Electrode of calorimetric micro-flow sensor and preparation method thereof

Abstract

The present invention discloses an electrode for a calorimetric micro-flow sensor and a method for making the same. The electrode is configured as an arched structure, with a 200μm gap between the lowest point of the arched structure and the electrode mounting plate. The present invention provides an electrode for a calorimetric micro-flow sensor and a method for making the same. The electrode is configured as an arched structure, and due to the gap between the electrode and the substrate, the electrode heating temperature is less consumed by conduction through the substrate. After the heating electrodes reach similar temperatures, the same gas flow rate is introduced, and the maximum temperature difference between the temperature measuring electrodes on both sides is 6°C and 55°C, respectively, improving the temperature difference by 49°C. This improves measurement accuracy. Furthermore, under different air temperatures and heating electrode temperatures, the electrode structure can achieve significant temperature difference discrimination at different flow rates, when the temperature measuring electrodes on both sides are at an optimal distance from the central heating electrode, thereby improving the resolution and sensitivity of the sensor.

Description

Technical Field

[0001] The present invention relates to the field of sensor design, and more particularly to an electrode of a calorimetric micro-flow sensor and a method for preparing the same. Background Art

[0002] Micro flow sensors, typically MEMS (micro-electromechanical systems) devices, are devices used to measure minute flows (such as air or liquid flows). Based on their operating principles, micro flow sensors can be divided into various types, such as thermal and piezoelectric. Thermal flow sensors detect flow velocity based on the principle of heat transfer in fluids. When a fluid passes through a stable thermal field heated by a heat source at a certain speed, the thermal field changes. By measuring this change, accurate flow velocity measurement can be achieved. Thermal flow sensors can be further divided into hot-wire and calorimetric flow sensors. Compared to hot-wire sensors, calorimetric sensors offer smaller size, a larger range, higher integration, and are less susceptible to environmental and environmental influences, making them particularly widely used. However, current methods for fabricating calorimetric micro sensors primarily utilize photolithography to create the sensor chip and integrate the channel and signal processing circuitry with the sensor chip. However, photolithography is costly, complex, and requires high operational requirements.

[0003] At the same time, the heating electrodes on existing calorimetric flow sensors all adopt a laminated design. Therefore, traditional flow sensors will create a hollow structure to improve sensor performance. However, due to the laminated design with the substrate, the temperature generated by the heating electrode will still diffuse from the substrate surface, affecting its detection sensitivity and increasing its power consumption. Summary of the Invention

[0004] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0005] To achieve these objectives and other advantages of the present invention, an electrode of a calorimetric micro-flow sensor is provided. The electrode is configured to have an arch structure, and a distance of 200 μm is between the lowest point of the arch structure and an electrode mounting plate.

[0006] Preferably, the electrode is configured to include:

[0007] Two metal pillars are arranged opposite to each other on the electrode mounting plate;

[0008] A comb-type electrode provided at the upper end of each metal column and used to connect two metal columns into an integrated structure;

[0009] The metal column has a height of 200 μm and a diameter of 50 μm.

[0010] Preferably, the overall size of the comb electrode is 650 μm×300 μm, and the electrode wire in the comb electrode has a width of 50 μm and a height of 20 μm.

[0011] A method for preparing an arch electrode, used in the preparation of an electrode for a calorimetric micro-flow sensor, comprises:

[0012] S1. preparing a conductive substrate;

[0013] S2, connecting the substrate to the negative electrode, and depositing metal pillars on the metal film by MCED electrochemical deposition method;

[0014] S3. Depositing a comb-type electrode structure laterally above the metal pillar.

[0015] Preferably, in S1, the preparation method of the conductive substrate includes:

[0016] S10, pre-treating the base material to remove grease, dust and other impurities on the surface of the base material;

[0017] S11. Place the base material in a vacuum chamber of predetermined cleanliness, and heat the selected metal material so that the metal atoms or ions evaporated or sputtered into gaseous form can be adsorbed and condensed on the surface of the silicon wafer, thereby obtaining a metal film layer on the base material through physical vapor deposition.

[0018] Preferably, it is characterized in that, in S2, the method of depositing the metal pillar comprises:

[0019] S20, adding an electrolyte solution for preparing deposited metal into a pipette, and inserting a metal wire into the pipette and connecting the metal wire to the positive electrode;

[0020] S21. When the electrolyte solution in the pipette contacts the conductive substrate, the metal ions in the electrolyte solution are reduced to metal by electrons and deposited on the substrate, while the metal in the pipette loses electrons and oxidizes to metal ions, replenishing the metal ions lost in the pipette.

[0021] S22. Adjust the height of the pipette to deposit the metal column until the metal column reaches a predetermined height.

[0022] Preferably, in S3, during the process of transversely depositing the comb-type electrode structure, the position of the deposition pipette is controlled by a multi-degree-of-freedom displacement component, and the multi-degree-of-freedom displacement component is communicatively connected to an external control terminal.

[0023] Preferably, the method further includes simulating the performance of the arch electrode through simulation, wherein the simulation process includes:

[0024] S4. Modeling the structures of the bonded electrode and the arch electrode respectively using modeling software;

[0025] S5. Import the modeled electrode models into COMSOL finite element simulation software, set the substrate material to silicon wafer, and set the electrode material to metal, to complete the establishment of the simulation model;

[0026] S6. Set free air with a height of 0.5 mm above each simulation model, and introduce air of different flow rates on one side. Set different heating powers for the middle heating electrodes of the sensors corresponding to the bonding electrode and the arch electrode to achieve the same heating electrode temperature. Compare the heating powers and complete the simulation analysis after the model is meshed.

[0027] S7. Through simulation analysis, the optimal distance between the temperature measuring electrodes on both sides and the central heating electrode at different flow rates is obtained.

[0028] Preferably, at an air temperature of 0 to 50° C. and an air flow rate of 0 to 1 m / s, the distance between the temperature measuring electrodes on both sides and the central heating electrode is 200 to 250 μm.

[0029] Preferably, by simulating different air temperatures of 0°C, 25°C, and 50°C and different heating electrode temperatures of 100°C and 150°C, and passing air flow rates of 0.1m / s, 0.4m / s, 0.7m / s, and 1.0m / s, it is obtained that the distance between the temperature measuring electrodes on both sides and the central heating electrode is preferably 238μm.

[0030] The present invention includes at least the following beneficial effects: First, the present invention provides an arch electrode. Since there is a distance between the electrode and the substrate, the conduction consumption of the electrode heating temperature in the substrate is reduced. After the heating electrodes produce similar temperatures, the same gas flow rate is introduced, and the maximum temperature difference between the temperature measuring electrodes on both sides is 6°C and 55°C respectively, which improves the temperature difference by 49°C, making its measurement accuracy better.

[0031] Secondly, through simulation experiments, it can be seen that the arch electrode of the present invention, under the influence of the ambient temperature of 0-50°C air temperature and the heating electrode temperature of 100°C and 150°C, can have a stable temperature difference with obvious temperature difference differentiation when the temperature measuring electrodes on both sides are about 238μm away from the central heating electrode, so that the measurement resolution and sensitivity are better.

[0032] Third, simulation tests show that the arch electrode of the present invention has a small contact area between the heating electrode and the substrate, so that the generated temperature will not diffuse in the substrate and cause temperature loss, and the contact area between the electrode and the gas is increased. Therefore, compared with traditional electrodes, the thermal power consumed to reach the same temperature is quite different. That is, if the temperature needs to reach 150°C, the traditional sensor needs to set a thermal power of 0.175W, while the new sensor of the present invention only needs to set a thermal power of 0.0435W, saving 75% of energy.

[0033] Fourthly, the present invention deposits metal electrodes on a substrate based on the MCED electrochemical deposition principle, so that the electrodes can have a complex three-dimensional structure and can reach a micron-level size, with better adaptability.

[0034] Fifth, compared with the existing photolithography technology that requires the preparation of flow sensors on a silicon wafer substrate, this patent can perform MCED electrochemical deposition of any depositable metal electrode on any conductive substrate, making the sensor substrate diverse.

[0035] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is the main view of the arch electrode structure deposited using MCED deposition technology;

[0037] Figure 2 Schematic diagram of the principle of the droplet confinement electrodeposition technology (MCED) used in the present invention;

[0038] Figure 3 Schematic diagram of the deposition of a metal film on a substrate using physical vapor deposition;

[0039] Figure 4 Schematic diagram of the process of depositing metal pillars on a conductive substrate using the MCED method of the present invention;

[0040] Figure 5 Schematic diagram of the metal pillars deposited on a conductive substrate using the MCED method of the present invention;

[0041] Figure 6 Schematic diagram of the process of depositing a comb-type electrode on a conductive substrate using the MCED method of the present invention;

[0042] Figure 7 This is the main dimension diagram of the laminated electrode after modeling;

[0043] Figure 8 A side dimensional diagram of the laminated electrode after modeling;

[0044] Figure 9 A front perspective view of the modeled arch electrode of the present invention;

[0045] Figure 10 Electrode top view dimensions after modeling the arch electrode and the fitted electrode;

[0046] Figure 11 A side dimensional diagram of the arch electrode after modeling of the present invention;

[0047] Figure 12 The COMSOL model diagram after the arch electrode is imported into the finite element simulation software;

[0048] Figure 13 The COMSOL model diagram after the bonded electrode is imported into the finite element simulation software;

[0049] Figure 14 The following is a simulation analysis curve diagram after meshing using the existing bonded electrode model when the air temperature is 25°C, the heating electrode temperature is 100°C, and the air flow rates are 0.1m / s, 0.4m / s, 0.7m / s, and 1.0m / s.

[0050] Figure 15 The following is a simulation analysis curve diagram after meshing using the arch electrode model of the present invention when the air temperature is 25°C, the heating electrode temperature is 100°C, and the air flow rates are 0.1m / s, 0.4m / s, 0.7m / s, and 1.0m / s;

[0051] Figure 16 The following is a simulation analysis curve diagram after meshing using the arch electrode model of the present invention when the air temperature is 0°C, the heating electrode temperature is 100°C, and the air flow rates are 0.1m / s, 0.4m / s, 0.7m / s, and 1.0m / s;

[0052] Figure 17 It is a simulation analysis curve diagram after meshing using the arch electrode model of the present invention when the air temperature is 0°C, the heating electrode temperature is 150°C, and the air flow rates are 0.1m / s, 0.4m / s, 0.7m / s and 1.0m / s.

[0053] Figure 18 The following is a simulation analysis curve diagram after meshing using the arch electrode model of the present invention when the air temperature is 25°C, the heating electrode temperature is 150°C, and the air flow rates are 0.1m / s, 0.4m / s, 0.7m / s, and 1.0m / s;

[0054] Figure 19The following is a simulation analysis curve diagram after meshing using the arch electrode model of the present invention when the air temperature is 50°C, the heating electrode temperature is 100°C, and the air flow rates are 0.1m / s, 0.4m / s, 0.7m / s, and 1.0m / s;

[0055] Figure 20 It is a simulation analysis curve diagram after meshing using the arch electrode model of the present invention when the air temperature is 50°C, the heating electrode temperature is 150°C, and the air flow rates are 0.1m / s, 0.4m / s, 0.7m / s and 1.0m / s. DETAILED DESCRIPTION

[0056] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0057] Electrochemical deposition (ECD) is a processing method that controls the electrochemical reaction conditions in micro-regions of an electrode surface to prepare metal or alloy materials and manufacture parts through atomic-scale layer-by-layer stacking. It boasts a wide range of materials, low processing temperatures, easy shape control, and high spatial resolution, making it a promising approach for metal micro- and nano-additive manufacturing. Electrochemical deposition techniques can be categorized into maskless and masked deposition based on their principle. Masked deposition, represented by through-mask electroplating (Through-mask Electroplating), instant masking plating (IMPlating), electrochemical fabrication (EFAB), and LIGA (Lithography, Electroforming, and Molding), offers the advantages of high precision and repeatability, but is also costly, requires a long preparation cycle, and the mask often remains on the structure. Maskless electrochemical deposition is represented by localized electrochemical deposition (LECD), jet electrochemical deposition (Jet ECD), fluid force microscope electrodeposition (FluidFM Electrodeposition), and meniscus-confined electroplating (MCED). Masked deposition technology usually has higher forming accuracy and better surface quality, but it is difficult to produce truly three-dimensional complex microstructures. Maskless deposition technology has the potential to produce complex three-dimensional microstructures, but it is usually not as good as masked deposition technology in terms of surface quality and geometric accuracy. Therefore, maskless deposition technology is still an important method for the preparation of micro-nanostructures. Among them, droplet confined electrodeposition technology (MCED) has become a research hotspot in electrochemical deposition technology due to its ability to directly print without a mold and meet the requirements of multi-material manufacturing.

[0058] The MCED method is a type of electrochemical three-dimensional micro-deposition technology that relies on a micropipette nozzle filled with an electrolyte. The outlet diameter of the pipette nozzle is usually between hundreds of nanometers and microns. When this micropipette nozzle approaches the surface of the substrate, a continuous and stable meniscus (also called a curved liquid surface or liquid) can be formed between the nozzle outlet and the substrate. Under the action of an external electric field, a chemical reaction will occur inside the meniscus, thereby forming a metal with three-dimensional shape characteristics on the conductive substrate. By coordinating the withdrawal speed of the pipette from the substrate surface with the growth rate of local deposition, the continuous growth of nanowires or microwires on the surface of the body can be achieved.

[0059] The system principle corresponding to the MCED method is as follows Figure 2 As shown in the figure, it mainly uses a glass probe drawn into a micron or nanometer diameter as the printing nozzle, a simple electrode wire as the counter electrode (CE), and a conductive substrate as the working electrode (WE). When a potential difference is applied between the substrate and the electrode wire, electron transfer is triggered in the droplet bridge contact area, causing electrodeposition to occur only in the area covered by the droplet bridge, achieving localized printing of the target structure. Its system principle.

[0060] Given the excellent performance of MCED in printing simple vertical structures, extending MCED technology from vertical structures to planar structure printing, creating complex three-dimensional structures in a layered form, can be used to fabricate micro flow sensor electrodes to meet the structural requirements of micro sensors. Therefore, in response to the current method of fabricating micro flow sensor chips, which primarily relies on photolithography and is characterized by high production costs, complex processes, and demanding operational requirements, this present invention proposes a method for fabricating micro flow sensors based on the principles of MCED electrochemical deposition, reducing the cost and difficulty of micro flow sensor fabrication and providing a new approach for micro flow sensor fabrication.

[0061] Example 1

[0062] A method for preparing an arch electrode for a calorimetric micro-flow sensor comprises the following steps:

[0063] Step 1: Prepare a conductive substrate, such as preparing a sensor chip on a silicon wafer.

[0064] 1. Silicon wafers need to go through rigorous pre-treatment steps to ensure their surfaces are clean, flat, and free of contaminants. This typically includes chemical cleaning, ultrasonic cleaning, and possibly a vacuum drying process to thoroughly remove grease, dust, and other impurities from the surface of the silicon wafer.

[0065] 2. The silicon wafer is placed in a highly clean vacuum chamber. In the vacuum chamber, the selected metal material is heated to a high temperature by a precisely controlled heating element or a high-energy particle beam (such as an electron beam or an ion beam), causing it to evaporate or sputter into gaseous metal atoms or ions. These gaseous metal atoms or ions diffuse freely in the vacuum and are adsorbed and condensed on the surface of the silicon wafer. By adjusting the deposition parameters (such as deposition temperature, gas pressure, deposition time, and the choice of metal material, etc.), the substrate layer (such as Figure 3 The thickness, composition and microstructure of the metal film on the PDMS microscope were analyzed.

[0066] Step 2: Connect the substrate to the negative electrode and deposit metal pillars on the metal film by MCED electrochemical deposition method.

[0067] 1. Prepare the electrolyte solution for metal deposition and add it into the pipette. Insert the metal wire into the pipette and connect the metal wire to the positive electrode, for example Figure 4 Depositing metal columns, when the electrolyte solution in the pipette contacts the conductive substrate, the metal cations in the electrolyte solution will gain electrons and be reduced to metal and deposited on the substrate, and the metal in the pipette will lose electrons and be oxidized to metal cations to replenish the lost metal cations in the pipette.

[0068] 2. Deposit metal pillars by continuously changing the height of the pipette. When the predetermined height is reached, stop energizing and remove the pipette to obtain the metal pillar structure in the electrode structure (such as Figure 5 shown).

[0069] Step 3: Deposit the comb electrode structure laterally above the metal pillars.

[0070] 1. Connect the substrate to the negative electrode, add the electrolyte solution of the deposited metal into the pipette, connect the metal in the pipette to the positive electrode, and then align the pipette nozzle with the metal column (such as Figure 6 shown).

[0071] 2. According to the shape and size of the comb electrode structure, move the pipette according to the parameters. Finally, after moving the pipette to the metal column on the other side, stop the power supply and move the pipette away to complete the horizontal comb electrode structure (such as Figure 7 shown).

[0072] Compared with the existing technology, this solution has the following effects:

[0073] 1. Different electrode manufacturing methods: The existing micro calorimetric flow sensor manufacturing method is mainly prepared by photolithography technology. This patent uses the MCED electrochemical deposition principle to deposit metal electrodes on the substrate, and can reach micron-level size.

[0074] 2. Different electrode structure: In existing calorimetric flow sensors, the electrodes are placed above the silicon wafer substrate. The electrodes of this patent are different from the traditional electrode structure and adopt an arched structure. This structure is suitable for the MCED electrochemical principle deposition structure, and this structure improves the sensor performance better than the traditional sensor electrode structure.

[0075] 3. Diverse sensor substrates: Existing photolithography technology for preparing flow sensors requires sensor preparation on a silicon wafer substrate. This patent allows MCED electrochemical deposition of any depositable metal electrode on any conductive substrate.

[0076] 4. Electrodes can have complex three-dimensional structures: The basic principle of photolithography is to utilize the properties of light to transfer a pattern onto the substrate to be processed through a series of steps, including a light source, mask, photosensitive material, and development. Therefore, the lack of vertical structure in sensor electrodes produced using photolithography limits the diversity of sensor electrode structures. However, the principle of MCED electrochemical deposition enables the fabrication of complex three-dimensional metal electrodes, increasing the diversity of sensor electrode fabrication.

[0077] 5. Better cost-effectiveness: Currently, photolithography equipment is complex and expensive, including photolithography machines, masks, and light sources, resulting in high investment costs. Operating costs, including electricity consumption, photoresist consumption, mask production costs, and equipment maintenance, are relatively high. Electrochemical deposition, on the other hand, is relatively simple, typically consisting of an electrolytic cell, power supply, and stirring device, resulting in lower investment costs. Operating costs, primarily electricity consumption, electrolyte consumption, and equipment maintenance, are relatively low. Photolithography is suitable for high-precision, small-batch production or R&D, while electrochemical deposition is suitable for large-scale production, meeting the demands of low cost and high efficiency.

[0078] Example 2

[0079] like Figure 1 、 Figure 9 As shown, an electrode of a calorimetric micro-flow sensor is configured as an arched structure, with a spacing of 200 μm between the lowest point of the arched structure and the electrode mounting plate (i.e., substrate 1), and the electrode is configured to include:

[0080] Two metal pillars 2 are arranged opposite to each other on the electrode mounting plate;

[0081] A comb-type electrode 3 is provided at the upper end of each metal column and is used to connect two metal columns into an integrated structure;

[0082] The metal column has a height of 200 μm and a diameter of 50 μm. The overall size of the comb electrode is 650 μm×300 μm. The electrode wire in the comb electrode has a width of 50 μm and a height of 20 μm.

[0083] This example designs an electrochemically deposited sensor electrode structure. Traditional flow sensors use hollow structures to improve sensor performance. This design, based on the MCED electrochemical deposition principle, creates an arched electrode structure that meets the electrode structure distribution requirements of calorimetric sensors while also improving sensor performance.

[0084] Simulation comparison example:

[0085] (1) In order to compare the performance of a conventional micro calorimetric flow sensor with the micro flow sensor of this patent, two sensor models were built using modeling software. The base size of both sensors was 2 mm × 1 mm × 0.5 mm, and the electrodes were comb structures with a width of 50 μm and a height of 20 μm. The overall length and width of the comb structure were 650 μm × 300 μm.

[0086] 1. Modeling of traditional micro calorimetric flow sensor: The cavity structure dimensions of the hollow structure sensor are: the cavity opening length and width are 650μm×50μm, the cavity length is 1800μm, the cavity depth is 200μm, the distance between the cavity bottom and the cavity top is 150μm, the distance between the cavity openings on both sides of the temperature measuring electrode area is 550μm, and the distance between the cavity openings on both sides of the heating electrode is 500μm. Among them, the size parameters of the bonded electrode model in the traditional sensor are as follows: Figure 3-Figure 4 、 Figure 6 shown.

[0087] 2. Modeling of a new calorimetric flow sensor: This sensor uses an arched comb-shaped electrode (the electrode size is consistent with that of the traditional sensor), the electrode height is 200 μm, and the cylindrical electrode with a diameter of 50 μm is located below the comb-shaped electrode. The arched electrode size parameters in the sensor model of the present invention are as follows: Figure 5-Figure 7 shown.

[0088] (2) After the model is built, the model is imported into the COMSOL finite element simulation software, and a free air volume with a height of 0.5 mm is set above the model, wherein the substrate material is set as a silicon wafer, and the electrode material is set as a metal electrode. Figure 13-14 COMSOL model of the sensor.

[0089] 1. After the model is established, air flow rates of 0.1m / s, 0.4m / s, 0.7m / s and 1m / s are introduced on one side. The thermal power of the intermediate heating electrode of the traditional sensor and the new sensor is set to 0.175W and 0.0435W respectively. The heating electrode can generate a temperature of 150℃. After the model is meshed, simulation analysis is performed to obtain the following results: Figure 14-15 The temperature distribution from Figures 14 to 15It can be seen that after the heating electrodes produce similar temperatures, the same gas flow rate is introduced, and the temperature differences between the temperature measuring electrodes on both sides are 6°C and 55°C respectively, which increases the temperature difference by 49°C. This is because the contact area between the temperature measuring electrode and the substrate is small, which greatly reduces the temperature diffusion of the temperature generated by the heating electrode on the substrate surface. The temperature source of the temperature measuring electrode is changed by the gas flow, which increases the temperature difference between the temperature measuring electrodes on both sides at the same flow rate. The temperature difference change is more sensitive, improving the sensor performance. At the same time, the arch structure sensor can find the placement position of the temperature measuring electrode 4 through this simulation method. At air flow rates of 0.1m / s, 0.4m / s, 0.7m / s and 1m / s, the most suitable distance from the central heating electrode 5 is 200 to 250μm.

[0090] The arch electrode of the present invention is simulated at different air temperatures of 0°C, 25°C, and 50°C and different heating electrode temperatures of 100°C and 150°C, with air flow rates of 0.1m / s, 0.4m / s, 0.7m / s, and 1.0m / s. It can be seen from the simulation test that the results of the simulation test are compared (such as Figures 16-20 ), when the temperature measuring electrodes on both sides are about 238μm away from the central heating electrode, they can have a stable temperature difference with obvious temperature difference differentiation, which makes the measurement resolution and sensitivity better.

[0091] The above solution is only an illustration of a preferred embodiment, but is not limited thereto. When implementing the present invention, appropriate replacements and / or modifications can be made according to user needs.

[0092] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and exemplary embodiments. They can be applied to a variety of fields suitable for the present invention. Further modifications will be readily apparent to those skilled in the art. Therefore, the present invention is not limited to the specific details and illustrations shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims

1. A method for preparing an electrode of a calorimetric micro-flow sensor, characterized in that: The electrode is configured to be an arched structure, and the electrode is configured to include a heating electrode and temperature measuring electrodes arranged on both sides of the heating electrode, and there is a distance of 200 μm between the lowest point of the arched structure and the conductive substrate; The electrode preparation method comprises: S1. Preparing a conductive substrate. The preparation method of the conductive substrate includes: S10, pre-treating the base material to remove grease, dust and other impurities on the surface of the base material; S11, placing the substrate material in a vacuum chamber of predetermined cleanliness, heating the selected metal material so that the metal atoms or ions in the gaseous state after evaporation or sputtering of the metal material can be adsorbed and condensed on the surface of the silicon wafer, thereby obtaining a metal thin film layer on the substrate material through physical vapor deposition; S2, connecting the substrate to the negative electrode, and depositing metal pillars on the metal film layer by MCED electrochemical deposition method; S3, depositing a comb-type electrode structure laterally above the metal pillar; The invention also includes simulating the performance of the arch electrode through simulation, wherein the simulation process includes: S4. Modeling the structures of the bonded electrode and the arch electrode respectively using modeling software; S5. Import the modeled electrode models into COMSOL finite element simulation software, set the substrate materials to silicon wafers, and set the electrode materials to metal electrodes, thus completing the establishment of the simulation model. S6. Set free air with a height of 0.5 mm above each simulation model, and introduce air of different flow rates on one side. Set the same thermal power for the middle heating electrode of the sensor corresponding to the bonding electrode and the arch electrode to achieve the same heating electrode temperature. Compare the heating power and complete the simulation analysis after the model is meshed. S7. Analyze and simulate to obtain the optimal distance between the temperature measuring electrodes on both sides and the central heating electrode at different flow rates; By simulating different air temperatures of 0℃, 25℃, and 50℃ and different heating electrode temperatures of 100℃ and 150℃, and passing air flow rates of 0.1m / s, 0.4m / s, 0.7m / s, and 1.0m / s, it was found that the distance between the temperature measuring electrodes on both sides and the central heating electrode is preferably 238μm.

2. The method for preparing an electrode of a calorimetric micro-flow sensor according to claim 1, wherein: The electrode is configured to include: two metal pillars disposed opposite to each other on a conductive substrate; A comb-type electrode provided at the upper end of each metal column and used to connect two metal columns into an integrated structure; The metal column has a height of 200 μm and a diameter of 50 μm.

3. The method for preparing an electrode of a calorimetric micro-flow sensor according to claim 2, wherein: The overall size of the comb-type electrode is 650 μm×300 μm, and the electrode wire in the comb-type electrode has a width of 50 μm and a height of 20 μm.

4. The method for preparing an electrode of a calorimetric micro-flow sensor according to claim 1, wherein: In S2, the method of depositing the metal pillar includes: S20, adding an electrolyte solution for preparing deposited metal into a pipette, and inserting a metal wire into the pipette and connecting the metal wire to the positive electrode; S21. When the electrolyte solution in the pipette contacts the conductive substrate, the metal ions in the electrolyte solution are reduced to metal by electrons and deposited on the substrate, while the metal in the pipette loses electrons and oxidizes to metal ions, replenishing the metal ions lost in the pipette. S22. Adjust the height of the pipette to deposit the metal column until the metal column reaches a predetermined height.

5. The method for preparing an electrode of a calorimetric micro-flow sensor according to claim 1, wherein: In S3 , during the lateral deposition of the comb-type electrode structure, the position of the deposition pipette is controlled by a multi-degree-of-freedom displacement component, and the multi-degree-of-freedom displacement component is communicatively connected to an external control terminal.

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