MEMS thermopile array chip and multi-component gas detection device

Abstract

The invention relates to an MEMS thermopile array chip and a multi-component gas detection device, the MEMS thermopile array chip comprises a silicon substrate, a plurality of thermopile unit groups are arranged on the silicon substrate in an array mode, and each thermopile unit group comprises a reference thermopile and a test thermopile. Each of the reference thermal pile and the test thermal pile comprises a heat insulation cavity, three layers of supporting films, a plurality of polycrystalline silicon thermocouple pairs, an annular heater, uniform heating metal, a heating electrode and an output electrode; the three layers of supporting films are arranged on the heat insulation cavity; a plurality of polycrystalline silicon thermocouple pairs are connected in series and are wrapped between the lower two layers of supporting films; the annular heater is wrapped between the upper two layers of supporting films; the uniform heating metal is wrapped between the upper two layers of supporting films and located in the middle of the annular heater, and the catalyst is located on the surface of the uppermost layer of supporting film and covers the uniform heating metal. The MEMS thermopile array chip provided by the invention has the characteristics of low detection lower limit, wide linear range, short response recovery time and the like, and can be used for detecting the concentration of multi-component gas.

Description

Technical Field

[0001] The present invention belongs to the technical field of microchips and intelligent sensors, and in particular relates to a MEMS thermal pile array chip and a multi-component gas detection device. Background Art

[0002] Combustible gas detection has a wide range of applications in industry, new energy, nuclear power, lithium-ion hydrogen vehicles, and other fields. For example, natural gas and liquefied petroleum gas are important fuels used in industrial boilers, power generation, and other fields. In the chemical industry, combustible gases such as hydrogen and methane are important raw materials used to synthesize chemicals such as ammonia and methanol. They are also key components of cracking and reforming processes in the petrochemical industry. More importantly, as the impact of global warming on the climate becomes increasingly significant, countries around the world are actively transforming their energy structures and setting carbon neutrality goals. Hydrogen, as an important clean energy source of the future, can be used to generate electricity in fuel cells and is used in automobiles, trains, ships, aviation, and other fields.

[0003] In many scenarios, flammable gases do not simply occur as a single component, but rather as a combination of two or more. For example, hydrogen is mixed into natural gas to create hydrogen-doped methane, which is used in both daily life and industrial production. This method not only improves the combustion efficiency of natural gas and reduces carbon emissions, but also leverages existing infrastructure such as natural gas pipelines for hydrogen transportation and use, significantly reducing the cost of hydrogen energy. This practice is gaining popularity worldwide. In substations, as transformers age, insulation between windings weakens, leading to arcing under high voltage. This arcing ultimately causes the sealing oil to release a variety of flammable gases, such as hydrogen, methane, and acetylene. Because these flammable gases are flammable and explosive, leaks during pipeline transportation or storage, or when transformers malfunction, can easily cause combustion and explosion, resulting in personal injury and economic losses. Therefore, rapid, real-time detection of trace amounts of flammable gases is essential.

[0004] Currently, combustible gas sensors primarily include electrochemical, semiconductor, and catalytic combustion types. Electrochemical and semiconductor sensors utilize the adsorption and diffusion of gas molecules, but their linear range of concentration detection is limited (typically spanning 1-2 orders of magnitude), and their response and recovery speeds are slow (tens to hundreds of seconds), making them unsuitable for rapid, real-time detection. Sensors based on catalytic combustion (such as ceramic tube structures) face challenges such as large size, high operating temperatures (e.g., 560°C for hydrogen), high power consumption (hundreds of milliwatts), and low detection limits.

[0005] More importantly, these sensors typically only detect a single gas component. Mixed combustible gases increase the complexity of gas detection, placing higher demands on sensor chips and detection devices, requiring them to possess high sensitivity, fast response, low power consumption, and multi-component detection capabilities. Summary of the Invention

[0006] The main purpose of the present invention is to propose a MEMS thermal pile array chip and a multi-component gas detection device, which can effectively solve the problems in the background technology.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] A MEMS thermal pile array chip includes a silicon substrate, on which a plurality of thermal pile unit groups are arranged in an array, wherein the thermal pile unit groups include a reference thermal pile and a test thermal pile, and the reference thermal pile and the test thermal pile both include

[0009] a heat-insulating cavity, formed on the upper surface of the silicon substrate;

[0010] Three layers of support membranes are provided on the thermal insulation cavity;

[0011] A plurality of polysilicon thermocouple pairs are connected in series and wrapped between the two lower support films, wherein the polysilicon thermocouple pairs are arranged in a centrally symmetrical manner, with their hot ends located in the central region of the support film and their cold ends located in the edge region of the support film;

[0012] a ring heater, wrapped between the two upper support films and located above the hot ends of the plurality of polysilicon thermocouple pairs;

[0013] A uniformly heated metal is wrapped between the two upper support films and located in the middle of the annular heater;

[0014] a heating electrode, disposed on the silicon substrate and electrically connected to the annular heater;

[0015] an output electrode, disposed on the silicon substrate and electrically connected to the plurality of polysilicon thermocouple pairs;

[0016] The test thermal stack further includes a catalyst, which is located on the surface of the uppermost support film and covers the uniform heat metal.

[0017] Preferably, the uniform heat metal is annular and made of metal Mo.

[0018] Preferably, the support film is made of silicon nitride.

[0019] Preferably, the polysilicon thermocouple pair is a linear structure.

[0020] A multi-component gas detection device, comprising the above-mentioned MEMS thermal pile array chip, and also comprising

[0021] a housing, wherein the housing has a display screen;

[0022] a test circuit, installed in the housing and electrically connected to the display screen;

[0023] A PCB board is plugged into the test circuit, the PCB board has a test cavity, and the MEMS thermopile array chip is installed in the test cavity;

[0024] A battery is installed in the housing and is used to supply power to the test circuit.

[0025] The present invention provides a MEMS thermal pile array chip and a multi-component gas detection device, which have the following beneficial effects:

[0026] 1. The MEMS thermopile array chip of the present invention detects the concentration of target combustible gas molecules through the differential signal after measuring the difference between the output voltage of the test thermopile and the output voltage of the reference thermopile. It has the characteristics of a low detection limit (0.5-1ppm), a wide linear range (spanning 4 orders of magnitude), and a short response recovery time (<1 second). Compared with existing sensors, it has superior and comprehensive performance and is capable of detecting the concentration of multiple components of gases, which has good application prospects.

[0027] 2. In the present invention, the support membrane has a three-layer structure, with several polysilicon thermocouples encapsulated between two layers of support membrane. The three-layer support membrane and the polysilicon thermocouples can be deposited via chemical vapor deposition. This results in thinner polysilicon thermocouples and the support membrane, and a smaller heat capacity for the support membrane. After the catalytic reaction releases heat, the support membrane absorbs heat and heats up faster, resulting in a shorter device response time and greater sensitivity to heat release from gases with lower concentrations. Furthermore, the thinner support membrane allows for a greater temperature rise when absorbing the same amount of heat, making it more sensitive to heat release from gases with lower concentrations. This reduces the required heating power consumption to achieve the same temperature.

[0028] 3. The presence of a uniform heating metal improves temperature uniformity in the central heating area of ​​the support membrane. With the metal in place, the device's temperature deviation in the heating area is only 1%, significantly better than devices without the metal. This improved temperature uniformity allows for more uniform heating of the catalyst, thereby increasing signal strength and enabling detection of even lower gas concentrations. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of the MEMS thermopile array chip of the present invention;

[0030] Figure 2 Schematic diagram of the structure of a single reference thermal pile and a test thermal pile of the present invention;

[0031] Figure 3 This is a schematic structural diagram of a three-layer support membrane and a polysilicon thermocouple pair according to the present invention;

[0032] Figure 4 This is a schematic structural diagram of two thermal stack unit groups according to the second embodiment of the present invention;

[0033] Figure 5 This is a schematic diagram of the response recovery curve of H2 and CH4 in Example 2 of the present invention;

[0034] Figure 6 This is a test effect diagram of different concentrations of H2 and CH4 and the corresponding differential signals in Example 2 of the present invention;

[0035] Figure 7 This is a schematic diagram of the detection concentration results of the H2 and CH4 mixed gas in Example 2 of the present invention;

[0036] Figure 8 This is a test diagram of the temperature uniformity of the central heating area of ​​the support film in the case of uniformly heated metal in the present invention;

[0037] Figure 9 This is a test diagram of the temperature uniformity of the central heating area of ​​the support film in the case of no uniform heating metal in the present invention;

[0038] Figure 10 This is an exploded view of the multi-component gas detection device of the present invention;

[0039] Figure 11 Schematic diagram of the test circuit of the present invention.

[0040] In the figure: 100, silicon substrate; 1, reference thermopile; 2, test thermopile; 10, thermal insulation cavity; 20, support membrane; 30, polysilicon thermocouple; 40, ring heater; 50, uniform heating metal; 60, heating electrode; 70, output electrode; 80, catalyst; 101, MEMS thermopile array chip; 102, housing; 103, test circuit; 104, PCB board; 105, battery; 106, display screen. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention.

[0042] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention.

[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a communication between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0045] Example 1

[0046] Reference Figure 1-3 A MEMS thermal pile array chip 101 includes a silicon substrate 100, on which a plurality of thermal pile unit groups are arranged in an array. The thermal pile unit groups include a reference thermal pile 1 and a test thermal pile 2. The reference thermal pile 1 and the test thermal pile 2 both include

[0047] A heat-insulating cavity 10 is provided on the upper surface of the silicon substrate 100;

[0048] Three layers of support film 20 are provided on the thermal insulation cavity 10;

[0049] A plurality of polysilicon thermocouple pairs 30 are connected in series and wrapped between the two lower support films 20. The polysilicon thermocouple pairs 30 are arranged in a centrally symmetrical manner, with their hot ends located in the central region of the support film 20 and their cold ends located in the edge region of the support film 20.

[0050] a ring heater 40 , wrapped between the two upper support films 20 and located above the hot ends of the plurality of polysilicon thermocouple pairs 30 ;

[0051] The uniform heat metal 50 is wrapped between the two upper support films 20 and located in the middle of the annular heater 40;

[0052] A heating electrode 60 is provided on the silicon substrate 100 and is electrically connected to the annular heater 40 ;

[0053] an output electrode 70 , disposed on the silicon substrate 100 and electrically connected to the plurality of polysilicon thermocouple pairs 30 ;

[0054] The test thermal stack 2 further includes a catalyst 80 , which is located on the surface of the uppermost support film 20 and covers the uniform heat metal 50 .

[0055] In this embodiment, the uniform heat metal 50 is annular and made of metal Mo, the support film 20 is made of silicon nitride, and the polysilicon thermocouple pair 30 is a linear structure.

[0056] In this embodiment, the thermal insulation cavity 10 is obtained by deep reactive ion etching on the silicon substrate 100, and the three-layer support film 20 and the polysilicon thermocouple pair 30 are obtained by chemical vapor deposition. The support film 20 can suspend the polysilicon thermocouple pair 30, the ring heater 40, and the uniform heat metal 50 above the thermal insulation cavity 10, thereby reducing the heat loss of the reference thermal pile 1 and the test thermal pile 2 and ensuring the accuracy of the test results. The diameter of the support film 20 is 600μm, the number of polysilicon thermocouple pairs 30 is 8 pairs, and the ring heater 40 and the uniform heat metal 50 are obtained by magnetron sputtering. The diameter surrounded by the ring heater 40 is 250μm.

[0057] The polycrystalline silicon thermocouple pair 30 includes an N-type polycrystalline silicon thermocouple and a P-type polycrystalline silicon thermocouple. The N-type and P-type single crystal silicon thermocouples are connected in series via a metal interconnect structure. Multiple single crystal silicon thermocouple pairs are also connected in series via a metal interconnect structure. When multiple pairs of thermocouples are connected in series, the resulting thermoelectromotive force is U = N(αA - αB)ΔT, where αA and αB are the Seebeck coefficients of p-type and n-type doped polycrystalline silicon, and N is the number of thermocouples.

[0058] In the present invention, a thermal stack unit group includes a reference thermal stack 1 and a test thermal stack 2. The surface of the uppermost support membrane 20 of the reference thermal stack 1 is not loaded with a catalyst 80, while the surface of the uppermost support membrane 20 of the test thermal stack 2 is loaded with a specific catalyst 80. The catalyst 80 can catalyze the target combustible gas molecules to undergo an oxidation reaction with oxygen in the air at the optimal catalytic temperature to release heat.

[0059] Specifically, when the MEMS thermopile array chip 101 of the present invention is in use, a heating voltage (V H), after the annular heater 40 releases heat, it controls the temperature of the reference thermal pile 1 and the test thermal pile 2 so that the temperature of the reference thermal pile 1 and the test thermal pile 2 reach the optimal catalytic temperature of the catalyst 80, wherein the heat of the annular heater 40 is transferred to the catalyst 80 through the uniform heat metal 50 and the support membrane 20.

[0060] The hot end of the polysilicon thermocouple pair 30 is located in the central area of ​​the support film 20, and the temperature of this end is the temperature of the reference thermopile 1 and the test thermopile 2. The cold end of the polysilicon thermocouple pair 30 is located in the edge area of ​​the support film 20, and the temperature is close to room temperature, so that a small thermoelectric potential is generated between the two ends (cold end and hot end) of the polysilicon thermocouple pair 30, and the small thermoelectric potential gradually accumulates on the polysilicon thermocouple pair 30 in series, and finally forms an output voltage (Vs) at the output electrode 70 of the test thermopile 2 and an output voltage (Vs) at the output electrode 70 of the reference thermopile 1. r ), after the output voltage (Vs) of the test thermal pile 2 is differentiated from the output voltage (Vr) of the reference thermal pile 1, the concentration of the target combustible gas molecules is detected by the differential signal ΔV (ΔV=Vs-Vr).

[0061] More specifically, when there is an extremely low concentration (ppm level) of target combustible gas molecules in the detection environment, under the catalysis of the catalyst 80, the target combustible gas molecules undergo an oxidation reaction with oxygen in the air to release heat, and the polysilicon thermocouple of the test thermal stack 2 absorbs the reaction heat and the temperature rises. The differential signal ΔV (ΔV=Vs-Vr) reflects the catalytic oxidation heat release process of the target combustible gas molecules in the detection environment, and its output signal intensity is proportional to the concentration of the target combustible gas molecules in the detection environment.

[0062] Example 2

[0063] The silicon substrate 100 of the present invention is provided with a plurality of thermal stack unit groups in an array. The thermal stack unit groups include a reference thermal stack and a test thermal stack, and can detect the concentration of multi-component gases. This will be further described below with reference to specific embodiments.

[0064] Reference Figure 4Taking a monolithic integrated 4-channel thermal stack array chip as an example, two thermal stack unit groups, Group A and Group B, comprised of a reference thermal stack a and a test thermal stack a, as well as a reference thermal stack b and a test thermal stack b, were used to verify the concentration of a two-component gas mixture of hydrogen (H2) and methane (CH4). The chip measures 2mm x 2mm. Test thermal stacks a and b were each loaded with a precious metal catalyst. Test thermal stack a was loaded with a platinum nanoparticle / alumina (Pt / Al2O3) catalyst. The Pt nanoparticles catalyze H2 at 120°C and are unaffected by moisture. Test thermal stack b was loaded with a palladium nanoparticle / alumina (Pd / Al2O3) catalyst. The Pd nanoparticles catalyze CH4 at 400°C. Reference thermal stacks a and b served as references for the two test thermal stacks.

[0065] A heating voltage (V H1 ), the annular heater 40 heats the reference thermal pile a and the test thermal pile a to 120°C, so that the catalyst 80Pt / Al2O3 works at the optimal temperature for H2 catalysis. During the test, the output electrode 70 of the test thermal pile a forms an output voltage (V s1 ), the output electrode 70 of the reference thermal pile a forms an output voltage (V r1 A heating voltage (V H2 ), the annular heater 40 heats the reference thermal pile b and the test thermal pile b to 400°C, so that the catalyst 80Pd / Al2O3 works at a suitable temperature for CH4 catalysis, and the output electrode 70 of the test thermal pile b forms an output voltage (V s2 ), the output electrode 70 of the reference thermopile b forms an output voltage (V r2 ).

[0066] like Figure 5 The figure shows the response curve of the MEMS thermal stack array chip to H2 and CH4. When only air is introduced, no catalytic reaction occurs, and the output differential voltage ΔV is almost 0. When a mixture of 1000ppm of hydrogen, methane and air is introduced, the catalyst 80 catalyzes the oxidation reaction to release heat, and the output signals of group a thermal stack unit group and group b thermal stack unit group are differentiated to output a corresponding differential voltage ΔV. When it is switched to only air again, the differential voltage ΔV is almost 0. The time required for the chip to be exposed to the target gas and for its output signal to reach 90% of the stable value is the response time. The time required for the chip to be out of the target gas environment and for its output signal to recover to 10% of the initial baseline value is the recovery time. Figure 5 It can be observed that the chip's response recovery time to H2 is 0.6s, and the response recovery time to CH4 is 0.9s.

[0067] Calibrate the gas detection performance of the thermal pile array chip, Figure 6 The chip demonstrates the concentration detection range and lower detection limit for a single component (H2 or CH4). When mixed gases of varying concentrations are introduced into the test chamber, the differential output voltage ΔV shows a linear relationship with the gas concentration. The thermopile array chip's detection range for H2 is 0.5ppm-2%, and for CH4, it is 1ppm-2%, spanning four orders of magnitude.

[0068] like Figure 7 The following is the detection result of H2 and CH4 mixed gas by MEMS thermal pile array chip. Figure 6 The calibrated test thermopile A and test thermopile B plotted the H2 and CH4 concentration-output voltage curves, respectively, to obtain sensitivity (the slope of the line). The resulting mixed gas signals, ΔV1 and ΔV2, were then used to calculate the H2 and CH4 concentrations, respectively. The experimental results show that the MEMS thermopile array chip can accurately detect the concentrations of hydrogen and methane, respectively, for mixed gases with concentrations ranging from 50 to 4000 ppm for H2 and 400 to 19000 ppm for CH4, with the deviation between the detected values ​​and the set values ​​being less than 5%.

[0069] The MEMS thermal pile array chip of the present invention has a plurality of thermal pile unit groups, and the output voltage (V sn ) and the reference thermal pile 1 output voltage (V rn ) after differential, through the differential signal ΔV n (ΔV n =V sn -V rn ) to detect the concentration of each target combustible gas molecule. It has the characteristics of low detection limit (0.5-1ppm), wide linear range (spanning 4 orders of magnitude), and short response recovery time (<1 second). Compared with existing sensors, it has superior and comprehensive performance, and can detect the concentration of multi-component gases, and has good application prospects.

[0070] It should be further explained that in the present invention, the support film 20 has a three-layer structure, and a plurality of polysilicon thermocouple pairs 30 are wrapped between two layers of support film 20. The three-layer support film 20 and the polysilicon thermocouple pairs 30 can be obtained by chemical vapor deposition. This makes the thickness of the polysilicon thermocouple pairs 30 and the support film 20 thinner, and the heat capacity of the support film 20 is also smaller. After the catalytic reaction releases heat, the support film 20 absorbs heat and heats up faster, the response time of the device is shorter, and it is more sensitive to heat release from gases with lower concentrations. At the same time, the thinner support film 20 allows it to increase its temperature more when absorbing the same amount of heat, and is more sensitive to heat release from gases with lower concentrations. At the same time, less heat is dissipated to the outside world, which means that the power required to heat to the same temperature is also smaller, which is beneficial to reducing the power consumption of the MEMS thermal stack array chip 101.

[0071] On the other hand, in the present invention, the temperature uniformity of the central heating area of ​​the support film 20 is improved by setting the uniform heating metal 50. Figure 8-9 Testing the temperature uniformity of the central heating area of ​​the support film 20 reveals that with the presence of the uniform heating metal 50, the temperature deviation is ±5°C, meaning the temperature deviation in the device's heating area is only approximately 1%, significantly better than a device without the uniform heating metal 50. This improved temperature uniformity allows for more uniform heating of the catalyst 80, thereby increasing signal strength and enabling detection of even lower gas concentrations.

[0072] Example 3

[0073] Reference Figure 10 The present invention also provides a multi-component gas detection device, including the above-mentioned MEMS thermal pile array chip 101, and also including

[0074] The housing 102 is composed of an upper and a lower part, and has a display screen 106 on the housing 102;

[0075] A test circuit 103 is installed in the housing 102 and is electrically connected to the display screen 106;

[0076] A PCB board 104 is plugged into the test circuit 103 . The PCB board 104 has a test cavity, and the MEMS thermopile array chip 101 is installed in the test cavity.

[0077] The battery 105 is installed in the housing 102 and is used to supply power to the test circuit 103 .

[0078] Specifically, refer to Figure 11The test circuit 103 mainly includes a heating and reading circuit and a control and processing circuit. Among them, the heating and reading circuit includes a power supply module, a heating module, and a multi-channel signal reading module. The control and processing circuit includes a heating control module, a signal processing module, and a screen display module. The heating module is responsible for converting the PWM heating voltage into an analog signal and providing it to the chip heater. The multi-channel signal reading module collects the output voltage of each thermal pile, and transmits it to the data processing module after filtering and amplification. The data processing module changes the thermal pile heating voltage by adjusting the duty cycle of the PWM signal, thereby adjusting the thermal pile temperature, and uses a 12-bit ADC to convert the thermal pile output voltage into a digital signal, which is calculated and processed by the STM32 and then transmitted to the screen for display. The test circuit can realize independent adjustment of the operating temperature of the thermal pile array and synchronous display of the thermal pile output voltage and gas concentration.

[0079] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A MEMS thermal pile array chip, characterized by: It includes a silicon substrate, on which a plurality of thermal pile unit groups are arranged in an array, wherein the thermal pile unit group includes a reference thermal pile and a test thermal pile, and the reference thermal pile and the test thermal pile both include a heat-insulating cavity, formed on the upper surface of the silicon substrate; Three layers of support membranes are provided on the thermal insulation cavity; A plurality of polysilicon thermocouple pairs are connected in series and wrapped between the two lower support films, wherein the polysilicon thermocouple pairs are arranged in a centrally symmetrical manner, with their hot ends located in the central region of the support film and their cold ends located in the edge region of the support film; a ring heater, wrapped between the two upper support films and located above the hot ends of the plurality of polysilicon thermocouple pairs; A uniformly heated metal is wrapped between the two upper support films and located in the middle of the annular heater; a heating electrode, disposed on the silicon substrate and electrically connected to the annular heater; an output electrode, disposed on the silicon substrate and electrically connected to the plurality of polysilicon thermocouple pairs; The test thermal stack further includes a catalyst, which is located on the surface of the uppermost support film and covers the uniform heat metal.

2. The MEMS thermopile array chip according to claim 1, characterized in that: The uniform heat metal is in the shape of a ring and is made of metal Mo.

3. The MEMS thermopile array chip according to claim 1, characterized in that: The material of the support film is silicon nitride.

4. The MEMS thermopile array chip according to claim 1, characterized in that: The polysilicon thermocouple pair is a linear structure.

5. A multi-component gas detection device comprising the MEMS thermopile array chip according to any one of claims 1 to 4, characterized in that: Also includes a housing, wherein the housing has a display screen; a test circuit, installed in the housing and electrically connected to the display screen; A PCB board is plugged into the test circuit, the PCB board has a test cavity, and the MEMS thermopile array chip is installed in the test cavity; A battery is installed in the housing and is used to supply power to the test circuit.

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