]
The flow velocity was simulated for Example 1 and Comparative Example 2. Comparative Example 2 has a structure in which a pipe-shaped flow path 14c is provided instead of the groove 14. In order to mount the detection elements 22a to 22d, the lower surface 21 side of the flow path 14c is flat. FIGS. 6A and 6B are cross-sectional views showing the gas velocity of Comparative Example 2 and Example 1 in Simulation 2, respectively. The solid lines in FIGS. 6(a) and 6(b) indicate flow velocity contour lines. No detection element is provided. Other simulation conditions are the same as simulation 1.

As shown in FIG. 6A, in Comparative Example 2, the cross-sectional shape of the flow path 14c is circular at the top and rectangular at the bottom, and the low-back portion 27b is not provided outside the region corresponding to the groove 14. The height and width of the flow path 14c are the same as the height H2 and width W1 of Example 1, respectively. As shown in FIG. 6(b), in the first embodiment, the height H1 of the upper surface of the groove 14 from the lower surface 21 of the storage chamber 12 is set to 2 mm, and The height H2 of the groove 14 was 1 mm, and the width W1 of the groove 14 was 2 mm.

As shown in FIG. 6(a), in Comparative Example 2, the flow velocity is highest in the flow path 14c near the center (1/2 of the height H1 from the lower surface 21 of the flow path 14c); The distribution is concentric. The height H3 of the detection elements 22a to 22d (see FIG. 4(b)) is smaller than the height H2 in the region 25. Therefore, most of the gas passes above the upper surfaces of the detection elements 22a to 22d, making it impossible to efficiently supply the gas to the sensitive parts 23 of the detection elements 22a to 22d. Sensitivity decreases. When the flow path 14c is pipe-shaped, a high-concentration portion is formed at the center, and distribution occurs outward from the center. This creates a height between the high concentration portion and the lower surface 21 of the flow path 14c. This causes variations in gas concentration and velocity at the positions of the upper surfaces of the detection elements 22a to 22d.

On the other hand, as shown in FIG. 6(b), in Example 1, the gas flow spreads from below the groove 14 to the region 25. Therefore, the flow velocity is highest below the groove 14, at around 1/4 of the height H1 from the lower surface 21 of the storage chamber 12. The flow velocity distribution has an elliptical shape extending from below the groove 14 to the region 25. The region where the gas flow rate is high is near the upper surface of the detection elements 22a to 22d, and the gas can be efficiently supplied to the sensitive parts 23 of the detection elements 22a to 22d, thereby improving the sensitivity of the detection elements 22a to 22d. A portion where the gas concentration distribution is uniform to some extent approaches the substrates 20a to 20c, and a portion where the gas concentration distribution is uniform spreads in the lateral direction. This has the effect of suppressing fluctuations in the detection values of the detection elements 22a to 22d.

As described above, according to the first embodiment, the groove 14 is provided in the first region 25a of the upper surface 11 of the storage chamber 12, extending linearly from the inlet 15 to the outlet 16. The detection elements 22a to 22d are provided at positions facing the grooves 14 on the lower surface 21 of the storage chamber 12. As a result, as shown in FIG. 5(b), compared to FIG. 5(a) of Comparative Example 1, the gas flows in a concentrated manner in the grooves 14, and the flow velocity near the grooves 14 is high, so that the detection elements 22a to 22d are efficiently Can supply gas well. Further, in the first embodiment, in the second region 25 other than the first region 25a where the groove 14 is provided, the upper surface 11 and the lower surface 21 of the storage chamber 12 face each other with a cavity interposed therebetween. As a result, as shown in FIG. 6(b), the region where the gas flow velocity is high is near the upper surfaces of the detection elements 22a to 22d. Therefore, gas can be efficiently supplied to the detection elements 22a to 22d. These improve the sensitivity of the detection elements 22a to 22d.

As shown in FIGS. 1 to 3(a), a plurality of detection elements 22a to 22d are provided at positions facing the first region 25a of the lower surface 21 of the storage chamber 12 in which the groove 14 is provided. As a result, as shown in FIG. 5(a), since the gas flows uniformly along the groove 14, the amount of gas supplied to the plurality of detection elements 22a to 22d can be made uniform, and the sensitivity of the detection elements 22a to 22d can be made uniform. Variations in can be suppressed.

The lower surface 21 of the storage chamber 12 may be a part of the housing 10. In this case, it is difficult to form the storage chamber 12 in the housing 10. Therefore, the detection elements 22a to 22d are mounted on the upper surfaces 21a to 21c (mounting surfaces) of the substrates 20a to 20c, and the lower surface 21 of the storage chamber 12 is the upper surface 21a to 21c of the substrates 20a to 20c. As a result, the storage chamber 12 can be easily formed by providing the storage section 13 on the bottom surface of the housing 10 and inserting the substrates 20a to 20c into the storage section 13, as shown in FIGS. 1 to 3(b). The number of substrates 20a to 20c is not limited to three, but may be one or more.

When the height H2 (that is, the distance between the upper surface 11 and the lower surface 21 in the region 25 other than the groove 14) is large, less gas passes through the groove 14, and the situation approaches the state of Comparative Example 1 in FIG. 5(a). . From this point of view, the height H2 is preferably 0.9 times or less, and 0.8 times or less of the height H1 (i.e., the distance between the farthest point from the bottom surface 21 of the groove 14 (first region 25a) and the bottom surface 21). is more preferable, and even more preferably 0.7 or less. When the height H2 is small, the gas cannot spread to the region 25 as shown in FIG. 6(b), and the state approaches the state of Comparative Example 2 shown in FIG. 6(a). From this viewpoint, the height H2 is preferably at least 0.1 times the height H1, more preferably at least 0.2 times, and even more preferably at least 0.3 times.

When the width W1 of the groove 14 is small, the amount of gas flowing in the groove 14 decreases, and the result approaches Comparative Example 1 of FIG. 5(a) in which the groove 14 is not provided. From this viewpoint, the width W1 of the groove 14 is preferably at least 0.2 times the height H1, more preferably at least 0.3 times, and even more preferably at least 0.5 times. When the width W1 of the groove 14 is large, the height H1 becomes relatively small, approaching Comparative Example 1 of FIG. 5A in which the groove 14 is not provided. From this viewpoint, the width W1 of the groove 14 is preferably 5 times or less than the height H1, more preferably 3.5 times or less, and even more preferably 2 times or less.

When the width W1 of the groove 14 is approximately the same as the width W4 of the storage chamber 12, the width approaches Comparative Example 2 shown in FIG. 6(a). From this viewpoint, the width W1 of the groove 14 is preferably 1/2 or less, more preferably 1/5 or less of the width W4 of the storage chamber 12.

If the height H3 (see FIG. 4(b)) of the detection elements 22a to 22d is too large, it becomes difficult for gas to spread from the groove 14 to the region 25. From this viewpoint, the height H3 is preferably 0.8 times or less than the height H2, more preferably 0.6 times or less, and even more preferably 0.4 times or less. If the height H3 of the detection elements 22a to 22d is too small, as shown in FIG. 6(b), the flow velocity of gas on the upper surfaces of the detection elements 22a to 22d becomes small, so that gas is not supplied to the upper surfaces of the detection elements 22a to 22d become less likely to be From this viewpoint, the height H3 is preferably 0.1 times or more, more preferably 0.2 times or more, the height H2.

7(a) is a plan view of a detection device according to Example 2, and FIG. 7(b) is a sectional view taken along line AA in FIG. 7(a). In FIG. 7(a), the storage chamber 12, the substrates 20a to 20c, and the detection elements 22a to 22d are shown in solid lines, and the groove 14, the inlet 15, the outlet 16, the inlet 17, and the outlet 18 are illustrated in broken lines. ing.

As shown in FIGS. 7(a) and 7(b), in the second embodiment, a member 26 is provided on the substrate 20b. The member 26 is, for example, a cover (metal cap) that covers the detection element 22b (another detection element) or a sealing body that seals the detection element 22b. By providing the cover, gas is not supplied to the detection element 22b inside the cover, and the detection element 22b can be used as a reference detection element to which no gas is supplied. The member 26 may be other than a cover, for example, it may be something that obstructs gas flow, such as a packaged electronic component. The width of the member 26 in the Y direction is W5, and the height of the member 26 is H5.

[Simulation 3]
Regarding Example 2 and Comparative Example 3, the flow of gas in the storage chamber 12 was simulated. Comparative Example 3 has the same structure as Example 2 except that the groove 14 is not provided. The height H5 of the member 26 is approximately the same as the height H2 of the storage chamber 12 in the region 25. Other simulation conditions are the same as simulation 1.

FIGS. 8A and 8B are plan views showing gas flows in Comparative Example 3 and Example 2, respectively, in Simulation 3. As shown in FIG. 8A, in Comparative Example 3, the flux 50 is unstable before the gas reaches the member 26, and a large vortex is formed immediately after the introduction port 15. As shown in FIG. 8(b), in the second embodiment, the flux 50 is along the groove 14 until just before the gas reaches the member 26. The flux 50 that forms the vortex in the storage chamber 12 is not as large as in Comparative Example 3.

If the member 26 is provided between the upper surface 11 of the storage chamber 12 and the substrates 20a to 20c (lower surface 21) as in Comparative Example 3, the gas flow becomes unstable. However, by providing the grooves 14 as in the second embodiment, the gas flow becomes stable. When the width W5 of the member 26 in the Y direction is large, the gas flow becomes unstable in Comparative Example 3. Therefore, when the member 26 is provided at a position facing the groove 14 and the width W5 of the member 26 is larger than the width W1 of the groove 14, the provision of the groove 14 can stabilize the flow of gas. Thereby, the sensitivity of the detection elements 22a to 22d can be improved with good reproducibility. If the width W5 is twice or more than the width W1, or more than three times the width W1, the gas flow becomes more unstable, so it is preferable to provide the grooves 14. When the height H5 of the member 26 is large, the flow of gas becomes unstable in Comparative Example 3. Therefore, when the height H5 of the member 26 is larger than the height H3 of the detection elements 22a to 22d, it is preferable to provide the groove 14. If the height H5 is 1.5 times or more or 3 times or more the height H3, the gas flow becomes more unstable, so it is preferable to provide the grooves 14.

9(a) is a plan view of a detection device according to Example 3, and FIG. 9(b) is a sectional view taken along line AA in FIG. 9(a). In FIG. 9(a), the storage chambers 12a and 12b, the substrates 20a to 20f, and the detection elements 22a to 22h are shown in solid lines, and the grooves 14a and 14b, the inlets 15a and 15b, the outlets 16a and 16b, and the inlet paths 17a to 22h are shown as solid lines. 17c and the discharge passages 18a to 18c are shown in broken lines.

As shown in FIGS. 9A and 9B, in the third embodiment, the housing 10 is provided with a plurality of elongated storage chambers 12a and 12b. Boards 20a to 20c on which detection elements 22a to 22d are mounted are provided within the storage chamber 12a. The upper surfaces 21a to 21c of the substrates 20a to 20c form the lower surface 21 of the storage chamber 12a. A groove 14a is provided in the upper surface 11a of the storage chamber 12a. In plan view, the groove 14a overlaps the detection elements 22a to 22d. Also in the storage chamber 12b, substrates 20d to 20f on which detection elements 22e to 22h are mounted are provided in the storage chamber 12b, and the upper surfaces 21d to 21f of the substrates 20d to 20f form the lower surface of the storage chamber 12b. A groove 14b that overlaps the detection elements 22e to 22h in plan view is provided on the upper surface of the storage chamber 12b.

Gas introduced into one introduction path 17c is distributed to a plurality of introduction paths 17a and 17b as shown by arrow 56, and introduced into storage chambers 12a and 12b as shown by arrows 52a and 52b, respectively. The gases discharged from the discharge ports 16a and 16b of the storage chambers 12a and 12b to the plurality of discharge passages 18a and 18b as shown by arrows 54a and 54b are combined into one discharge passage 18c, and as shown by arrow 58, the gas is discharged from the discharge passages It is discharged from 18c. The introduction passages 17a and 17b are provided almost symmetrically with respect to a straight line extending from the center line of the introduction passage 17c. Thereby, the gas flowing through the introduction path 17c is distributed almost equally between the introduction paths 17a and 17b. The discharge passages 18a and 18b are provided substantially symmetrically with respect to a straight line extending from the center line of the discharge passage 18c. Thereby, the gases flowing through the discharge passages 18a and 18b become almost equal. The center line of the introduction path 17c and the center line of the discharge path 18c substantially coincide with each other, and the storage chambers 12a and 12b are provided almost symmetrically with respect to a straight line extending the center lines of the introduction path 17c and the discharge path 18c. Thereby, the flow of gas in the storage chamber 12a and the flow of gas in the storage chamber 12b can be made approximately equal. Note that, as shown in FIG. 9(a), a partition wall made of the housing 10 exists like a spine between the storage chambers 12a and 12b. As the number of detection elements 22a to 22d increases to 5, 6, etc., the storage chambers 12a and 12b become elongated, and the strength of the housing 10 becomes a problem. However, the presence of the partition wall makes it possible to maintain the strength of the housing 10.

[Simulation 4]
Regarding Example 3, the flow of gas in the storage chambers 12a and 12b was simulated. The simulation conditions are the same as simulation 1.

FIG. 10 is a plan view showing the gas flow in Example 3 in Simulation 4. As shown in FIG. 10, the flux 50a in the storage chamber 12a and the flux 50b in the storage chamber 12b are substantially symmetrical with respect to the extending direction of the introduction path 17c and the discharge path 18c.

When the number of detection elements 22a to 22h is increased and the detection elements 22a to 22h are provided in one storage chamber 12, the detection elements near the inlet 15 and the detection element near the outlet 16 are supplied with the detection elements 22a to 22h. This results in a difference in gas flow rate or flux. In the third embodiment, a plurality of storage chambers 12a and 12b are provided, and a plurality of introduction paths 17a and 17b are provided that branch from one introduction path 17c and connect to the introduction ports 15a and 15b of the plurality of storage chambers 12a and 12b, respectively. It is being A plurality of discharge passages 18a and 18b are provided which branch from one discharge passage 18c and connect to discharge ports 16a and 16b of the plurality of storage chambers 12a and 12b, respectively. Thereby, the flow rate and flux of the gas supplied to the detection elements 22a to 22h can be made uniform. Therefore, variations in sensitivity of the detection elements 22a to 22h can be suppressed. Note that the discharge passages 18a and 18b may not be combined into one discharge passage 18c, but may be independently opened to the outside.

[Modification 1 of Example 3]
FIG. 11 is a plan view showing the gas flow in Modification 1 of Example 3 in Simulation 4. As shown in FIG. 11, in the first modification of the third embodiment, the angle θ between the extending direction of the grooves 14a and 14b and the extending direction of the inlet passages 17a and 17b, and the angle θ between the extending direction of the grooves 14a and 14b and the extending direction of the discharge passage 18a and The angle θ formed by the stretching direction of 18b is 45 degrees. In the first modification of the third embodiment, the fluxes 50a and 50b form a vortex in the region near the discharge ports 16a and 16b. In this way, in the first modification of the third embodiment, the flow of gas in the storage chambers 12a and 12b becomes unstable.

In Example 3, the angle θ formed by the extending direction of the inlet channels 17a and 17b and the extending direction of the grooves 14a and 14b is approximately 0°, and the extending direction of the outlet channels 18a and 18b and the extending direction of the grooves 14a and 14b is approximately 0°. The angle θ between the two and the respective angles θ is approximately 0°. Thereby, the flow of gas in the storage chambers 12a and 12b becomes stable as shown in FIG. 10. The angle θ is preferably 10° or less, more preferably 5° or less. The length of each of the inlet passages 17a, 17b and the discharge passages 18a and 18b, where the extending direction is approximately the same as that of the grooves 14a and 14b (θ is 10° or less), is equal to the length of the grooves 14a and 14b. 1/10 or more is preferable. Thereby, it is possible to suppress the flow of gas in the storage chambers 12a and 12b from becoming unstable due to the influence of the hook-shaped portions of the introduction channels 17a and 17b and the discharge channels 18a and 18b.

FIG. 12 is a block diagram of a detection device according to the fourth embodiment. As shown in FIG. 12, in the fourth embodiment, a plurality of detection elements 22 are provided within the storage chamber 12. Gas is introduced into the storage chamber 12 through an introduction path 17, and gas is carried out through an exhaust path 18. The configurations of the storage chamber 12 and the detection element 22 are, for example, the same as in Examples 1 to 3. The plurality of measuring devices 30 each measure an output value such as a resonance frequency or a resistance value of the detection element 22. The determination unit 32 determines information such as the type or odor of a substance in the gas based on the output value of the detection element 22 measured by the measuring device 30. The measuring device 30 and the determining section 32 are provided, for example, on the substrate 24 shown in FIGS. 1 to 3(b).

The detection elements 22 have, for example, different configurations of the sensitive parts of the respective detection elements 22, and adsorb different substances in the gas. By determining the odor or the like using the output values of the plurality of detection elements 22, the odor or the like can be determined with higher accuracy.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and variations can be made within the scope of the gist of the present invention as described in the claims. Changes are possible.

10 Housing 11 Top surface 12, 12a, 12b Storage chamber 13 Storage section 14, 14a, 14b Groove 15, 15a, 15b Inlet 16, 16a, 16b Outlet 17, 17a-17c Inlet path 18, 18a-18c Outlet path 20a ~20f, 24 Substrate 21 Lower surface 21a~20f Upper surface 22, 22a~22h Detection element 25 Region 30 Measuring device 32 Judgment section

Claims (14)

a first surface, a second surface opposite to the first surface, an inlet through which a fluid is introduced, an outlet through which the fluid is discharged; a groove extending linearly to a discharge port, the first surface and the second surface facing each other via a cavity in a second region other than the first region of the first surface; room and
a detection element provided on the second surface at a position opposite to the first region;
A detection device comprising: The detection device according to claim 1, wherein a plurality of the detection elements are provided at positions facing the first region on the second surface. The detection device according to claim 1, further comprising a cover provided on the second surface at a position facing the first region and covering another detection element or a sealing body sealing another detection element. a plurality of the storage chambers;
a plurality of introduction paths branching from one introduction path and respectively connected to the introduction ports of the plurality of storage chambers;
a plurality of discharge passages branching from one discharge passage and respectively connected to the discharge ports of the plurality of storage chambers;
The detection device according to claim 1, comprising: comprising an introduction path for introducing the fluid into the introduction port, and a discharge path for discharging the fluid from the discharge port,
The detection device according to any one of claims 1 to 4, wherein the angle between the extending direction of the introduction path and the extending direction of the first region is 10° or less. The distance between the first surface and the second surface in the second region of the storage chamber is 0.1 times the distance between the second surface and a point farthest from the second surface in the first region. The detection device according to any one of claims 1 to 4, which is greater than or equal to 0.9 times or less. Any one of claims 1 to 4, wherein the width of the first region is 0.2 times or more and 5 times or less the distance between the part of the first region farthest from the second surface and the second surface. Detection device according to item 1. comprising a substrate on which the detection element is mounted on a mounting surface;
The detection device according to any one of claims 1 to 4, wherein the second surface is the mounting surface. The detection device according to any one of claims 1 to 4, wherein the fluid is a gas. The detection device according to claim 9, further comprising a determination unit that determines the odor of the gas based on the output value of the detection element. A casing having a lower surface, an upper surface opposite to the lower surface, and a side surface provided from around the upper surface toward the lower surface as an inner wall of a detection space;
a first detection element having a first sensing portion on its upper surface;
The first detection element is bonded to the upper surface, and the lower surface of the detection space has a first pad provided around the first detection element and electrically connected to the first electrode of the first detection element. a first substrate provided in;
Equipped with
The casing is
spaced apart from the first sensing section, overlapping with the first sensing section, and provided on the upper surface of the detection space, one side and the other side of two opposing sides of the upper surface of the detection space. a groove extending upward as a concave portion connecting the two;
an introduction path connected to one end of the groove on the one side of the upper surface of the detection space, provided in the housing outward from the one end of the groove, and into which fluid is introduced;
a discharge path connected to the other end of the groove on the other side of the upper surface of the detection space, provided in the housing outward from the other end of the groove, and through which the fluid is discharged;
has
The detection space is provided continuously with a high back portion, which is a space between the groove and the first substrate, and the side surfaces on both sides in the extending direction of the groove. 1 and a low back portion that is a space between the substrate and the substrate,
A detection device in which a boundary between the high back portion and the low back portion is located so as to sandwich the first detection element. 12. The detection device according to claim 11, wherein the groove is provided linearly, and the cross-sectional shape of the groove is a part of an ellipse or a part of a circle. a second detection element provided with a second sensing portion on its upper surface;
The second detection element is bonded to the upper surface, and the lower surface of the detection space has a second pad provided around the second detection element and electrically connected to the second electrode of the second detection element. a second substrate provided in;
Equipped with
The detection device according to claim 12, wherein the groove is spaced apart from the second sensing section and overlaps with the second sensing section. The first electrode and the first pad are connected by a thin metal wire,
The detection device according to claim 13, wherein the thin metal wire passes through a boundary between the high back portion and the low back portion.

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