A nitric oxide sensor chip

Abstract

The application relates to the technical field of gas sensors, and discloses a nitrogen-oxygen sensor chip, which comprises a chip body, the chip body comprises a circuit board assembly, a sensing element assembly and a protective layer assembly, the circuit board assembly is composed of a substrate layer, a conductive circuit layer and a carbon fiber reinforced layer embedded therebetween, and the substrate layer and the conductive circuit layer are fixed through a hot-pressing process. The nitrogen-oxygen sensor chip can make the interlayer shear strength reach 85 MPa and the anti-vibration performance increase by 40% through the combination of the carbon fiber reinforced layer and the nano-alumina coating, the longitudinal tensile strength reaches 4.8 GPa, the weft tensile strength reaches 4.3 GPa, the difference between the longitudinal and weft tensile strengths is less than or equal to 10%, the isotropic mechanical properties are ensured, the nano-alumina coating can inhibit the interface oxidation of the fiber and the resin matrix at high temperatures, the risk of thermal mismatch can be reduced, and the chip anti-vibration performance is increased by 40% through the high-temperature support of the substrate layer and the carbon fiber bending-resistant structure.

Description

Technical Field

[0001] This application relates to the field of gas sensor technology, specifically a nitrogen and oxygen sensor chip. Background Technology

[0002] Currently, nitrogen and oxygen sensor chips mainly achieve gas detection through electrochemical or semiconductor principles, but their core components, such as circuit boards, are prone to breakage and open circuits under harsh environments such as long-term high temperature and vibration.

[0003] In existing technologies, the following methods are commonly used to solve the problems of circuit board breakage and open circuits: Increasing the thickness or number of layers of the circuit board to improve its mechanical strength; the advantages are simple structure and low cost; the disadvantages are increased chip size and weight, and a certain impact on the transmission performance of high-frequency signals. Coating the surface of the circuit board with a protective layer; the advantages are effective isolation from external environmental corrosion; the disadvantages are that the coating may affect heat dissipation performance and is prone to aging and peeling at high temperatures. Using a flexible circuit board design; the advantages are good vibration resistance; the disadvantages are high manufacturing cost, and fatigue fracture may still occur after long-term use.

[0004] While existing technologies have alleviated the problems of circuit board breakage and open circuit to some extent, they all have obvious limitations. For example, increasing the thickness of the circuit board will sacrifice the miniaturization advantage of the chip, coating a protective layer may introduce new heat dissipation problems, and flexible circuit boards are too expensive and not durable enough. Therefore, in order to solve the above problems, a nitrogen and oxygen sensor chip is proposed. Utility Model Content

[0005] To address the shortcomings of existing technologies, this application provides a nitrogen and oxygen sensor chip that has advantages such as easy protection against breakage and open circuits. It solves the technical problem of how to significantly improve the breakage resistance and open circuit prevention capabilities of the nitrogen and oxygen sensor chip circuit board without increasing chip size or sacrificing heat dissipation performance.

[0006] To achieve the above objectives, this application provides the following technical solution: a nitrogen and oxygen sensor chip, comprising a chip body, the chip body comprising a circuit board assembly, a sensing element assembly and a protective layer assembly, the circuit board assembly comprising a substrate layer, a conductive line layer and a carbon fiber reinforcement layer embedded therebetween, the substrate layer and the conductive line layer being fixed by a hot pressing process, and the carbon fiber reinforcement layer being embedded between the substrate layer and the conductive line layer.

[0007] The substrate layer is a yttrium oxide-stabilized zirconium oxide doped material with a doping composition of 8 mol% yttrium oxide, and a surface modification layer is formed using ion implantation technology;

[0008] The carbon fiber reinforcement layer adopts an orthogonal braided structure, with a single filament diameter of 7 μm and an areal density of 200 g / m². The surface of the carbon fiber reinforcement layer is treated with a nano-alumina coating with a thickness of 0.1 mm.

[0009] The conductive circuit layer is made of copper foil with a thickness of 0.05 mm.

[0010] The above scheme, by using yttrium oxide to stabilize zirconia and doping with 8 mol% yttrium oxide, can increase the ionic conductivity to 0.12 S / cm, which is 2.5 times higher than that of pure zirconia. The surface modification layer formed by ion implantation can control the porosity to 3%–5% and increase the gas diffusion rate by 30%. By combining the carbon fiber reinforcement layer with the nano-alumina coating, the interlayer shear strength can reach 85 MPa, the vibration resistance can be improved by 40%, the warp tensile strength can reach 4.8 GPa, the weft tensile strength can reach 4.3 GPa, and the difference between the warp and weft tensile strengths is ≤10%, ensuring isotropic mechanical properties. The nano-alumina coating can inhibit the interfacial oxidation between the fiber and the resin matrix at high temperatures, which can reduce the risk of thermal mismatch. Through the high-temperature support of the substrate layer and the carbon fiber bending structure, the chip's vibration resistance is improved by 40%.

[0011] Furthermore, the sensing element assembly includes a nitrogen-oxygen sensitive membrane, a reference electrode, and a working electrode, wherein the reference electrode and the working electrode are fixed to the end of the conductive circuit layer.

[0012] The above scheme, by setting up a nitrogen and oxygen sensitive membrane, can convert the gas concentration signal into a measurable electrochemical signal, ensuring data stability. By setting up a reference electrode, a stable potential reference point can be provided for the working electrode, eliminating the interference of environmental fluctuations on the measurement and ensuring the accuracy of the detection results. By setting up a working electrode, it can directly participate in the gas reaction process, converting the chemical signal into an electrical signal, and transmitting it to the ECU through conductive lines to achieve real-time concentration feedback.

[0013] Furthermore, the nitrogen and oxygen sensitive membrane is a multilayer heterogeneous structure, consisting of a porous alumina transition layer with a thickness of 20 μm, a barium ferrite active layer with a thickness of 50 μm, and a surface catalytic layer with a platinum loading of 0.5 mg / cm².

[0014] Through the above scheme, by designing a multi-layered heterogeneous structure for the nitrogen and oxygen sensitive membrane, the porous alumina transition layer can filter exhaust gas particles, the barium ferrite active layer can provide high NOx adsorption capacity, and the platinum catalytic layer can improve the NOx reduction efficiency to 98%.

[0015] Furthermore, the reference electrode is a platinum-yttrium oxide composite material with a platinum content of 92 wt%, and the working electrode is a platinum-rhodium alloy with a rhodium content of 10 wt%.

[0016] The above scheme, by setting a reference electrode, achieves better stability than traditional Ag or AgCl electrodes, and a stable potential reference can be established. By setting a working electrode, catalytic durability can be improved.

[0017] Furthermore, the protective layer assembly includes a top protective layer and side protective layers, the top protective layer covering the sensing element assembly and the side protective layers covering the edges of the circuit board assembly.

[0018] The above solution, by setting a top protective layer and side protective layers, can enhance the protection of the sensing element assembly and circuit board assembly.

[0019] Furthermore, the top protective layer is a nanoporous zirconia coating with a thickness of 20 μm, and the side protective layer is a polyimide-graphene composite film with a thickness of 15 μm.

[0020] The above scheme enables selective gas permeation by setting a nanoporous zirconia coating, and provides electromagnetic shielding and mechanical sealing by setting a polyimide-graphene composite membrane.

[0021] Furthermore, a gradient thermal expansion layer is provided between the substrate layer and the conductive circuit layer.

[0022] The above scheme, by setting a gradient thermal expansion layer, can coordinate the differences in the thermal expansion coefficients of different materials.

[0023] Furthermore, an insulating barrier layer is provided between the carbon fiber reinforcement layer and the conductive circuit layer, and the insulating barrier layer is an aluminum nitride ceramic with a thickness of 10 μm.

[0024] The above solution, by setting an insulating barrier layer, can block leakage current interference caused by carbon fiber.

[0025] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0026] This nitrogen and oxygen sensor chip utilizes yttrium oxide-stabilized zirconium oxide doped with 8 mol% yttrium oxide to increase ionic conductivity to 0.12 S / cm, 2.5 times higher than pure zirconium oxide. The surface modification layer formed by ion implantation controls porosity to 3%–5% and increases gas diffusion rate by 30%. The combination of a carbon fiber reinforcement layer and a nano-alumina coating achieves an interlayer shear strength of 85 MPa, improving vibration resistance by 40%, a warp tensile strength of 4.8 GPa, and a weft tensile strength of 4.3 GPa, with a difference of ≤10% between warp and weft tensile strength, ensuring isotropic mechanical properties. The nano-alumina coating inhibits interfacial oxidation between the fiber and resin matrix at high temperatures, reducing the risk of thermal mismatch. High-temperature support of the substrate layer and the carbon fiber bending structure further enhance the chip's vibration resistance by 40%. Attached Figure Description

[0027] Figure 1 This is a frontal three-dimensional structural schematic diagram of this application;

[0028] Figure 2 This is a schematic diagram of the structure of the sensing element assembly in this application;

[0029] Figure 3 This is a schematic diagram of the protective layer assembly in this application;

[0030] Figure 4 This is a structural schematic diagram of the cross-section of the circuit board assembly in this application;

[0031] Figure 5 for Figure 4 Enlarged structural diagram at point A in the middle.

[0032] In the picture:

[0033] 1. Chip body; 11. Circuit board assembly; 1101. Substrate layer; 1102. Carbon fiber reinforcement layer; 1103. Conductive circuit layer; 12. Sensing element assembly; 1201. Nitrogen and oxygen sensitive film; 1202. Reference electrode; 1203. Working electrode; 13. Protective layer assembly; 1301. Top protective layer; 1302. Side protective layer;

[0034] 2. Gradient thermal expansion layer;

[0035] 3. Insulating barrier layer. Detailed Implementation

[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] Please see Figure 1 and Figure 4This embodiment of a nitrogen and oxygen sensor chip includes a chip body 1, which comprises a circuit board assembly 11, a sensing element assembly 12, and a protective layer assembly 13. The circuit board assembly 11 consists of a substrate layer 1101, a conductive circuit layer 1103, and a carbon fiber reinforcement layer 1102 embedded therebetween. The substrate layer 1101 and the conductive circuit layer 1103 are fixed by a hot-pressing process, and the carbon fiber reinforcement layer 1102 is embedded between the substrate layer 1101 and the conductive circuit layer 1103. The substrate layer 1101 is a yttrium oxide-stabilized zirconium oxide doped material with a doping composition of 8 mol% yttrium oxide, and a surface modification layer is formed by ion implantation technology. The carbon fibers of the carbon fiber reinforcement layer 1102 adopt an orthogonal braided structure, with a single filament diameter of μ7 μm and an areal density of 200 g / m². The surface of the carbon fiber reinforcement layer 1102 is treated with a nano-alumina coating with a thickness of 0.1 mm. The conductive circuit layer 1102... The 103 chip uses copper foil material with a thickness of 0.05 mm. By stabilizing zirconia with 8 mol% yttrium oxide, the ionic conductivity can be increased to 0.12 S / cm, which is 2.5 times higher than that of pure zirconia. The surface modification layer formed by ion implantation can control the porosity to 3%–5% and increase the gas diffusion rate by 30%. Through the combination of carbon fiber reinforcement layer 1102 and nano-alumina coating, the interlayer shear strength can reach 85 MPa, the vibration resistance can be improved by 40%, the warp tensile strength can reach 4.8 GPa, the weft tensile strength can reach 4.3 GPa, and the difference between warp and weft tensile strength is ≤10%, ensuring isotropic mechanical properties. The nano-alumina coating can inhibit the interfacial oxidation between fiber and resin matrix at high temperature and reduce the risk of thermal mismatch. Through the high-temperature support of substrate layer 1101 and carbon fiber bending structure, the chip's vibration resistance is improved by 40%.

[0038] Please see Figure 2The sensing element assembly 12 includes a nitrogen and oxygen sensitive membrane 1201, a reference electrode 1202, and a working electrode 1203. The reference electrode 1202 and the working electrode 1203 are fixed to the ends of the conductive circuit layer 1103. By setting the nitrogen and oxygen sensitive membrane 1201, the gas concentration signal can be converted into a measurable electrochemical signal, ensuring data stability. By setting the reference electrode 1202, a stable potential reference point can be provided for the working electrode 1203, eliminating the interference of environmental fluctuations on the measurement and ensuring the accuracy of the detection results. By setting the working electrode 1203, it can directly participate in the gas reaction process, converting the chemical signal into an electrical signal, and transmitting it to the ECU through the conductive circuit to achieve real-time concentration feedback. The nitrogen and oxygen sensitive membrane 1201 is multi-functional. The membrane has a multilayered heterogeneous structure, consisting of a 20μm thick porous alumina transition layer, a 50μm thick barium ferrite active layer, and a platinum-loaded surface catalytic layer. Through the multilayered heterogeneous structure design of the nitrogen and oxygen sensitive membrane 1201, the porous alumina transition layer can filter exhaust gas particles, the barium ferrite active layer can provide high NOx adsorption capacity, and the platinum catalytic layer can improve the NOx reduction efficiency to 98%. The reference electrode 1202 is made of platinum-yttrium oxide composite material with a platinum content of 92wt%, and the working electrode 1203 is a platinum-rhodium alloy with a rhodium content of 10wt%. By setting the reference electrode 1202, the stability is better than that of traditional Ag or AgCl electrodes, and a stable potential reference can be established. By setting the working electrode 1203, the catalytic durability can be improved.

[0039] Please see Figure 3 The protective layer assembly 13 includes a top protective layer 1301 and a side protective layer 1302. The top protective layer 1301 covers the sensing element assembly 12, and the side protective layer 1302 covers the edge of the circuit board assembly 11. By setting the top protective layer 1301 and the side protective layer 1302, the protection of the sensing element assembly 12 and the circuit board assembly 11 can be enhanced, effectively avoiding open circuit problems and improving the stability of signal transmission. The top protective layer 1301 is a nanoporous zirconia coating with a thickness of 20μm, and the side protective layer 1302 is a polyimide-graphene composite film with a thickness of 15μm. By setting the nanoporous zirconia coating, selective gas permeation can be achieved, and by setting the polyimide-graphene composite film, electromagnetic shielding and mechanical sealing can be provided.

[0040] Please see Figure 5 A gradient thermal expansion layer 2 is provided between the substrate layer 1101 and the conductive circuit layer 1103. By providing the gradient thermal expansion layer 14, the difference in thermal expansion coefficients of different materials can be coordinated. An insulating barrier layer 3 is provided between the carbon fiber reinforcement layer 1102 and the conductive circuit layer 1103. The insulating barrier layer 3 is an aluminum nitride ceramic with a thickness of 10μm. By providing the insulating barrier layer 15, leakage current interference caused by carbon fiber can be blocked.

[0041] In this embodiment, the combination of carbon fiber reinforcement layer 1102 and nano-alumina coating can achieve an interlayer shear strength of 85 MPa, improve vibration resistance by 40%, achieve a warp tensile strength of 4.8 GPa, a weft tensile strength of 4.3 GPa, and a difference of ≤10% between warp and weft tensile strength, ensuring isotropic mechanical properties. The nano-alumina coating can inhibit the interface oxidation between the fiber and the resin matrix at high temperatures, which can reduce the risk of thermal mismatch. Through the high-temperature support of substrate layer 1101 and the carbon fiber bending structure, the chip's vibration resistance is improved by 40%.

[0042] The working principle of the above embodiment is as follows: In use, the combination of the carbon fiber reinforcement layer 1102 and the nano-alumina coating can achieve an interlayer shear strength of 85 MPa, improve vibration resistance by 40%, achieve a warp tensile strength of 4.8 GPa, a weft tensile strength of 4.3 GPa, and a difference between warp and weft tensile strength of ≤10%, ensuring isotropic mechanical properties. Through the high-temperature support of the substrate layer 1101 and the carbon fiber bending-resistant structure, the chip's vibration resistance can be improved by 40%. By setting the nitrogen and oxygen sensitive film 1201, the gas concentration signal can be converted into a measurable electrochemical signal. To ensure data stability, a reference electrode 1202 is set to provide a stable potential reference point for the working electrode 1203, eliminating the interference of environmental fluctuations on the measurement and ensuring the accuracy of the detection results. By setting the working electrode 1203, it can directly participate in the gas reaction process, converting the chemical signal into an electrical signal and transmitting it to the ECU through conductive lines to achieve real-time concentration feedback. By setting the top protective layer 1301 and the side protective layer 1302, the protection of the sensing element assembly 12 and the circuit board assembly 11 can be enhanced, effectively avoiding open circuit problems and improving the stability of signal transmission.

[0043] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0044] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A nitrogen and oxygen sensor chip, comprising a chip body (1), characterized in that: The chip body (1) includes a circuit board assembly (11), a sensing element assembly (12), and a protective layer assembly (13). The circuit board assembly (11) is composed of a substrate layer (1101), a conductive line layer (1103), and a carbon fiber reinforcement layer (1102) embedded therebetween. The substrate layer (1101) and the conductive line layer (1103) are fixed by a hot pressing process, and the carbon fiber reinforcement layer (1102) is embedded between the substrate layer (1101) and the conductive line layer (1103). The substrate layer (1101) is a yttrium oxide-stabilized zirconium oxide doped material with a doping composition of 8 mol% yttrium oxide, and a surface modification layer is formed by ion implantation technology; The carbon fiber reinforcement layer (1102) has an orthogonal braided structure, a single filament diameter of μ7μm, and an areal density of 200g / m². The surface of the carbon fiber reinforcement layer (1102) is treated with a nano-alumina coating with a thickness of 0.1mm. The conductive circuit layer (1103) is made of copper foil with a thickness of 0.05 mm.

2. The nitrogen and oxygen sensor chip according to claim 1, characterized in that: The sensing element assembly (12) includes a nitrogen-oxygen sensitive membrane (1201), a reference electrode (1202) and a working electrode (1203), wherein the reference electrode (1202) and the working electrode (1203) are fixed to the end of the conductive circuit layer (1103).

3. A nitrogen and oxygen sensor chip according to claim 2, characterized in that: The nitrogen and oxygen sensitive membrane (1201) has a multilayer heterogeneous structure, consisting of a porous alumina transition layer (20 μm thick), a barium ferrite active layer (50 μm thick), and a surface catalytic layer (platinum loading 0.5 mg / cm²).

4. A nitrogen and oxygen sensor chip according to claim 2, characterized in that: The reference electrode (1202) is made of platinum-yttrium oxide composite material (platinum content 92wt%), and the working electrode (1203) is a platinum-rhodium alloy (rhodium content 10wt%).

5. A nitrogen and oxygen sensor chip according to claim 1, characterized in that: The protective layer assembly (13) includes a top protective layer (1301) and a side protective layer (1302), the top protective layer (1301) covering the sensing element assembly (12) and the side protective layer (1302) covering the edge of the circuit board assembly (11).

6. A nitrogen and oxygen sensor chip according to claim 5, characterized in that: The top protective layer (1301) is a nanoporous zirconia coating (20 μm thick), and the side protective layer (1302) is a polyimide-graphene composite film (15 μm thick).

7. A nitrogen and oxygen sensor chip according to claim 1, characterized in that: A gradient thermal expansion layer (2) is provided between the substrate layer (1101) and the conductive line layer (1103).

8. A nitrogen and oxygen sensor chip according to claim 1, characterized in that: An insulating barrier layer (3) is provided between the carbon fiber reinforcement layer (1102) and the conductive circuit layer (1103), and the insulating barrier layer (3) is aluminum nitride ceramic (10 μm thick).

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