CN116165396A

CN116165396A - Fluid detection device, microphone, and electronic apparatus

Info

Publication number: CN116165396A
Application number: CN202111405550.8A
Authority: CN
Inventors: 于媛媛; 李英明; 朱梦尧; 陈家熠; 卢明辉; 许相园
Original assignee: Nanjing University; Huawei Technologies Co Ltd
Current assignee: Nanjing University; Huawei Technologies Co Ltd
Priority date: 2021-11-24
Filing date: 2021-11-24
Publication date: 2023-05-26
Also published as: WO2023093471A1

Abstract

The application provides a fluid detection device, a microphone and electronic equipment, wherein the fluid detection device comprises a substrate, a first electrode pair, a second electrode pair, a heating unit and a sensitive unit, wherein the heating unit and the sensitive unit are arranged in parallel at intervals; the sensing unit comprises a plurality of sensing wires, and the sensing wires are distributed in parallel along the length direction perpendicular to the sensing wires; the multiple sensitive wires are connected in series or in parallel with the positive electrode and the negative electrode of the second electrode pair, and the signal to noise ratio of the fluid detection device can be improved on the premise that the size (such as length, width, thickness and the like) of the sensitive wires is not changed and the working temperature is not required to be improved.

Description

Fluid detection device, microphone, and electronic apparatus

Technical Field

The present disclosure relates to the field of acoustic sensors, and more particularly, to a fluid detection device, a microphone, and an electronic apparatus.

Background

The thermal acoustic vector sensor is used as a fluid detection device, can directly measure the vibration velocity of medium sound field particles by utilizing temperature change, generally consists of three parallel heat resistance wires with a certain interval, wherein the middle heat resistance wire is used as a heating wire, and the heat resistance wires symmetrically arranged at two sides are used as sensitive wires.

The thermal stress of the device (such as a thermal resistance wire) of the thermal acoustic vector sensor at high temperature can cause larger thermal deformation of the device, and even bending and fracture of the device can be caused, so that the reliability of the device is greatly reduced.

In the prior art, in order to ensure the reliability of the device, a device with a larger thickness/length ratio (for example, a heat resistance wire) is generally adopted, but the device with a larger thickness/length ratio can cause the sensitivity of the thermal acoustic vector sensor to be reduced, so that the signal to noise ratio is poor.

It can be seen that the prior art has the problem of poor signal-to-noise ratio of the fluid detection device (e.g., a thermal acoustic vector sensor).

Disclosure of Invention

The purpose of this application is to solve the poor problem of signal to noise ratio of fluid detection device among the prior art. Therefore, the embodiment of the application provides a fluid detection device, a microphone and an electronic device, wherein a plurality of parallel sensitive wires are connected in series or in parallel to a positive electrode and a negative electrode of an electrode pair, and the size (such as length, width, thickness and the like) of the sensitive wires is not changed, so that the fluid detection device can meet the reliability of a device to a certain extent, and meanwhile, the signal-to-noise ratio of the fluid detection device is improved.

The embodiment of the application provides a fluid detection device, which comprises a substrate, a first electrode pair, a second electrode pair, a heating unit and a sensitive unit, wherein the heating unit and the sensitive unit are arranged in parallel at intervals, and the first electrode pair and the second electrode pair are fixed on the substrate; the heating unit is electrically connected with the positive electrode and the negative electrode of the first electrode pair, the sensing unit is electrically connected with the positive electrode and the negative electrode of the second electrode pair, and the sensing unit is used for sensing the ambient temperature of the sensing unit; the sensing unit comprises a plurality of sensing wires, and the sensing wires are distributed in parallel along the length direction perpendicular to the sensing wires; the plurality of sensing wires are connected in series or parallel to the positive and negative electrodes of the second electrode pair.

In this embodiment, the input voltage of the sensing unit is improved by adopting the sensing unit formed by connecting the plurality of sensing wires in series, so that the voltage value output by the sensing unit in the circuit is increased by several times, and the voltage difference between the sensing units is increased by several times. Further, according to the fluid detection device, the plurality of sensitive wires are arranged in parallel, compared with a scheme of serial arrangement, the size of the fluid detection device along the length direction of the sensitive wires can be greatly reduced, and miniaturization of the fluid detection device is facilitated.

In some embodiments, an end of each of the plurality of sensing wires in series, which is not connected to the second electrode pair, is respectively fixed to the substrate.

In some embodiments, the substrate is provided with a channel for fluid flow, the fluid flowing through the sensing unit when the fluid flows within the channel.

The end part of each of the plurality of serially connected sensitive wires, which is not connected with the second electrode pair, is fixed on the substrate, so that the stability of the sensitive wires can be enhanced, and the reliability of the sensitive unit can be improved.

In some embodiments, the heating unit comprises a plurality of heating wires, and the plurality of heating wires are distributed in parallel along a direction perpendicular to the length direction of the heating wires; the plurality of heating wires are connected in series or in parallel to the positive electrode and the negative electrode of the first electrode pair.

In this embodiment, through setting up many heater strips to set up many heater strips side by side, on the one hand, compare in the fluid detection device of single heater strip, under the condition that satisfies the same operating temperature, many heater strips that set up side by side can reduce the temperature of every heater strip to a certain extent, thereby help avoiding the self-fluxing phenomenon of heater strip under the high temperature, on the other hand, compare in the fluid detection device of single heater strip, because the temperature of every heater strip of this embodiment is lower, therefore this embodiment of the application can effectively promote the working sensitivity under the unit consumption of fluid detection device, further, under the prerequisite that the heater strip can normally work (or understand to be guaranteeing fluid detection device's reliability), promote fluid detection device's the highest operating temperature, thereby help promoting fluid detection device's sensitivity and signal to noise ratio.

In some embodiments, an end portion of each of the plurality of heating wires connected in series, to which the first electrode pair is not connected, is fixed to the substrate, respectively.

The end part of each heating wire, which is not connected with the first electrode pair, of the plurality of heating wires after being connected in series is fixed on the substrate, so that the stability of the heating wires can be enhanced, and the reliability of the heating unit is improved.

In some embodiments, the heating unit is multiplexed into another sensing unit, and the heating wire in the heating unit multiplexed into another sensing unit doubles as the sensing wire, and the structure of the heating unit multiplexed into another sensing unit is the same as that of the sensing unit.

In this embodiment, by multiplexing the heating unit as the sensing unit, the structure of the fluid detection apparatus can be simplified, the production cost can be saved, and the miniaturization of the fluid detection apparatus can be facilitated.

In some embodiments, the fluid detection device further includes another sensing unit and a third electrode pair, the third electrode pair is fixed on the substrate, the other sensing unit is electrically connected to the positive electrode and the negative electrode of the third electrode pair, the heating unit, the sensing unit and the other sensing unit are arranged in parallel and at intervals, and the structure of the other sensing unit is the same as the structure of the sensing unit.

In some embodiments, at least a portion of the wire segments of the sensing wire are serrated or wavy, and/or: when the heating unit comprises a plurality of heating wires, at least part of wire sections of the heating wires are in a zigzag shape or a wavy shape.

In some embodiments, a portion of the wire segments of the heating wire are serrated or wavy, and another portion of the wire segments of the heating wire are straight; part of the wire sections of the sensitive wires are saw-tooth-shaped or wave-shaped, and the other part of the wire sections of the sensitive wires are straight.

In this embodiment, at least part of the wire sections of the sensitive wire and/or the heating wire are designed to be zigzag or wavy, and because the zigzag or wavy heating wire/the sensitive wire has higher thermal deformation capability at high temperature, more thermal stress can be released, so that the heating wire and/or the sensitive wire is not easy to bend and break, further, the reliability of the fluid detection device can be effectively improved.

In some embodiments, the fluid detection apparatus further comprises a first support; the first bracket is supported between the sawtooth-shaped or wave-shaped wire sections of two adjacent sensitive wires;

when the heating unit comprises a plurality of heating wires, the fluid detection device further comprises a second support, and the second support is supported between the sawtooth-shaped or wave-shaped wire sections of the two adjacent heating wires.

In this embodiment, through set up first support between two adjacent sensitive silk, set up the second support between two adjacent heater strips can improve the stability between two adjacent sensitive silk, between two adjacent heater strips for heater strip and/or sensitive silk are difficult for buckling, rupture, and then can effectively improve fluid detection device's reliability.

In some embodiments, the first stent comprises a plurality of first stent segments distributed along the length of the sensing wire, each first stent segment being supported between a portion of wire segments of corresponding adjacent two sensing wires;

the second support includes a plurality of second support sections, and a plurality of second support sections are along the length direction distribution of heater strip, and every second support section all supports between the partial silk section of two adjacent two corresponding heater strips.

In some embodiments, the sensing filaments are in a grid-like structure, or, alternatively, a plurality of sensing filaments form a grid-like structure; and/or:

when the heating unit comprises a plurality of heating wires, the heating wires are in a grid-like structure, or the plurality of heating wires form the grid-like structure.

In this embodiment, since the grid-shaped sensing wire/heating wire has a larger thermal deformation capability, more thermal stress can be released at a higher working temperature, and the sensing wire/heating wire is not easy to break, so that the reliability of the sensing wire/heating wire can be improved.

In some embodiments, a first beam structure is connected between the plurality of sensing wires along a direction perpendicular to the length of the sensing wires; and/or: when the heating unit comprises a plurality of heating wires, a second beam structure is connected between the plurality of heating wires along the length direction perpendicular to the heating wires.

In some embodiments, a third beam structure is connected between the sensing unit and the heating unit along the length direction perpendicular to the sensing wire;

in some possible embodiments, a beam structure is connected between some of the plurality of sensing wires along a direction perpendicular to the length of the sensing wires; when the heating unit comprises a plurality of heating wires, a beam structure is connected between part of the heating wires in the plurality of heating wires along the length direction perpendicular to the heating wires.

In this embodiment, through set up crossbeam structure between the sensitive silk, between the heater strip, between sensitive unit and the heating unit, can improve the stability between the sensitive silk, between the heater strip and between heater strip and the sensitive silk for the heater strip and/or sensitive silk are difficult for buckling, and then can effectively improve fluid detection device's reliability.

In some embodiments, the spacing between two adjacent sensing filaments in a sensing unit is greater than or equal to 1 μm and less than or equal to 10 μm; and/or:

when the heating unit includes a plurality of heating wires, a distance between two adjacent heating wires is greater than or equal to 1 μm and less than or equal to 10 μm.

Embodiments of the present application provide a microphone comprising a fluid detection device as provided in any one of the above embodiments or any one of the possible embodiments.

In some possible embodiments, the microphone further includes a power supply module, a noise filtering module, and a signal processing module, the power supply end of the fluid detection device is electrically connected to the power supply module, the signal output end of the fluid detection device is electrically connected to the input end of the noise filtering module, so as to obtain a processed electrical signal through processing of the noise filtering module, and the output end of the noise filtering module is electrically connected to the input end of the signal processing module, so as to amplify the processed electrical signal through the signal processing module and output the amplified electrical signal.

An embodiment of the present application provides an electronic device comprising a microphone provided in any one of the above embodiments or any one of the possible embodiments.

Drawings

FIG. 1a is a schematic structural diagram of a fluid detection device according to an embodiment of the present application, in which a plurality of sensing wires are connected in series;

FIG. 1b is a schematic structural diagram of a fluid detection device according to an embodiment of the present application, in which a plurality of sensing wires are connected in parallel;

FIG. 1c is a schematic perspective view of a fluid detection apparatus according to an embodiment of the present application, wherein a plurality of sensing wires are connected in parallel;

FIG. 2a is a schematic structural diagram of a fluid detection apparatus according to an embodiment of the present application, in which a plurality of sensing wires are connected in series and a plurality of heating wires are connected in series;

FIG. 2b is a schematic structural diagram of a fluid detection device according to an embodiment of the present application, in which a plurality of sensing wires are connected in parallel and a plurality of heating wires are connected in parallel;

FIG. 2c is a schematic perspective view of a fluid detection apparatus according to an embodiment of the present application, wherein a plurality of sensing wires are connected in parallel and a plurality of heating wires are connected in parallel;

fig. 3a is a schematic structural diagram of a fluid detection device according to an embodiment of the present application, wherein a plurality of heating wires are connected in series and a plurality of sensing wires are connected in series;

fig. 3b is a schematic structural diagram of the fluid detection apparatus according to the embodiment of the present application when the heating wires are used as sensing wires, wherein a plurality of heating wires are connected in parallel and a plurality of sensing wires are connected in parallel;

FIG. 3c is a schematic structural diagram of a fluid detection apparatus according to an embodiment of the present application, wherein the number of sensing units is 4, and the number of heating units is 1;

FIG. 3d is a schematic perspective view of a fluid detection apparatus according to an embodiment of the present application, wherein the number of sensing units is 4, and the number of heating units is 1;

FIG. 4 is a graph showing frequency response curves of sensing units of a fluid sensing apparatus according to an embodiment of the present disclosure when different numbers of sensing wires are used;

FIG. 5 is a schematic structural diagram of a fluid detection device according to an embodiment of the present application, wherein both the sensing wire and the heating wire are saw-toothed;

FIG. 6 is a schematic structural diagram of a fluid detecting device according to an embodiment of the present application, wherein a portion of the sensing wire is saw-toothed and another portion of the sensing wire is linear; part of the wire sections of the heating wire are in a saw-tooth shape, and the other part of the wire sections are in a straight line shape;

FIG. 7 is a schematic structural diagram of a fluid detection device according to an embodiment of the present application, wherein both the sensing wire and the heating wire are wavy;

FIG. 8 is a schematic structural diagram of a fluid detection device according to an embodiment of the present application, wherein a first beam structure is connected between a plurality of sensing wires of a sensing unit;

FIG. 9 is a schematic structural diagram of a fluid detection device according to an embodiment of the present application, wherein a first beam structure is connected between a plurality of sensing wires, a second beam structure is connected between a plurality of heating wires, and a third beam structure is connected between a heating unit and a sensing unit;

FIG. 10 is a schematic structural view of a fluid detection apparatus according to an embodiment of the present application, wherein both the sensing wires and the heating wires are in a grid structure;

FIG. 11 is a schematic diagram of a mesh-like structure of a fluid detection apparatus according to an embodiment of the present application;

fig. 12a is a schematic diagram of a system configuration of a microphone according to an embodiment of the present application;

fig. 12b is a schematic circuit diagram of a microphone according to an embodiment of the present application;

fig. 13a is a schematic structural diagram of a fluid detection device according to an embodiment of the present application, where the number of sensing wires is 3 and 3 sensing wires are connected in parallel, and the number of heating wires is 3 and 3 heating wires are connected in parallel;

fig. 13b is a schematic diagram of an equivalent circuit of a microphone according to an embodiment of the present application, in which a plurality of sensing wires are connected in parallel;

Fig. 14a is a schematic structural diagram of a fluid detection device according to an embodiment of the present application, wherein the number of the sensing wires is 3 and the 3 sensing wires are connected in series, and the number of the heating wires is 3 and the 3 heating wires are connected in series;

fig. 14b is a schematic diagram of an equivalent circuit of a microphone according to an embodiment of the present application, in which a plurality of sensing wires are connected in series;

fig. 15 is an equivalent circuit schematic diagram of a microphone according to an embodiment of the present application, where the number of sensing units is 4, and the number of heating units is 1.

Reference numerals illustrate:

1: a fluid detection device;

101: a first beam structure; 102: a beam structure; 11: a sensitive unit; 111: a sensitive wire; 11A: a sensitive unit; 111A: a sensitive wire; 112: a first bracket; 1121: a first bracket section; 12: a heating unit; 121: a heating wire; 122: a second bracket; 1221: a second bracket section; 13: a sensitive unit; 131: a sensitive wire; 13A: a sensitive unit; 131A: a sensitive wire; 141: a positive electrode; 142: a negative electrode; 151: a positive electrode; 152: a negative electrode; 153 positive electrode; 154: a negative electrode; 161: a positive electrode; 162: a negative electrode; 163: positive electrode: 164: a negative electrode; 17: a substrate; 171: a first base portion; 172: a second base portion; 173: a third base portion;

2: a microphone;

21: a noise filtering module; 22: a signal processing module; 23: a power supply module;

R0、R1、R2、R3、R4、R5、R6、R ₁₁ 、R _11A 、R ₁₃ 、R _13A : a resistor; c: a capacitor; a: an amplifier; v+: a power supply end; vout: an output end;

l: and a length direction.

Detailed Description

Further advantages and effects of the present application will be readily apparent to those skilled in the art from the present disclosure, by describing embodiments of the present application with specific examples. While the description of the present application will be presented in conjunction with some embodiments, it is not intended that the features of this application be limited to only this embodiment. Rather, the purpose of the description presented in connection with the embodiments is to cover other alternatives or modifications, which may be extended by the claims based on the present application. The following description contains many specific details in order to provide a thorough understanding of the present application. The present application may be practiced without these specific details. Furthermore, some specific details are omitted from the description in order to avoid obscuring the focus of the application. It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other.

It should be noted that in this specification, like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the description of the present application, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of description of the present application and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art in a specific context.

In the description of the present application, it should be understood that "electrically connected" in the present application may be understood as components in physical contact and in electrical conduction; it is also understood that the various components in the wiring structure are connected by physical wires such as printed circuit board (printed circuit board, PCB) copper foil or leads that carry electrical signals. "communication connection" may refer to transmission of electrical signals, including wireless communication connections and wired communication connections. The wireless communication connection does not require physical intermediaries and does not belong to a connection relationship defining the product architecture.

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

Referring to fig. 1a to 1c, fig. 1a is a schematic structural diagram of a fluid detection apparatus according to an embodiment of the present application, in which a plurality of sensing wires are connected in series; fig. 1b is a schematic structural diagram of a fluid detection device according to an embodiment of the present application, in which a plurality of sensing wires are connected in parallel, and fig. 1c is a schematic structural diagram of a fluid detection device according to an embodiment of the present application, in which a plurality of sensing wires are connected in parallel.

As shown in fig. 1a to 1c, the embodiment of the present application provides a fluid detection apparatus 1, which includes a substrate 17, a first electrode pair, a second electrode pair, and a heating unit 12 and a sensing unit 11 arranged in parallel at intervals. The first electrode pair (including the positive electrode 141 and the negative electrode 142) and the second electrode pair (including the positive electrode 151 and the negative electrode 152) are each fixed to the substrate 17 (including a first substrate portion 171 and a second substrate portion 172 mentioned later). The positive electrode is understood to be the electrode connected to the positive electrode of the power supply, the negative electrode is understood to be the electrode connected to the negative electrode of the power supply, if the power supply is dc, the positive electrode is understood to be the electrode of the live wire, and the negative electrode is understood to be the electrode connected to the neutral wire.

In some embodiments, the first electrode pair and the second electrode pair may be fixed to the substrate 17 through an electrode insulating layer fixed to the substrate 17 (including the first substrate portion 171 and the second substrate portion 172), and in other embodiments, may be fixed to the substrate 17 through other manners. The material of the electrode insulating layer is not limited, and in one example, the electrode insulating layer may be silicon dioxide (SiO ₂ ) In other examples, silicon nitride (Si ₃ N ₄ ) Aluminum nitride (AlN), aluminum oxide (Al) ₂ O ₃ ) Etc.

As shown in fig. 1a to 1c, the substrate 17 is provided with a channel for fluid to flow, when the fluid flows in the channel, the fluid flows through the sensing unit (for example, the sensing unit 11 and the sensing unit 13 mentioned later), in other embodiments, when the fluid flows in the channel, the fluid may also flow through the sensing unit (for example, the sensing unit 11 and the sensing unit 13 mentioned later) and the heating unit 12, in one embodiment, the substrate 17 may include a first substrate portion 171 and a second substrate portion 172 which are disposed at intervals, and the first substrate portion 171 and the second substrate portion 172 may be independent from each other, the space formed by the first substrate portion 171 and the second substrate portion 172 disposed at intervals forms the channel for fluid to flow, and the sensing unit 11 and the heating unit 12 are connected across the first substrate portion 171 and the second substrate portion 172 of the substrate 17. In other embodiments, the substrate may be two parts formed on the same component, for example, in some embodiments, the substrate 17 is provided with grooves (not shown), the sensing unit 11 and the heating unit 12 are connected across two sidewalls in the grooves, one of the two sidewalls in the grooves may be understood as a first substrate part, the other of the two sidewalls in the grooves may be understood as a second substrate part, and the space in the grooves forms a channel for fluid flow. In other embodiments, the substrate 17 may have other structures, as long as the electrode pairs (e.g., the first electrode pair, the second electrode pair) can be fixed and the sensing unit 11 and the heating unit 12 can be electrically connected to the corresponding electrode pairs, without departing from the scope of the present embodiment. The material of the substrate 17 is not limited, and may be, for example, a silicon substrate, or may be any other material in other embodiments, and the present application is not limited thereto.

The heating unit 12 is electrically connected to the positive electrode 141 and the negative electrode 142 of the first electrode pair, and the sensing unit 11 is electrically connected to the positive electrode 151 and the negative electrode 152 of the second electrode pair. Specifically, the heating unit 12 includes at least one heating wire 121, one end of the heating wire 121 is connected to the positive electrode 141 of the first electrode pair, the other end is connected to the negative electrode 142 of the first electrode pair, and the heating wire 121 is used for generating heat after being electrified so as to meet the working temperature of the fluid detection device. In the present embodiment, the number of the heating wires 121 is 1, and in other embodiments, the number of the heating wires 121 may be plural.

In one embodiment, the heating wire 121 includes a heating wire metal layer electrically connected to the positive electrode 141 and the negative electrode 142 of the first electrode pair for generating heat upon energization. The material of the metal layer of the heating wire is not limited, and may be a material with high thermal conductivity, such as a metal wire, highly doped silicon, or the like, or may be a metal composite laminate, such as a composite laminate of platinum, cadmium, or silicon nitride group, or may be other materials in other embodiments. In one embodiment, the heating wire 121 further includes a heating wire insulation layer for supporting the heating wire metal layer and fixing the heating wire to the substrate (e.g. the first substrate portion 171 or the second substrate portion 172), and the heating wire insulation layer is not limited, and may be silicon dioxide (SiO ₂ ) In other examples, silicon nitride (Si ₃ N ₄ ) Aluminum nitride (AlN), aluminum oxide (Al) ₂ O ₃ ) Etc.

The sensing unit 11 is used for sensing the temperature of the environment where the sensing unit 11 is located, and the sensing unit 11 can change the temperature of the sensing unit 11 when the fluid flows through and output corresponding electric signals, wherein the electric signals change along with the change of the temperature of the sensing unit 11. The sensing unit 11 includes a plurality of sensing wires 111, and the plurality of sensing wires 111 are arranged in parallel along a length direction L perpendicular to the sensing wires. Reference herein to "perpendicular" includes substantially perpendicular, i.e., offset by an angle, e.g., 0.1 °, 0.5 °, 1 °, etc., in a direction L perpendicular to the length of the sensing wire. The plurality of sensing wires 111 are connected in series or parallel to the positive electrode 151 and the negative electrode 152 of the second electrode pair. The number of sensing wires is not limited, and in one embodiment, the number of sensing wires is 5, and in other embodiments, other numbers are also possible. The distance between any two adjacent sensing wires in the plurality of sensing wires 111 can be the same or different, the sensing wires 111 are used for sensing the particle vibration velocity, a high thermal resistivity material such as a thermal resistance wire is generally adopted, and according to the thermal resistance effect, the thermal resistance wire has the characteristic of changing the resistance value along with the self temperature, so that the thermal resistance wire can respond to the fluid flowing in the environment to generate temperature change, and an electric signal corresponding to the resistance value such as a voltage change value is output by changing the self resistance value. In other examples, the sensing wire 111 may be other devices, as long as the device is capable of changing its temperature and outputting a corresponding electrical signal when the fluid flows therethrough, without departing from the scope of the present embodiment. Further, the shape of the sensing wire 111 and the heating wire 121 may be linear, or may be other shapes, such as zigzag, wave, spring, etc., or may be a composite of linear and other shapes.

In one embodiment, the sensing wire 111 includes a sensing wire metal layer electrically connected to the positive electrode 151 and the negative electrode 152 of the second electrode pair for sensing a temperature change. The material of the sensitive wire metal layer is not limited, and may be a high thermal resistivity material, for example, a composite stack of platinum, cadmium and silicon nitride groups, and in other embodiments, may be other materials. In one embodiment, the sensing wire 111 further includes a sensing wire insulation layer for supporting the sensing wire metal layer and fixing the sensing wire to the substrate (e.g., the first substrate portion 171 or the second substrate portion 172), and the sensing wire insulation layer is not limited, and may be silicon dioxide (SiO ₂ ) In other examples, silicon nitride (Si ₃ N ₄ ) Aluminum nitride (AlN), aluminum oxide (Al) ₂ O ₃ ) Etc.

Further, the sizes of the heating wires and the sensing wires are not limited, and as long as the above functional requirements can be satisfied, the thicknesses of the sensing wires and the heating wires are generally 0.3 μm in an exemplary embodiment, wherein the metal layer is 0.1 μm, the insulating layer is 0.2 μm, the length of each sensing wire 111 of the sensing unit 11 and each heating wire 121 of the heating unit 12 is 0.5mm-2mm, generally 1mm, and the width is 0.5 μm-2 μm.

Furthermore, the distance between the sensing unit 11 and the heating unit 12 is typically less than 500 μm.

Further, the distance between two adjacent sensing wires 111 in the sensing unit 11 of the fluid detection apparatus according to the embodiment of the present application is greater than or equal to 1 μm and less than or equal to 10 μm, for example, 1 μm,2 μm,5 μm,10 μm, etc., and the distance between two adjacent heating wires 121 is less than or equal to 10 μm, and because the distance is small, all the heating wires and all the sensing wires are simultaneously operated when the fluid is disturbed. However, the interval is not too small, and when the interval is too small, the processing is difficult, and the phenomenon that adjacent heating wires or adjacent sensitive wires are adhered together can occur. The interval is also not suitable to be too large, and when the interval is too large, the frequency response characteristics of adjacent sensitive wires or adjacent heating wires are inconsistent, so that all the heating wires and all the sensitive wires cannot work simultaneously.

It will be appreciated by those skilled in the art that there are at least two sensing units, and in some embodiments, the two sensing units may be two sensing units that operate independently, and in other embodiments, one of the two sensing units is a sensing unit that operates independently, and the other sensing unit is a sensing unit that is multiplexed by a heating unit, and the specific structure will be understood later.

As shown in fig. 1a and 1b, the fluid detecting apparatus 1 further includes a third electrode pair (including a positive electrode 161 and a negative electrode 162) fixed to the substrate 17, wherein the positive electrode 161 of the third electrode pair is fixed to the first substrate portion 171, the negative electrode 162 of the third electrode pair is fixed to the second substrate portion 172, and the structure and the fixing manner of the third electrode pair are similar to those of the first electrode pair and the second electrode pair, which are not described herein again. The number of the sensitive units is 2, namely the

sensitive units

11 and 13, and the

sensitive units

11 and 13 are distributed on two sides of the heating unit 12, and the distance between the

sensitive units

11 and 12 and the distance between the

sensitive units

13 and 12 can be the same or different. In other alternative embodiments, the sensing unit 11 and the sensing unit 13 may be located on the same side of the heating unit 12, where the sensing unit 11 is electrically connected to the positive electrode 151 of the second electrode pair and the negative electrode 152 of the second electrode pair, the sensing unit 13 is electrically connected to the positive electrode 161 of the third electrode pair and the negative electrode 162 of the third electrode pair, the sensing unit 11 has a plurality of sensing wires 111, the sensing unit 13 has a plurality of sensing wires 131, and in one embodiment, the number of sensing wires in the sensing unit 11 and the sensing unit 13 is 5, and in other embodiments, other numbers, such as 3, 7, etc., are also possible.

The structures and the number of the sensing wires in the

sensing units

11 and 13 are the same, so that the same resistance variation of the two sensing units is ensured and the resistance variation is only related to the vibration speed of the acoustic particles. Wherein, the same structure can be specifically understood as: if the plurality of sensing wires 111 in the sensing unit 11 adopts the above-mentioned serial structure, the plurality of sensing wires 131 in the sensing unit 13 also adopts the same serial structure, and the number of the plurality of sensing wires 131 is the same as the number of the plurality of sensing wires 111, and if the plurality of sensing wires 111 in the sensing unit 11 adopts the above-mentioned parallel structure, the plurality of sensing wires 131 in the sensing unit 13 also adopts the same parallel structure, and the number of the plurality of sensing wires 131 is the same as the number of the plurality of sensing wires 111.

It is understood that thermal stress refers to the internal stress of a structure due to a temperature change, and thermal deformation refers to the expansion or contraction deformation of a structure due to a temperature change.

The signal-to-noise ratio refers to the ratio of signal to noise in dB in an electronic device or system. The signal-to-noise ratio can also be expressed by the ratio of the power of the output signal to the power of the noise output simultaneously, the higher the signal-to-noise ratio of the device indicating that it produces less noise and a higher sound quality.

Sensitivity is understood to be the ability to convert a fluid disturbance to an electrical signal, for example, a thermal acoustic vector sensor, and refers to the ability of a thermal acoustic vector sensor to convert a fluid disturbance, which is disturbed by acoustic waves (or, alternatively, by acoustic pressure), to an electrical signal in dBV. The higher the sensitivity, the better the performance of the characterization sensor.

Self-fluxing phenomenon: the material breaks due to self-heating effect (self-heating effect), which is a phenomenon in which the operating current is too high to raise the internal temperature.

The fluid detection device provided by the application can be applied to various scenes of detecting the flow speed and the flow rate of fluid such as aerospace, biochemical detection and medical instruments, in one implementation mode, the fluid among the sensitive units can vibrate under the disturbance of sound wave incidence, when the fluid in the fluid detection device adopts gas such as air, particles (or particles) in the air vibrate to transmit sound waves, and at the moment, the fluid detection device can be used as a thermal acoustic vector sensor.

In an exemplary operation of the thermal acoustic vector sensor, the heating unit 12 provides an operating temperature of the thermal acoustic vector sensor, at the operating temperature, when an acoustic wave is incident to the thermal acoustic vector sensor, particles in fluid (such as air, water, castor oil, etc.) between the sensing units vibrate reciprocally to form forced convection heat transfer, so that heat of one sensing unit is transferred to another sensing unit, causing a change in temperature between the sensing units, for example, in fig. 1b, the acoustic wave S1 is incident from an arrow direction, the fluid between the disturbance sensing unit 11 and the sensing unit 13 causes convection heat transfer between the sensing unit 11 and the sensing unit 13, at this time, the temperature of the sensing unit 11 is reduced, that is, a change in temperature between the sensing unit 11 and the sensing unit 13 occurs in opposite directions, and then, resistance values of sensing wires 111 in the sensing unit 11 and sensing wires 131 in the sensing unit 13 change with the temperature, for example, the temperature of the sensing unit 11 is reduced, the resistance values of the sensing wires 111 in the sensing unit 13 are reduced, the temperature of the sensing unit 13 is increased, and the resistance values of the sensing wires 131 are converted into the change in the sense signal by converting the resistance values of the two sensing wires into the change in the voltage.

In another example working process, the sound wave S2 is incident from the direction indicated by the arrow, the fluid between the sensitive unit 11 and the sensitive unit 13 is disturbed to cause convection heat transfer between the sensitive unit 11 and the sensitive unit 13, at this time, the temperature of the sensitive unit 13 is reduced, the temperature of the sensitive unit 11 is increased, that is, the temperature between the sensitive unit 11 and the sensitive unit 13 is changed in the opposite direction, further, the resistance value of each sensitive wire 111 in the sensitive unit 11 and each sensitive wire 131 in the sensitive unit 13 is changed along with the temperature, for example, the temperature of the sensitive unit 11 is increased, so that the resistance value of each sensitive wire 111 in the sensitive unit 11 is increased, the temperature of the sensitive unit 13 is reduced, so that the resistance value of each sensitive wire 131 in the sensitive unit 13 is reduced, and the change of the resistance values of the two sensitive units is converted into voltage change through a circuit to output, thereby realizing the process of converting the sound signal into the electric signal.

When the sound wave is incident to cause air disturbance and cause temperature change of the sensitive wire 111 (for example, heat resistance wire), the temperature change value is Δt, and Δt can be calculated by the following formula:

wherein f: the frequency of the sound wave;

v, particle vibration speed;

p: total power of the sensitive wire;

k: thermal conductivity of the fluid;

ly: the sensitive silk thread is long;

d: the thermal diffusivity of the fluid;

a: the distance between the sensitive wire and the heating wire;

gamma: euler constant, γ=0.577;

l: the width of the sensitive wire metal layer;

h: the thickness of the sensitive wire metal layer;

(ρcp) air: air density and specific heat capacity;

(ρcp) sensor: the product of the density of the sensing yarn and the specific heat capacity of the sensing yarn;

f _hc characterizing the inflection point of-3 dB frequency caused by parameters such as sensitive wire size, heat capacity and the like;

f _D : -3dB frequency inflection point caused by parameters such as air thermal diffusion coefficient and the like.

The-3 dB frequency inflection point is understood to be the frequency of the thermal acoustic vector sensor when the sensitivity is-3 dB, wherein the thermal acoustic vector sensor can meet the normal use requirement when the sensitivity is within-3 dB.

Further, the change of the resistance values of the

sensing units

11 and 13 further causes the change of the voltage difference between the sensing

units

11 and 13, the voltage difference Deltau ₀ In proportion to the temperature change value DeltaT, the voltage difference Deltau ₀ Can be used for characterizing the sensitivity of the thermal acoustic vector sensor, the voltage difference Deltau ₀ The method can be calculated by the following formula:

wherein V: a bias voltage;

v: particle vibration velocity;

alpha: thermal resistivity.

It can be appreciated that the voltage difference Deltau ₀ The larger the sensitivity of the characterization thermal acoustic vector sensor is, the better the performance is, and the larger the output voltage difference is under the condition that the noise is unchanged, the higher the signal-to-noise ratio of the thermal acoustic vector sensor is, because the signal-to-noise ratio can be represented by the ratio of the power of the output signal to the noise power which is output simultaneously.

According to the embodiment of the application, the input voltage of the sensitive unit is improved through the multi-sensitive-wire serial structure, so that the voltage difference between the sensitive units is increased by several times, and the voltage difference is related to the sensitivity of the fluid detection device (such as the thermal acoustic vector sensor), so that the sensitivity and the signal-to-noise ratio of the fluid detection device can be improved on the premise that the size (such as the length, the width and the thickness) of the sensitive wires are not changed and the working temperature is not improved, the reliability of the device is not influenced, the improvement of performance (including the sensitivity and the signal-to-noise ratio) is realized, the sensitive unit is formed by connecting the multi-sensitive wires in parallel, the bottom noise (or the thermal noise) of the fluid detection device (such as the thermal acoustic vector sensor) can be effectively reduced, and the signal-to-noise ratio of the fluid detection device is improved. Further, according to the fluid detection device, the plurality of sensitive wires are arranged in parallel, compared with a scheme of serial arrangement, the size of the fluid detection device along the length direction of the sensitive wires can be greatly reduced, and miniaturization of the fluid detection device is facilitated.

Further, referring to fig. 1a, the end of each sensing wire 111 of the plurality of sensing wires 111 connected in series, which is not connected to the second electrode pair, is fixed to the substrate 17, or can be understood as: each sensing wire 111 of the plurality of sensing wires 111 overlaps the substrate 17 with a sensing wire segment connected to an adjacent sensing wire 111. It may be directly attached to the substrate 17 or indirectly attached to the substrate 17 by an attachment bracket. Specifically, in the left-to-right direction in fig. 1a, one end of the first sensing wire of the plurality of sensing wires 111 after being connected in series, which is close to the positive electrode 151 of the second electrode pair, is electrically connected to the positive electrode 151 of the second electrode pair, one end of the positive electrode 151, which is far from the second electrode pair, is connected to the second sensing wire 111 and is fixed on the second substrate portion 172 of the substrate 17, one end of the last sensing wire 111 of the plurality of sensing wires 111 after being connected in series, which is close to the negative electrode 152 of the second electrode pair, is electrically connected to the negative electrode 152 of the second electrode pair, and one end of the negative electrode 152, which is far from the second electrode pair, is connected to the previous sensing wire 111 and is fixed on the first substrate portion 171 of the substrate 17.

According to the embodiment of the application, the end part of each of the plurality of serially connected sensing wires 111, which is not connected with the second electrode pair, is fixed on the substrate (for example, the first substrate part 171 or the second substrate part 172), so that the stability of the sensing wires 111 can be enhanced, and the reliability of the sensing unit 11 can be improved.

Referring to fig. 1b and 1c, in the plurality of parallel sensing wires 111, two ends of each sensing wire 111 are electrically connected to corresponding electrodes, and meanwhile, two ends of each sensing wire 111 are further fixed to a substrate (for example, a first substrate portion 171 and a second substrate portion 172), which may be directly fixed to the substrate through a sensing wire insulating layer, or may be fixed to the substrate 17 through a sensing wire insulating layer and the electrode insulating layer mentioned above, in other embodiments, other fixing manners may also be used, so long as two ends of each sensing wire in the plurality of parallel sensing wires are fixed to the substrate 17, without departing from the scope of the present embodiment.

Referring to fig. 2a to fig. 2c, fig. 2a is a schematic structural diagram of a fluid detection device according to an embodiment of the present application, in which a plurality of sensing wires 111 are connected in series and a plurality of heating wires 121 are connected in series, fig. 2b is a schematic structural diagram of a fluid detection device according to an embodiment of the present application, in which a plurality of sensing wires 111 are connected in parallel and a plurality of heating wires 121 are connected in parallel, and fig. 2c is a schematic structural diagram of a fluid detection device according to an embodiment of the present application, in which a plurality of heating wires are connected in parallel 121 and a plurality of sensing wires 111 are connected in parallel.

Further, referring to fig. 2a, the heating unit 12 includes a plurality of heating wires 121, and the plurality of heating wires 121 are arranged in parallel along a length direction L perpendicular to the heating wires; the plurality of heating wires 121 are connected in series or parallel to the positive electrode 141 and the negative electrode 142 of the first electrode pair.

By arranging the plurality of heating wires 121 and arranging the plurality of heating wires 121 in parallel, on one hand, compared with a fluid detection device with a single heating wire, the temperature of each heating wire can be reduced to a certain extent by the plurality of heating wires 121 arranged in parallel under the condition of meeting the same working temperature, so that the self-melting phenomenon of the heating wires at high temperature can be avoided, on the other hand, compared with the fluid detection device with a single heating wire, on the premise of meeting the same working temperature, the working sensitivity of the fluid detection device per unit power consumption can be effectively improved, or on the premise of meeting certain sensitivity requirements, the power consumption of the thermal acoustic vector sensing heating unit is smaller; further, under the premise that the heating wire can work normally (or under the premise that the reliability of the fluid detection device is guaranteed), the highest working temperature of the fluid detection device is improved, and therefore the sensitivity and the signal-to-noise ratio of the fluid detection device are improved.

Further, referring to fig. 2a, the end of each of the plurality of heating wires 121 connected in series, to which the first electrode pair is not connected, is fixed to the substrate (the first substrate portion 171 or the second substrate portion 172), respectively, or can be understood as: each of the plurality of heating wires 121 overlaps the substrate (the first substrate portion 171 or the second substrate portion 172) with the heating wire segment of the adjacent heating wire 121. Specifically, along the direction from right to left in fig. 2a, one end of the first heating wire 121 of the plurality of heating wires 121 connected in series, which is close to the positive electrode 141 of the first electrode pair, is electrically connected to the positive electrode 141 of the first electrode pair, one end of the positive electrode 141 of the plurality of heating wires 121, which is far from the first electrode pair, is connected to the second heating wire 121 and is fixed on the second substrate portion 172 of the substrate, one end of the last heating wire 121 of the plurality of heating wires 121 connected in series, which is close to the negative electrode 142 of the first electrode pair, is electrically connected to the negative electrode 142 of the first electrode pair, one end of the negative electrode 142, which is far from the first electrode pair, is connected to the previous heating wire 121 and is fixed on the first substrate portion 171 of the substrate, and by fixing the end of each heating wire 121 connected in series, which is not connected to the first electrode pair, on the substrate, the stability of the heating wire can be enhanced, and the reliability of the heating unit can be improved.

Referring to fig. 3a to 3b, fig. 3a is a schematic structural view of a heater wire of the fluid detection device according to the embodiment of the present application, and fig. 3b is a schematic structural view of the heater wire of the fluid detection device according to the embodiment of the present application, wherein the structure of the fluid detection device 1 shown in fig. 3a is substantially the same as that of fig. 1a, and the structure of the fluid detection device shown in fig. 3b is substantially the same as that of fig. 1b, and the difference is that: in the fluid detecting apparatus 1 shown in fig. 3a and 3b, the sensing unit 13 and the third electrode pair are omitted, the heating unit 12 includes a plurality of heating wires 121, and the heating unit 12 may be multiplexed into another sensing unit, and the heating wires 121 in the heating unit 12 may also be used as sensing wires of the other sensing unit.

It should be noted that, when the heating unit 12 is not multiplexed into another sensing unit, the plurality of heating wires in the heating unit 12 may have the same structure as the sensing unit 11, or may have a structure different from the sensing unit 11, for example, the plurality of heating wires in the heating unit 12 may have the same number as the plurality of sensing wires 111 in the sensing unit 11, or may have a different number, and the plurality of heating wires in the heating unit 12 may be connected in series to the positive electrode 141 and the negative electrode 142 of the first electrode pair, or may be connected in parallel to the positive electrode 141 and the negative electrode 142 of the first electrode pair. When the heating unit 12 is multiplexed as another sensing unit, the heating unit 12 should have the same structure as the sensing unit 11, and the number of the heating wires 121 should be the same as the number of the sensing wires 111. It will be appreciated by those skilled in the art that when the heating unit 12 is multiplexed into another sensitive unit, the material of the heating wire may be selected to have both high thermal resistivity and high thermal conductivity. In the embodiment shown in fig. 3a, the number of sensing wires in the sensing unit 11 is 5, and 5 sensing wires are connected in series to the positive electrode 151 and the negative electrode 152 of the second electrode pair, the number of heating wires in the heating unit 12 (multiplexed into another sensing unit) is 5, and 5 heating wires 121 are connected in series to the positive electrode 141 and the negative electrode 142 of the first electrode pair, in the embodiment shown in fig. 3b, the number of sensing wires in the sensing unit 11 is 5, and 5 sensing wires are connected in parallel to the positive electrode 151 and the negative electrode 152 of the second electrode pair, the number of heating wires in the heating unit 12 (multiplexed into another sensing unit) is 5, and 5 heating wires 121 are connected in parallel to the positive electrode 141 and the negative electrode 142 of the first electrode pair.

It will be appreciated by those skilled in the art that the embodiments of the present application may be combined, for example, when the heating unit 12 is not multiplexed into another sensing unit, and when there are multiple heating wires in the heating unit 12, no matter what connection manner is adopted for the sensing wires in the sensing units (for example, the sensing unit 11 and the sensing unit 13), the heating wires may be connected in series, or may be connected in parallel.

By multiplexing the heating unit 12 as a sensitive unit, the structure of the fluid detection apparatus 1 can be simplified, the production cost can be saved, and the miniaturization of the fluid detection apparatus 1 can be facilitated.

Further, please refer to fig. 3c and fig. 3d, wherein fig. 3c is a schematic structural diagram of the fluid detection apparatus according to an embodiment of the present application, and fig. 3d is a schematic structural diagram of the fluid detection apparatus according to an embodiment of the present application; wherein, the number of the sensing units is 4, the number of the heating units is 1, the structure of the fluid detection device shown in fig. 3c and 3d is basically the same as that of fig. 1b, and the difference is that:

the fluid detection apparatus 1 further includes a fourth electrode pair (including a positive electrode 153 and a negative electrode 154), a fifth electrode pair (including a positive electrode 163 and a negative electrode 164), further includes a sensing unit 11A and a sensing unit 13A, and the substrate 17 further includes a third substrate portion 173. The

sensing units

11A and 13A are arranged in parallel and are connected across the second substrate portion 172 and the third substrate portion 173, the sensing unit 11A is electrically connected to the positive electrode 153 and the negative electrode 154 of the fourth electrode pair, and the sensing unit 13A is electrically connected to the positive electrode 163 and the negative electrode 164 of the fifth electrode pair. The sensing wire structures and the number of the

sensing units

11A and 13A are the same as those of the sensing units 11. The

sensing units

11A and 13A are distributed on both sides of the heating unit 12, and in other embodiments, may be located on the same side of the heating unit 12. In the present embodiment, the number of the heating wires 121 of the heating unit 12 is one, and in other embodiments, the number of the heating wires 121 may be plural, for example, 3, 5, 7, or the like.

The four sensing units share one heating unit 12, wherein sensing unit 11A and sensing unit 13A may be understood as one sensing unit group and sensing unit 11 and sensing unit 13 may be understood as another sensing unit group. When fluid flows through each sensitive unit group, heat transfer occurs between the two sensitive units in each sensitive unit group, so that the temperature change of each sensitive unit is caused, the resistance value of the sensitive wire in each sensitive unit changes along with the temperature change, and the resistance value change of each sensitive wire in the two sensitive unit groups is converted into voltage change through a circuit and output.

According to the embodiment of the application, the sensing unit 11, the sensing unit 13, the sensing unit 11A and the sensing unit 13A are utilized, the Wheatstone full-bridge differential output on the circuit structure is constructed, so that the output voltage difference of the fluid detection device is multiplied, and the sensitivity of the fluid detection device is effectively improved.

The application performs performance detection analysis on the fluid detection devices of the 3-wire structure sensitive unit, the 5-wire structure sensitive unit and the 11-wire structure sensitive unit respectively and obtains a frequency response curve shown in fig. 4 and a performance improvement analysis table shown in the following table 1;

TABLE 1

It should be noted that, 3 line structures are a reference design structure of a fluid detection device, it has a heater strip and 2 sensitive wires, 5 line structures are the structure of a fluid detection device in this application embodiment, its sensitive unit 11 is two, 2 sensitive wires have in every sensitive unit and 2 sensitive wires are established ties, the heating unit is 1, the heating unit has 1 heater strip, 7 line structures are the structure of a fluid detection device in another embodiment of this application, its sensitive unit 11 is two, have 3 sensitive wires and 3 sensitive wires are established ties in every sensitive unit, the heating unit has 1 heater strip.

Referring to fig. 4, fig. 4 is a frequency response curve of a sensing unit of the fluid detection apparatus according to the embodiment of the present application when different numbers of sensing wires are used. In fig. 4, the abscissa indicates frequency in Hz, and the ordinate indicates sensitivity in dBV. It should be understood that background noise, also known as background noise, generally refers to the total noise in an electroacoustic system, except for the useful signal.

As can be seen from fig. 4 and table 1, the bottom noise of the 7-wire structure is about 5dBV, the bottom noise of the 11-wire structure is about 7dBV, the signal to noise ratio of the 7-wire structure is improved by about 10dB, the signal to noise ratio of the 11-wire structure is improved by about 12dB, the signal to noise ratio of the 7-wire structure is improved by about 7dB, the sensitivity is improved by about 12dBV, the signal to noise ratio of the 11-wire structure is improved by about 9dB, the sensitivity is improved by about 16dBV, the signal to noise ratio of the 7-wire structure is improved by about 3dB, the sensitivity is improved by about 8dBV, the signal to noise ratio of the 11-wire structure is improved by about 3dB, and the sensitivity is improved by about 10dBV, when the frequency is 10 kHz.

Further, at least part of the wire sections of the sensitive wire are in a zigzag shape or a wavy shape, and at least part of the wire sections of the heating wire are in a zigzag shape or a wavy shape. Wherein at least part of the wire segments can be understood as: only part of the wire sections are saw-tooth-shaped or wavy, or the whole wire sections are saw-tooth-shaped or wavy.

Referring to fig. 5, fig. 5 is a schematic structural diagram of a fluid detection apparatus according to an embodiment of the present application, and the structure of the fluid detection apparatus 1 shown in fig. 5 is substantially the same as that of fig. 2b, wherein the number of the sensing wires 111 of the sensing unit is two, the number of the heating wires in the heating unit is 2, and the sensing wires 111 and the heating wires 121 are all in a zigzag shape. In other embodiments, the number of the sensing wires 111 in the sensing unit may be more than 2, and the number of the heating wires may be more than 1 or 2.

In one embodiment, when the fluid detection apparatus further comprises another sensing unit 13, the sensing wire 131 in the sensing unit 13 is also serrated.

By designing at least part of the wire sections of the sensing wires (e.g. the sensing wires 111, 131) and/or the heating wires 121 to be saw-tooth-shaped or wave-shaped, the saw-tooth-shaped or wave-shaped heating wires/sensing wires have higher thermal deformation capability at high temperature, so that more thermal stress can be released, the maximum thermal stress of the heating wires/sensing wires is reduced, the heating wires and/or the sensing wires are not easy to bend and break, and the reliability of the fluid detection device can be effectively improved.

In other alternative embodiments, the plurality of sensing wires 111 may be interwoven to form a grid structure, if the heating unit 12 has the plurality of heating wires 121, the plurality of heating wires 121 may also be interwoven to form a grid structure, and since the grid-shaped sensing wires/heating wires have a larger thermal deformation capability, more thermal stress can be released at a higher working temperature, and the sensing wires/heating wires are not easy to break, so that the reliability of the sensing wires/heating wires can be improved, and meanwhile, the contact area between the sensing wires/heating wires and air is increased under the same cross-sectional area due to the design of the grid structure, which is beneficial to heat exchange between the sensing units/heating units, thereby helping to improve the signal-to-noise ratio of the fluid detection device.

Referring to fig. 6, fig. 6 is a schematic structural diagram of a fluid detection apparatus according to an embodiment of the present application, and the structure of the fluid detection apparatus 1 shown in fig. 6 is substantially the same as that of fig. 5, except that: part of the wire sections of the sensitive wire 111 are saw-tooth-shaped, and the other part of the wire sections are linear; the part of the wire sections of the heating wire 121 are in a zigzag shape, the other part of the wire sections are in a straight line shape, specifically, the part of the wire sections of the sensitive wire 111 close to the electrodes (such as the positive electrode 151 and the negative electrode 152) are in a zigzag shape, the part of the wire sections far away from the electrodes (such as the positive electrode 151 and the negative electrode 152) are in a straight line shape, and likewise, the part of the wire sections of the heating wire 121 close to the electrodes (such as the positive electrode 141 and the negative electrode 142) are in a zigzag shape, and the part of the wire sections far away from the electrodes (such as the positive electrode 141 and the negative electrode 142) are in a straight line shape. In one embodiment, when the fluid detection apparatus further includes another sensing unit 13, the sensing wire 131 in the sensing unit 13 adopts the same structure as the sensing wire 111 in the present embodiment.

The sensitive wire (for example, the sensitive wire 111 and the sensitive wire 131) and the heating wire 121 in the embodiment of the application adopt a serrated or wavy and linear composite structure, on one hand, the maximum thermal stress of the sensitive wire/the heating wire can be reduced through the serrated or wavy wire sections, so that the reliability of the fluid detection device is improved, and on the other hand, the excessive thermal deformation (which causes serious deviation of a device from design parameters and further reduces the sensitivity) of the heating wire/the sensitive wire can be avoided through the linear wire sections, so that the sensitivity of the fluid detection device is not affected.

Further, referring to fig. 7, fig. 7 is a schematic structural diagram of a fluid detection apparatus according to an embodiment of the present application, and the structure of the fluid detection apparatus 1 shown in fig. 7 is substantially the same as that of fig. 5, except that: the sensing wire 111 and the heating wire 121 are both wavy, and further, the fluid detection device 1 further includes a first bracket 112; the first support 112 is supported between the zigzag or wavy wire sections of the two adjacent sensitive wires 111, the first support 112 is arranged along the length direction perpendicular to the sensitive wires 111, a bamboo-like structure is formed between the first support 112 and the two adjacent sensitive wires 111, when the heating unit 12 comprises a plurality of heating wires 121, the fluid detection device 1 further comprises a second support 122, the second support 122 is supported between the zigzag or wavy wire sections of the two adjacent heating wires 121, the second support 122 is arranged along the length direction perpendicular to the heating wires 121, and a bamboo-like structure is formed between the second support 122 and the two adjacent heating wires 121.

In one embodiment, the first support 112 includes a plurality of first support segments 1121, where the plurality of first support segments 1121 are distributed along the length direction L of the sensing wire, and each first support segment 1121 is supported between the zigzag or wavy wire segments of the corresponding adjacent two sensing wires 111; the second support 122 includes a plurality of second support sections 1221, where the plurality of second support sections 1221 are distributed along the length direction L of the heating wires, and each second support section 1221 is supported between the zigzag or wavy wire sections of the corresponding adjacent two heating wires. In one embodiment, when the fluid detection apparatus further includes another sensing unit 13, the sensing wire 131 in the sensing unit 13 adopts the same structure as the sensing wire 111 in the present embodiment.

According to the embodiment of the application, the first support is arranged between the two adjacent sensitive wires, the second support is arranged between the two adjacent heating wires, and stability between the two adjacent sensitive wires and between the two adjacent heating wires can be improved, so that the heating wires and/or the sensitive wires are not easy to bend and break, and further reliability of the fluid detection device can be effectively improved.

It should be noted that, the embodiments of the present application may be freely combined, for example, the sensing wires in the sensing unit and the heating wires in the heating unit may take the same shape, or may take different shapes, and the plurality of sensing wires in the same sensing unit and the plurality of heating wires in the same heating unit may take the same shape, or may take different shapes.

Further, referring to fig. 8 to 9, fig. 8 and 9 are schematic structural views of a fluid detection apparatus according to an embodiment of the present application, and the structure of the fluid detection apparatus 1 shown in fig. 8 and 9 is substantially the same as that of fig. 2b, except that: along the length direction (direction M indicated by an arrow in fig. 8) perpendicular to the sensing wires 111, a first beam structure 101 is connected between the plurality of sensing wires 131, in one embodiment, when the heating unit 12 includes a plurality of heating wires 121, a second beam structure (not shown in the figure) is connected between the plurality of heating wires 121 along the length direction (direction M indicated by an arrow in fig. 8) perpendicular to the heating wires 121, in one embodiment, a third beam structure (not shown in the figure) is connected between the sensing unit 11 and the heating unit 12 along the length direction (direction M indicated by an arrow in fig. 8) perpendicular to the sensing wires, and a third beam structure (not shown in the figure) is connected between the sensing unit 13 and the heating unit 12. In one embodiment, the plurality of beam structures may be an integral body, forming the beam structure 102 as shown in fig. 9, and in other embodiments, the plurality of beam structures may be disposed independently, for example, the plurality of beam structures may be disposed in parallel but not in a staggered manner on the same straight line. Further, the beam structure may be connected only between some of the sensing wires or only between some of the heating wires.

According to the embodiment of the application, the beam structures are arranged among the sensitive wires 111, among the sensitive wires 131, among the heating wires 121, among the

sensitive units

11 and 12, among the sensitive units 13 and among the heating units, so that stability among the sensitive wires 111, among the sensitive wires 131, among the

heating wires

121 and 111, among the heating wires 121 and among the sensitive wires 131 is improved, and among the

heating wires

121 and 131, the heating wires 121, the

sensitive wires

111 and 131 are not easy to bend and break, and reliability of the fluid detection device is further effectively improved.

Further, referring to fig. 10 to 11, fig. 10 is a schematic structural view of a fluid detection apparatus according to an embodiment of the present application, and fig. 11 is a schematic grid-like structure of the fluid detection apparatus according to an embodiment of the present application.

In one embodiment, the fluid detection apparatus 1 includes a substrate (including a first substrate portion 171 and a second substrate portion 172), a first electrode pair (including a positive electrode 141 and a negative electrode 142), a second electrode pair (including a positive electrode 151 and a negative electrode 152), a third electrode pair (including a positive electrode 161 and a negative electrode 162), and heating units 12, sensing units 11, and sensing units 13 arranged in parallel and spaced apart.

The first electrode pair (including the positive electrode 141 and the negative electrode 142) and the second electrode pair (including the positive electrode 151 and the negative electrode 152) and the third electrode pair (positive electrode 161 and the negative electrode 162) are each fixed to the substrate 17, specifically, the positive electrode 141 of the first electrode pair, the positive electrode 151 of the second electrode pair and the positive electrode 161 of the third electrode pair are each fixed to the first substrate portion 171, and the negative electrode 142 of the first electrode pair, the negative electrode 152 of the second electrode pair and the negative electrode 162 of the third electrode pair are each fixed to the second substrate portion 172.

In one embodiment, the

sensing units

11 and 13 are distributed on two sides of the heating unit 12, and in other embodiments, the

sensing units

11 and 13 may be distributed on the same side of the heating unit 12.

The heating unit comprises at least one heating wire 121, the sensing unit 11 comprises at least one sensing wire 111, the sensing unit 13 comprises at least one sensing wire 131, and the sensing wire 111, the sensing wire 131 and the heating wire 121 are in hollow grid structures.

In this embodiment, the number of sensing wires of the sensing unit 11 and the sensing unit 13 is one, the number of heating wires of the heating unit 12 is 1, in other embodiments, the number of sensing wires of each sensing unit may be multiple, for example, 3, 5, 7, etc., and the number of heating wires of the heating unit may be multiple, for example, 3, 5, 7, etc.

It should be noted that: the number of sensing wires in the sensing unit 11 and the sensing unit 13 is the same. The number of heating wires 121 in the heating unit 12 may be the same as or different from the

sensing units

11 and 13.

The first electrode pair, the second electrode pair, and the third electrode pair may be fixed to the substrate 17 by interlayer insulation of electrodes fixed to the substrate 17 (including the first substrate portion 171 and the second substrate portion 172), but may be fixed to the substrate 17 by other means in other embodiments. The material of the electrode insulating layer is not limited, and in one example, the electrode insulating layer may be silicon dioxide (SiO ₂ ) In other examples, silicon nitride (Si ₃ N ₄ ) Aluminum nitride (AlN), aluminum oxide (Al) ₂ O ₃ ) Etc.

In one embodiment, the heating wire 121 includes a heating wire metal layer having a hollow grid structure, and the heating wire metal layer is electrically connected to the positive electrode 141 and the negative electrode 142 of the first electrode pair, for generating heat after being electrified. The material of the metal layer of the heating wire is not limited, and may be a material with high thermal conductivity, such as a metal wire, highly doped silicon, or the like, or may be a metal composite laminate, such as a composite laminate of platinum, cadmium, or silicon nitride group, or may be other materials in other embodiments.

In one embodiment, the heating wire 121 further includes a heating wire insulation layer for supporting the heating wire metal layer and fixing the heating wire to the substrate (e.g. the first substrate portion 171 or the second substrate portion 172), and the heating wire insulation layer is not limited, and may be silicon dioxide (SiO ₂ ) In other examples, silicon nitride (Si ₃ N ₄ ) Aluminum nitride (AlN), aluminum oxide (Al) ₂ O ₃ ) Etc.

The

sensing wires

111 and 131 each include a sensing wire metal layer having a hollow lattice structure, and the sensing wire metal layer is electrically connected to a corresponding positive electrode and a corresponding negative electrode for sensing a temperature change. The corresponding positive electrode and the corresponding negative electrode are specifically: the sensing wire 111 is electrically connected to the positive electrode 151 and the negative electrode 152 of the second electrode pair, and the sensing wire 131 is electrically connected to the positive electrode 161 and the negative electrode 162 of the third electrode pair. The material of the sensitive wire metal layer is not limited, and may be a high thermal resistivity material, for example, a composite stack of platinum, cadmium and silicon nitride groups, and in other embodiments, may be other materials.

In one embodiment, the sensing wire 111 further includes a sensing wire insulation layer for supporting the sensing wire metal layer and fixing the sensing wire to the substrate (e.g. the first substrate portion 171 or the second substrate portion 172), and the sensing wire insulation layer is not limited, and may be silicon dioxide (SiO ₂ ) In other examples, silicon nitride (Si ₃ N ₄ ) Aluminum nitride (AlN), aluminum oxide (Al) ₂ O ₃ ) Etc.

Further, the sizes of the heating wires and the sensing wires are not limited, and as long as the above functional requirements can be satisfied, the thickness of the sensing wires and the heating wires is generally 0.3 μm, wherein the metal layer is 0.1 μm, the insulating layer is 0.2 μm, the length of each sensing wire 111 or each heating wire 121 of the sensing unit 11 and the heating unit 12 is 0.5-2mm, generally 1mm, and the width is 0.5-2 μm in an exemplary embodiment.

Further, when there are a plurality of heating wires and/or there are a plurality of sensing wires, the distance between two adjacent sensing wires 111 in the sensing unit 11 of the fluid detection device according to the embodiment of the present application is greater than or equal to 1 μm and less than or equal to 10 μm, and the distance between two adjacent heating wires 121 is less than or equal to 10 μm, and due to the smaller distance, all the heating wires and all the sensing wires are operated simultaneously when the fluid is disturbed. However, the interval is not too small, and when the interval is too small, the processing is difficult, and the phenomenon that adjacent heating wires or adjacent sensitive wires are adhered together can occur. The interval is also not suitable to be too large, and when the interval is too large, the frequency response characteristics of adjacent sensitive wires or adjacent heating wires are inconsistent, so that all the heating wires and all the sensitive wires cannot work simultaneously.

Further, in one embodiment, the fluid detecting apparatus 1 may eliminate the sensing unit 13 and the third electrode pair, the heating unit 12 is used as the sensing unit, and the heating wire 121 in the heating unit 12 is used as the sensing wire.

According to the embodiment of the application, the sensitive wires and the heating wires are designed into the grid-shaped structure, so that the sensitive wires and the heating wires have larger thermal deformation capacity, further more thermal stress can be released at a higher working temperature, and the sensitive wires and the heating wires are not easy to break, so that reliability is improved.

Further, when the heating wire and/or the sensing wire has a plurality of sensing wires, the plurality of sensing wires are distributed in parallel along the length direction perpendicular to the sensing wires, and the plurality of sensing wires may be connected to the corresponding electrode pair, for example, in series, or may be connected to the corresponding electrode pair, for example, in parallel, if the fluid detection device of the embodiment of the present application has a plurality of sensing units (for example, the sensing units 11 and 13), the plurality of sensing wires in the sensing unit 11 and the plurality of sensing wires in the sensing unit 13 should adopt the same structure, the number of sensing wires, and the spacing between the sensing wires, so as to ensure that the resistance variation amounts of the two sensing units are the same and only related to the acoustic particle vibration velocity.

In one embodiment, the plurality of heating wires are arranged in parallel in a direction perpendicular to the length direction of the heating wires, and the plurality of heating wires may be connected to the first electrode pair in series, for example, or may be connected to the first electrode pair in parallel, for example.

In one embodiment, the end of each of the plurality of sensing wires connected in series, which is not connected to the electrode pair, is fixed to the substrate 17, and taking the plurality of sensing wires 111 connected in series as an example, each sensing wire 111 of the plurality of sensing wires 111 is overlapped with the sensing wire segment connected to the adjacent sensing wire 111 to be connected to the substrate 17. It may be directly overlapped with the substrate 17 or indirectly overlapped with the substrate 17 through an overlapped bracket, and it can be understood that: if the plurality of heating wires are connected in series, the plurality of heating wires can also be lapped on the substrate by adopting the structure, and if the fluid detection device also comprises other sensitive units (such as the sensitive unit 13), the plurality of sensitive wires are arranged in the other sensitive units, and the plurality of sensitive wires in the other sensitive units can also be lapped on the substrate by adopting the structure.

According to the embodiment of the application, the plurality of sensitive wires are adopted to connect in series to form the sensitive unit, so that the input voltage of the sensitive unit is improved through the multi-sensitive wire serial structure, the voltage value output by the sensitive unit in a circuit is increased by several times, the voltage difference between the sensitive units is increased by several times, the sensitivity and the signal-to-noise ratio of the fluid detection device are improved on the premise that the size (such as the length, the width and the thickness) of the sensitive wires are not changed, the working temperature is not required to be improved, the plurality of sensitive wires are adopted to connect in parallel to form the sensitive unit, the bottom noise (or the thermal noise) of the fluid detection device can be effectively reduced, and the signal-to-noise ratio of the fluid detection device is improved.

Further, the embodiment of the application can reduce the temperature of each heating wire to a certain extent by adopting a plurality of heating wires which are arranged side by side, thereby being beneficial to avoiding the self-fluxing phenomenon of the heating wires at high temperature, and simultaneously, compared with a fluid detection device with a single heating wire, under the premise of meeting the same working temperature, the working sensitivity and the signal-to-noise ratio of the fluid detection device under unit power consumption can be effectively improved due to the fact that the temperature of each heating wire of the embodiment of the application is lower.

Referring to fig. 12a, fig. 12a is a schematic diagram of a system structure of a microphone according to an embodiment of the present application, and the present application further provides a microphone 2, including the fluid detection device 1 according to any one of the foregoing embodiments. The microphone 2 further comprises a power supply module 23, a noise filtering module 21 and a signal processing module 22.

Referring to fig. 12b, fig. 12b is a schematic circuit diagram of a microphone according to an embodiment of the present application, a power supply end v+ of the fluid detection device is electrically connected to a power supply module (not shown in the drawings), a signal output end of the fluid detection device 1 is electrically connected to an input end of the noise filtering module 21, so as to obtain a processed electrical signal through processing by the noise filtering module 21, and an output end of the noise filtering module 21 is electrically connected to an input end of the signal processing module 22, so as to amplify the processed electrical signal through the signal processing module 22 and output the amplified electrical signal through an output end Vout of the microphone. The noise filtering module 21 may be implemented by, for example, a capacitor C, and the signal processing module 22 may be implemented by, for example, an amplifier a and two auxiliary resistors R0 connected to the output of the amplifier. Further, the microphone may further include a speaker module electrically connected to the signal processing module 22 to output or play sound.

Referring to fig. 13a to 13b, fig. 13a is a schematic structural view of a fluid detection apparatus according to an embodiment of the present application, and the structure of the fluid detection apparatus shown in fig. 13a is substantially the same as that of fig. 3b, except that: the number of the sensitive wires is 3 and the 3 sensitive wires are connected in parallel, and the number of the heating wires is 3 and the 3 heating wires are connected in parallel. Fig. 13b is a schematic diagram of an equivalent circuit of a microphone according to an embodiment of the present application, and the microphone shown in fig. 13b employs the fluid detection apparatus 1 shown in fig. 13 a. The resistances of the 3 sensing wires 111 can be represented by a resistor R1, a resistor R2, and a resistor R3, and the resistances of the 3 heating wires 121 can be represented by a resistor R4, a resistor R5, and a resistor R6. In the present embodiment, the heating unit 12 is multiplexed as a sensing unit, and the heating wire 121 also serves as a sensing wire.

In this embodiment, the wheatstone half-bridge principle is adopted to perform differential detection on an electrical signal to obtain an output voltage difference Δu, a resistor R0 is an auxiliary resistor in a wheatstone half-bridge circuit, when the microphone works, sound waves are incident to enable temperatures of the sensing unit 11 and the heating unit 12 (which also serves as the sensing unit) to change inversely, for example, the temperature of the sensing unit 11 is reduced, the temperature of the heating unit 12 is increased, then the resistance of the sensing unit 11 is reduced, the resistance of the heating unit 12 is increased, and a voltage difference Δu between the sensing unit 11 and the heating unit 12 is further acquired through an amplifier a, namely Δu=u2-U1 is amplified and then is output through an output end Vout, and Δ U, U2 and U1 can be calculated by the following formula:

Wherein U1 represents the output voltage of the sensing unit 11, U2 represents the output voltage of the heating unit 12, Δu represents the voltage difference between the output voltage of the sensing unit 11 and the output voltage of the heating unit 12;

because the structures and the numbers of the sensitive wires in the sensitive unit 11 and the heating wires in the heating unit 12 are the same, R represents the resistance value of a single sensitive wire (or a single heating wire) before the incidence of the sound wave, n represents the number of the sensitive wires in the sensitive unit 11, n represents the number of the heating wires in the heating unit 12, in the embodiment, n=3, and in the embodiment, the resistance value of the resistor R0 is R/n; Δr represents the resistance change value of each sensitive wire 111 after the sound wave is incident, and also represents the resistance change value of each heating wire 121 after the sound wave is incident;

V ₊ characterizing a supply voltage of the fluid detection device;

n characterizes the background noise (or alternatively, thermal noise) of the fluid detection device;

K _B is Boltzmann constant, K _B ＝1.38×10 ^-23 J/K；

T is the temperature of the fluid detection device;

it can be seen that the embodiments of the present application can reduce the noise floor (or thermal noise) of the fluid detection device

Doubling the signal-to-noise ratio of the fluid detection device and thereby increasing +. >

Multiple times.

Referring to fig. 14a to 14b, fig. 14a is a schematic structural view of a fluid detection apparatus according to an embodiment of the present application, and the structure of the fluid detection apparatus shown in fig. 14a is substantially the same as that of fig. 3a, except that: the number of the sensitive wires is 3 and the 3 sensitive wires are connected in series, and the number of the heating wires is 3 and the 3 heating wires are connected in series. Fig. 14b is a schematic diagram of an equivalent circuit of a microphone according to an embodiment of the present application, and the microphone shown in fig. 14b employs the fluid detection apparatus 1 shown in fig. 14 a. The resistances of the 3 sensing wires 111 can be represented by a resistor R1, a resistor R2, and a resistor R3, and the resistances of the 3 heating wires 121 can be represented by a resistor R4, a resistor R5, and a resistor R6. The resistor R0 is an auxiliary resistor constituting a wheatstone half-bridge circuit, and in this embodiment, the heating unit 12 is multiplexed as a sensing unit, and the heating wire 121 also serves as a sensing wire.

When the microphone works, the sound wave incidence causes the temperature of the sensitive unit 11 and the heating unit 12 to change inversely, for example, the temperature of the sensitive unit 11 decreases, the temperature of the heating unit 12 (also used as the sensitive unit) increases, and then the resistance of the sensitive unit 11 decreases, the resistance of the heating unit 12 increases, the voltage difference Δu between the sensitive unit 11 and the heating unit 12 is further collected by the amplifier a, that is, Δu=u2-U1, and is output through the output terminal Vout after being amplified, and Δ U, U2, U1 can be calculated by the following formula:

because the structures and the numbers of the sensitive wires in the sensitive unit 11 and the heating wires in the heating unit 12 are the same, R represents the resistance value of a single sensitive wire (or a single heating wire) before the sound wave is incident, n represents the number of the sensitive wires of the sensitive unit 11, n represents the number of the heating wires in the heating unit 12, in the embodiment, n=3, and in the embodiment, the resistance value of the resistor R0 is nR; Δr represents the resistance change value of each sensitive wire 111 after the sound wave is incident, and also represents the resistance change value of each heating wire 121 after the sound wave is incident;

V ₊ characterizing the power supply voltage of each sensitive wire of the fluid detection device;

K _B is Boltzmann constant, K _B ＝1.38×10 ^-23 J/K；

T is the temperature of the fluid detection device;

it can be seen that, in comparison with the conventional fluid detection device, the input voltage of each sensing wire is ensured to be unchanged (in this case, the total input voltage is nV ₊ ) According to the embodiment of the application, the output voltage difference DeltaU of the fluid detection device can be improved by n times, so that the sensitivity is improved by n times, and meanwhile, the background noise (or can be understood as thermal noise) is reduced

Doubling, thereby improving the signal-to-noise ratio>

Multiple times.

Fig. 15 is an equivalent circuit schematic diagram of a microphone according to an embodiment of the present application, and the structure of the fluid detection device is shown in fig. 3c and 3d. Wherein the number of the sensitive units is 4, and the number of the heating units is 1. The total resistance of the sensor unit 11 can be defined by R ₁₁ The total resistance of the sensitive unit 13 can be characterized by R ₁₃ The total resistance of the sensitive cell 11A can be characterized by R _11A The resistance of the sensitive unit 13A can be characterized by R _13A To characterize.

In this embodiment, the sensing unit 11, the sensing unit 13, the sensing unit 11A and the sensing unit 13A are used to construct a wheatstone full bridge circuit, and the wheatstone full bridge principle is adopted to perform electric signal differential detection so as to obtain the output voltage difference Δu. The output voltages of the sensing unit 11 and the sensing unit 13A and the voltage difference Δu between the output voltages of the sensing unit 13 and the sensing unit 11A are further collected by the amplifier a, that is, Δu=u2-U1 is amplified and then output through the output terminal Vout, and Δ U, U2, U1 may be calculated by the following formula:

Wherein U1 represents the output voltages of the sensing unit 11 and the sensing unit 13A, U2 represents the output voltages of the sensing unit 13 and the sensing unit 11A, deltaU represents the output voltages of the sensing unit 11 and the sensing unit 13A, and the voltage difference between the output voltages of the sensing unit 13 and the sensing unit 11A;

because the sensitive wires in the

sensitive units

11, 13, 11A and 13A all adopt the same structure and number, R simultaneously represents the resistance values of the

sensitive wires

111, 111A, 131 and 131A before the incidence of the sound wave, and DeltaR represents the resistance change value of each sensitive wire after the incidence of the sound wave;

V ₊ characterizing a supply voltage of the fluid detection device;

therefore, it can be seen that, according to the embodiment of the present application, the output voltage difference Δu of the fluid detection device is improved by two times compared with the fluid detection device illustrated in fig. 13b, and thus, the sensitivity and the signal-to-noise ratio of the fluid detection device are improved by two times.

Further, the microphone provided in the embodiments of the present application may be, for example, a microphone, which may be disposed in an electronic device, and specifically, the microphone may include a circuit board for carrying the above circuit, and further includes a microphone housing, a mems chip, and a functional integrated circuit chip, where the microphone housing is disposed on the microphone circuit board and forms a microphone cavity with the microphone circuit board. The micro-electromechanical system chip and the functional integrated circuit chip are arranged in the microphone cavity, and the microphone circuit board can be arranged on the electronic equipment circuit board and electrically connected with the electronic equipment circuit board. In other embodiments, the microphone may have other structures, which the present application is not limited to.

The application also provides electronic equipment comprising the microphone related to the embodiments. The electronic device may be, for example, a smart television, a smart speaker, a smart large screen conference system, a smart car, and so forth.

For example, the electronic device provided by the embodiment of the application scene of the smart television needs to pick up sound, 8-shaped pointing pickup can be performed through the microphone, sound on the front side and the back side of the smart television, such as voice, is collected, and the electronic device is suitable for scenes such as man-machine voice conversations.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present application without departing from the spirit or scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims and the equivalents thereof, the present application is intended to cover such modifications and variations.

Claims

1. A fluid detection device comprises a substrate, a first electrode pair, a second electrode pair, a heating unit and a sensing unit which are arranged in parallel at intervals, wherein the first electrode pair and the second electrode pair are fixed on the substrate; the heating unit is electrically connected with the positive electrode and the negative electrode of the first electrode pair, the sensitive unit is electrically connected with the positive electrode and the negative electrode of the second electrode pair, and the sensitive unit is used for sensing the ambient temperature where the sensitive unit is positioned; the method is characterized in that:

The sensing unit comprises a plurality of sensing wires, and the sensing wires are distributed in parallel along the length direction perpendicular to the sensing wires; the plurality of sensing wires are connected in series or parallel to the positive and negative electrodes of the second electrode pair.

2. The fluid detection apparatus according to claim 1, wherein:

and the end part of each of the plurality of sensing wires which are connected in series and are not connected with the second electrode pair is respectively fixed on the substrate.

3. A fluid detection apparatus according to claim 1 or claim 2, wherein the substrate is provided with a channel for fluid flow, the fluid flowing through the sensing unit when the fluid flows within the channel.

4. A fluid detection apparatus according to any one of claims 1 to 3, wherein the heating unit includes a plurality of heating wires arranged in parallel in a direction perpendicular to a length direction of the heating wires; the plurality of heating wires are connected in series or in parallel to the positive electrode and the negative electrode of the first electrode pair.

5. The fluid detection device of claim 4, wherein ends of each of the plurality of heater wires connected in series, which are not connected to the first electrode pair, are respectively fixed to the substrate.

6. The fluid detection apparatus according to claim 4 or 5, wherein the heating unit is multiplexed as another sensing unit, a heating wire in the heating unit multiplexed as the other sensing unit doubles as a sensing wire, and a structure of the heating unit multiplexed as the other sensing unit is the same as that of the sensing unit.

7. The fluid detection apparatus according to any one of claims 1 to 5, further comprising another sensing unit and a third electrode pair, the third electrode pair being fixed to the substrate, the other sensing unit being electrically connected to a positive electrode and a negative electrode of the third electrode pair, the heating unit, the sensing unit, and the other sensing unit being arranged in parallel at a spacing, and the structure of the other sensing unit being identical to that of the sensing unit.

8. The fluid detection device of any one of claims 1-7, wherein at least a portion of the wire segments of the sensing wire are serrated or wavy; and/or:

when the heating unit comprises a plurality of heating wires, at least part of wire sections of the heating wires are in a zigzag shape or a wavy shape.

9. The fluid detection device of claim 8, wherein a portion of the wire section of the heating wire is saw-tooth-shaped or wave-shaped, and another portion of the wire section of the heating wire is linear; a part of the wire sections of the sensitive wire are in a zigzag shape or a wavy shape, and the other part of the wire sections of the sensitive wire are in a straight line shape.

10. The fluid detection apparatus according to claim 8 or 9, wherein the fluid detection apparatus further comprises a first bracket; the first support is supported between the sawtooth-shaped or wave-shaped wire sections of two adjacent sensitive wires; and/or:

11. The fluid detection device of claim 10, wherein the first support comprises a plurality of first support segments distributed along a length of the sensing wire, each first support segment being supported between the partial wire segments of corresponding adjacent two sensing wires;

the second support comprises a plurality of second support sections, the second support sections are distributed along the length direction of the heating wires, and each second support section is supported between the partial wire sections of the corresponding adjacent two heating wires.

12. The fluid detection apparatus according to any one of claims 1 to 7, wherein the sensing filaments are in a grid-like structure, or the plurality of sensing filaments form a grid-like structure; and/or:

When the heating unit comprises a plurality of heating wires, the heating wires are in a grid structure, or the plurality of heating wires form a grid structure.

13. The fluid detection apparatus according to any one of claims 1 to 11, wherein a first beam structure is connected between the plurality of sensing wires in a direction perpendicular to a length direction of the sensing wires; and/or:

when the heating unit comprises a plurality of heating wires, a second beam structure is connected between the plurality of heating wires along the length direction perpendicular to the heating wires.

14. A fluid sensing apparatus according to any one of claims 1 to 13, wherein a third beam structure is connected between the sensing unit and the heating unit in a direction perpendicular to the length of the sensing wire.

15. A fluid detection apparatus according to any one of claims 1 to 14, wherein:

the distance between two adjacent sensitive wires in the sensitive unit is more than or equal to 1 mu m and less than or equal to 10 mu m; and/or:

16. A microphone comprising a fluid detection device according to any one of claims 1 to 15.

17. An electronic device comprising the microphone of claim 16.