A multilayer three-dimensional interdigital electrode for exhaust gas sensors

Abstract

The utility model discloses a kind of multilayer three-dimensional interdigital electrode for tail gas sensor, belong to tail gas sensor technical field, including multiple insulating plates, two the insulating plate are all installed with pin electrode piece, multiple insulating plates on the adjacent side of two the insulating plate are sequentially installed with pin electrode piece, anode electrode piece, heating electrode piece, cathode electrode piece and temperature measuring electrode piece from top to bottom, the utility model is built by new three-dimensional electrode group framework, realize the efficient detection of 10 μm-20 μm wide particle size range tail gas, make up the defect that traditional sensor detects narrow particle size range, and utilize the innovative design of interlayer isolation, completely solve the short-circuit failure problem caused by particulate matter accumulation, substantially improve the structural stability and service life of sensor, while, by embedded temperature measuring electrode design, enhance the durability of temperature measuring electrode, ensure the accuracy and long-term stability of tail gas temperature measurement, provide reliable basis for temperature compensation of detection data.

Description

Technical Field

[0001] This utility model relates to the field of exhaust gas sensor technology, specifically a multilayer three-dimensional interdigitated electrode for exhaust gas sensors. Background Technology

[0002] In the field of automotive exhaust treatment, increasingly stringent environmental standards place higher demands on the accuracy and reliability of diesel vehicle exhaust gas detection. Traditional particulate matter sensors, with Bosch PM sensors as a typical example, employ a planar interdigitated electrode structure, which has revealed several technical shortcomings in practical applications:

[0003] Limited particle size detection range: The electrode spacing is usually limited to 20-50μm. It is not sensitive to large carbon soot particles with a particle size greater than 10μm, making it difficult to accurately detect exhaust gas with a wide particle size distribution and unable to fully reflect the exhaust gas pollution status.

[0004] Poor structural stability: The single-layer planar structure makes the sensor prone to short circuit when faced with a large amount of particulate matter in the exhaust gas, which seriously affects the service life and detection stability of the sensor, increases maintenance costs and vehicle operation risks.

[0005] Significant installation limitations: The single-sided interdigitated electrode design makes the sensor extremely sensitive to the installation direction. Even a slight deviation in the installation angle will significantly affect the detection accuracy, placing extremely high demands on actual installation operations and limiting its widespread application.

[0006] Temperature sensing electrodes are easily damaged: The temperature sensing electrodes are exposed to the exhaust gas environment and are subjected to long-term erosion by high temperature and corrosive exhaust gas, which leads to a decrease in temperature measurement accuracy and a shortened electrode life. This, in turn, affects the accurate measurement and compensation of exhaust gas temperature-related parameters by the entire sensor. To address this, a multilayer three-dimensional interdigitated electrode for exhaust gas sensors is proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a multilayer three-dimensional interdigitated electrode for exhaust gas sensors to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a multi-layer three-dimensional interdigitated electrode for an exhaust gas sensor, comprising multiple insulating plates, each of which is equipped with a lead electrode plate, and the multiple insulating plates on an adjacent side of the two insulating plates are sequentially equipped with a lead electrode plate, an anode electrode plate, a heating electrode plate, a cathode electrode plate and a temperature measuring electrode plate from top to bottom.

[0009] Each of the insulating plates has multiple through holes.

[0010] As a further preferred embodiment of this technical solution: the heating electrode is a serpentine Pt electrode, and the linewidth of the heating electrode is 30μm±5%;

[0011] The resistance of the heating electrode sheet after co-firing is 25Ω±5%.

[0012] As a further preferred embodiment of this technical solution: the temperature measuring electrode is an embedded NTC, and the temperature measuring electrode has a thermistor index of 3950±1%.

[0013] As a further preferred embodiment of this technical solution: all of the aforementioned through holes are ZrO2 through holes.

[0014] As a further preferred embodiment of this technical solution: all of the insulating boards are made of Al2O3 ceramic substrate.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] This invention achieves efficient detection of exhaust gas with a wide particle size range of 10μm-20μm by constructing a novel three-dimensional electrode array architecture, overcoming the shortcomings of traditional sensors in detecting narrow particle sizes. Furthermore, the innovative interlayer isolation design completely solves the problem of short-circuit failure caused by particulate matter accumulation, significantly improving the structural stability and service life of the sensor. At the same time, the embedded temperature sensing electrode design enhances the durability of the temperature sensing electrode, ensuring the accuracy and long-term stability of exhaust gas temperature measurement and providing a reliable basis for temperature compensation of the detection data. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a multilayer three-dimensional interdigitated electrode for an exhaust gas sensor according to the present invention.

[0018] Figure 2 This is a schematic diagram of the structure of a second embodiment of the multilayer three-dimensional interdigitated electrode for exhaust gas sensors according to this utility model.

[0019] In the diagram: 1. Insulating plate; 2. Lead electrode plate; 3. Anode electrode plate; 4. Heating electrode plate; 5. Cathode electrode plate; 6. Temperature measuring electrode plate; 7. Through hole. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0021] Example 1

[0022] Please see Figure 1This utility model provides a technical solution: a multi-layer three-dimensional interdigitated electrode for exhaust gas sensors, including multiple insulating plates 1, each of which is equipped with a lead electrode piece 2, and on the multiple insulating plates 1 on the adjacent side of the two insulating plates 1, the lead electrode piece 2, the anode electrode piece 3, the heating electrode piece 4, the cathode electrode piece 5 and the temperature measuring electrode piece 6 are installed sequentially from top to bottom.

[0023] Multiple through holes 7 are provided on multiple insulating plates 1.

[0024] In this embodiment, specifically: the pin electrode 2 is used to connect the electrode system with the external circuit and transmit signals. As a connecting bridge in the multi-layer electrode structure, the pin electrode 2 is distributed at specific positions on the insulating plate (the pin electrode 2 is installed on part of the insulating plate, and the component is included in the distribution from top to bottom in the multi-layer structure). It can export the electrical signals generated by the core functional electrodes such as the anode electrode 3 and the cathode electrode 5 to the external detection device. At the same time, it can also receive control signals from the external circuit (such as the adjustment command for the heating electrode 4), thereby realizing the information interaction between the entire exhaust gas sensor and the external system, ensuring the effective transmission of sensor detection data and the precise control of the sensor's working state by the external system.

[0025] In this embodiment, specifically: the anode electrode 3 and cathode electrode 5 are the core functional components for detecting exhaust gas components. They work together to form an electrode pair. Specific components in the exhaust gas (such as oxygen, harmful gases, etc.) undergo oxidation-reduction reactions on the electrode surface. The electrical signals generated during the reaction (such as changes in current and potential) reflect the concentration of the target components in the exhaust gas. At the same time, the electrical signals generated by the electrochemical reaction are exported through the anode electrode 3 and cathode electrode 5, and then transmitted to the external detection system through the pin electrode 2 and other structures. Finally, quantitative or qualitative analysis of the exhaust gas components is achieved, providing key data for exhaust gas emission monitoring.

[0026] The stable operation of the anode electrode 3 and cathode electrode 5 depends on the suitable temperature environment provided by the heating electrode 4 (to ensure efficient reaction) and the insulating support of the insulating plate (to avoid signal interference), which together ensure the detection accuracy and reliability of the exhaust gas sensor.

[0027] In this embodiment, specifically: the heating electrode 4 is a serpentine Pt electrode with a linewidth of 30μm±5%. The heating electrode 4 is used to provide a stable operating temperature environment for the sensor. Through its own heating function, it can be adjusted according to the temperature data fed back by the temperature measuring electrode 6, so that the core components such as the anode electrode 3 and the cathode electrode 5 are in the optimal reaction temperature range. This ensures that the relevant components in the exhaust gas can undergo a stable electrochemical reaction on the electrode surface, thereby ensuring the accuracy and reliability of the sensor in detecting exhaust gas components and meeting the requirements of exhaust gas emission monitoring.

[0028] Among them, the serpentine structure design helps to increase the heating area and make the temperature distribution more uniform, while the choice of Pt material ensures its stability and conductivity in high-temperature environments.

[0029] The resistance of the heating electrode 4 after co-firing is 25Ω±5%.

[0030] In this embodiment, specifically: the temperature sensing electrode 6 is an embedded NTC, and the thermal index of the temperature sensing electrode 6 is 3950±1%. The temperature sensing electrode 6 is used to monitor the operating temperature of the exhaust gas sensor in real time. Through the temperature change sensitivity of the NTC, it accurately senses the temperature fluctuations inside the sensor and the exhaust gas environment, providing key data support for the temperature control of the heating electrode 4. With the help of this temperature information, the heating electrode 4 can adjust its working state in a targeted manner, so that the sensor is always in the optimal reaction temperature range, thereby ensuring the detection accuracy of core components such as the anode electrode 3 and the cathode electrode 5, and ensuring that the exhaust gas sensor can stably and accurately monitor the exhaust gas composition, meeting the requirements of exhaust gas emission monitoring.

[0031] In this embodiment, specifically: multiple through holes 7 are ZrO2 vias, and the through holes 7 are used to guide current.

[0032] In this embodiment, specifically: the multiple insulating plates 1 are all made of Al2O3 ceramic substrate. The insulating plates made of Al2O3 ceramic substrate have excellent insulation performance, which can effectively isolate multiple layers of electrodes such as pin electrode plates, anode electrode plates, and heating electrode plates, prevent short circuits, ensure stable operation of the electrode system, and have outstanding high temperature resistance. They can maintain stable physical and chemical properties in the high temperature working environment of the exhaust gas sensor, ensuring the integrity of the electrode structure and the reliability of its function. At the same time, they have good mechanical strength, providing solid support for the multi-layer three-dimensional interdigitated electrode structure, resisting external forces such as vibration and impact, and extending service life.

[0033] Among them, the insulating board made of Al2O3 ceramic substrate also has excellent chemical stability, is not easy to react with corrosive components in exhaust gas, maintains stable performance in complex environments, ensures detection accuracy and long-term effectiveness, and has good material compatibility, making it easy to combine with Pt electrodes and other components and ZrO vias. It is structurally stable in processes such as co-firing, which is conducive to the integrated fabrication of multilayer electrodes.

[0034] Example 2

[0035] Please see Figure 2 The only difference between this embodiment and Embodiment 1 is that it includes multiple insulating plates 1, which are located on the adjacent side of the anode electrode plate 3 and the cathode electrode plate 5, and multiple through holes 7 are opened on each of the multiple insulating plates 1.

[0036] In this embodiment, specifically: it is composed of 11 layers of Al2O3 ceramic substrates stacked together, and the electrode sheets are installed from top to bottom as follows: lead electrode sheet 2, anode electrode sheet 3, heating electrode sheet 4, cathode electrode sheet 5, Al2O3 ceramic substrate (for insulation to avoid short circuit), anode electrode sheet 3, Al2O3 ceramic substrate (for insulation to avoid short circuit), anode electrode sheet 3, temperature measuring electrode sheet 6, cathode electrode sheet 5 and lead electrode sheet 2.

[0037] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multilayer three-dimensional interdigitated electrode for an exhaust gas sensor, comprising multiple insulating plates (1), characterized in that: Both insulating plates (1) are equipped with lead electrode plates (2), and multiple insulating plates (1) on the adjacent side of the two insulating plates (1) are equipped with lead electrode plates (2), anode electrode plates (3), heating electrode plates (4), cathode electrode plates (5) and temperature measuring electrode plates (6) in sequence from top to bottom; Each of the insulating plates (1) has multiple through holes (7).

2. The multilayer three-dimensional interdigitated electrode for an exhaust gas sensor according to claim 1, characterized in that: The heating electrode (4) is a serpentine Pt electrode, and the line width of the heating electrode (4) is 30 μm ± 5%. The resistance of the heating electrode sheet (4) after co-firing is 25Ω±5%.

3. The multilayer three-dimensional interdigitated electrode for an exhaust gas sensor according to claim 1, characterized in that: The temperature measuring electrode (6) is an embedded NTC, and the temperature measuring electrode (6) has a thermistor index of 3950±1%.

4. A multilayer three-dimensional interdigitated electrode for an exhaust gas sensor according to claim 1, characterized in that: All of the aforementioned through holes (7) are ZrO2 through holes.

5. A multilayer three-dimensional interdigitated electrode for an exhaust gas sensor according to claim 1, characterized in that: All of the insulating boards (1) are made of Al2O3 ceramic substrate.

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