Ceramic chip and nitrogen-oxygen sensor thereof

Abstract

The utility model discloses a ceramic chip and a nitrogen-oxygen sensor thereof, and relates to the technical field of sensors. The ceramic chip comprises a chip body, an auxiliary pump negative electrode, a measuring electrode and a partition plate, a measuring cavity is formed in the chip body, the auxiliary pump negative electrode is arranged in the measuring cavity, and the measuring electrode is arranged in the measuring cavity and located on one side of the auxiliary pump negative electrode; the partition plates are arranged in the measuring cavity and located between the negative electrode of the auxiliary pump and the measuring electrode, the partition plates comprise the first partition plate and the second partition plate which are arranged in a staggered mode in the height direction of the chip body, and a channel is defined between the first partition plate and the second partition plate. In the technical scheme provided by the invention, the first partition plate and the second partition plate which are arranged in an up-and-down staggered manner can effectively prevent the problem of pollution of the measuring electrode caused by volatilization of gold, and are convenient for gas to flow to the area where the measuring electrode is located from the area where the negative electrode of the auxiliary pump is located through the channel, so that the gas is in smooth contact with the measuring electrode; the detection effect of the measuring electrode is ensured.

Description

Technical Field

[0001] This application relates to the field of sensor technology, and in particular to a ceramic chip and its nitrogen and oxygen sensor. Background Technology

[0002] Nitrogen oxide (NOx) sensors are used to detect the concentration of NOx (nitrogen oxides) in automobile exhaust emissions. Currently, the most commonly used type is the current-type NOx sensor. The detection component of this sensor is a ceramic chip, co-fired from multiple layers of YSZ (yttrium-stabilized zirconium oxide). It includes three oxygen pump cells and a heater. During operation, exhaust gas enters the first chamber (control chamber) after passing through a diffusion channel. The oxygen pump cells in this chamber are controlled by feedback to maintain the oxygen concentration at a preset level, and the following reaction occurs: NO2 → 2NO2 + O2.

[0003] After being treated in the first chamber, the exhaust gas, containing a low concentration of oxygen, enters the second chamber (measuring chamber). This chamber contains an oxygen pump battery and a detection electrode. The oxygen pump battery further controls the oxygen concentration in the chamber to a level close to 0 (10). -3 (Approximately ppm). The detection electrode is actually a pump battery specifically designed to measure the oxygen concentration after NOx decomposition. Because the oxygen in the second chamber is further pumped out, disrupting the equilibrium of the O2 and NO reaction, NO decomposes at the detection electrode, primarily through the following reaction: 2NO → N2 + O2. The decomposed oxygen is then pumped away by the oxygen pump battery. By measuring the corresponding pumping current, the final concentration of decomposed oxygen can be determined. After conversion, this allows for the measurement of NOx.

[0004] In existing ceramic chips, the auxiliary pump negative electrode and the measuring electrode are located in the same chamber (measuring chamber). The auxiliary pump negative electrode is made of Pt-Au (platinum-gold) based electrode paste, and Au has no catalytic activity for nitric oxide. Because Au has a low melting point (1064℃), while the sintering temperature during ceramic chip fabrication is 1400–1500℃, gold easily volatilizes during sintering, contaminating the measuring electrode and affecting its performance. Alternatively, a porous protective layer is applied to the surface of the measuring electrode; however, volatilized gold deposits on this layer, affecting gas diffusion and also potentially impacting the measuring electrode's performance. Utility Model Content

[0005] The main objective of this application is to propose a ceramic chip and its nitrogen and oxygen sensor, which aims to solve the problems of gold volatilization during the fabrication of existing ceramic chips causing contamination of the measuring electrodes, or the volatilization of gold affecting the diffusion of gas through the porous protective layer.

[0006] To achieve the above objectives, this application proposes a ceramic chip comprising:

[0007] The chip body has a measurement cavity.

[0008] an auxiliary pump negative electrode disposed in the measurement cavity;

[0009] a measurement electrode disposed in the measurement cavity and located on one side of the auxiliary pump negative electrode; and

[0010] a partition plate disposed in the measurement cavity and located between the auxiliary pump negative electrode and the measurement electrode, the partition plate comprising a first partition plate and a second partition plate staggered along the height direction of the chip body, and a channel being defined between the first partition plate and the second partition plate;

[0011] wherein one side of the channel is in communication with the region where the auxiliary pump negative electrode is located, and the other side is in communication with the region where the measurement electrode is located.

[0012] In an embodiment, the width of the channel is 50-100 μm.

[0013] In an embodiment, the first partition plate and the second partition plate are inclined away from the auxiliary pump negative electrode, and the angle of inclination is α, 40°≤α≤60°.

[0014] In an embodiment, the first partition plate and the second partition plate have a fixed end and a free end, and the thickness of the fixed end is not less than the thickness of the free end.

[0015] In an embodiment, the thickness of the first partition plate and the second partition plate gradually decreases from the fixed end to the corresponding free end.

[0016] In an embodiment, the chip body further comprises a heating electrode, the heating electrode comprising a heating section and a lead section connected to the heating section, and the resistance of the heating section is 1.3-1.8 times the total resistance of the lead section.

[0017] In an embodiment, the heating section comprises a first bending section and a second bending section connected to the first bending section, the protrusion of the first bending section is arranged corresponding to the recess of the second bending section, and the recess of the first bending section is arranged corresponding to the protrusion of the second bending section.

[0018] In an embodiment, the ceramic chip further comprises an insulating layer, the heating electrode has two opposite sides along the height direction of the chip body, and the insulating layer is disposed on the two opposite sides of the heating electrode.

[0019] In an embodiment, the chip body further comprises a reference gas channel, and a pressure relief hole is disposed between the heating electrode and the reference gas channel.

[0020] The application further provides a nitrogen-oxygen sensor comprising the ceramic chip.

[0021] In the technical scheme, the partition plate is arranged in the measuring cavity and between the auxiliary pump negative electrode and the measuring electrode, the partition plate separates the auxiliary pump negative electrode and the measuring electrode in space, so that the region where the auxiliary pump negative electrode is located and the region where the measuring electrode is located are separated, the volatilization of gold in the sintering process can be avoided to pollute the measuring electrode, and the detection performance of the measuring electrode is ensured. If the porous protective layer is arranged on the measuring electrode, the volatilized gold can be prevented from being deposited on the porous protective layer by arranging the partition plate, the diffusion of the gas is ensured, and the detection performance of the measuring electrode is ensured. The partition plate comprises the first partition plate and the second partition plate which are staggered along the height direction of the chip body, and a channel is defined between the first partition plate and the second partition plate, one side of the channel is communicated with the region where the auxiliary pump negative electrode is located, and the other side of the channel is communicated with the region where the measuring electrode is located. In this way, the first partition plate and the second partition plate which are staggered up and down can effectively prevent the volatilization of gold from polluting the measuring electrode, and the gas can flow from the region where the auxiliary pump negative electrode is located to the region where the measuring electrode is located through the channel, so that the gas can contact the measuring electrode more smoothly, and the detection effect of the measuring electrode is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical scheme in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings shown.

[0023] Figure 1 The cross-sectional structure schematic diagram of an embodiment of the ceramic chip provided by the application is shown in the figure.

[0024] Figure 2 The cross-sectional structure schematic diagram of an embodiment of the ceramic chip provided by the application is shown in the figure. Figure 1 The top view structure schematic diagram of the heating electrode is shown in the figure.

[0025] Explanation of reference numerals:

[0026] 100, ceramic chip; 1, first YSZ membrane; 11, heating electrode; 111, heating section; 111a, first bending section; 111b, second bending section; 112, lead section; 112a, first lead section; 112b, second lead section; 12, insulation layer; 2, second YSZ membrane; 21, reference electrode; 22, reference electrode protection layer; 23, pressure relief hole; 3, third YSZ membrane; 31, reference gas channel; 4, fourth YSZ membrane; 41, collection cavity; 42, buffer cavity; 43, control cavity; 44, measurement cavity; 45, first diffusion barrier; 46, second diffusion barrier; 47, third diffusion barrier; 48, main oxygen pump negative electrode; 49, auxiliary pump negative electrode; 410, measurement electrode; 411, porous protection layer; 412, first partition; 413, second partition; 414, channel; 5, fifth YSZ membrane; 51, oxygen pump positive electrode; 52, oxygen pump positive electrode protection layer; 6, chip body.

[0027] The implementation, functional features and advantages of the present application will be further described with reference to the accompanying drawings. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0029] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship, movement condition, etc. between the components in a certain posture, and if the certain posture changes, the directional indications also change accordingly.

[0030] In addition, if the embodiments of the present application involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In addition, "and / or" or "and / or" appearing throughout the text means that the three parallel solutions are included, for example, "A and / or B" includes A solution, or B solution, or A and B solutions are satisfied at the same time. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor is it within the scope of protection claimed by the present application.

[0031] The existing ceramic chip auxiliary pump negative electrode and the measuring electrode are in the same chamber (measuring cavity), the auxiliary pump negative electrode is made of Pt-Au (platinum-gold) based electrode paste, and Au has no catalytic activity to nitrogen monoxide. Since the melting point of Au is relatively low (1064℃), and the sintering temperature during the production of the ceramic chip is 1400-1500℃, the gold is easy to volatilize during the sintering process, pollutes the measuring electrode, and affects the performance of the measuring electrode. There is also a porous protective layer on the surface of the measuring electrode, however, the volatilized gold is deposited on the porous protective layer, affects the diffusion of the gas, and also affects the performance of the measuring electrode. In view of this, the present application proposes a ceramic chip and a nitrogen oxygen sensor thereof, to solve the problem that the volatilization of gold during the production of the existing ceramic chip pollutes the measuring electrode, or the volatilization of gold affects the diffusion of the gas by the porous protective layer.

[0032] Please refer to Figure 1 and Figure 2 In an embodiment of the present application, the ceramic chip 100 comprises a chip body 6, an auxiliary pump negative electrode 49, a measuring electrode 410, and a partition plate, the chip body 6 is provided with a measuring cavity 44; the auxiliary pump negative electrode 49 is arranged in the measuring cavity 44; the measuring electrode 410 is arranged in the measuring cavity 44 and located on one side of the auxiliary pump negative electrode 49; the partition plate is arranged in the measuring cavity 44 and located between the auxiliary pump negative electrode 49 and the measuring electrode 410, the partition plate comprises first partition plates 412 and second partition plates 413 staggered along the height direction of the chip body 6, and a channel 414 is defined between the first partition plates 412 and the second partition plates 413; wherein one side of the channel 414 communicates with the area where the auxiliary pump negative electrode 49 is located, and the other side communicates with the area where the measuring electrode 410 is located.

[0033] In the technical solution of the application, the partition plate is arranged in the measuring cavity 44 and between the auxiliary pump negative electrode 49 and the measuring electrode 410, the partition plate separates the auxiliary pump negative electrode 49 and the measuring electrode 410 in space, so that the area where the auxiliary pump negative electrode 49 is located and the area where the measuring electrode 410 is located are separated, the volatilization of gold in the sintering process can be avoided to pollute the measuring electrode 410, and the detection performance of the measuring electrode 410 is ensured. If the porous protective layer 411 is arranged on the measuring electrode 410, the volatilized gold can also be prevented from being deposited on the porous protective layer 411 by arranging the partition plate, the diffusion problem of the gas is avoided, and the detection performance of the measuring electrode 410 is ensured. The partition plate comprises the first partition plate 412 and the second partition plate 413 which are staggered along the height direction of the chip main body 6, and a channel 414 is defined between the first partition plate 412 and the second partition plate 413. One side of the channel 414 communicates with the area where the auxiliary pump negative electrode 49 is located, and the other side of the channel 414 communicates with the area where the measuring electrode 410 is located. In this way, the first partition plate 412 and the second partition plate 413 which are staggered up and down can effectively prevent the volatilization of gold from causing the pollution problem of the measuring electrode 410, and also facilitate the gas to flow from the area where the auxiliary pump negative electrode 49 is located to the area where the measuring electrode 410 is located, so that the gas can contact the measuring electrode 410 more smoothly, and the detection effect of the measuring electrode 410 is ensured.

[0034] It should be noted that the chip main body 6 is composed of the first YSZ film 1, the second YSZ film 2, the third YSZ film 3, the fourth YSZ film 4 and the fifth YSZ film 5 which are arranged in sequence.

[0035] The thickness of the first YSZ film 1 is 150-300 μm, and the heating electrode 11 is arranged on the side of the first YSZ film 1 close to the second YSZ film 2. The heating electrode 11 is used to heat the ceramic chip 100, so that the ceramic chip 100 quickly reaches the optimal working temperature (about 800℃).

[0036] The thickness of the second YSZ film 2 is 100-200 μm, the reference electrode 21 is arranged on the side of the second YSZ film 2 away from the first YSZ film 1, the reference electrode protective layer 22 is arranged on the reference electrode 21, the pressure relief hole 23 is arranged on the second YSZ film 2 on the side of the reference electrode 21, and one end of the pressure relief hole 23 corresponds to the heating electrode 11.

[0037] The third YSZ film 3 has a thickness of 100-200 μm, and is provided with, in sequence, a main oxygen pump half-negative electrode, an auxiliary pump half-negative electrode, a second partition plate 413, and a measurement electrode 410 on a side away from the second YSZ film 2. The third YSZ film 3 on a side of the measurement electrode 410 is provided with a reference gas passage 31, and the other end of the pressure relief hole 23 is in communication with the reference gas passage 31. The pressure relief hole 23 is connected to the reference gas passage 31 to relieve stress changes generated by the heating layer during heating of the ceramic chip 100. It should be noted that the second partition plate 413 is made of the same material as the third YSZ film 3, and is integrally provided with the third YSZ film 3.

[0038] The fourth YSZ film 4 has a thickness of 100-200 μm, and is provided with, in sequence, a collection cavity 41, a buffer cavity 42, a control cavity 43, and a measurement cavity 44. The collection cavity 41 is provided with a first diffusion barrier 45 between the collection cavity 41 and the buffer cavity 42, the buffer cavity 42 is provided with a second diffusion barrier 46 between the buffer cavity 42 and the control cavity 43, and the control cavity 43 is provided with a third diffusion barrier 47 between the control cavity 43 and the measurement cavity 44. The tail gas enters the buffer cavity 42 through the collection cavity 41 and the first diffusion barrier 45, and the rapid change of the gas flow becomes stable through the weakening of the first diffusion barrier 45 and the buffer cavity 42. The gas in the buffer cavity 42 enters the control cavity 43 through the second diffusion barrier 46, and most of the O2 in the measured gas is pumped out by the oxygen pumping effect of the main oxygen pump, so that the O2 concentration in the control cavity 43 is maintained at about 1 ppm. The gas in the control cavity 43 enters the measurement cavity 44 through the third diffusion barrier 47, and the O2 concentration of the measured gas is further reduced to about 10 ppm by the oxygen pumping effect of the auxiliary pump, thereby facilitating detection by the measurement electrode 410. -3

[0039] The fifth YSZ film 5 has a thickness of 100-200 μm, and is provided with an oxygen pump positive electrode 51 on a side away from the fourth YSZ film 4. The oxygen pump positive electrode 51 is provided with an oxygen pump positive electrode protection layer 52, and is provided with, in sequence, a main oxygen pump half-negative electrode, an auxiliary pump half-negative electrode, and a first partition plate 412 on a side close to the fourth YSZ film 4. The main oxygen pump half-negative electrode provided on the fifth YSZ film 5 and the main oxygen pump half-negative electrode provided on the third YSZ film 3 form a main oxygen pump negative electrode 48, and the main oxygen pump negative electrode 48 is located in the control cavity 43. The auxiliary pump half-negative electrode provided on the fifth YSZ film 5 and the auxiliary pump half-negative electrode provided on the third YSZ film 3 form an auxiliary pump negative electrode 49. The oxygen pump positive electrode 51, the main oxygen pump negative electrode 48, and the auxiliary pump negative electrode 49 together form two oxygen pump cells. X ​When the sensor is in operation, the oxygen pump cell pumps oxygen out of the exhaust gas, so that the O2 concentration in the measurement chamber is maintained at a certain level. It should be noted that the first partition plate 412 is made of the same material as the fifth YSZ diaphragm 5, and the first partition plate 412 is integrally arranged with the fifth YSZ diaphragm 5.

[0040] Further, the measurement electrode 410 can be provided with a porous protective layer 411, and the material of the porous protective layer 411 includes porous Al2O3. The gas passes through the porous protective layer 411 to reach the measurement electrode 410, so as to realize the detection of the gas concentration. It can be understood that the material of the reference electrode protective layer 22 and the material of the oxygen pump positive electrode protective layer 52 are the same as the material of the porous protective layer 411.

[0041] In the embodiments of the present application, the width of the channel is 50-100 μm.

[0042] By limiting the width D of the channel 414 defined by the first partition plate 412 and the second partition plate 413, and the width D is 50-100 μm, the influence of gold evaporation on the measurement electrode 410 can be better avoided, and the to-be-measured gas can flow more smoothly into the area where the measurement electrode 410 is located, so as to better ensure the detection effect.

[0043] In the embodiments of the present application, the first partition plate 412 and the second partition plate 413 are inclined away from the auxiliary pump negative electrode 49, and the inclination angle is α, 40°≤α≤60°.

[0044] By adopting the above technical solution, the first partition plate 412 and the second partition plate 413 are arranged to be inclined away from the auxiliary pump negative electrode 49, and the inclination angle α is between 40° and 60°, so that the influence of gold evaporation on the measurement electrode 410 can be better avoided. The first partition plate 412 and the second partition plate 413 arranged to be inclined away from the auxiliary pump negative electrode 49 can better form a barrier layer to prevent gold from evaporating to the area where the measurement electrode 410 is located. Specifically, the first partition plate 412 forms a first barrier layer, and the first partition plate 412 is inclined away from the auxiliary pump, so that part of the evaporated gold can be deposited on the first partition plate 412; the second partition plate 413 forms a second barrier layer, and part of the evaporated gold can be deposited on the second partition plate 413; the surface of the fifth YSZ diaphragm 5 between the first partition plate 412 and the second partition plate 413 forms a third barrier layer, and a small amount of gold is deposited thereon, so that the evaporated gold is basically deposited on the three barrier layers, and the area where the measurement electrode 410 is located can be better ensured to be almost not contaminated by gold, and the detection performance of the measurement electrode 410 is ensured.

[0045] In the embodiments of the present application, the first partition plate 412 and the second partition plate 413 have fixed ends and free ends, and the thickness of the fixed end is not less than the thickness of the free end.

[0046] By using the above technical solution, the thickness of the fixed end of the first partition plate 412 and the second partition plate 413 is greater than or equal to the thickness of the free end, so as to better ensure the structural stability of the first partition plate 412 and the second partition plate 413. It can be understood that the fixed end of the first partition plate 412 is connected with the fifth YSZ diaphragm 5, and the fixed end of the second partition plate 413 is connected with the third YSZ diaphragm 3.

[0047] In the embodiments of the present application, the first partition plate 412 and the second partition plate 413 gradually decrease in thickness from the fixed end to the corresponding free end.

[0048] By using the above technical solution, the thickness of the first partition plate 412 gradually decreases from the fixed end to the free end, and the thickness of the second partition plate 413 gradually decreases from the fixed end to the free end, so as to better ensure the structural stability of the first partition plate 412 and the second partition plate 413.

[0049] In order to make the ceramic chip 100 quickly reach the optimal working temperature, in the embodiments of the present application, the heating electrode 11 includes a heating section 111 and a lead section 112 connected with the heating section 111, and the resistance of the heating section 111 is 1.3-1.8 times the total resistance of the lead section 112.

[0050] By using the above technical solution, the resistance of the heating section 111 is 1.3-1.8 times the total resistance of the lead section 112, so as to better meet the temperature distribution requirements of the head of the ceramic chip 100 during working, and ensure that the head of the ceramic chip 100 rapidly heats up to the optimal working temperature.

[0051] It should be noted that the lead section 112 includes a first lead section 112a and a second lead section 112b, the first lead section 112a is connected with one end of the heating section 111, and the second lead section 112b is connected with the other end of the heating section 111. The total resistance of the lead section 112 refers to the sum of the resistance of the first lead section 112a and the resistance of the second lead section 112b.

[0052] In order to make the temperature of the head of the ceramic chip 100 quickly rise to the optimal working temperature, the heating section 111 includes a first bending section 111a and a second bending section 111b connected with the first bending section 111a, the protrusion of the first bending section 111a is arranged corresponding to the recess of the second bending section 111b, and the recess of the first bending section 111a is arranged corresponding to the protrusion of the second bending section 111b.

[0053] By adopting the above technical solution, the heating section 111 comprises a first bending section and a second bending section, and the protrusion of the first bending section is arranged corresponding to the recess of the second bending section, and the recess of the first bending section is arranged corresponding to the protrusion of the second bending section, so that the heating temperature of the heating section 111 is relatively uniform and stable, so that the ceramic chip 100 quickly reaches the optimal working temperature.

[0054] In the embodiments of the present application, the ceramic chip 100 further comprises an insulating layer 12, the heating electrode 11 has opposite two sides in the height direction of the chip body 6, and the insulating layer 12 is arranged on the opposite two sides of the heating electrode 11.

[0055] By adopting the above technical solution, an insulating layer 12 is attached to each of the opposite two sides of the heating electrode 11 to realize that the insulating layer wraps the heating electrode, which can prevent current leakage caused by the short and strong heating pulse current of the heating element. It should be noted that the thickness of each insulating layer 12 is 20-40 μm, and the insulating layer 12 can be a dense Al2O3 insulating layer.

[0056] The present application also proposes a nitrogen-oxygen sensor, which comprises a ceramic chip 100, and the specific structure of the ceramic chip 100 is referred to the above embodiments. Since the nitrogen-oxygen sensor adopts all the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0057] The above is only an exemplary embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made by using the content of the present application specification and drawings, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A ceramic chip, characterized by, The ceramic chip comprises: a chip body provided with a measuring cavity; an auxiliary pump negative electrode arranged in the measuring cavity; a measuring electrode arranged in the measuring cavity and located on one side of the auxiliary pump negative electrode; and a partition plate arranged in the measuring cavity and located between the auxiliary pump negative electrode and the measuring electrode, the partition plate comprising a first partition plate and a second partition plate staggered along the height direction of the chip body, and a channel being defined between the first partition plate and the second partition plate; wherein one side of the channel is in communication with the area where the auxiliary pump negative electrode is located, and the other side is in communication with the area where the measuring electrode is located.

2. The ceramic chip of claim 1, wherein, The width of the channel is 50-100 μm.

3. The ceramic chip of claim 1, wherein, The first partition plate and the second partition plate are inclined away from the auxiliary pump negative electrode, and the angle of inclination is α, 40°≤α≤60°.

4. The ceramic chip of claim 1, wherein, The first partition plate and the second partition plate have a fixed end and a free end, and the thickness of the fixed end is not less than the thickness of the free end.

5. The ceramic chip of claim 4, wherein, The thickness of the first partition plate and the second partition plate gradually decreases from the fixed end to the corresponding free end.

6. The ceramic chip of claim 1, wherein, The chip body is further provided with a heating electrode, the heating electrode comprising a heating section and a lead section connected with the heating section, and the resistance of the heating section is 1.3-1.8 times the total resistance of the lead section.

7. The ceramic chip of claim 6 wherein, The heating section comprises a first bending section and a second bending section connected with the first bending section, the protrusion of the first bending section is arranged corresponding to the recess of the second bending section, and the recess of the first bending section is arranged corresponding to the protrusion of the second bending section.

8. The ceramic chip of claim 7, wherein, The ceramic chip further comprises an insulating layer, the heating electrode has two opposite sides along the height direction of the chip body, and the insulating layer is arranged on the two opposite sides of the heating electrode.

9. The ceramic chip of claim 7 wherein, The chip body is further provided with a reference gas channel, and a pressure relief hole is arranged between the heating electrode and the reference gas channel.

10. A nitrogen oxide sensor, characterized by The ceramic chip comprises: a chip body provided with a measuring cavity; an auxiliary pump negative electrode arranged in the measuring cavity; a measuring electrode arranged in the measuring cavity and located on one side of the auxiliary pump negative electrode; and a partition plate arranged in the measuring cavity and located between the auxiliary pump negative electrode and the measuring electrode, the partition plate comprising a first partition plate and a second partition plate staggered along the height direction of the chip body, and a channel being defined between the first partition plate and the second partition plate; wherein one side of the channel is in communication with the area where the auxiliary pump negative electrode is located, and the other side is in communication with the area where the measuring electrode is located. The width of the channel is 50-100 μm. The first partition plate and the second partition plate are inclined away from the auxiliary pump negative electrode, and the angle of inclination is α, 40°≤α≤60°. The first partition plate and the second partition plate have a fixed end and a free end, and the thickness of the fixed end is not less than the thickness of the free end. The thickness of the first partition plate and the second partition plate gradually decreases from the fixed end to the corresponding free end. The chip body is further provided with a heating electrode, the heating electrode comprising a heating section and a lead section connected with the heating section, and the resistance of the heating section is 1.3-1.8 times the total resistance of the lead section. The heating section comprises a first bending section and a second bending section connected with the first bending section, the protrusion of the first bending section is arranged corresponding to the recess of the second bending section, and the recess of the first bending section is arranged corresponding to the protrusion of the second bending section. The ceramic chip further comprises an insulating layer, the heating electrode has two opposite sides along the height direction of the chip body, and the insulating layer is arranged on the two opposite sides of the heating electrode. The chip body is further provided with a reference gas channel, and a pressure relief hole is arranged between the heating electrode and the reference gas channel.

Images