A nitrogen oxide sensor chip with independent design of pump unit

Abstract

The present application discloses a nitrogen oxygen sensor chip with an independently designed pump unit, including a substrate, wherein the substrate is composed of a multi-layer aluminum oxide substrate and a multi-layer zirconium oxide substrate stacked in sequence. The multi-layer aluminum oxide substrate includes aluminum oxide substrate one, aluminum oxide substrate two, aluminum oxide substrate three and aluminum oxide substrate four, and the multi-layer zirconium oxide substrate includes zirconium oxide substrate one, zirconium oxide substrate two and zirconium oxide substrate three. By adopting the above-mentioned nitrogen oxygen sensor chip with an independently designed pump unit, the pump oxygen units of the nitrogen oxygen sensor are separated from each other, which can improve the accuracy of the product, especially reduce the influence of oxygen content on nitrogen oxygen content determination when the oxygen content changes drastically, and greatly shorten the chip size, while improving performance and reducing costs.

Description

Technical Field

[0001] The present invention relates to the technical field of nitrogen oxygen sensors, and in particular to a nitrogen oxygen sensor chip with an independently designed pump unit. Background Art

[0002] The research and development of nitrogen oxide sensors is mainly to solve the problem of NO X (Including NO, NO 2 ) emission problem, and can accurately and quickly determine NO X The product is currently mainly used in the after-treatment system of medium and heavy-duty diesel vehicles and industrial flue systems to achieve NO X Precise measurement and control.

[0003] Traditional NOx sensor chips such as Figure 1 As shown, the conventional nitrogen oxygen sensor is formed on the basis of a conventional substrate 110 formed by stacking multiple layers of zirconium oxide substrates. The conventional substrate 110 is provided with a conventional opening 112, a conventional first chamber 114, a conventional second chamber 116 and a conventional reference gas channel 118. A conventional outer electrode 122 is arranged outside the conventional substrate 110, a conventional first inner electrode 124 is arranged inside the conventional first chamber 114, and a conventional second inner electrode 126 and a conventional third inner electrode 128 are arranged inside the conventional second chamber 116. Among them, the conventional outer electrode 122, the conventional first inner electrode 124 and part of the substrate constitute a conventional main oxygen pump, the conventional outer electrode 122, the conventional second inner electrode 126 and part of the substrate constitute a conventional auxiliary oxygen pump, and the conventional outer electrode 122, the conventional third electrode 128 and part of the substrate constitute a conventional measuring oxygen pump. When nitrogen oxides enter the traditional first chamber 114 from the traditional opening 112, the traditional main oxygen pump pumps away part of the oxygen, and the remaining gas enters the traditional second chamber 116. The traditional auxiliary oxygen pump further pumps away the oxygen, so that nitric oxide is reduced to oxygen and nitrogen on the surface of the traditional third electrode 128. The traditional measuring oxygen pump can obtain the nitrogen oxide concentration in the gas entering from the traditional opening 112 by measuring the concentration of the decomposed oxygen.

[0004] In this traditional structure, the zirconia between the oxygen pumps are interconnected. When faced with drastic changes in oxygen concentration, this will cause mutual interference between the oxygen signal and the nitrogen oxygen signal, leading to inaccurate nitrogen oxygen concentration testing under certain working conditions, which requires improvement. Summary of the invention

[0005] The present invention aims to solve one of the technical problems existing in the prior art.

[0006] The present application provides a nitrogen oxygen sensor chip with an independently designed pump unit, comprising a substrate, wherein the substrate is formed by sequentially stacking a multi-layer aluminum oxide substrate and a multi-layer zirconium oxide substrate.

[0007] Preferably, the multilayer alumina substrate includes an alumina substrate one, an alumina substrate two, an alumina substrate three and an alumina substrate four, and the multilayer zirconia substrate includes a zirconia substrate one, a zirconia substrate two and a zirconia substrate three.

[0008] Preferably, the substrate is composed of, from top to bottom, an alumina substrate 1, a zirconia substrate 1, an alumina substrate 2, a zirconia substrate 2, an alumina substrate 3, a zirconia substrate 3 and an alumina substrate 4.

[0009] Preferably, an air inlet hole is provided from top to bottom on the alumina substrate 1, the zirconia substrate 1 and the alumina substrate 2; a reaction cavity 1 is provided on the alumina substrate 2, an inner oxygen electrode 1 and a reference electrode are arranged in the reaction cavity 1; one side of the reaction cavity 1 is connected with the air inlet hole, and a reaction cavity 2 is provided on the other side; the reaction cavity 2 passes through the zirconia substrate 2 and is formed in the alumina substrate 3; an activation electrode is arranged in the reaction cavity 2; an oxygen exhaust cavity is provided on the alumina substrate 4 and below the reaction cavity 2, an inner oxygen electrode 2 is arranged in the oxygen exhaust cavity; a reference cavity 1 is provided on the alumina substrate 3 and below the reaction cavity 1, a reference electrode is arranged in the reference cavity 1; a groove is provided on the alumina substrate 1, an outer electrode is arranged in the groove.

[0010] Preferably, one side of the reaction cavity 1 is connected to the air inlet through the diffusion layer 1.

[0011] Preferably, a heating electrode is provided in the alumina substrate 4.

[0012] Preferably, the method further comprises a protection layer arranged in the groove for covering and protecting the outer electrode.

[0013] Preferably, the outer electrode, the inner oxygen electrode and the zirconium oxide substrate form an oxygen pump to pump the oxygen in the reaction cavity to the outside of the reaction cavity.

[0014] Preferably, the remaining gas enters the second reaction cavity through the second diffusion layer and reaches the surface of the activation electrode. The activation electrode is a platinum-rhodium electrode, which can convert nitric oxide into nitrogen and oxygen. The second oxygen pump is formed by the activation electrode, the second inner oxygen electrode and the third zirconium oxide matrix to pump the decomposed oxygen into the oxygen exhaust cavity.

[0015] By using the above-mentioned nitrogen oxygen sensor chip with an independently designed pump unit, the pump oxygen units of the nitrogen oxygen sensor are separated from each other, which can improve the accuracy of the product, especially reduce the impact of drastic changes in oxygen content on nitrogen oxygen content determination, and greatly shorten the chip size, thereby reducing costs while improving performance.

[0016] The beneficial effects of the present invention will be described in detail in the examples to make the beneficial effects more obvious. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the cross-sectional structure of a traditional nitrogen oxide sensor chip head.

[0018] Figure 2 Schematic diagram of the cross-sectional structure of the NOx sensor chip head designed independently for the pump unit.

[0019] Figure 3 This is a schematic diagram of the wiring structure of the eight-wire nitrogen oxide sensor chip.

[0020] Figure 4 This is a schematic diagram of the wiring structure of the six-wire nitrogen oxide sensor chip.

[0021] Figure 5 This is a schematic diagram of the front and back top view of the nitrogen oxide sensor chip with eight pins.

[0022] Figure 6 This is a schematic diagram of the front and back top view of the six-pin nitrogen oxide sensor chip. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0024] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable when appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0025] The embodiments of the present application are described in detail below through specific embodiments and their application scenarios in conjunction with the accompanying drawings.

[0026] Embodiment 1:

[0027] like Figure 2 As shown, a nitrogen oxygen sensor chip with an independently designed pump unit includes a substrate. In a specific embodiment of the present invention, the substrate is formed by stacking and compounding a multi-layer aluminum oxide substrate and a multi-layer zirconium oxide substrate in sequence. The multi-layer aluminum oxide substrate includes an aluminum oxide substrate 16, an aluminum oxide substrate 2 18, an aluminum oxide substrate 3 20 and an aluminum oxide substrate 4 22. The multi-layer zirconium oxide substrate includes a zirconium oxide substrate 1 17, a zirconium oxide substrate 2 19 and a zirconium oxide substrate 3 21. The substrate is composed of an aluminum oxide substrate 1 16, a zirconium oxide substrate 1 17, an aluminum oxide substrate 2 18, a zirconium oxide substrate 2 19, an aluminum oxide substrate 3 20, a zirconium oxide substrate 3 21 and an aluminum oxide substrate 4 22 from top to bottom.

[0028] The difference from the traditional NOx sensor chip is that each layer of zirconium oxide is separated by aluminum oxide, such as Figure 2 The substrate shown is composed of an alumina substrate 16, a zirconia substrate 17, an alumina substrate 2 18, a zirconia substrate 2 19, an alumina substrate 3 20, a zirconia substrate 3 21 and an alumina substrate 4 22 from top to bottom, so as to ensure that the zirconia electrolytes between each oxygen pump electrode are independent and will not interfere with each other.

[0029] In a specific embodiment of the present invention, an air inlet 2 is provided from top to bottom on the alumina substrate 16, the zirconia substrate 17, and the alumina substrate 2 18. A reaction cavity 6 is provided on the alumina substrate 2 18. An internal oxygen electrode 5 and a comparison electrode 7 are arranged in the reaction cavity 6. One side of the reaction cavity 6 is connected to the air inlet 2, and a reaction cavity 11 is provided on the other side. The reaction cavity 11 passes through the zirconia substrate 2 19 and is formed in the alumina substrate 3 20. An activation electrode 12 is arranged in the reaction cavity 11. An oxygen exhaust cavity 14 is provided on the alumina substrate 4 22 and below the reaction cavity 11. An internal oxygen electrode 13 is arranged in the oxygen exhaust cavity 14. The alumina substrate 3 20 A reference cavity 10 is arranged above and below the reaction cavity 6, and a reference electrode 9 is arranged in the reference cavity 10. A groove is opened on the alumina substrate 16, and an external electrode 3 is arranged in the groove. One side of the reaction cavity 6 is connected with the air inlet 2 through a diffusion layer 4. A heating electrode 15 is arranged in the alumina substrate 22, and also includes a protective layer 1 arranged in the groove for covering and protecting the external electrode 3.

[0030] The specific working principle is: the exhaust gas passes through the air inlet 2, and then enters the reaction cavity 6 through the diffusion layer 4. The outer electrode 3, the inner oxygen electrode 5 and the zirconia substrate 17 form an oxygen pump to pump the oxygen in the reaction cavity 6 to the outside of the cavity. The pump current IP1 is linearly corresponding to the oxygen concentration. The voltage between the comparison electrode 7 and the reference electrode 9 is controlled to be 450mV (oxygen concentration is 0) as the target value. The remaining gas enters the reaction cavity 11 through the diffusion layer 8 and reaches the surface of the activation electrode 12. The activation electrode 12 is a platinum-rhodium electrode that can convert nitric oxide into nitrogen and oxygen. The activation electrode 12, the inner oxygen electrode 13 and the zirconia substrate 3 21 form a second oxygen pump to pump the decomposed oxygen to the oxygen exhaust cavity 14. The pump current IP 2 It has a linear relationship with the concentration of nitrogen oxides.

[0031] Embodiment 2:

[0032] In addition to the structural features of the aforementioned embodiments, in a specific embodiment of the present invention, the nitrogen oxygen sensor chip can be designed as a structure with eight pins, such as Figure 3 As shown; it can also be designed into a six-pin structure, such as Figure 4 shown.

[0033] According to the signal processing of the ECU, the common groundable electrode can be connected to form a pin electrode lead. Figure 1 The inner oxygen electrode 5, the comparison electrode 7, and the activation electrode 12 can be connected at the tail of the chip to form a lead electrode. With this design, the nitrogen oxygen sensor only has 6 wires from the outside, but it actually has 8 electrodes. Figure 5 and Figure 6 shown.

[0034] It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a..." does not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0035] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A nitrogen oxygen sensor chip with an independently designed pump unit, comprising a substrate, characterized in that: The substrate is formed by stacking and compounding a plurality of alumina substrates and a plurality of zirconia substrates in sequence. The plurality of alumina substrates include an alumina substrate 1 (16), an alumina substrate 2 (18), an alumina substrate 3 (20) and an alumina substrate 4 (22). The plurality of zirconia substrates include a zirconia substrate 1 (17), a zirconia substrate 2 (19) and a zirconia substrate 3 (21). The substrate is composed of an alumina substrate 1 (16), a zirconia substrate 1 (17), an alumina substrate 2 (18), a zirconia substrate 2 (19), an alumina substrate 3 (20) and a zirconia substrate 3 (21) from top to bottom. and an alumina substrate four (22), wherein the alumina substrate one (16), the zirconia substrate one (17), and the alumina substrate two (18) are provided with an air inlet hole (2) from top to bottom, the alumina substrate two (18) is provided with a reaction cavity one (6), and the reaction cavity one (6) is provided with an internal oxygen electrode one (5) and a comparison electrode (7), one side of the reaction cavity one (6) is connected to the air inlet hole (2), and the other side is provided with a reaction cavity two (11), the reaction cavity two (11) passes through the zirconia substrate two (19) and is formed in the alumina substrate three (20), and the reaction cavity An activation electrode (12) is arranged in the second cavity (11); an oxygen exhaust cavity (14) is arranged on the fourth alumina substrate (22) and below the second reaction cavity (11); an inner oxygen electrode (13) is arranged in the oxygen exhaust cavity (14); a reference cavity (10) is arranged on the third alumina substrate (20) and below the first reaction cavity (6); a reference electrode (9) is arranged in the first reference cavity (10); a groove is provided on the first alumina substrate (16); an outer electrode (3) is arranged in the groove; the outer electrode (3), the inner oxygen electrode (5) and the zirconium oxide substrate One (17) forms an oxygen pump to pump the oxygen in the reaction cavity one (6) to the outside of the reaction cavity one (6), and the remaining gas enters the reaction cavity two (11) through the diffusion layer two (8) and reaches the surface of the activation electrode (12). The activation electrode (12) is a platinum-rhodium electrode that can convert nitric oxide into nitrogen and oxygen. The activation electrode (12), the inner oxygen electrode two (13) and the zirconium oxide matrix three (21) form a second oxygen pump to pump the decomposed oxygen to the oxygen exhaust cavity (14). One side of the reaction cavity one (6) is connected to the reaction cavity two (11) through the diffusion layer two (8).

2. A nitrogen oxygen sensor chip with an independently designed pump unit according to claim 1, characterized in that: One side of the reaction cavity one (6) is connected to the air inlet (2) through the diffusion layer one (4).

3. A nitrogen oxygen sensor chip with an independently designed pump unit according to claim 1 or 2, characterized in that: A heating electrode (15) is provided in the alumina substrate 4 (22).

4. A nitrogen oxygen sensor chip with an independently designed pump unit according to claim 1 or 2, characterized in that: It also includes a protective layer (1) arranged in the groove and used for covering and protecting the external electrode (3).

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