A multi-channel array integrated gas sensing module

Abstract

This invention discloses a multi-channel array integrated gas sensing module. The gas sensing module adopts a three-dimensional stacked structure, divided into an interface layer, a circuit layer, and a sensing layer. The circuit layer and the sensing layer are physically isolated by a sealing partition. The sensing layer includes a multi-channel gas sensing array and a pre-gas path cavity. The multi-channel gas sensing array includes several pairs of sensing units. The circuit layer includes a multi-select analog switch array, an instrumentation amplifier, an analog-to-digital converter, and a communication interface chip connected in sequence. The gas outlet of the pre-gas path cavity faces the sensitive surface of each sensing chip. The differential signal output terminal of each sensing unit pair is connected to the input terminal of the multi-select analog switch array. The communication interface chip is connected to the electrical contacts of the interface layer. The multi-select analog switch switches sequentially according to a preset order, turning on each sensing unit in turn to the instrumentation amplifier. Based on this, this invention achieves miniaturized integration and high signal-to-noise ratio output.

Description

Technical Field

[0001] This invention relates to the field of electrochemical energy storage safety monitoring technology, specifically to a multi-channel array integrated gas sensing module. Background Technology

[0002] In electrochemical energy storage systems, lithium-ion batteries release characteristic gases in the early stages of thermal runaway. Sensing chips based on transition metal-doped two-dimensional materials are used for thermal runaway early warning due to their high sensitivity to these characteristic gases. However, the integration from sensing chips to practically deployable sensing modules faces the following challenges at the integration level:

[0003] (1) Signal crosstalk problem in multi-channel integration. To cover a variety of characteristic gases, multiple sensing channels need to be integrated in a single module. The spacing between the sensing chips of each channel is limited, and electromagnetic coupling and power conduction crosstalk between channels cause mutual interference of signals.

[0004] (2) The transmission path of weak signals is too long. The original signal output by the sensor chip is a weak current in the nanoampere range. If the distance between the sensor chip and the subsequent amplifier circuit is too far, the noise coupled along the transmission path will drown out the effective signal.

[0005] (3) Interference between functional areas within the module. The gas sensing unit needs to be in contact with the gas to be measured, the signal processing circuit needs to be kept clean, and the power supply and communication interface need to be connected to the outside. If there is no clear physical isolation between the three, trace components in the gas may come into contact with the circuit, and power supply noise may interfere with weak signals.

[0006] (4) Limited in-situ installation space. The internal space of the energy storage battery cabinet is compact, requiring the sensor module to be small in size, with standardized interfaces and easy to install and disassemble.

[0007] Existing gas sensing modules mostly adopt a split architecture, with the gas path, sensing chip, circuit board, and communication board placed in different housings and connected by ribbon cables. This results in large size, long wiring, and poor anti-interference ability. Summary of the Invention

[0008] To overcome the shortcomings of existing technologies, such as signal crosstalk, excessively long weak signal transmission paths, mutual interference between functional areas within the module, and limited in-situ installation space, this invention provides a gas sensing module with multi-channel array integration. Through layered layout of internal functional areas, sensor-reference differential topology, multi-channel scanning switching, and standardized electrical interface, it achieves miniaturized integration and high signal-to-noise ratio output.

[0009] According to one aspect of this specification, a multi-channel array integrated gas sensing module is provided. The gas sensing module adopts a three-dimensional stacked structure, which is divided into an interface layer, a circuit layer, and a sensing layer from bottom to top. The circuit layer and the sensing layer are physically isolated by a sealing partition. The sensing layer includes a multi-channel gas sensing array and a pre-gas path cavity. The multi-channel gas sensing array includes several pairs of sensing units, and each pair of sensing units includes a detection sensing chip and a reference sensing chip. The circuit layer includes a multi-select analog switch array, an instrumentation amplifier, an analog-to-digital converter, and a communication interface chip connected in sequence. The outlet of the pre-gas path cavity faces the sensitive surface of each detection sensing chip. The differential signal output terminal of each sensing unit pair is connected to the corresponding input terminal of the multi-select analog switch array. The communication interface chip is connected to the interface layer. The multi-select analog switch switches sequentially according to a preset order, turning on each sensing unit in turn to the instrumentation amplifier.

[0010] Furthermore, the detection sensor chip is exposed to the gas to be tested output from the pre-gas passage cavity, while the reference sensor chip is enclosed in a sealed compartment and does not come into contact with the gas to be tested.

[0011] Furthermore, the detection sensor chip and the reference sensor chip use the same type of transition metal-doped two-dimensional material sensing element, and have the same temperature coefficient and electrical characteristics.

[0012] Furthermore, each detection sensor chip is coated with a different sensitive material, and each detection sensor chip is designed to identify a specific gas to be tested.

[0013] Furthermore, the differential output terminals of the multi-select analog switch array are respectively connected to the non-inverting input terminal and the inverting input terminal of the instrumentation amplifier, the output terminal of the instrumentation amplifier is connected to the input terminal of the analog-to-digital converter, the output terminal of the analog-to-digital converter is connected to the input terminal of the communication interface chip, and the positive and negative differential output terminals of the communication interface chip are respectively connected to the electrical contacts of the interface layer.

[0014] Furthermore, the turn-on time of each sensor unit pair is in the microsecond range, and the total turn-on time of all sensor unit pairs is in the millisecond range.

[0015] Furthermore, the circuit layer adopts a four-layer printed circuit board design, consisting of a top signal layer, a ground layer, a power layer, and a bottom signal layer from top to bottom. All grounding pins and grounding traces on the top and bottom signal layers are vertically connected to the ground layer through vias. All power supply pins and power supply traces connected to the positive terminal on the top and bottom signal layers are vertically connected to the power layer through vias. The top and bottom signal layers are used to place components and lay out various signal lines, and are electrically connected to the middle ground and power layers through vias, respectively.

[0016] Furthermore, the multi-select analog switch array, instrumentation amplifier, and analog-to-digital converter are all located on the top signal layer, the communication interface chip is located on the bottom signal layer, the input signal traces of the instrumentation amplifier are located on the top signal layer, and the corresponding areas of the ground layer and power layer directly below it are not separated.

[0017] Furthermore, the interface layer includes a set of centrally arranged electrical contacts, including a power positive contact, a power ground contact, a digital signal positive contact, and a digital signal negative contact. The power positive contact and the power ground contact are respectively connected to the power layer and the ground layer in the circuit layer, and the digital signal positive contact and the digital signal negative contact are respectively connected to the differential output positive terminal and the differential output negative terminal of the communication interface chip.

[0018] Furthermore, the interface layer also includes a mechanical snap-fit ​​structure, which includes two symmetrically arranged elastic claws. Each elastic claw includes a root, an end, and a pinching part located between the two. The root is fixed to both sides of the bottom surface of the module, and the pinching part and the end are exposed on both sides of the bottom surface of the module, and the end is provided with a barb.

[0019] The above embodiment provides a multi-channel array integrated gas sensing module. This gas sensing module adopts a three-dimensional layered structure, divided from bottom to top into an interface layer, a circuit layer, and a sensing layer. The circuit layer and the sensing layer are physically isolated by a sealing partition. The sensing layer includes a multi-channel gas sensing array and a pre-gas path cavity. The multi-channel gas sensing array includes several pairs of sensing units. The circuit layer includes a multi-select analog switch array, an instrumentation amplifier, an analog-to-digital converter, and a communication interface chip connected in sequence. The outlet of the pre-gas path cavity faces each pair of sensing units. The differential signal output terminals of each pair of sensing units are connected to the corresponding input terminals of the multi-select analog switch array. The communication interface chip is connected to the interface layer. The multi-select analog switches switch sequentially according to a preset order, turning on each sensing unit in turn to the instrumentation amplifier. Through the layered layout of internal functional areas, the sensor-reference differential topology, multi-channel scanning switching, and standardized electrical interfaces, miniaturized integration and high signal-to-noise ratio output are achieved.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] (1) The interface, circuit and sensing functional layers are physically separated by a three-dimensional stacked layout. A sealed partition is set between the sensing layer and the circuit layer to achieve isolation. The circuit layer is divided by a complete ground plane and power layer to ensure signal integrity, which solves the problem of mutual interference when integrating the multi-functional area.

[0022] (2) Through the sensor-reference differential topology, the detection sensor chip and the reference sensor chip of each sensing unit pair share the same instrumentation amplifier to form a hardware subtractor. The common-mode interference is physically canceled while the differential sensing signal is retained, realizing high signal-to-noise ratio amplification of nanoampere weak signals.

[0023] (3) By using a multi-channel time-division scanning multiplexing single amplification and acquisition link through a multi-select analog switch array, signal crosstalk during multi-channel parallel operation is avoided, hardware resources are saved, and module miniaturization is facilitated.

[0024] (4) Through the four-core contacts arranged in a concentrated manner on the interface layer and the elastic snap-fit ​​structure, the gas sensing module can be installed in a plug-and-play manner, requiring only two power lines and two differential signal lines. No tools are needed for installation and disassembly.

[0025] (5) The entire gas sensing module integrates gas sensing, signal conditioning, analog-to-digital conversion and digital communication into one unit. It outputs digital signals, has strong anti-interference ability, long transmission distance, and can be directly connected to the monitoring bus of the energy storage battery cabinet. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic cross-sectional view of the overall layered structure of a multi-channel array integrated gas sensing module provided in an embodiment of the present invention.

[0028] Figure 2 This is a signal link block diagram of the circuit layer provided in an embodiment of the present invention. Detailed Implementation

[0029] It should be noted that:

[0030] The terms “comprising” and “having”, and any variations thereof, in the specification, claims, and accompanying drawings of this invention are intended to cover a non-exclusive inclusion, such as a process, method, system, product, or apparatus that includes a series of steps or units, not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0031] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices. The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be decomposed, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In addition, the technical features of the various embodiments or individual embodiments provided by the present invention can be arbitrarily combined to form new technical solutions. Such combinations are not bound by the order of steps and / or structural composition patterns, but must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0033] 1. Overall architecture and functional area division

[0034] like Figure 1 As shown, this invention provides a multi-channel array integrated gas sensing module, particularly suitable for in-situ installation and long-term monitoring inside the battery cabinet of an energy storage power station. The gas sensing module adopts a three-dimensional layered structure, divided into an interface layer, a circuit layer, and a sensing layer from bottom to top. The interface layer is located on the bottom surface of the module and is used to establish electrical connections. The circuit layer is located in the middle layer of the module and is used for signal processing. The sensing layer is located on the top layer of the module and is used for gas detection.

[0035] Furthermore, the three layers are electrically interconnected via electrical connection lines and isolated by partitions. Specifically, a sealed partition is installed between the sensing layer and the circuit layer. The sealed partition is sealed to the inner wall of the gas sensing module's outer shell on all four sides. Only through holes for the power connection lines are opened on the sealed partition, and these through holes are filled with sealant. Understandably, the sensing layer directly contacts the gas being measured, and the circuit layer needs to be kept clean to prevent gas corrosion or short circuits; therefore, a sealed partition is necessary for physical isolation between the two. The interface layer, however, only handles external electrical connections and does not involve gas flow channels, so no additional sealing is required between the interface layer and the circuit layer. Preferably, the sealed partition is a thin metal plate with a thickness of not less than 0.5 mm.

[0036] The gas sensing module connects to the external device motherboard and external circuitry via the interface layer on its bottom surface, so the interface layer needs to provide external electrical connections. Firstly, the various chips and circuits within the gas sensing module require an external power supply to function properly. Secondly, the gas sensing module needs to acquire and process signals, receiving the signals to be measured from the outside and transmitting the processed gas detection data and instructions. Thirdly, connecting the gas sensing module's ground wire to the overall device ground wire ensures consistent potential and prevents interference that could damage weak signals.

[0037] 2. Sensing layer structure

[0038] The sensing layer comprises a multi-channel gas sensing array and a front-end gas path cavity. The multi-channel gas sensing array consists of several sensing unit pairs. Each sensing unit pair contains a detection sensor chip and a reference sensor chip. The detection sensor chip is exposed to the gas to be measured output from the front-end gas path cavity, sensing physicochemical changes such as the concentration and composition of the gas and converting these changes into weak analog electrical signals. It is the core of the module's original detection signal acquisition. The reference sensor chip is in the same environment as the detection sensor chip, but it is enclosed in a sealed compartment and does not contact the gas to be measured. It does not respond to the gas and is mainly used to compensate for errors caused by temperature, air pressure, environmental noise, and the circuit's own temperature drift, providing a reference signal, offsetting external environmental interference, and improving the accuracy of gas detection results. The front-end gas path cavity is located at the front end of the sensing layer. The inlet of the front-end gas path cavity faces the outside of the gas sensing module, and the outlet faces the sensitive surface of each detection sensor chip in the multi-channel gas sensing array.

[0039] It should be noted that each detection sensor chip in this invention identifies one of the target gases by coating different sensitive materials, and then uses a multi-channel time-division switching readout via a multi-select analog switch array, thereby achieving accurate differentiation of different target gases. This avoids signal crosstalk when multiple channels work in parallel, saves hardware resources, and facilitates module miniaturization.

[0040] Preferably, the detection sensor chip and the reference sensor chip are made of the same type of transition metal-doped two-dimensional material sensing element, and have the same temperature coefficient and electrical characteristics.

[0041] Preferably, the detection sensor chip and the reference sensor chip in the same sensing unit pair are arranged side by side on the sensing layer circuit board with a spacing of no more than 5mm.

[0042] 3. Circuit layer structure

[0043] like Figure 2 As shown, the circuit layer includes a multi-select analog switch array, an instrumentation amplifier, an analog-to-digital converter, and a communication interface chip. The multi-select analog switch array, instrumentation amplifier, analog-to-digital converter, and communication interface chip are connected sequentially. The instrumentation amplifier is used to amplify the weak analog electrical signal (microvolt to millivolt level) difference between the outputs of the detection sensor chip and the reference sensor chip with high precision, while effectively suppressing common-mode electromagnetic interference, ensuring that the weak analog electrical signal difference is not contaminated by noise during amplification, and providing a stable and usable analog electrical signal difference for subsequent circuits. The communication interface chip is responsible for data interaction between the gas sensing module and the external main control device. On the one hand, it transmits the gas detection data and device status information processed by the gas sensing module to the external main control device; on the other hand, it receives control commands and configuration signals issued by the external main control device, realizing communication interface between the gas sensing module and the entire system.

[0044] The specific connection relationships of the various components in the sensing layer are as follows: the differential signal output terminals of each sensing unit pair are respectively connected to the corresponding input terminals of the multi-select analog switch array. All sensing unit pairs share the same instrumentation amplifier. The differential output terminals of the multi-select analog switch array are respectively connected to the non-inverting and inverting input terminals of the instrumentation amplifier. The output terminal of the instrumentation amplifier is connected to the input terminal of the analog-to-digital converter. The output terminal of the analog-to-digital converter is connected to the input terminal of the communication interface chip. The positive and negative differential output terminals of the communication interface chip are respectively connected to the electrical contacts of the interface layer.

[0045] Preferably, the analog-to-digital converter is a Σ-Δ type analog-to-digital converter with a precision of 16 bits or higher.

[0046] Preferably, the circuit layer adopts a four-layer printed circuit board design, which consists of the following layers from top to bottom: top signal layer, ground layer, power layer, and bottom signal layer.

[0047] It should be noted that the top signal layer is the uppermost layer of the four-layer circuit board and is the main layout area for the core components of the module. It is used to lay out analog and digital signal traces, and to support key components such as detection and reference sensors (it should be noted that while the detection and reference sensors are physically located on the sensing layer, the top signal layer carries their output signals and signal processing circuits), instrumentation amplifiers, analog switch arrays, and analog-to-digital converters, thus completing the internal signal circuitry. The ground layer, located below the top signal layer, serves as a unified system reference ground plane for the entire board, providing a reference potential for all circuits. It also serves as the main signal return path, reducing the return loop area, suppressing electromagnetic interference, and acting as inter-layer shielding to isolate crosstalk between different areas and types of signals, with a focus on protecting weak analog electrical signals. The power layer, located below the ground layer, serves as a dedicated conductive plane for the positive terminal of the power bus, evenly distributing the supply voltage to all chips and electronic components within the board, providing stable power with low impedance and low ripple, ensuring the normal operation of all devices. The bottom signal layer is the lowest layer of the four-layer circuit board. It is used to lay out auxiliary signal traces, expand wiring space, and can accommodate communication interface chips and other devices. At the same time, this bottom signal layer corresponds to the interface area on the bottom of the module, which carries various external electrical contacts to realize the mechanical docking and electrical connection between the module and the external motherboard.

[0048] The input signal traces of the instrumentation amplifier are routed on the top signal layer, with the corresponding ground and power layers directly below them undivided. Understandably, the copper traces on the ground and power layers directly below the input signal traces must remain intact and cannot be broken in this area. If the copper traces below the traces are intact, interference return current flows directly back along the trace, resulting in a very small loop area and reducing the likelihood of coupling with external noise. If the copper traces below the traces are broken, the loop area increases, attracting spatial electromagnetic interference and contaminating the signal.

[0049] 4. Interface layer structure

[0050] The interface layer is located on the bottom surface of the module and includes a set of centrally arranged electrical contacts and a mechanical snap-fit ​​structure.

[0051] The electrical contacts consist of four cores: a positive power contact, a ground power contact, a positive digital signal contact, and a negative digital signal contact. The four cores are arranged in a rectangular pattern, and the contact spacing can be set according to actual needs; for example, a contact spacing of 2.54mm.

[0052] The positive power contact is the module's external electrical interface, serving as the access port for external power. It is responsible for introducing the positive terminal of the external power bus into the module and connecting it to the board's power layer, supplying operating voltage to all components on the board. The ground power contact is also an external electrical interface, used to connect to the system ground. It introduces the external ground potential into the module and connects it to the internal ground layer, unifying the reference potential between the gas sensing module and the entire system, preventing interference caused by potential differences, and ensuring stable circuit operation. The positive and negative digital signal contacts form a digital signal transmission channel, responsible for bidirectional transmission of digital signals between the gas sensing module and external devices. It transmits digital information such as gas detection data, control commands, and device status, serving as the physical interface for digital communication.

[0053] The mechanical latching structure consists of two symmetrically arranged elastic claws. Each claw comprises a root, a pinching part, and an end. The root serves as the mounting reference for the claw, being closest to the base and not involved in the pinching or locking action. The pinching part, located between the root and end sections, is the core area for external force pressing and clamping, situated in the middle axially. The end section, located at the outermost point of the claw, primarily serves to guide, clamp, and limit movement, and is furthest from the base. The root of the claw is fixed to both sides of the module's bottom surface, while the end section has barbs. The pinching part of the claw protrudes from the outer surfaces of both sides of the module. It should be noted that the mechanical latching structure is located on the disassembled gas sensing module, while the base is the fixed part retained on the cabinet after disassembly.

[0054] 5. Connection relationships between layers

[0055] In the sensing layer, the output terminals of the detection sensing chip and the reference sensing chip of each sensing unit pair are connected to the corresponding input terminals of the analog switch array in the circuit layer via differential twisted pair traces, with a trace length not exceeding 15mm.

[0056] The output of the multi-select analog switch array in the circuit layer is connected to the input of the instrumentation amplifier via differential traces. The output of the instrumentation amplifier is connected to the input of the analog-to-digital converter via single-ended traces. The digital output of the analog-to-digital converter is connected to the communication interface chip via the SPI bus.

[0057] In the interface layer, the positive power contact and the ground contact are connected to the positive and ground terminals of the power bus in the circuit layer, respectively. The positive digital signal contact and the negative digital signal contact are connected to the positive and negative terminals of the differential output of the communication interface chip, respectively. It should be noted that the primary carrier of the aforementioned ground is the ground layer in the circuit layer; the primary carrier of the positive power bus in the circuit is the power layer in the circuit layer.

[0058] It should be noted that the ground plane in the circuit is primarily carried by the ground layer in the four-layer structure. All ground pins and ground traces on the top and bottom signal layers are vertically connected to this ground layer through vias. Similarly, the positive terminal of the power bus in the circuit is primarily carried by the power layer in the four-layer structure. All pins and power traces connected to the positive terminal of the power supply on the top and bottom signal layers are vertically connected to this power layer through vias. The top and bottom signal layers are only used for placing components and routing various signal lines; they do not serve as large-area conductive planes for the positive terminal of the power bus and ground. They are only electrically connected to the intermediate ground and power layers through vias, respectively.

[0059] 6. Work Process

[0060] After the gas sensing module is powered on, the multi-select analog switch array switches sequentially in a preset order, so that the differential signals of each sensing unit pair are turned on to the input of the instrumentation amplifier in turn. The turn-on time of each channel (i.e., the turn-on time of each sensing unit pair) is in the microsecond range, and the complete scan of all channels takes milliseconds.

[0061] The signal processing for a single sensing unit pair is as follows: the output signals of the detection sensing chip and the reference sensing chip are input to an instrumentation amplifier in differential form. The instrumentation amplifier outputs the difference between the two signals, i.e., the differential amplified signal. This differential amplified signal eliminates the temperature drift and power supply ripple components shared by both chips, retaining only the sensing signal component generated by the detection sensing chip's contact with the target gas. The differential amplified signal is then converted into a digital signal by an analog-to-digital converter, i.e., a digital differential amplified signal. The digital differential amplified signal is output to the outside of the module through a communication interface chip.

[0062] In summary, this invention addresses the shortcomings of existing technologies, such as signal crosstalk during multi-channel integration, excessively long transmission paths for weak signals, mutual interference between functional areas within the module, and limited in-situ installation space. It provides a multi-channel array integrated gas sensing module that achieves miniaturization and high signal-to-noise ratio output through a layered layout of internal functional areas, a sensor-reference differential topology, multi-channel scanning switching, and a standardized electrical interface. Specifically, firstly, a three-dimensional layered layout physically separates the interface, circuit, and sensing functional layers. A sealed partition isolates the sensing layer from the circuit layer, and the circuit layer employs a complete ground plane and power layer segmentation to ensure signal integrity, thus resolving the mutual interference problem during multi-functional area integration. Secondly, through a sensor-reference differential topology, each sensing unit pair's detection and reference sensing chips share the same instrumentation amplifier to form a hardware subtractor. Common-mode interference is physically canceled while the differential sensing signal is preserved, achieving high signal-to-noise ratio amplification of nanoampere-level weak signals. Third, by using a multi-select analog switch array to achieve multi-channel time-division scanning multiplexing of a single amplification and acquisition link, signal crosstalk during multi-channel parallel operation is avoided, hardware resources are saved, and module miniaturization is facilitated. Fourth, the four-core contacts and flexible snap-fit ​​structure arranged centrally at the interface layer enable plug-and-play installation of the gas sensing module, requiring only two power lines and two differential signal lines, and no tools are needed for installation and removal. Fifth, the entire gas sensing module integrates gas sensing, signal conditioning, analog-to-digital conversion, and digital communication into one unit, outputting digital signals with strong anti-interference capabilities, long transmission distance, and direct connection to the monitoring bus of the energy storage battery cabinet.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A multi-channel array integrated gas sensing module, characterized in that, The gas sensing module adopts a three-dimensional stacked structure, divided into an interface layer, a circuit layer, and a sensing layer from bottom to top. The circuit layer and the sensing layer are physically isolated by a sealing partition. The sensing layer includes a multi-channel gas sensing array and a pre-gas path cavity. The multi-channel gas sensing array includes several pairs of sensing units, each pair of sensing units including a detection sensing chip and a reference sensing chip. The circuit layer includes a multi-select analog switch array, an instrumentation amplifier, an analog-to-digital converter, and a communication interface chip connected in sequence. The outlet of the pre-gas path cavity faces the sensitive surface of each detection sensing chip. The differential signal output terminal of each sensing unit pair is connected to the corresponding input terminal of the multi-select analog switch array. The communication interface chip is connected to the interface layer. The multi-select analog switch switches sequentially according to a preset order, turning on each sensing unit in turn to the instrumentation amplifier.

2. The gas sensing module with multi-channel array integration as described in claim 1, characterized in that, The detection sensor chip is exposed to the gas to be tested output from the front gas path cavity, while the reference sensor chip is enclosed in a sealed compartment and does not come into contact with the gas to be tested.

3. The gas sensing module with multi-channel array integration as described in claim 1, characterized in that, The detection sensor chip and the reference sensor chip use the same type of transition metal-doped two-dimensional material sensing element, and have the same temperature coefficient and electrical characteristics.

4. The gas sensing module with multi-channel array integration as described in claim 1, characterized in that, Each detection sensor chip is coated with a different sensitive material, and each detection sensor chip is responsible for identifying a specific gas to be tested.

5. The gas sensing module with multi-channel array integration as described in claim 1, characterized in that, The differential output terminals of the multi-select analog switch array are respectively connected to the non-inverting input terminal and the inverting input terminal of the instrumentation amplifier. The output terminal of the instrumentation amplifier is connected to the input terminal of the analog-to-digital converter. The output terminal of the analog-to-digital converter is connected to the input terminal of the communication interface chip. The positive and negative differential output terminals of the communication interface chip are respectively connected to the electrical contacts of the interface layer.

6. The gas sensing module with multi-channel array integration as described in claim 1, characterized in that, The turn-on time of each sensor unit pair is in the microsecond range, and the total turn-on time of all sensor unit pairs is in the millisecond range.

7. The gas sensing module with multi-channel array integration as described in claim 1, characterized in that, The circuit layer adopts a four-layer printed circuit board design, consisting of a top signal layer, a ground layer, a power layer, and a bottom signal layer from top to bottom. All ground pins and ground traces on the top and bottom signal layers are vertically connected to the ground layer through vias. All positive power pins and power traces on the top and bottom signal layers are vertically connected to the power layer through vias. The top and bottom signal layers are used to place components and lay out various signal lines, and are electrically connected to the middle ground and power layers through vias, respectively.

8. The gas sensing module with multi-channel array integration as described in claim 7, characterized in that, The multi-select analog switch array, instrumentation amplifier, and analog-to-digital converter are all located on the top signal layer, the communication interface chip is located on the bottom signal layer, the input signal traces of the instrumentation amplifier are located on the top signal layer, and the corresponding areas of the ground layer and power layer directly below it are not separated.

9. A multi-channel array integrated gas sensing module as described in claim 7, characterized in that, The interface layer includes a set of centrally arranged electrical contacts, including a power positive contact, a power ground contact, a digital signal positive contact, and a digital signal negative contact. The power positive contact and the power ground contact are respectively connected to the power layer and the ground layer in the circuit layer, and the digital signal positive contact and the digital signal negative contact are respectively connected to the differential output positive terminal and the differential output negative terminal of the communication interface chip.

10. A multi-channel array integrated gas sensing module as described in claim 1, characterized in that, The interface layer also includes a mechanical snap-fit ​​structure, which includes two symmetrically arranged elastic claws. Each elastic claw includes a root, an end, and a pinching part located between the two. The root is fixed to both sides of the bottom surface of the module, and the pinching part and the end are exposed on both sides of the bottom surface of the module, and the end is provided with a barb.

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