A gas sensor integrated by a multi-stage composite structure

Abstract

The present application relates to a kind of gas sensor integrated by multistage composite structure, comprising: first support layer and second support layer, first support layer is configured as the insulation layer of heating composite and second assembly, at least part for reducing stress second support layer is arranged between third assembly and heating composite to reduce the heat loss of heating composite along the direction of third assembly, heating composite is in the way of partial entity embedding first support layer and second support layer by first support layer and second support layer are clamped, first support layer is provided with first compensation layer by at least one material in the form of single layer or multilayer composite on the side away from heating composite, second support layer is provided with second compensation layer by at least one material in the form of single layer or multilayer composite on the side away from heating composite, second compensation layer has several contact interfaces, the distribution density of contact interface gradually increases in the direction close to first assembly linearly or nonlinearly.

Description

Technical Field

[0001] This invention relates to the field of gas sensor technology, and more particularly to a gas sensor integrated through a multi-level composite structure. Background Technology

[0002] The MOX gas sensor is a MEMS device fabricated as a multi-chip module (MCM). By applying controlled heat in the presence of clean air, the resistance of the MOX coating is measured. Then, the resistance of the MOX coating is measured again in air with a controlled amount of the target gas (in parts per million). The ratio of these two measurements is used to calibrate the device. In practical operation, the calibrated MOX resistance measurement indicates the density of the target gas in the environment.

[0003] A prior art resistive integrated gas sensor, as disclosed in patent document CN111351821A, includes a substrate, a first metal oxide layer, an insulating layer, a contact metal layer, contact holes, a second metal oxide layer, and a forked electrode layer. The first metal oxide layer is disposed in the substrate. The insulating layer is disposed on the substrate and the first metal oxide layer. The contact metal layer and contact holes are disposed in the insulating layer. The second metal oxide layer is disposed on the insulating layer. A portion of the forked electrode layer is disposed on the insulating layer, and another portion is disposed in the second metal oxide layer. The contact metal layer and contact holes connect the first metal oxide layer and the forked electrode layer.

[0004] A ceramic-structured flat-plate gas sensor with a bending compensation layer, as proposed in patent document CN102680553A, includes one or more solid electrolyte layers and one or more insulating layers. Its key feature is that two planes equidistant from the two outer surfaces along the length of the flat-plate sensing unit are defined as the geometric center plane. This geometric center plane divides the sensor unit into two parts: the part containing one or more electrolyte layers is called the sensing section, and the part containing the heater is called the heater section. One or more bending compensation layers made of the same material as the electrolyte are added to the heater section. This invention does not require redesigning the multi-layer structure of the sensing unit and the printed circuitry between the layers into a symmetrical structure, nor does it require time-consuming and laborious changes to the formulation of each material layer to match the shrinkage rate of each material layer. This invention can tolerate unavoidable material shrinkage rate deviations, thickness deviations of each material layer, and other factors that may cause bending or internal defects in the sensing unit during manufacturing.

[0005] The solution proposed in the aforementioned patent designs the structure of the sensor, which further enhances the mechanical strength of the sensor, but it increases the energy consumption of the sensor. Therefore, it is necessary to design the structure of the sensor so that the sensor can have lower energy consumption while meeting the necessary mechanical strength.

[0006] Furthermore, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the inventors studied a large number of documents and patents when making this invention, but due to space limitations, not all details and contents were listed in detail. However, this does not mean that the present invention does not possess the features of these prior art. On the contrary, the present invention already possesses all the features of the prior art, and the applicant reserves the right to add relevant prior art to the background art. Summary of the Invention

[0007] The present invention discloses a gas sensor integrated by a multi-level composite structure, comprising: a first support layer and a second support layer, wherein the first support layer is configured to act as an insulating layer for the heating composite and the second assembly.

[0008] According to a preferred embodiment, a second support layer, at least partially used to reduce stress, is arranged between the third assembly and the heating composite to reduce heat loss of the heating composite along the direction of the third assembly. The heating composite is sandwiched between the first and second support layers in such a way that it is partially embedded in the first and second support layers.

[0009] Existing semiconductor gas sensors often exhibit good gas sensitivity only at high temperatures, necessitating the introduction of a heating platform. The power consumption of this heating platform is a major source of sensor power consumption. To further reduce energy consumption, most existing technologies employ a cantilever design, with the sensing material and the heating unit with an insulating layer positioned on opposite sides of the suspended area connected by the cantilever. This cantilever design effectively reduces internal heat conduction between the sensing material and the insulating layer, thus reducing energy consumption to some extent. However, the cantilever requires etching, increasing manufacturing complexity and reducing the mechanical strength of the etched structure (especially at the cantilever, deformation or even breakage can occur), resulting in a smaller sensing area. Closed-loop gas sensors without cantilever designs typically etch the back side of the silicon substrate where the sensing unit is located, reducing heat conduction to some extent, but still consuming more energy than sensors with cantilever structures. Therefore, this invention is designed to address the heat conduction process of the sensor. Different support layers are provided on both sides of the heating unit. The thermal conductivity of the first support layer (preferably silicon dioxide) located between the heating composite and the second assembly is higher than that of the second support layer (preferably silicon nitride) located between the heating composite and the silicon substrate. The thermal conductivity of the second support layer is lower than that of the silicon substrate, which reduces the heat conduction between the heating composite and the silicon substrate. The lower thermal conductivity of the second support layer reduces the heat transferred by the heating composite along the direction of the silicon substrate. The heat loss generated by the internal heat conduction of the part where the silicon substrate and the heating composite are in direct contact is greatly reduced because the contact part is replaced by the second support layer. At the same time, the low thermal conductivity of the first and second support layers avoids a large amount of heat conduction along the interior of the first and second support layers.

[0010] The second assembly formed by depositing sensing material on a substrate improves sensing sensitivity and reduces energy consumption to some extent. However, the sensing material formed by this method has poor mechanical strength. In existing technologies, a single support layer is often used to electrically insulate the detection electrode and support the sensing unit and heating electrode. However, the support provided by a single material is limited. Especially in high-temperature operating environments, the first support layer will expand due to heat, and its deformation will be conducted to the sensing material and detection electrode, causing them to break, undergo structural changes, and other adverse changes to sensor performance. Therefore, in this invention, a first support layer and a second support layer are used to clamp the heating composite, and a portion of the heating composite is embedded in the first and second support layers. The first and second support layers can eliminate the stress during the heating and annealing process by wrapping the heating composite, preventing changes in the sensor structure, and thus improving the durability of the sensor.

[0011] Furthermore, due to the different coefficients of thermal expansion between the support layer and the heating composite, the expansion of the heating composite is greater than that of the support layer during heating. This causes the support layer to tend to stretch. Conversely, during annealing, the shrinkage of the heating composite is greater than that of the support layer, causing the support layer to tend to compress under the stress of the heating current. In existing technologies, a first support layer is typically used as a single support layer, primarily made of silicon dioxide. While it can resist compressive stress, it cannot block tensile stress. Therefore, the second support layer introduced in this invention acts as a support layer to resist tensile stress, enabling the first assembly to disperse both compressive and tensile stresses, thereby reducing the possibility of deformation and improving overall mechanical strength.

[0012] According to a preferred embodiment, a first compensation layer composed of at least one material in single or multiple layers is provided on the side of the first support layer away from the heating composite, and a second compensation layer composed of at least one material in single or multiple layers is provided on the side of the second support layer away from the heating composite.

[0013] According to a preferred embodiment, the second compensation layer, which is composed of several layers, has several contact interfaces, and the distribution density of the contact interfaces gradually increases linearly or nonlinearly in the direction close to the third assembly.

[0014] The above measures reduce sensor energy consumption and improve sensor mechanical strength to some extent. The materials used in each layer of the composite structure are relatively simple, greatly reducing manufacturing difficulty. However, in practical applications, taking the first support layer made of silicon dioxide as an example, it needs a certain thickness to meet the required support function. But as the thickness increases, the heat conduction loss inside the first support layer increases, and the time it takes for the heating composite to heat the second assembly to the operating temperature becomes longer. Taking the second support layer made of silicon nitride as an example, silicon nitride has poor adhesion to the silicon substrate and is prone to falling off the third assembly (silicon substrate), resulting in deterioration of sensor performance.

[0015] Furthermore, the cyclic heating and annealing operation mode of the gas sensor exacerbates the aforementioned problems. Therefore, this invention improves energy consumption and stress by setting a first compensation layer and a second compensation layer on both sides of the first assembly, respectively. At the nanoscale, the layers of the second compensation layer are not in complete contact. Compared with an ideal flat plane, there are more obvious undulations on the layer surface. Therefore, the actual contact between the layers is partial, while the non-contact surfaces are filled with air or other filling media. Thus, heat conduction between the layers only occurs in the contact area, while heat transfer in the non-contact area occurs through heat conduction in the air medium and near-field thermal radiation (which is almost negligible at the microscale). Since the heat transfer efficiency in the non-contact area is low, the contact thermal resistance at the contact interface of the multilayer film is further reduced compared to a single-layer film of the same thickness. At the same time, the voids provide a buffer area for material expansion, and the heat conduction received is reduced, further reducing residual thermal stress and indirectly improving the stress dispersion capability of the second support layer.

[0016] In existing technologies, silicon dioxide deposition methods often involve creating grooves on the surface of a silicon substrate and gradually forming it through atomic deposition. Therefore, the density of the contact interface is gradually increased in the direction near the bottom of the groove to minimize the heat transfer to the silicon substrate. Thus, during the fabrication process, the thickness of the support layer can be adjusted by controlling the deposition time of each deposition. Based on the same thickness requirement, the number of support layers can be adjusted by the deposition time, thereby reducing the energy consumption of the second support layer by increasing the thermal resistance of the support layer and further improving the performance of the sensor.

[0017] According to a preferred embodiment, at least one heating composite is provided on the side of the first support layer away from the first compensation layer. The heating composite is provided with a first size in at least one first region of the first support layer and with a second size different from the first size in at least one second region of the first support layer.

[0018] According to a preferred embodiment, the heating composite is composed of a first material layer having a first characteristic, and a second material layer having a second characteristic is provided in at least a partial area on the side of at least one first material layer facing the first support layer or the second support layer for bonding the first support layer and the second support layer.

[0019] According to a preferred embodiment, the gas sensor further includes a second assembly providing at least one first functional region and at least one second functional region, the first and second functional regions being alternately arranged such that a medium inside the second functional region contacts the first functional region, thereby changing the electrical characteristics of the first functional region.

[0020] According to a preferred embodiment, at least one side of the first functional region is provided with a third functional region having a conductive material, the conductive material of the third functional region being electrically connected to a second region of the first functional region, and the first functional region having a plurality of first regions, the first regions being electrically insulated from the second regions and the third functional region.

[0021] According to a preferred embodiment, the conductive material of the third functional region is connected to the first functional region at a position on the first functional region corresponding to the heating composite, and the conductive material of the third functional region is constructed in at least one first functional region in a first-size manner and in at least one first functional region in a second-size manner, so that the conductive material of the third functional region is arranged in the first functional region in a linear and / or dotted manner.

[0022] This invention discloses a gas sensor integrated through a multi-level composite structure, comprising: a first assembly, a second assembly, and a third assembly. The first assembly is configured to heat the second assembly, the second assembly is configured to sense gas, and the third assembly is configured to support the first and second assemblies. The gas sensor further includes at least a first compensation layer and a second compensation layer for adjusting the direction of heat transfer. The first assembly is interconnected with the second and third assemblies through the first and second compensation layers.

[0023] According to a preferred embodiment, a first compensation layer is disposed between a first assembly and a second assembly, and a second compensation layer is disposed between a first assembly and a third assembly. The second compensation layer, composed of several layers, has several contact interfaces, and the distribution density of the contact interfaces gradually increases linearly or nonlinearly in the direction closer to the third assembly.

[0024] According to a preferred embodiment, the second assembly provides at least one first functional region and at least one second functional region, the first functional region and the second functional region being alternately arranged so that a medium inside the second functional region contacts the first functional region, thereby changing the electrical characteristics of the first functional region. The first functional region includes a first area for heat conduction and a second area for sensing, and the second area is formed in an electrically isolated state from the first area by depositing at least two sensing materials in the first area.

[0025] Existing technologies often employ a planar gas-sensitive thin film formed by depositing sensing materials on silicon dioxide. This dense surface structure significantly reduces the response and sensitivity of the gas-sensitive material. Furthermore, the internal thermal conduction of the gas-sensitive thin film causes even non-sensing areas to be heated, resulting in substantial heat loss. Therefore, this invention increases the sensitivity of the sensing layer by introducing a porous thin film material onto the substrate. Taking a common second assembly based on an AAO substrate as an example, the contact between the gas and the sensing material is increased by increasing the specific surface area, thereby improving the sensor's sensitivity. The second assembly includes multiple second functional regions capable of accommodating air. Since the thermal conductivity of air is lower than that of the first functional region, the heat from the first assembly is primarily transferred along the extension direction of the second functional regions, and mainly along the areas corresponding to the heated composite. The increased energy consumption due to internal thermal conduction in the second assembly is effectively suppressed, and the heat loss from non-sensing areas is significantly reduced, greatly lowering the sensor's energy consumption. Attached Figure Description

[0026] Figure 1 This is a simplified overall structural diagram of the gas sensor integrated through a multi-level composite structure according to the present invention;

[0027] Figure 2 This is a simplified overall structural diagram of the second assembly of the gas sensor of the present invention;

[0028] Figure 3 This is a simplified overall structural diagram of the compensation layer of the gas sensor of the present invention;

[0029] Figure 4 This is a simplified schematic diagram of the third functional area of ​​the gas sensor of the present invention.

[0030] List of reference numerals

[0031] 1: First assembly; 2: Second assembly; 3: Third assembly; 11: First support layer; 12: Second support layer; 13: Heating composite; 21: First functional area; 22: Second functional area; 23: Third functional area; 41: First compensation layer; 42: Second compensation layer; 211: First zone; 212: Second zone; 421: Contact interface. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings.

[0033] like Figure 1 and Figure 3The present invention discloses a gas sensor integrated through a multi-level composite structure, comprising: a first assembly 1, a second assembly 2, and a third assembly 3. The first assembly 1 is configured to heat the second assembly 2, the second assembly 2 is configured to sense gas, and the third assembly 3 is configured to support the first assembly 1 and the second assembly 2. The gas sensor further includes at least a first compensation layer 41 and a second compensation layer 42 for adjusting the direction of heat transfer. The first assembly 1 is interconnected with the second assembly 2 and the third assembly 3 through the first compensation layer 41 and the second compensation layer 42.

[0034] like Figure 2 The second assembly 2 of the present invention shown includes at least one first functional region 21 and at least one second functional region 22. The first functional region 21 and the second functional region 22 are alternately arranged so that the medium inside the second functional region 22 contacts the first functional region 21, thereby changing the electrical characteristics of the first functional region 21. The first functional region 21 includes a first region 211 for heat conduction and a second region 212 for sensing. The second region 212 is electrically isolated from the first region 211 by depositing at least two sensing materials in the first region 211.

[0035] In other words, the second assembly 2 is a porous thin film formed by depositing sensing material on the first region 211 as a substrate. The pores communicating with the external air are the second functional regions 22, and the electrodes used to detect changes in the resistance of the sensing material are the third functional regions 23. The air medium present in the second functional regions 22 causes heat transfer within the second assembly 2 to primarily occur along the extension direction of the second functional regions 22. Considering the internal heat conduction of the second assembly 2, since the first and second functional regions are alternately arranged, the energy consumption caused by internal heat conduction in existing second assemblies 2 composed entirely of the first functional regions 21 is relatively high. However, in this invention, some areas of the first functional regions 21 are replaced by the second functional regions 22, significantly reducing heat conduction perpendicular to the extension direction of the second functional regions. This further reduces the heat consumed by parts of the second assembly 2 that are not used as sensing regions. Simultaneously, the first functional regions 21 increase the specific surface area of ​​the second assembly 2, expanding the contact between the second region 212 and the air. Furthermore, the third functional region 23 does not affect air diffusion in the second functional regions 22.

[0036] According to a preferred embodiment, a first compensation layer 41 is disposed between a first assembly 1 and a second assembly 2, and a second compensation layer 42 is disposed between a first assembly 1 and a third assembly 3. The second compensation layer 42, which is composed of several layers, has several contact interfaces 421, and the distribution density of the contact interfaces 421 gradually increases linearly or nonlinearly in the direction close to the third assembly 3.

[0037] Specifically, existing technologies do not consider the changes in strength and energy consumption caused by deposition thickness and microstructure during the deposition of materials such as silicon dioxide to form the second compensation layer and support layer. Therefore, this invention designs the structure during the deposition process to further improve the strength of the sensor and reduce energy consumption. At the nanoscale, the layers of the second compensation layer are not in complete contact. Compared with an ideal flat plane, there are obvious undulations on the surface of the layers. Therefore, the actual contact between the layers is partial, while the non-contact surfaces are filled with air or other filling media. Thus, heat conduction between the layers only occurs in the contact area, while heat transfer in the non-contact area occurs through heat conduction in the air and near-field thermal radiation. This part is almost negligible at the microscale. Since the heat transfer efficiency in the non-contact area is low, the contact thermal resistance at the contact interface of the multilayer film is further reduced compared to the single-layer film of the same thickness. At the same time, the voids provide a buffer area for material expansion, and the heat conduction received is reduced, further reducing residual thermal stress and indirectly improving the stress dispersion ability of the second support layer. To further enhance the effect of the compensation layer, its deposition thickness is controlled, and the thickness of several first or second materials constituting the compensation layer gradually decreases in the direction approaching the third assembly 3. The second compensation layer is designed in the above manner, with less internal heat conduction in the portion of the second compensation layer closer to the third assembly, and the heat conduction between the multiple layers of the second compensation layer also decreases as it gets closer to the third assembly.

[0038] The present invention discloses a gas sensor integrated by a multi-level composite structure, comprising: a first support layer 11 and a second support layer 12, wherein the first support layer 11 is configured to serve as an insulating layer for the heating composite 13 and the second assembly 2.

[0039] According to a preferred embodiment, a second support layer 12, at least partially used to reduce stress, is arranged between the third assembly 3 and the heating composite 13 to reduce heat loss of the heating composite 13 along the direction of the third assembly 3. The heating composite 13 is held by the first support layer 11 and the second support layer 12 in such a way that it is partially embedded in the first support layer 11 and the second support layer 12.

[0040] According to a preferred embodiment, a first compensation layer 41 composed of at least one material in single or multiple layers is provided on the side of the first support layer 11 away from the heating composite 13, and a second compensation layer 42 composed of at least one material in single or multiple layers is provided on the side of the second support layer 12 away from the heating composite 13.

[0041] According to a preferred embodiment, the second compensation layer 42, which is composed of several layers, has several contact interfaces 421, and the distribution density of the contact interfaces 421 gradually increases linearly or nonlinearly in the direction close to the third assembly 3.

[0042] According to a preferred embodiment, at least one heating composite 13 is provided on the side of the first support layer 11 away from the first compensation layer 41. The heating composite 13 is provided with a first size in at least one first region of the first support layer 11 and with a second size different from the first size in at least one second region of the first support layer 11.

[0043] According to a preferred embodiment, the heating composite 13 is composed of a first material layer having a first characteristic, and a second material layer having a second characteristic is provided in at least a partial area on the side of at least one first material layer facing the first support layer 11 or the second support layer 12 for bonding the first support layer 11 and the second support layer 12.

[0044] According to a preferred embodiment, the gas sensor further includes a second assembly 2, which provides at least one first functional region 21 and at least one second functional region 22, wherein the first functional region 21 and the second functional region 22 are alternately arranged so that the medium inside the second functional region 22 contacts the first functional region 21, thereby changing the electrical characteristics of the first functional region 21.

[0045] According to a preferred embodiment, a third functional region 23 having a conductive material is provided on at least one side of the first functional region 21. The conductive material of the third functional region 23 is electrically connected to the second region 212 of the first functional region 21. The first functional region 21 has a plurality of first regions 211, and the first regions 211 are electrically insulated from the second regions 212 and the third functional region 23.

[0046] According to a preferred embodiment, the conductive material of the third functional region 23 is connected to the first functional region 21 at a position on the first functional region 21 corresponding to the heating composite 13, and the conductive material of the third functional region 23 is constructed in at least one first functional region 21 in a first-size manner and in at least one first functional region 21 in a second-size manner, so that the conductive material of the third functional region 23 is arranged in the first functional region 21 in a linear and / or dotted manner.

[0047] like Figure 4 As shown, the third functional region 23 consists of a fork-shaped sensing region for sensing the resistance change of the first functional region 21 and a connector region with a size larger than the fork electrode portion and formed in a second size.

[0048] To facilitate the description of the structure of the sensor proposed in this invention, the structural principle of this invention is explained below based on existing technology:

[0049] A silicon dioxide and silicon nitride film is formed on the third assembly 3 (preferably a silicon substrate) to serve as a second support layer 12 (preferably using atomic deposition technology). A heating composite 13 is formed on the second support layer 12 (preferably using sputtering deposition technology). After the heating composite 13 is formed, a first support layer 11 is formed on the heating composite 13. Then, metallic aluminum is deposited on the first support layer 11 by atomic deposition. A first region 211 and a second functional region 22 (porous alumina) are formed by two-step anodizing. A metal oxide gas-sensitive material is atomically deposited on the first region 211. Then, a noble metal catalytic material is atomically deposited to form the first functional region 21.

[0050] Optionally, the first assembly 1 is manufactured using a complete set of MEMS processes. Preferably, the heated composite 13 is prepared by electron beam evaporation or sputtering using a metal mask. Aluminum is sputtered using semiconductor processes, and a first region 211 is formed using a two-step anodizing process. The second region 212 is formed by atomic layer deposition, and the material includes one or more of SnO2, ZnO, In2O3, NiO, etc. The second region is modified with noble metals such as Pt and Pd deposited by atomic layer deposition.

[0051] Throughout the text, the features indicated by “preferred” are only optional and should not be construed as mandatory. Therefore, the applicant reserves the right to abandon or delete the relevant preferred features at any time.

[0052] It should be noted that the specific embodiments described above are exemplary, and those skilled in the art can devise various solutions inspired by the disclosure of this invention. These solutions all fall within the scope of this invention and its protection. Those skilled in the art should understand that this specification and its accompanying drawings are illustrative and not intended to limit the scope of the claims. The scope of protection of this invention is defined by the claims and their equivalents.

Claims

1. A gas sensor integrated by a multistage composite structure, comprising: a first support layer (11) and a second support layer (12), the first support layer (11) is configured to act as an insulation layer for the heating composite (13) and the second assembly (2), characterized in that at least part of the second support layer (12) for reducing stress is arranged between the third assembly (3) and the heating composite (13), the thermal conductivity of the first support layer (11) is higher than that of the second support layer (12), and the thermal conductivity of the second support layer (12) is lower than that of the third assembly (3), so that the heat conduction between the heating composite (13) and the third assembly (3) is reduced, the heat loss of the heating composite (13) along the third assembly (3) is reduced, and the heating composite (13) is clamped by the first support layer (11) and the second support layer (12) in a way that the heating composite (13) is partially embedded in the first support layer (11) and the second support layer (12), and the first support layer (11) and the second support layer (12) can wrap the heating composite (13) to eliminate the stress during the heating annealing process; a first compensation layer (41) composed of at least one material in a single layer or multiple layers is arranged on the side of the first support layer (11) away from the heating composite (13), and a second compensation layer (42) composed of at least one material in a single layer or multiple layers is arranged on the side of the second support layer (12) away from the heating composite (13), and the thickness of the first material or the second material constituting the second compensation layer (42) gradually decreases in the direction close to the third assembly (3).

2. The gas sensor integrated through a multi-level composite structure according to claim 1, characterized in that, The second compensation layer (42) composed of multiple layers has multiple contact interfaces (421), and the distribution density of the contact interfaces (421) gradually increases linearly or nonlinearly in the direction close to the third assembly (3).

3. The gas sensor integrated through a multi-level composite structure according to claim 1, characterized in that, At least one heating composite (13) is arranged on the side of the first support layer (11) away from the first compensation layer (41), and the heating composite (13) is arranged in a first size in at least one first area of the first support layer (11) and in a second size different from the first size in at least one second area of the first support layer (11).

4. The gas sensor integrated through a multi-stage composite structure according to claim 3, characterized in that, The heating composite (13) is composed of a first material layer with a first property, and a second material layer with a second property is arranged on at least one side of at least one of the first material layers towards the first support layer (11) or the second support layer (12) in at least a partial area for fitting the first support layer (11) and the second support layer (12).

5. The gas sensor integrated through a multi-level composite structure according to claim 1, characterized in that, The second assembly (2) provides at least one first functional area (21) and at least one second functional area (22), and the first functional area (21) and the second functional area (22) are arranged alternately so that the medium inside the second functional area (22) contacts the first functional area (21), thereby changing the electrical characteristics of the first functional area (21).

6. The gas sensor integrated through a multi-level composite structure according to claim 5, characterized in that, At least one side of the first functional area (21) is provided with a third functional area (23) having a conductive material, the conductive material of the third functional area (23) is electrically connected to the second area (212) of the first functional area (21), and the first functional area (21) has a plurality of first areas (211) which are electrically insulated from the second area (212) and the third functional area (23).

7. The gas sensor integrated through a multi-level composite structure according to claim 6, characterized in that, The conductive material of the third functional area (23) is connected to the first functional area (21) at a position corresponding to the heating composite (13) on the first functional area (21), and The conductive material of the third functional area (23) is configured in a first size in at least one first functional area (21) and in a second size in at least one first functional area (21), so that the conductive material of the third functional area (23) is arranged in a linear and / or point-like manner in the first functional area (21).

8. A gas sensor integrated by a multistage composite structure, comprising: The first assembly (1), the second assembly (2) and the third assembly (3), wherein, The first assembly (1) is configured to heat the second assembly (2), The second assembly (2) is configured to sense a gas, The third assembly (3) is configured to support the first assembly (1) and the second assembly (2), Characterized in that the gas sensor further comprises at least a first compensation layer (41) and a second compensation layer (42) for adjusting the direction of heat transfer, the first assembly (1) is connected with the second assembly (2) and the third assembly (3) through the first compensation layer (41) and the second compensation layer (42), wherein, The first compensation layer (41) is arranged between the first assembly (1) and the second assembly (2), and the second compensation layer (42) is arranged between the first assembly (1) and the third assembly (3), the thickness of the first material or the second material constituting the second compensation layer (42) gradually decreases in the direction close to the third assembly (3); Wherein, the second compensation layer (42) composed of a plurality of layers has a plurality of contact interfaces (421), the distribution density of the contact interfaces (421) gradually increases in the direction close to the third assembly (3) in a linear or nonlinear manner.

9. The gas sensor integrated through a multi-level composite structure according to claim 8, characterized in that, The second assembly (2) provides at least one first functional area (21) and at least one second functional area (22), the first functional area (21) and the second functional area (22) are arranged alternately, so that the medium inside the second functional area (22) contacts the first functional area (21), thereby changing the electrical characteristics of the first functional area (21), the first functional area (21) includes a first area (211) for heat conduction and a second area (212) for sensing, at least two sensing materials are deposited in the first area (211) to form the second area (212) which is in an electrically isolated state with the first area (211).

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