Sensor and energy storage device

Abstract

The application provides a sensor and an energy storage device, and belongs to the technical field of gas detection. The sensor comprises a frame, a micro-hot plate, a gas-sensitive layer and a support arm. The micro-hot plate is located inside the frame and comprises a substrate and a functional layer arranged on the substrate, and the functional layer comprises a heating electrode. The gas-sensitive layer is arranged on the side of the functional layer away from the substrate, and the heating electrode is used for heating the gas-sensitive layer. One end of the support arm is connected with the substrate, the other end is connected with the frame, and the support arm has a deformation buffer zone capable of deforming along the extension direction of the support arm. When impacted by the outside, the deformation buffer zone absorbs the impact energy by deforming itself, reduces the tensile stress of the support arm, avoids breakage, and improves the impact resistance and service life. At the same time, the deformation buffer zone increases the thermal resistance by increasing the length of the heat conduction path, prevents a large amount of heat from being conducted to the frame through the support arm, and maintains the advantages of high heating efficiency and low power consumption.

Description

Technical Field

[0001] This application relates to the field of gas detection technology, and more particularly to a sensor and energy storage device. Background Technology

[0002] As a key component of new energy systems, the safe operation of lithium-ion battery energy storage power stations is of paramount importance. Under abnormal operating conditions such as overcharging, overheating, or internal short circuits, individual battery cells may experience thermal runaway, leading not only to rapid performance degradation but also the release of flammable gases such as hydrogen, posing a serious safety hazard. Therefore, real-time and accurate monitoring of hydrogen concentration has become a crucial technical means for early warning and risk control in energy storage power stations.

[0003] Micro-electro-mechanical systems (MEMS) are a microfabrication technology that integrates micro-mechanical structures and electronic integrated circuits onto a single chip, enabling sensing, processing, and actuation functions at the micrometer scale. Sensors based on MEMS technology are widely used in the safety monitoring of battery energy storage systems due to their advantages such as small size, low power consumption, and ease of integration. Currently, MEMS sensors generally adopt a suspended structure design. These chips typically include a frame and a micro-hotplate. The micro-hotplate is connected to the frame by multiple connecting beams, thus suspending the micro-hotplate inside the frame. To improve the heating efficiency of the micro-hotplate and prevent heat conduction to the frame through the connecting beams, the connecting beams are usually designed to be quite thin to increase thermal resistance. However, this thin structure leads to poor shock resistance of the sensor, affecting its lifespan. Summary of the Invention

[0004] This application provides a sensor and energy storage device that can improve the lifespan of MEMS sensors.

[0005] To achieve the above objectives, the embodiments of this application adopt the following technical solutions: In a first aspect, this application provides a sensor comprising a frame, a substrate, a functional layer, a gas-sensitive layer, and a support arm; the substrate, the functional layer, and the gas-sensitive layer are sequentially stacked inside the frame, the functional layer includes a heating electrode for heating the gas-sensitive layer; one end of the support arm is connected to the substrate, and the other end is connected to the frame; wherein the support arm has a deformation buffer, the deformation buffer being capable of deformation along the extension direction of the support arm.

[0006] The aforementioned deformation buffer is configured to deform along the extension direction of the support arm. When the sensor is subjected to external mechanical impact or vibration, the deformation buffer effectively absorbs and dissipates the impact energy through its own deformation, releasing and transforming the tensile or compressive stress originally concentrated on the support arm. This significantly reduces the direct stress level borne by the support arm, effectively preventing breakage and greatly improving the sensor's impact resistance and lifespan. Simultaneously, the deformation buffer increases its thermal resistance by extending the heat conduction path, effectively preventing heat generated by the heating electrode from being conducted to the frame via the support arm. This enhances the chip's mechanical reliability while maintaining the heating efficiency and low power consumption characteristics of the heating electrode.

[0007] In one feasible approach, the deformation buffer can be a wavy or serpentine structure.

[0008] This effectively transforms the relative displacement of the support arm under mechanical impact or thermal expansion into the elastic deformation of the deformation buffer itself, thereby dispersing and absorbing mechanical stress more evenly and further improving the sensor's impact resistance and structural stability.

[0009] In one possible implementation, the support arm includes a first connecting segment, a second connecting segment, and a deformation buffer. The two ends of the deformation buffer are connected to the first and second connecting segments, respectively. The end of the first connecting segment facing away from the deformation buffer is connected to a substrate, and the end of the second connecting segment facing away from the deformation buffer is connected to a frame. The cross-sectional areas of the first and second connecting segments gradually increase along the direction away from the deformation buffer.

[0010] Through the aforementioned structural design with gradually increasing cross-sectional area, the stiffness of the first and second connecting sections exhibits a smooth transition along the extension direction of the support arm: in the end region connected to the substrate and frame, the larger cross-sectional area provides higher structural stiffness and stable support; in the region adjacent to the deformation buffer zone, the smaller cross-sectional area results in relatively lower stiffness, enhancing the deformation adaptability of this region. This gradual stiffness distribution allows the stress that might have been concentrated near the connection point to be evenly distributed and gradually released along the entire connecting section when the support arm is subjected to external mechanical impact or thermal cycling. This effectively avoids local stress overload, reduces the risk of breakage at the connection between the support arm and the substrate and frame, and improves the mechanical reliability and service life of the sensor.

[0011] In one feasible approach, the stiffness of both the first and second connecting segments is greater than the stiffness of the deformation buffer.

[0012] The first and second connecting sections have high hardness, which can effectively transmit the stress generated by external mechanical impact or thermal cycling to the deformation buffer. The deformation buffer has low hardness and is prone to elastic deformation, becoming the main area for stress release. This avoids stress concentration at the connection between the support arm and the substrate and frame, significantly reducing the risk of breakage.

[0013] In one feasible approach, the thickness of the support arm ranges from 5 μm to 100 μm.

[0014] This design ensures the support arm has sufficient mechanical strength while effectively controlling heat conduction loss through the support arm, achieving a good balance between mechanical reliability and heating efficiency, and meeting the requirements for long-term stable operation of the sensor. In one possible implementation, the sensor also includes a connection layer located between the functional layer and the gas-sensitive layer, the thickness of which is less than the thickness of the gas-sensitive layer.

[0015] As an intermediate transition layer, the connecting layer has good adhesion to the functional layer. At the same time, it is made of the same material as the gas-sensitive layer above, which can form a strong interface bond, effectively preventing the gas-sensitive layer from cracking during long-term use and improving the service life of the sensor.

[0016] In one feasible approach, the thickness of the connecting layer ranges from 50 nm to 100 μm.

[0017] In one possible implementation, the connecting layer includes at least one of SnO2, ZnO, WO3, In2O3, or TiO2.

[0018] In one possible implementation, the functional layer includes a first insulating layer, a second insulating layer, a test electrode, and a heating electrode; the substrate, the first insulating layer, the heating electrode, the second insulating layer, the test electrode, and the connection layer are stacked sequentially.

[0019] The connecting layer, serving as an intermediate transition layer, is positioned between the test electrode and the gas-sensitive layer. It forms a good adhesion interface with the underlying test electrode and the second insulating layer, providing a high-quality substrate interface for the subsequent deposition of the gas-sensitive layer. Meanwhile, each functional layer is deposited layer by layer using standard MEMS processes, resulting in tight interlayer bonding, high structural consistency, and facilitating mass production.

[0020] Secondly, this application provides an energy storage device, which includes a battery pack, a battery management unit, and the aforementioned sensor; the sensor and the battery management unit are electrically connected and are used to monitor the gas released by the battery pack and transmit the detection signal to the battery management unit.

[0021] The energy storage device provided in this application includes the aforementioned sensor. Therefore, the energy storage device provided in this application and the sensor in the aforementioned technical solution can solve the same technical problem and have the same technical effect, which will not be elaborated here. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a sensor provided in an embodiment of this application; Figure 2 yes Figure 1 Cross-sectional view at point A-A'; Figure 3 This is a schematic diagram of the structure of a deformation buffer provided in an embodiment of this application; Figure 4 This is a schematic diagram of the formation of the first insulating layer in the manufacturing method of this application embodiment; Figure 5 This is a schematic diagram of the formation of heating electrodes in the manufacturing method of an embodiment of this application; Figure 6 This is a schematic diagram of the formation of the second insulating layer in the manufacturing method of this application embodiment; Figure 7 This is a schematic diagram of the formation of test electrodes in the manufacturing method of an embodiment of this application; Figure 8 This is a schematic diagram of the forming of the connecting layer in the manufacturing method of this application embodiment; Figure 9 This is a schematic diagram of the cavity formed by back-side etching in the manufacturing method of this application embodiment; Figure 10 This is a schematic diagram of the front etching process for forming a suspended structure in the manufacturing method of this application embodiment; Figure 11 This is a schematic diagram of the formation of the gas-sensitive layer in the manufacturing method of this application embodiment.

[0023] Figure label: 000 - Sensor; 100 - Frame; 200 - Micro-hot plate; 210 - Substrate; 220 - Functional layer; 221 - Heating electrode; 222 - First insulating layer; 223 - Second insulating layer; 224 - Test electrode; 300 - Support arm; 310 - First connecting segment; 320 - Second connecting segment; B - Deformation buffer; 331 - Connecting part; 332 - Strip part; 332A - First strip part; 332B - Second strip part; 332C - Third strip part; 400 - Gas-sensitive layer; 500 - Connecting layer; K - Cavity. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them.

[0025] In this application, the terms "first," "second," etc., are used only to distinguish different technical features or components, and do not indicate any priority or importance among these features, nor do they imply the number of technical features involved. Therefore, technical features described with "first," "second," etc., should be understood to include one or more.

[0026] In this application, unless otherwise expressly stated and limited, "multiple" means two or more.

[0027] Furthermore, in this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0028] In the accompanying drawings of the embodiments of this application, in order to clearly express different structural elements, solid structures such as parts and components are represented by guide lines, openings and holes are represented by broken lines, and hollow structures such as spaces and cavities are identified by guide lines with arrows.

[0029] To facilitate a better understanding of the embodiments of this application, the relevant concepts involved in this application will be introduced first below.

[0030] 1. MEMS Microelectromechanical systems (MEMS) are high-tech devices with dimensions of a few millimeters or even smaller. Their internal structures are generally at the micrometer or even nanometer scale. They are generally considered to be micro-systems composed of micro-mechanical sensors, actuators, and microelectronic circuits, and are independent intelligent systems.

[0031] MEMS chip manufacturing technology utilizes microfabrication techniques, especially semiconductor wafer manufacturing technology, to create various micro-mechanical structures. These structures are then combined with dedicated control integrated circuits to form intelligent micro-sensors, micro-actuators, micro-optical devices, and other MEMS components. Common MEMS products include MEMS accelerometers, MEMS optical sensors, MEMS pressure sensors, MEMS gyroscopes, MEMS humidity sensors, MEMS gas sensors, and their integrated products.

[0032] MEMS products, with their advantages of small size, low power consumption, high reliability, and easy integration, are widely used in consumer electronics such as mobile phones, tablets, digital cameras, game consoles, and remote controls; in the defense industry, such as aerospace, marine, diving, and unmanned aerial vehicles; in industrial products such as automobiles, communications, robotics, intelligent transportation, industrial automation, environmental monitoring, platform stability control, modern agriculture, and security monitoring; and in the new energy field, such as lithium-ion battery energy storage power stations, electric vehicle battery management systems, and home energy storage devices. MEMS products are the cornerstone of IoT technology and a core component of industrial modernization.

[0033] Based on this, this application provides an energy storage device, which may include a battery pack, a battery management unit (BMU), and sensors. The battery pack, composed of multiple integrated cells, is used to store and release electrical energy. Under abnormal operating conditions such as overcharging, internal short circuits, or high temperatures, the battery pack may experience thermal runaway, releasing flammable gases, including hydrogen. Sensors are used to monitor the released flammable gases, such as hydrogen, from the battery pack in real time. The sensors are electrically connected to the BMU via leads or connectors, enabling real-time transmission of the collected detection signals to the BMU. The BMU receives and processes the detection signals. When it determines that the hydrogen concentration exceeds a preset safety threshold, it immediately triggers corresponding safety protection mechanisms, such as issuing audible and visual warnings, cutting off the charging and discharging circuit, or sending fault alarm information to a remote monitoring platform. This achieves early identification and proactive intervention in thermal runaway events, improving the operational reliability and safety of the energy storage device.

[0034] The sensor in this application can specifically be a MEMS sensor manufactured using Micro-Electro-Mechanical Systems (MEMS) technology. MEMS sensors offer significant advantages such as small size, low power consumption, fast response speed, and ease of integration. Specifically, the size of MEMS sensors can be reduced to the micrometer level or even smaller, enabling easy integration into space-constrained battery packs or critical components of energy storage devices. Furthermore, MEMS sensors can be mass-produced using semiconductor processes, offering advantages such as good consistency, high reliability, and low cost.

[0035] For a clearer illustration of the sensor's structure, please refer to [reference needed]. Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the structure of a sensor provided in an embodiment of this application. Figure 2 yes Figure 1 Cross-sectional view at point A-A'. (See diagram below.) Figure 1 and Figure 2 As shown, sensor 000 may include a frame 100, a micro-heat plate 200, and a support arm 300.

[0036] The frame 100 in sensor 000 is a frame-shaped structure located in the peripheral area of ​​sensor 000, serving to provide mechanical support and fixation for the internal structure of sensor 000. Exemplarily, the frame 100 is a rectangular frame structure. This application does not limit the specific shape of the frame; in other embodiments, the frame 100 may also be designed as a circular frame, a polygonal frame, or other suitable shapes. In some embodiments, the frame 100 may be made of monocrystalline silicon material, with a thickness, for example, between 100 μm and 1000 μm.

[0037] In sensor 000, both the micro-heat plate 200 and the support arm 300 are located within the internal space of the frame 100. The micro-heat plate 200 is connected to the frame 100 via the support arm 300; that is, one end of the support arm 300 is connected to the micro-heat plate 200, and the other end is connected to the frame 100, thus suspending and supporting the micro-heat plate 200 within the frame 100. For example, sensor 000 may include four support arms 300, symmetrically arranged between the four corners of the micro-heat plate 200 and the corresponding corners of the frame 100. By providing multiple support arms 300, the support stability of the micro-heat plate 200 can be improved.

[0038] Continue to refer to Figure 2 The micro-hot plate 200 in sensor 000 includes a substrate 210 and a functional layer 220 disposed on the substrate 210. Here, one end of the support arm 300 can be connected to the frame 100, and the other end can be connected to the substrate 210. The substrate 210 serves as the base of the micro-hot plate 200, providing stable support for the upper functional structure 220.

[0039] In some embodiments, such as Figure 2 As shown, the sensor 000 also includes a gas-sensitive layer 400. This gas-sensitive layer 400 is disposed on the side of the functional layer 220 facing away from the substrate 210, and is used to contact and react with the gas to be measured (such as hydrogen), thereby causing a change in its own resistance. In other words, the substrate 210, the functional layer 220, and the gas-sensitive layer 400 are sequentially stacked inside the frame 100. The material of the gas-sensitive layer 400 can be one or more of metal oxide semiconductor gas-sensitive materials, including but not limited to tin dioxide (SnO2), zinc oxide (ZnO), tungsten trioxide (WO3), indium oxide (In2O3), and titanium dioxide (TiO2). When these materials are heated to their operating temperature, oxygen adsorbs on their surface to form oxygen anions. When these anions come into contact with reducing gases such as hydrogen, a redox reaction occurs, causing a change in the material's resistance, thereby enabling the detection of the gas to be measured.

[0040] To ensure the proper functioning and detection sensitivity of the gas-sensitive layer 400, it needs to be heated to a temperature range suitable for gas adsorption and reaction. Therefore, the aforementioned functional layer 220 includes at least a heating electrode 221. The heating electrode 221 constitutes the core heating element of the micro-hot plate 200, used to generate heat through the Joule effect when energized, heating the gas-sensitive layer 400 to operate within a temperature range suitable for hydrogen adsorption and reaction, such as 200°C to 400°C. For example, the substrate 210 may be made of single-crystal silicon.

[0041] In some embodiments, such as Figure 2 As shown, the functional layer 220 in the micro-hot plate 200 may further include a first insulating layer 222, a second insulating layer 223, and a test electrode 224. Specifically, the first insulating layer 222 is disposed on the substrate 210 and covers the upper surface of the substrate 210. The first insulating layer 222 may be made of insulating materials such as silicon dioxide (SiO2) or silicon nitride (SiN), and its thickness is between 100nm and 1000nm. The first insulating layer 222 is used to achieve electrical insulation isolation between the heating electrode 221 and the substrate 210, preventing heating current leakage to the substrate 210. The heating electrode 221 is disposed on the side of the first insulating layer 222 away from the substrate 210. The material of the heating electrode 221 may be one or more of platinum (Pt), polycrystalline silicon (Poly-Si), or nickel-chromium alloy (Ni-Cr). These materials have high melting points, good stability, and appropriate resistivity, and can maintain structural stability at high temperatures. The thickness of the heating electrode 221 can be designed to be between 100 nm and 1000 nm. A thinner heating electrode 221 can generate sufficient heat at a lower current to achieve low power consumption, while a thicker heating electrode has better mechanical strength to improve reliability. A second insulating layer 223 is disposed on the side of the heating electrode 221 opposite to the first insulating layer 222 and covers the heating electrode 221. The second insulating layer 223 can also be made of insulating materials such as silicon dioxide (SiO2) or silicon nitride (SiN), with a thickness, for example, between 200 nm and 1500 nm. The second insulating layer 223 serves to achieve electrical insulation between the heating electrode 221 and the test electrode 224, and protects the heating electrode 221 from oxidation or contamination during subsequent processes or use, ensuring long-term stable operation of the heating electrode 221. The test electrode 224 is disposed on the side of the second insulating layer 223 opposite to the heating electrode 221 and is used for electrical connection with the gas-sensitive layer 400 to read the resistance change signal generated when the gas-sensitive layer 400 comes into contact with hydrogen gas. The test electrode 224 can be made of conductive materials such as gold (Au), platinum (Pt), aluminum (Al) or titanium (Ti), and its thickness is, for example, between 100 nm and 1000 nm.

[0042] In the embodiments of this application, such as Figure 1As shown, the support arm 300 in sensor 000 has a deformation buffer B, which can deform along the extension direction of the support arm 300. Thus, when the sensor is subjected to external mechanical impact or vibration, the deformation buffer B can absorb or buffer this impact energy through its own deformation. The tensile or compressive stress originally applied directly to the support arm 300 is now mainly borne and transformed by the deformation of the deformation buffer B, thereby significantly reducing the direct tensile stress on the support arm 300, preventing breakage, and significantly improving the impact resistance and service life of sensor 000. Furthermore, the deformation buffer B can increase its thermal resistance by increasing the length of the heat conduction path, preventing the heat generated by the heating electrode 221 in the micro-hot plate 200 from being largely conducted to the frame 100 through the support arm 300. This improves impact resistance while maintaining the heating efficiency and low power consumption advantages of the heating electrode 221.

[0043] In some embodiments, to enable the deformation buffer B to better adapt to relative displacement along its extension direction and provide effective buffering and deformation capabilities, the shape of the deformation buffer B can be designed as a wave-like or serpentine structure. These structural forms can achieve a large elastic deformation stroke within a limited space while maintaining structural stability.

[0044] Of course, the deformation buffer B can also adopt other shapes with similar functions, such as S-shaped, sawtooth-shaped or spiral-shaped, as long as it can ensure that the deformation buffer B has sufficient deformation margin and reliable connection performance when subjected to displacement or vibration. This application does not limit the specific shape of the deformation buffer B, and it can be flexibly selected according to the actual application scenario.

[0045] The specific structure of the deformation buffer zone B in the support arm 300 is described in detail below. Figure 3 This is a schematic diagram of a deformation buffer structure provided in an embodiment of this application. Figure 3 As shown, the deformation buffer zone B in the support arm 300 includes multiple connecting portions 331 and multiple parallel and spaced strip portions 332. The strip portions 332 are arranged perpendicular to the extension direction of the support arm 300, are parallel to each other and spaced at a certain distance, so as to increase the effective length of the support arm 300 within a limited space. The connecting portions 331 are disposed between the ends of adjacent strip portions 332 to connect the strip portions 332 to form a continuous bending path.

[0046] Specifically, such as Figure 3As shown, in any three adjacent strip sections 332, the one in the middle is the first strip section 332A, and the two on either side are the second strip section 332B and the third strip section 332C, respectively. The first end of the first strip section 332A is connected to the first end of the second strip section 332B through a connecting part 331, and the second end of the first strip section 332A is connected to the second end of the third strip section 332C through another connecting part 331. Through this alternating connection layout, the strip sections 332 and the connecting parts 331 are connected end to end, forming a serpentine bending structure, allowing the support arm 300 to achieve a longer path length within a limited space.

[0047] In one possible implementation, the number of strips 332 in the deformation buffer B can be three, five, seven, or more (an odd number) to ensure that both ends of the deformation buffer B are on the same straight line, facilitating connection with other parts of the support arm 300. The more strips 332 there are, the longer the deformation buffer B becomes, and the greater its stress absorption capacity and thermal resistance.

[0048] In this configuration, when the sensor 000 is subjected to external mechanical impact or thermal expansion, the deformation buffer B can absorb relative displacement and mechanical energy through the serpentine structure composed of the strip portion 332 and the connecting portion 331. This improves the structural stability and reliability under thermal cycling and mechanical load conditions, prevents the support arm 300 from breaking, and enhances the sensor 000's impact resistance and mechanical reliability. Simultaneously, the serpentine structure of the deformation buffer B increases the length of the heat conduction path. According to the principle of heat conduction, a longer path results in greater thermal resistance, thereby reducing heat loss from the heating electrode 221 in the micro-hot plate 200 through the support arm 300 to the frame 100, maintaining the heating efficiency and low power consumption advantages of the heating electrode 221.

[0049] Continue to refer to Figure 1 The support arm 300 in the sensor 000 may further include a first connecting segment 310 and a second connecting segment 320, with both ends of the deformation buffer B connected to the first connecting segment 310 and the second connecting segment 320, respectively. The end of the first connecting segment 310 facing away from the deformation buffer B is connected to the substrate 210 of the micro-hot plate 200, and the end of the second connecting segment 320 facing away from the deformation buffer B is connected to the frame 100. The cross-sectional areas of the first connecting segment 310 and the second connecting segment 320 gradually increase along the direction away from the deformation buffer B, that is, from the end closer to the deformation buffer B to the end farther away from the deformation buffer B, the cross-sectional areas of the first connecting segment 310 and the second connecting segment 320 gradually increase.

[0050] This structural design, with its gradually increasing cross-sectional area, allows the first connecting segment 310 and the second connecting segment 320 to have larger cross-sectional areas near the substrate 210 and the frame 100, resulting in higher structural stiffness; and smaller cross-sectional areas near the deformation buffer zone B, resulting in lower stiffness. This gradual transition in stiffness effectively alleviates stress concentration at the connection between the support arm 300 and the substrate 210 and the frame 100. When the sensor 000 is subjected to external mechanical impact or thermal cycling, the stress that would otherwise concentrate at the connection is dispersed throughout the gradual transition area of ​​the first connecting segment 310 and the second connecting segment 320, significantly reducing the stress at the connection, preventing the support arm 300 from breaking, and further improving the mechanical reliability and service life of the sensor 000.

[0051] In one alternative implementation, the cross-sectional areas of the first connecting segment 310 and the second connecting segment 320 can be gradually increased in a continuous and gradual manner, for example, through a continuous linear change in width or thickness.

[0052] In another alternative embodiment, the first connecting segment 310 and the second connecting segment 320 can adopt a stepped structure, that is, the cross-sectional area increases in multiple steps along the extension direction of the support arm 300. For example, multiple steps with progressively increasing widths can be arranged sequentially from the end near the deformation buffer B to the end away from the deformation buffer B. The stepped structure has high design flexibility. For example, by adjusting the number of steps, the width and length of each step, various stiffness transition curves can be flexibly designed to meet different mechanical performance requirements.

[0053] In this embodiment, the hardness of both the first connecting segment 310 and the second connecting segment 320 is greater than the hardness of the deformation buffer B. Because the first connecting segment 310 and the second connecting segment 320 have higher hardness, they can effectively transmit stress generated by external mechanical impact or thermal cycling to the deformation buffer B. Meanwhile, the deformation buffer B has lower hardness and is prone to elastic deformation, becoming the main area for stress release. This avoids stress concentration at the connection points between the support arm 300 and the substrate 210 and the frame 100, significantly reducing the risk of breakage.

[0054] Optionally, the thickness of the support arm 300 can be reasonably designed according to mechanical strength and thermal performance requirements. Specifically, the thickness of the support arm 300 ranges from 5μm to 100μm, for example, it can be 5μm, 10μm, 20μm, 30μm, 50μm, 80μm, or 100μm. The choice of the thickness of the support arm 300 has a significant impact on the performance of the sensor 000. If the thickness of the support arm 300 is too thin, although it is beneficial to reduce heat conduction loss and improve the heating efficiency of the micro-hot plate 200, it will lead to insufficient mechanical strength of the support arm 300, making it prone to breakage under external mechanical impact or thermal cycling stress, thus reducing the reliability of the sensor 000. If the thickness of the support arm 300 is too thick, although it can improve the mechanical strength and impact resistance of the support arm 300, it will increase the heat conduction cross-sectional area, making it easier for the heat of the micro-hot plate 200 to be conducted to the frame 100 through the support arm 300, reducing heating efficiency and increasing power consumption.

[0055] By controlling the thickness of the support arm 300 within the range of 5μm to 100μm, sufficient mechanical strength can be ensured while effectively controlling heat conduction loss, achieving a good balance between mechanical reliability and heating efficiency, and meeting the energy storage device's requirement for the long-term stable operation of the sensor 000.

[0056] However, the long-term reliability of sensor 000 depends not only on the mechanical structure of support arm 300, but also on the interfacial bonding strength between gas-sensitive layer 400 and micro-hot plate 200. In related technologies, the material of gas-sensitive layer 400 typically has a large thickness and porous structure, and its coefficient of thermal expansion and mechanical properties differ significantly from those of the functional layer 220 in micro-hot plate 200. This results in significant thermal expansion mismatch stress at the interface during long-term heating and frequent start-stop processes. This stress accumulates continuously during repeated thermal cycling, easily leading to cracks or detachment of gas-sensitive layer 400 at the interface between functional layer 220 and gas-sensitive layer 400. This causes sensitivity drift, decreased response stability, and even device failure in sensor 000, thus limiting its lifespan and long-term reliability.

[0057] To address the above problems, this application provides an improvement. For example... Figure 2 As shown, the sensor 000 also includes a connection layer 500, which is disposed between the functional layer 220 and the gas-sensitive layer 400, specifically on the side of the functional layer 220 facing away from the substrate 210. In other words, the substrate 210, the first insulating layer 222, the heating electrode 221, the second insulating layer 223, the test electrode 224, and the connection layer 500 are stacked sequentially, with the connection layer 500 disposed on the test electrode 224 and covering the second insulating layer 223.

[0058] Furthermore, the thickness of the connecting layer 500 is less than that of the gas-sensitive layer 400. Specifically, the thickness of the connecting layer 500 can range from 50 nm to 100 μm, while the thickness of the gas-sensitive layer 400 can range from 1 μm to 100 μm. Due to the thinner thickness of the connecting layer 500, the thermal expansion mismatch stress between it and the underlying functional layer 220 is smaller. At the same time, the thinner structure also gives it better flexibility and stress adaptability, enabling it to adhere tightly to the surface of the functional layer 220, thereby significantly improving the bonding strength between the connecting layer 500 and the functional layer 220.

[0059] Optionally, the material of the connecting layer 500 can be the same as that of the gas-sensitive layer 400, both being metal oxide semiconductor gas-sensitive materials, such as at least one of SnO2, ZnO, WO3, In2O3, or TiO2. Using the same material ensures that the connecting layer 500 and the gas-sensitive layer 400 have similar coefficients of thermal expansion, allowing them to expand and contract synchronously during thermal cycling. This effectively reduces the interfacial thermal stress between the connecting layer 500 and the gas-sensitive layer 400, avoiding interfacial cracking caused by differences in coefficients of thermal expansion.

[0060] With the aforementioned connection layer 500, the connection layer 500 serves as an intermediate transition layer, exhibiting good adhesion to the functional layer 220 below. Simultaneously, it is made of the same material as the gas-sensitive layer 400 above, enabling the formation of a strong interface bond. This effectively prevents the gas-sensitive layer 400 from cracking or detaching during long-term use, thereby improving the service life of the sensor 000.

[0061] This application also provides a method for manufacturing a sensor 000, which will be described in detail below with reference to the accompanying drawings. Figures 4 to 11 This is a process flow diagram of a sensor manufacturing method provided in an embodiment of this application. For example... Figures 4 to 11 As shown, the manufacturing method includes the following steps: S1: Reference Figure 4 , Figure 4 This is a schematic diagram of the formation of the first insulating layer in the manufacturing method of this application embodiment. First, a silicon wafer with a thickness of 300 μm is selected, and the patterned area of ​​the first insulating layer 222 is defined on the surface of the silicon wafer by photolithography. Then, a silicon dioxide (SiO2) layer with a thickness of about 200 nm is deposited by plasma-enhanced chemical vapor deposition (PECVD) to form the first insulating layer 222.

[0062] S2: Reference Figure 5 , Figure 5 This is a schematic diagram of the formation of a heating electrode in the manufacturing method of this application embodiment. The pattern of the heating electrode 221 is defined on the first insulating layer 222 by photolithography, and then a platinum (Pt) layer with a thickness of 200 nm is deposited by magnetron sputtering to form the heating electrode 221.

[0063] S3: Reference Figure 6 , Figure 6 This is a schematic diagram of the formation of the second insulating layer in the manufacturing method of this application embodiment. A silicon nitride (SiN) layer with a thickness of 300 nm is deposited on the surface of the heating electrode 221 by plasma-enhanced chemical vapor deposition (PECVD) process to form a second insulating layer 223 covering the heating electrode 221 and the first insulating layer 222.

[0064] S4: Reference Figure 7 , Figure 7 This is a schematic diagram of the formation of a test electrode in the manufacturing method of this application embodiment. The pattern of the test electrode 224 is defined on the second insulating layer 223 by photolithography, and then a titanium (Ti) layer with a thickness of 20 nm and a gold (Au) layer with a thickness of 200 nm are deposited sequentially by magnetron sputtering to form the test electrode 224.

[0065] S5: Reference Figure 8 , Figure 8 This is a schematic diagram of the formation of the interconnect layer in the manufacturing method of this application embodiment. A tin dioxide (SnO2) layer with a thickness of 500 nm is formed on the surface of the second insulating layer 223 and the test electrode 224 by magnetron sputtering, forming the interconnect layer 500. The interconnect layer 500 covers the test electrode 224 and the second insulating layer 223.

[0066] S6: Reference Figure 9 , Figure 9 This is a schematic diagram of the back-side etching process for forming a cavity in the manufacturing method of this application embodiment. A cavity K region is defined on the back side of the silicon wafer using photolithography, and then the back side of the silicon wafer is etched using deep reactive ion etching (DRIE) to form a cavity K with a depth of 250 μm. By controlling the etching depth, a silicon thin film layer of a predetermined thickness is retained in the micro-hotplate 200 region to prepare for the subsequent formation of the suspended structure.

[0067] S7: Reference Figure 10 (and combined) Figure 1 ), Figure 10 This is a schematic diagram of the suspended structure formed by front etching in the manufacturing method of this application embodiment. The pattern of the frame 100, support arm 300, and substrate 210 is defined on the front side of the silicon wafer using photolithography. Then, deep reactive ion etching (DRIE) is used to release the pattern on the front side of the silicon wafer, forming the substrate 210, and simultaneously obtaining the frame 100 and support arm 300. The cavity K formed in step S6, combined with the front etching in step S7, allows the substrate 210 to be suspended and supported inside the frame 100 by the support arm 300, forming a suspended structure.

[0068] S8: Reference Figure 11 , Figure 11 This is a schematic diagram illustrating the formation of the gas-sensitive layer in the manufacturing method of this application embodiment. Tin dioxide (SnO2) gas-sensitive paste is applied to the upper surface of the connecting layer 500 using a dispensing machine, and then annealed at 400°C for 1 hour to form a gas-sensitive layer 400 with a thickness of 20 μm. This gas-sensitive layer 400, serving as the main sensitive layer, has a large specific surface area and a porous structure, allowing it to contact and react with hydrogen gas, thereby causing a change in resistance. This completes the fabrication of the sensor 000.

[0069] It should be noted that the specific process parameters (such as thickness, temperature, time, etc.) in the above steps are merely illustrative. Those skilled in the art can make appropriate adjustments according to actual needs and equipment conditions, as long as the technical solution of this application can be achieved. This application does not impose any specific limitations.

[0070] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0071] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A sensor, characterized in that, It includes a frame, substrate, functional layer, gas-sensitive layer, and support arm; The substrate, the functional layer, and the gas-sensitive layer are sequentially stacked inside the frame. The functional layer includes a heating electrode for heating the gas-sensitive layer. One end of the support arm is connected to the substrate, and the other end is connected to the frame. The support arm has a deformation buffer zone, which is capable of deforming along the extension direction of the support arm.

2. The sensor according to claim 1, characterized in that, The deformation buffer zone has a wavy or serpentine structure.

3. The sensor according to claim 1 or 2, characterized in that, The support arm includes a first connecting segment, a second connecting segment, and the deformation buffer. The two ends of the deformation buffer are connected to the first connecting segment and the second connecting segment, respectively. The end of the first connecting segment facing away from the deformation buffer is connected to the substrate, and the end of the second connecting segment facing away from the deformation buffer is connected to the frame. The cross-sectional areas of the first connecting segment and the second connecting segment gradually increase along the direction away from the deformation buffer.

4. The sensor according to claim 3, characterized in that, The hardness of both the first connecting segment and the second connecting segment is greater than the hardness of the deformation buffer.

5. The sensor according to any one of claims 1-4, characterized in that, The thickness of the support arm ranges from 5 μm to 100 μm.

6. The sensor according to any one of claims 1-5, characterized in that, The sensor further includes a connection layer located between the functional layer and the gas-sensitive layer, the thickness of which is less than the thickness of the gas-sensitive layer.

7. The sensor according to claim 6, characterized in that, The thickness of the connecting layer ranges from 50 nm to 100 μm.

8. The sensor according to claim 6, characterized in that, The connecting layer includes at least one of SnO2, ZnO, WO3, In2O3, or TiO2.

9. The sensor according to any one of claims 6-8, characterized in that, The functional layer includes a first insulating layer, a second insulating layer, a test electrode, and a heating electrode; the substrate, the first insulating layer, the heating electrode, the second insulating layer, the test electrode, and the connection layer are stacked sequentially.

10. An energy storage device, characterized in that, It includes a battery pack, a battery management unit, and a sensor as described in any one of claims 1-9; the sensor and the battery management unit are electrically connected, and the sensor is used to monitor the gas released by the battery pack and transmit the detection signal to the battery management unit.

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