CN210465205U

CN210465205U - Particulate matter sensor chip with filter large granule thing function

Info

Publication number: CN210465205U
Application number: CN201921366063.3U
Authority: CN
Inventors: 张琛; 洪旭
Original assignee: Xiamen Haisai Mike New Material Technology Co ltd
Current assignee: Xiamen Haisai Mike New Material Technology Co ltd
Priority date: 2019-08-21
Filing date: 2019-08-21
Publication date: 2020-05-05
Anticipated expiration: 2029-08-21

Abstract

The utility model provides a particulate matter sensor chip with filter large granule thing function, include: a first alumina substrate; a second alumina substrate superimposed with said first alumina substrate; a narrow gas channel between the first alumina substrate and the second alumina substrate; the working electrode pair is arranged in the narrow air passage and comprises two working electrodes arranged in opposite directions, any one of the working electrodes is provided with a plurality of comb-shaped electrode teeth, and the electrode teeth of one working electrode and the electrode teeth of the other working electrode are arranged in opposite directions in a crossed manner; and the narrow air channel is communicated with the outside, and the height of the narrow air channel is less than or equal to half of the distance between any two adjacent electrode teeth. The utility model discloses have the function of filtering large granule thing, prevent that large grain size particulate matter from deposiing on the cross electrode of PM sensor to prevent to cause the irrelevant condition of actual PM quantity and output signal to appear because of the resistance sudden change between the electrode.

Description

Particulate matter sensor chip with filter large granule thing function

Technical Field

The utility model relates to a particulate matter sensor chip.

Background

Emission regulations are becoming more and more strict, and with the implementation of "national vi" emission standards, research on various exhaust gas filtration modes is actively carried out both at home and abroad in order to control a large amount of Particulate Matters (PM), particularly PM2.5 particulate matters, contained in the exhaust emission of diesel engines. Particulate matter traps (DPFs) are widely used on diesel vehicles, which is also the most effective and simple way to achieve diesel particulate matter emission control. Reliable regeneration and failure monitoring of a DPF requires accurate detection methods, and particulate matter sensors (PM sensors) play a very important role in this regard.

The PM sensor is classified into a resistive type, an electrochemical type, a leakage current type, and the like, and among them, the resistive type PM sensor is used in many cases. A resistive PM sensor is known whose principle is based on multilayer ceramic sensing technology.

As shown in fig. 1, the device comprises a zirconia substrate 1 ', an alumina insulating layer 2', a working electrode pair 3 ', a heating element (not shown) and a temperature measuring element (not shown), wherein the working electrode pair 3' is formed by a pair of working electrodes 3 'printed on the zirconia substrate 1', each working electrode 32 'has a plurality of comb-shaped electrode teeth 322', and the electrode teeth 322 'of one working electrode 32' and the electrode teeth 322 'of the other working electrode 32' are arranged in a mutually meshed state in an opposite and crossed manner. As shown in fig. 2, the initial resistance of the electrode is infinite, when a voltage is applied to the working electrode pair 3 ', the particulate matter K in the exhaust gas is adsorbed between the two working electrodes 32 ' due to the presence of the electric field, and the resistance between the two working electrodes 32 ' is different according to the difference in the accumulation amount of the particulate matter K, so that the conductivity of the PM sensor is changed, when the resistance reaches a certain threshold value, regeneration is performed by heating of the heating element, and the output current signal is used to evaluate the mass of the PM, thereby realizing detection of the concentration of the particulate matter in the exhaust gas.

The exhaust gas particulates have a particle size of less than 2.5 μm accounting for about 80%, but small amounts of irregular large-particle-size particulates K are still present_{Big (a)}In the case of large-particle-diameter particles K_{Big (a)}When deposited on the working electrode 32' of the PM sensor, it causes an abrupt change in resistance between the electrodes, causing the actual amount of PM to appear uncorrelated with the output signal.

Disclosure of Invention

The to-be-solved technical problem of the utility model lies in providing a particulate matter sensor chip, has the function of filtering large granule thing, prevents that large grain diameter particulate matter from deposiing on the cross electrode of PM sensor to prevent to cause the irrelevant condition of actual PM quantity and output signal to appear because of the resistance sudden change between the electrode.

The utility model discloses a realize like this: a particle sensor chip having a function of filtering large particles, comprising:

a first alumina substrate;

a second alumina substrate superimposed with said first alumina substrate;

the narrow air channel is positioned between the first aluminum oxide substrate and the second aluminum oxide substrate, is communicated with the outside, and has the height less than or equal to half of the distance between any two adjacent electrode teeth;

and the working electrode pair is arranged in the narrow air passage and comprises two working electrodes which are arranged in opposite directions, each working electrode is provided with a plurality of comb-shaped electrode teeth, and the electrode teeth of one working electrode and the electrode teeth of the other working electrode are arranged in opposite directions in a crossed manner.

Further, in accordance with a specific embodiment of the present invention, the width of the narrow air passage is greater than or equal to the length of the working electrode pair.

Further, the utility model discloses still include:

a third aluminum oxide substrate superposed with the second aluminum oxide substrate;

the temperature measuring electrode is arranged between the second aluminum oxide substrate and the third aluminum oxide substrate;

a fourth alumina substrate laminated with the third alumina substrate;

and the heater is arranged between the third alumina substrate and the fourth alumina substrate.

Further in accordance with an embodiment of the present invention, the first alumina substrate and the fourth alumina substrate have a thickness of 150 to 300 μm.

The utility model has the advantages that: the utility model discloses locate the working electrode pair and lie in the narrow air flue between two aluminium oxide substrates to communicate in the outside, through the height of the narrow air flue of design, make the narrow air flue have the effect of filtering big particulate matter, even contain big particulate matter in the waste gas, because blockking of narrow air flue, the large granule thing is difficult to enter into the working electrode surface, consequently, can restrain because of the large granule thing adsorbs on the working electrode and arouses the sudden change of resistance between the working electrode, prevent to cause the irrelevant condition of actual PM quantity and output signal to appear.

Drawings

The invention will be further described with reference to the following examples with reference to the accompanying drawings.

Fig. 1 is a schematic structural view of a conventional resistive PM sensor.

Fig. 2 is a schematic structural diagram of the principle of detecting the particulate matter concentration of the conventional resistance type PM sensor.

Fig. 3 is a schematic view of the overall structure of the resistive PM sensor of the present invention.

Fig. 4 is an exploded schematic view of the resistance type PM sensor of the present invention.

Fig. 5 is a schematic diagram of the critical dimension relationship of the resistive PM sensor of the present invention.

Fig. 6 is the schematic structural diagram of the principle of detecting the particle concentration of the resistance type PM sensor of the present invention.

Detailed Description

Referring to fig. 3 to 6, a particle sensor chip 100 with a function of filtering large particles according to the present invention includes a first alumina substrate 1, a second alumina substrate 2, a narrow air channel 3, and a working electrode pair 4.

The second alumina substrate 2 is overlapped with the first alumina substrate 1;

the narrow air channel 3 is positioned between the first alumina substrate 1 and the second alumina substrate 2 and communicated with the outside of the particle sensor chip 100; the height H is less than or equal to the distance D between any two adjacent electrode teeth 422, and the width of the narrow air channel 3 is greater than W or equal to the length L of the working electrode pair 4.

The working electrode pair 4 is arranged in the narrow air passage 3 and comprises two working electrodes 42 which are arranged in opposite directions, any one of the working electrodes 42 is provided with a plurality of comb-shaped electrode teeth 422, and the electrode teeth 422 of one working electrode 42 and the electrode teeth 422 of the other working electrode 42 are arranged in opposite directions in a crossed manner and are in a mutually meshed state;

the utility model discloses a particulate matter sensor chip 100 still includes third alumina substrate 6, temperature measurement electrode 7, fourth alumina substrate 8 and heater 9.

A third aluminum oxide substrate 6 superposed with the second aluminum oxide substrate 2;

the temperature measuring electrode 7 is arranged between the second aluminum oxide substrate 2 and the third aluminum oxide substrate 6;

a fourth alumina substrate 8 laminated with the third alumina substrate 6;

and a heater 9 disposed between the third alumina substrate 6 and the fourth alumina substrate 8.

According to the embodiment of the present invention, the thickness of the first alumina substrate 1 and the fourth alumina substrate 8 is 150 to 300 μm, which can just meet the requirement of strength and temperature conduction, and the preparation process is simple.

The utility model discloses a theory of operation is:

mainly as shown in fig. 5 and 6, the utility model discloses locate working electrode pair 4 be located first alumina substrate 1 with in the narrow air flue 3 between the second alumina substrate 2, narrow air flue 3 communicates in the outside, highly design for being less than or equal to the half of interval D between arbitrary double-phase adjacent electrode tooth 422 with narrow air flue 3, make the large granule thing that is greater than half of interval D can't reach working electrode pair through narrow air flue, more can't reach the position between the double-phase adjacent electrode tooth 422, therefore, even contain big particulate matter in the waste gas, because the blockking of narrow air flue, can effectively restrain and arouse the resistance sudden change between the working electrode because of the large granule thing adsorbs on the working electrode, prevent to cause the irrelevant condition of actual PM quantity and output signal to appear.

Wherein, fig. 5 shows the size and working power of the narrow air passage 3 of the utility modelThe relationship between the spacing of the electrode teeth 422 of the pole pair is that in order to improve the accuracy of the PM sensor, the size of the narrow air passage 3 and the spacing of the working electrode teeth 422 are limited, and the height H of the narrow air passage 3 is required to be less than or equal to half of the spacing D of the working electrodes, in which case, assuming that the maximum particle size of the particulate matter K entering the surface of the working electrode 42 through the narrow air passage 3 is D, the maximum value of D is theoretically equal to H, and in order to cause the resistance between the two working electrodes 42 to be liable to sudden change, at least two large particulate matters K with the maximum particle size of D are required_{Big (a)}Simultaneously exist. This arrangement greatly reduces the occurrence of situations where the actual amount of PM is not correlated with the output signal.

Mainly as shown in fig. 4, the utility model discloses when specifically realizing:

the working electrode pair 4 further comprises a working electrode lead 43 and a working electrode pin 44, wherein the working electrode lead 43 is connected with the working electrode pin 44 through a via hole 10 pre-arranged on the first alumina substrate 1.

Similarly, the temperature measuring electrode 7 further comprises a temperature measuring electrode lead 71 and a temperature measuring electrode pin 72, and the temperature measuring electrode lead 71 is connected with the temperature measuring electrode pin 72 sequentially through the via holes 10 pre-arranged on the third alumina substrate 6 and the fourth alumina substrate 8. And

the heater 9 further comprises a heater lead 91 and a heater pin 92, wherein the heater lead 91 is connected with the heater pin 92 through a via 10 preset on the fourth alumina substrate 8.

The manufacturing method of the embodiment is as follows: firstly, punching a group of through holes 10 on a first alumina substrate 1, a third alumina substrate 6 and a fourth alumina substrate 8 respectively, wherein the number of the through holes 10 is 1, and the aperture is 0.3 mm. Then, silk-printing a working electrode pin 44 on the upper surface of the punched first alumina substrate 1, silk-printing a carbon layer on the lower surface, wherein the thickness of the carbon layer can be determined according to different use environments, such as 2 μm to 5 μm, in the embodiment, 4 μm is adopted, and the carbon layer can volatilize in the subsequent sintering process, so as to form a narrow air passage 5; a pair of working electrodes 32 with comb-shaped crossed electrode teeth 422 are silk-screened on the upper surface of the second aluminum oxide substrate 2; the temperature measuring electrode 7 and a temperature measuring electrode lead 71 are silk-screened on the upper surface of the punched alumina substrate 3; the heater 9 and the heater lead 91 are silk-screened on the upper surface of the fourth alumina substrate 8 after punching, and the heater pin 92 and the temperature measuring electrode pin 72 are silk-screened on the lower surface. The method comprises the following steps of sequentially laminating, isostatic pressing, cutting and binder removal sintering the silk-screen-printed alumina substrate, wherein in the binder removal sintering process, a carbon layer volatilizes, so that the PM sensor chip 100 with a narrow air passage structure is obtained, and the PM sensor chip 100 has the function of filtering large particles.

Although specific embodiments of the present invention have been described, it will be understood by those skilled in the art that the specific embodiments described are illustrative only and are not limiting upon the scope of the invention, and that equivalent modifications and variations can be made by those skilled in the art without departing from the spirit of the invention, which is to be limited only by the claims appended hereto.

Claims

1. The utility model provides a particulate matter sensor chip with filter large granule thing function which characterized in that: the method comprises the following steps:

a first alumina substrate;

a second alumina substrate superimposed with said first alumina substrate;

2. The particle sensor chip with the function of filtering large particles according to claim 1, wherein: the narrow air channel width is greater than or equal to the length of the working electrode pair.

3. The particle sensor chip with the function of filtering large particles according to claim 1, wherein: further comprising:

a fourth alumina substrate laminated with the third alumina substrate;

4. The particle sensor chip with the function of filtering large particles as claimed in claim 3, wherein: the first alumina substrate and the fourth alumina substrate have a thickness of 150 to 300 [ mu ] m.