KR20190031076A - Particulate material sensor and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a particulate material sensor which provides high temperature stability and stiffness, and less uses precious metals to lower manufacturing costs, and a manufacturing method thereof. According to the present invention, the particulate material sensor comprises an inner electrode, a via electrode, a heater electrode, and a temperature detection electrode, which include one or more first metals selected from a group consisting of Mo, W, MoSi_2, and MoMn. Moreover, an outer sensor electrode includes one or more first metals selected from a group consisting of Mo, W, MoSi_2, and MoMn, and is coated with one or more kinds of second metals selected from a group consisting of Pt and Pd.

Description

TECHNICAL FIELD [0001] The present invention relates to a particulate matter sensor and a method for manufacturing the same,

The present invention relates to a particulate matter sensor excellent in high-temperature stability and robustness, low in noble metal use and low in production cost, and a method for producing the same.

Recently, as regulations on automobile exhaust gas have been strengthened, regulations on particulate materials (PM), which are known to be the main causes of air pollution, have become strict, and researches on sensors that detect them have become active. Particularly, researches on sensors that detect particulate matter accurately and quickly are continuing, and research to remove the particulate matter attached to the sensor to maintain the sensitivity of the sensor, and studies to improve the strength of the sensor portion are also carried out .

For example, Korean Patent No. 10-1305198 discloses a plasma display panel comprising a projection protruding from a front surface and arranged at a specific width, a heater electrode for burning and removing particulate matter adhered to the front surface, And a sensing electrode pad for transmitting the sensing signal to the outside.

Further, in the case of the sensor electrode or the sensing electrode as described above, since the temperature of the exhaust gas rises to 400 ° C or more and 800 ° C or more, it is common to use a noble metal material such as platinum which is stable at high temperature. However, since the noble metal causes the manufacturing cost of the sensor to increase, it is urgent to develop an alternative to replace the sensor.

Korean Patent No. 10-1305198

Accordingly, an object of the present invention is to provide a particulate matter sensor having a high temperature stability and robustness as well as a conventional sensor including a noble metal and reducing the manufacturing cost by reducing the use of precious metals, and a method of manufacturing the particulate matter sensor.

In order to achieve the above object,

A particulate matter sensor including a ceramic substrate, an insulating layer, an inner electrode, a via electrode, a heater electrode, a temperature sensing electrode, and an outer sensor electrode,

Wherein the inner electrode, the via electrode, the heater electrode and the temperature sensing electrode comprise at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ) and molybdenum and,

Wherein the external sensor electrode comprises at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ) and molybdenum (MoMn) Pt), and palladium (Pd) are coated on the surface of the substrate.

In another embodiment,

A particulate matter sensor including a ceramic substrate, an insulating layer, an inner electrode, a via electrode, a heater electrode, a temperature sensing electrode, and an outer sensor electrode,

Wherein the inner electrode, the via electrode, the heater electrode and the temperature sensing electrode comprise at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ) and molybdenum and,

Wherein the external sensor electrode comprises at least one second metal selected from the group consisting of platinum (Pt) and palladium (Pd).

In another embodiment,

(1) providing a plurality of ceramic green sheets having at least one through hole;

(2) forming an internal electrode, a via electrode, a heater electrode and a temperature sensing electrode as a first electrode paste on the ceramic green sheet;

(3) stacking a plurality of ceramic green sheets having the electrodes formed thereon, and then forming an insulating layer on one surface of the stacked body;

(4) co-firing the electrodes, the ceramic green sheet and the insulating layer after forming the external sensor electrode with the first electrode paste on the insulating layer; And

(5) forming a coating layer on the outer sensor electrode of the fired laminate,

Wherein the first electrode paste includes at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ), and molybdenum (MoMn)

Wherein the coating layer comprises at least one second metal selected from the group consisting of platinum (Pt) and palladium (Pd).

In another embodiment,

(A) providing a plurality of ceramic green sheets having at least one through hole;

(B) forming an internal electrode, a via electrode, a heater electrode and a temperature sensing electrode as a first electrode paste on the ceramic green sheet;

(C) depositing a plurality of ceramic green sheets on which the electrodes are formed, and then forming an insulating layer on one surface of the stacked body;

(D) forming an external sensor electrode with a second electrode paste on the insulating layer; And

(E) co-firing the electrodes, the ceramic green sheet and the insulating layer,

Wherein the first electrode paste includes at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ), and molybdenum (MoMn)

Wherein the second electrode paste includes at least one second metal selected from the group consisting of platinum (Pt) and palladium (Pd).

The particulate matter sensor according to the embodiment is excellent in high-temperature stability and robustness as in a conventional sensor including a noble metal, and has a low manufacturing cost because it reduces the use of precious metals.

Also, the manufacturing method of the particulate matter sensor according to the embodiment can simplify the manufacturing process by simultaneously firing the internal electrode, the ceramic sheet, and the external electrode.

1 is a cross-sectional view of a particulate matter sensor according to an embodiment.

An embodiment is a particulate matter sensor including a ceramic substrate, an insulating layer, an inner electrode, a via electrode, a heater electrode, a temperature sensing electrode, and an outer sensor electrode,

Wherein the inner electrode, the via electrode, the heater electrode and the temperature sensing electrode comprise at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ) and molybdenum and,

Wherein the external sensor electrode comprises at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ) and molybdenum (MoMn) Pt), and palladium (Pd) are coated on the surface of the substrate.

Another embodiment is a particulate matter sensor including a ceramic substrate, an insulating layer, an inner electrode, a via electrode, a heater electrode, a temperature sensing electrode, and an outer sensor electrode,

Wherein the inner electrode, the via electrode, the heater electrode and the temperature sensing electrode comprise at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ) and molybdenum and,

Wherein the external sensor electrode comprises at least one second metal selected from the group consisting of platinum (Pt) and palladium (Pd).

1, the particulate matter sensor 100 of the embodiment includes ceramic substrates 102 and 103, an insulating layer 101, an internal electrode 221, a heater electrode 222, a temperature sensing electrode 223, Electrode 210 as shown in FIG. In addition, the ceramic substrate may include at least one via electrode 310 penetrating therethrough.

Ceramic substrate

The ceramic substrate may comprise at least one member selected from the group consisting of alumina (Al ₂ O _3), zirconia (ZrO _2), talc, silica (SiO _2), manganese dioxide (MnO ₂₎ and calcium carbonate (CaCO ₃₎ have. Specifically, the ceramic substrate may include at least one selected from the group consisting of alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), and silica. More specifically, the ceramic substrate may comprise 80 to 98 wt%, 85 to 98 wt%, or 90 to 97 wt% alumina, zirconia, or a mixture thereof based on the total weight of the substrate.

The ceramic substrate may comprise alumina, zirconia or mixtures thereof, and silica. Specifically, the ceramic substrate comprises 80 to 98% by weight, 85 to 98% by weight, or 90 to 98% by weight alumina, zirconia or mixtures thereof, and 1 to 20% by weight, 15 wt%, or 2 to 10 wt% silica.

Preferably, the ceramic substrate contains alumina as a main component, and when the ceramic substrate further contains zirconia, the strength and density of the ceramic substrate can be improved.

On the other hand, the ceramic substrate may include 75 to 95 wt% alumina and 1 to 15 wt% zirconia based on the total weight of the ceramic substrate. Specifically, the ceramic substrate may comprise 75 to 95 wt% alumina, 1 to 15 wt% zirconia, and 0.5 to 15 wt% talc, silica, manganese dioxide, calcium carbonate, or mixtures thereof, based on the total weight of the ceramic substrate .

The talc may be included in an amount of 0.5 to 3 wt% based on the total weight of the ceramic substrate. In addition, the silica may be contained in an amount of 1 to 5 wt% based on the total weight of the ceramic substrate. Further, the manganese dioxide may be contained in an amount of 2 to 5% by weight based on the total weight of the ceramic substrate. In addition, the calcium carbonate may be contained in an amount of 0.5 to 2% by weight based on the total weight of the ceramic substrate.

Insulating layer

Referring to FIG. 1, the insulating layer 101 is interposed between the internal electrode 221 and the external sensor electrode 210. The insulating layer may have an average thickness of 20 to 40 mu m.

When the insulating layer has a thickness within the thickness range, it is possible to prevent a problem that measurement of particulate matter occurs due to occurrence of electrical short due to the thickness of the insulating layer and that the capacitance of the sensor is reduced.

The insulating layer may be formed by applying a ceramic green sheet, or by printing and firing a ceramic paste. However, when the ceramic green sheet is applied, the thickness of the green sheet is too thin to be damaged or deformed. Therefore, it is more preferable that the insulating layer is produced by printing and firing a ceramic paste.

electrode

The inner electrode, the via electrode, the heater electrode, and the temperature sensing electrode include a material capable of co-firing with the ceramic green sheet. Specifically, the inner electrode, the via electrode, the heater electrode, and the temperature sensing electrode may be formed of at least one first material selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ), and molybdenum Metal. More specifically, the internal electrode, the via electrode, the heater electrode, and the temperature sensing electrode may include molybdenum (Mo) or tungsten (W), respectively.

The thickness of the internal electrode, the heater electrode, and the temperature sensing electrode may be 5 to 50 탆, respectively. Specifically, the inner electrode, the heater electrode, and the temperature sensing electrode may each have a thickness of 10 to 40 탆. When the thickness of the internal electrode, the heater electrode, and the temperature sensing electrode is within the above range, the problem that the surface of the manufactured sensor is not uniform due to the difference in shrinkage ratio between the electrode paste and the ceramic green sheet can be prevented.

The diameter of the via-electrode may be 80 to 300 탆. Specifically, the via electrode may have a diameter of 100 to 300 mu m, 100 to 250 mu m, or 100 to 200 mu m. When the diameter of the via electrode is within the above range, the problem that the via electrode paste spreads to the outside or the paste filling rate is lowered can be prevented.

The external sensor electrode includes a material capable of co-firing with a ceramic green sheet, and may include a metal coating layer on the co-firing material to ensure high temperature stability and robustness of the electrode. In addition, the external sensor electrode may include a metal having a high temperature stability and a high toughness.

Specifically, the external sensor electrode includes at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ), and molybdenum (MoMn) May be coated with at least one second metal selected from the group consisting of platinum (Pt) and palladium (Pd). Alternatively, the external sensor electrode may include at least one second metal selected from the group consisting of platinum (Pt) and palladium (Pd).

More specifically, the external sensor electrode may be formed by coating a first metal of molybdenum (Mo) or tungsten (W) with a second metal of platinum (Pt) or palladium (Pd); Platinum (Pt) or a second metal of palladium (Pd).

The outer sensor electrode includes the second metal or includes the second metal coating layer, thereby improving the stability and robustness of the outer sensor electrode at high temperature.

The average particle diameter (D ₅₀ ) of the first metal may be 0.5 to 2 탆. Specifically, the average particle diameter (D ₅₀ ) of the first metal may be 0.7 to 1.8 탆, or 1 to 1.8 탆. When the average particle diameter of the first metal is within the above range, the problem that the surface of the manufactured sensor is not uniform due to the difference in shrinkage ratio between the electrode paste and the ceramic green sheet during manufacturing can be prevented.

The average particle diameter (D ₅₀ ) of the second metal may be 0.5 to 2.5 μm. Specifically, the average particle diameter (D ₅₀ ) of the second metal may be 1 to 2 탆. When the average particle diameter of the second metal is within the above range, peeling due to shrinkage in the sintering process can be prevented.

When the external sensor electrode has a structure in which the second metal is coated on the first metal, the average thickness of the coating layer including the second metal may be 1 m or more. Specifically, the average thickness of the coating layer containing the second metal may be 1 to 5 占 퐉, 1 to 4 占 퐉, or 1 to 3 占 퐉. When the average thickness of the coating layer containing the second metal is within the above range, it is possible to prevent the problem that the coating layer easily peels off and the problem that the coating time is long and productivity is low.

Referring to FIG. 1, the external sensor electrode has a line width W and a pattern interval D. Specifically, the external sensor electrode may have a line width of 30 to 80 占 퐉 and a pattern interval of 30 to 80 占 퐉.

Manufacturing method of particulate matter sensor

Another embodiment includes the steps of: (1) providing a plurality of ceramic green sheets having at least one through hole;

(2) forming an internal electrode, a via electrode, a heater electrode and a temperature sensing electrode as a first electrode paste on the ceramic green sheet;

(3) stacking a plurality of ceramic green sheets having the electrodes formed thereon, and then forming an insulating layer on one surface of the stacked body;

(4) co-firing the electrodes, the ceramic green sheet and the insulating layer after forming the external sensor electrode with the first electrode paste on the insulating layer; And

(5) forming a coating layer on the outer sensor electrode of the fired laminate,

Wherein the first electrode paste includes at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ), and molybdenum (MoMn) And at least one second metal selected from the group consisting of palladium (Pd), and the like.

Step (1)

In this step, a plurality of ceramic green sheets having at least one through hole are provided.

The through-hole may be formed through a process such as punching, laser irradiation, or the like. Specifically, the ceramic green sheet may be a ceramic green sheet having a through hole formed by punching or the like.

The ceramic green sheet contain alumina (Al ₂ O _3), zirconia (ZrO _2), talc, silica (SiO _2), manganese dioxide (MnO ₂₎ and calcium carbonate (CaCO ₃₎ 1 or more selected from the group consisting of lead . Specifically, the ceramic green sheet may include at least one selected from the group consisting of alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), and silica.

The ceramic green sheet may be prepared by molding a slurry in which a ceramic mixed powder, a binder and a dispersing agent are mixed in a certain ratio in a solvent into a sheet form. The sheet-form molding is performed, for example, by defoaming the slurry and introducing the slurried slurry into a tape casting facility to form a sheet, whereby a ceramic sheet can be produced.

Specifically, the ceramic sheet may comprise 80 to 95 wt% alumina, zirconia or mixtures thereof, and 1 to 15 wt% silica, based on the total weight. In addition, the ceramic sheet may comprise from 80 to 95 weight percent alumina, from 1 to 10 weight percent silica, and from 1 to 10 weight percent binder based on total weight.

The binder may be ethyl cellulose. The ethylcellulose may have a weight average molecular weight of 10,000 to 1,000,000 g / mol. Specifically, the ethylcellulose may have a weight average molecular weight of 100,000 to 700,000 g / mol.

In addition, the ceramic sheet may comprise 75 to 95 wt% alumina and 1 to 15 wt% zirconia based on the total weight. Specifically, the ceramic sheet comprises 75 to 95 wt% alumina, 1 to 15 wt% zirconia, and 0.5 to 15 wt% talc, silica, manganese dioxide, calcium carbonate, or mixtures thereof, based on total weight .

The talc may be included in an amount of 0.5 to 3 wt% based on the total weight of the ceramic substrate. In addition, the silica may be contained in an amount of 1 to 5 wt% based on the total weight of the ceramic substrate. Further, the manganese dioxide may be contained in an amount of 2 to 5% by weight based on the total weight of the ceramic substrate. In addition, the calcium carbonate may be contained in an amount of 0.5 to 2% by weight based on the total weight of the ceramic substrate.

Step (2)

In this step, an internal electrode, a via electrode, a heater electrode, and a temperature sensing electrode are formed as a first electrode paste on the ceramic green sheet. Specifically, the first electrode paste may be coated on the ceramic green sheet and dried to form an internal electrode, a via electrode, a heater electrode, and a temperature sensing electrode. In addition, the first electrode paste may be printed on the ceramic green sheet and dried to form the internal electrode, the via electrode, the heater electrode, and the temperature sensing electrode.

The drying may be carried out at 50 to 70 DEG C for 5 to 20 minutes. Specifically, the drying may be performed at 50 to 65 ° C for 10 to 15 minutes.

When the first electrode paste is applied or printed on the ceramic green sheet, the first electrode paste may be filled in the through hole of the ceramic green sheet. Specifically, when the first electrode paste is applied or printed on the ceramic green sheet, the via hole of the ceramic green sheet may be filled with the first electrode paste to form the via electrode.

The first electrode paste includes at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ), and molybdenum (MoMn). Specifically, the first electrode paste may include molybdenum (Mo) or tungsten (W).

Also, the first electrode paste may include 70 to 90 wt% of the first metal and 10 to 30 wt% of the organic solvent based on the total weight of the paste. Specifically, the first electrode paste may contain 70 to 85% by weight, 75 to 85% by weight, or 75 to 80% by weight of the first metal and 10 to 25% by weight, 15 to 25% by weight, 20 to 25% by weight of an organic solvent.

The organic solvent may include at least one selected from the group consisting of alpha-terpineol, ethyl cellulose, and 2-buthoxy ethoxyethanol acetate.

Specifically, the first electrode paste comprises 70 to 92% by weight of the first metal, 3 to 10% by weight of 2-butoxyethoxyethanol acetate, 1 to 3% by weight of ethylcellulose and 5 To 20% by weight alpha-terpinol.

The ethylcellulose may have a weight average molecular weight of 10,000 to 1,000,000 g / mol. Specifically, the ethylcellulose may have a weight average molecular weight of 100,000 to 700,000 g / mol.

The first electrode paste may have a viscosity of 35,000 to 140,000 cps at 25 ° C. When the viscosity of the first electrode paste is within the above-mentioned range, it is possible to prevent a problem that a short circuit occurs in the electrode paste and a problem that a portion in which the electrode paste is not printed is generated.

The first electrode paste (hereinafter referred to as " 1-1 electrode paste ") used for the production of the inner electrode, the heater electrode and the temperature sensing electrode has the same viscosity value for printing a planar circuit pattern, The first electrode paste (hereinafter referred to as the first electrode paste) used for manufacturing the filled via electrode may have a higher viscosity value.

Specifically, the 1-1 electrode paste may have a viscosity of 35,000 to 50,000 cps at 25 ° C. More specifically, the 1-1 electrode paste may have a viscosity at 25 ° C of 35,000 to 45,000 cps, or 40,000 to 45,000 cps.

The 1-2 electrode paste may have a viscosity of 90,000 to 140,000 cps or 110,000 to 130,000 cps at 25 ° C. When the viscosity of the first-second electrode paste is within the above-mentioned range, the problem of sinking of the via electrode in the drying process after filling the paste and the problem that the paste is not filled up to the bottom of the via hole can be prevented.

The first electrode paste may include 80 to 93 wt% of a first metal, 1 to 10 wt% of acetic acid 2-butoxyethoxy ethanol, 1 to 5 wt% of an ethyl cellulose ) And 5 to 10% by weight alpha-terpinol. At this time, ethylcellulose is as defined above.

Step (3)

In this step, a plurality of ceramic green sheets on which the electrodes are formed are laminated, and then an insulating layer is formed on one surface of the laminate.

The insulating layer may be formed by laminating a ceramic green sheet or by printing an insulating layer paste. When an insulating layer is formed by laminating a ceramic green sheet, there is a possibility that the sheet is too thin to be damaged or deformed. Therefore, it is preferable that the insulating layer is formed by printing an insulating layer paste. When the insulating layer is formed by printing an insulating layer paste, a thick and flat insulating layer having a thickness of 20 占 퐉 or more can be manufactured.

The insulating layer paste may be printed twice or more. Specifically, the insulating layer may be coated with an insulating layer paste, dried, and then coated with an insulating layer paste. More specifically, the insulating layer may be formed by (i) printing an insulating layer paste on one side of the laminate using a screen mask of 300 to 350 mesh; (ii) drying at 100 to 150 DEG C for 10 to 80 minutes; (iii) printing the insulating layer paste using a screen mast of 400 to 500 mesh; And (iv) drying at 100 to 150 DEG C for 10 to 80 minutes.

Step (4)

In this step, an external sensor electrode is formed as a first electrode paste on the insulating layer, and then the electrodes, the ceramic green sheet and the insulating layer are simultaneously fired.

The external sensor electrode may be formed by applying and drying a first electrode paste on an insulating layer, or printing and drying a first electrode paste. The drying may be carried out at 50 to 70 ° C for 5 to 20 minutes. Specifically, the drying may be performed at 50 to 65 ° C for 10 to 15 minutes.

The co-firing may be performed at 1,300 to 1,600 ° C. Concretely, the co-firing may be performed at 1,350 to 1,550 DEG C for 30 to 120 minutes.

In particular, molybdenum (Mo), tungsten (W), yigyuhwa molybdenum (MoSi _2), and Morley first electrode paste manganese (MoMn) comprising a first metal selected at least one from the group consisting of alumina (Al ₂ O ₃₎ Or zirconia (ZrO ₂ ) can be co-fired in this temperature range. Therefore, the problem of cracking and peeling in the firing process can be prevented.

Step (5)

In this step, a coating layer is formed on the outer sensor electrode of the fired laminate.

The coating layer may include at least one second metal selected from the group consisting of platinum (Pt) and palladium (Pd). Specifically, the coating layer may comprise platinum (Pt) or a second metal of palladium (Pd). When the coating layer includes the second metal, high temperature stability and robustness of the outer sensor electrode are improved.

The coating layer may be formed by plating a second metal on the fired laminate.

The plating is not particularly limited as long as it is a conventional metal plating method.

The coating layer may have an average thickness of 1 占 퐉 or more. Specifically, the coating layer may have an average thickness of 1 to 5 mu m, 1 to 4 mu m, or 1 to 3 mu m.

Yet another embodiment provides a method of manufacturing a ceramic green sheet, comprising: (A) providing a plurality of ceramic green sheets having at least one through hole;

(B) forming an internal electrode, a via electrode, a heater electrode and a temperature sensing electrode as a first electrode paste on the ceramic green sheet;

(C) depositing a plurality of ceramic green sheets on which the electrodes are formed, and then forming an insulating layer on one surface of the stacked body;

(D) forming an external sensor electrode with a second electrode paste on the insulating layer; And

(E) co-firing the electrodes, the ceramic green sheet and the insulating layer,

Wherein the first electrode paste includes at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ), and molybdenum (MoMn) And at least one second metal selected from the group consisting of palladium (Pt) and palladium (Pd).

The steps (A) to (C) are as described in the above steps (1) to (3), respectively.

Step (D)

In this step, an external sensor electrode is formed as a second electrode paste on the insulating layer.

The external sensor electrode may be formed by applying and drying a second electrode paste on the insulating layer, printing and drying the second electrode paste, or printing and patterning the second electrode paste.

The drying may be carried out at 50 to 70 DEG C for 5 to 20 minutes. Specifically, the drying may be performed at 50 to 65 ° C for 10 to 15 minutes.

The second electrode paste may include 60 to 93 wt% of the second metal and 5 to 35 wt% of the organic solvent based on the total weight of the paste. Specifically, the second electrode paste may contain 70 to 94 wt%, 80 to 95 wt%, or 80 to 90 wt% of the second metal, and 5 to 30 wt%, 10 to 30 wt% , And 15 to 28 wt% of an organic solvent. More specifically, the second electrode paste comprises 70 to 90 wt% of a second metal, 1 to 10 wt% of acetic acid 2-butoxyethoxy ethanol, 0.5 to 5 wt% of ethyl cellulose ( ethyl cellulose) and 8 to 20% by weight alpha-terpinol. At this time, ethyl cellulose is as defined in the first electrode paste.

The second electrode paste may have a viscosity of 35,000 to 50,000 cps at 25 ° C. Specifically, the second electrode paste may have a viscosity of 40,000 to 45,000 cps at 25 ° C. When the viscosity of the second electrode paste is within the above-mentioned range, it is possible to prevent a problem that a short circuit occurs in the electrode paste and a problem that a portion in which the electrode paste is not printed is generated.

The step (E) is as described in the step (4).

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

[ Example ]

Example  1. Manufacture of particulate matter sensor

1-1: Manufacture of Ceramic Green Sheet

180 g of alumina, 6 g of silica and 4 g of ethylcellulose (weight average molecular weight: 400,000 g / mol) were mixed with a binder to prepare a slurry. The bubbles in the prepared slurry were defoamed in vacuo and the slurry was put into a tape casting facility to prepare a ceramic green sheet having an average thickness of 0.2 mm.

1-2: Of the laminate  Produce

A transparent protective film (manufactured by NITTO DENKO, product name: T-APN10) was attached to the upper surface of the ceramic green sheet of Example 1-1 and a through hole was formed by a mechanical punching method.

Specifically, the punching was drilled while positioning ceramic green sheets between pins and dies of a punching unit consisting of a set of pins with a diameter of 0.15 mm and a die with a diameter of 0.17 mm.

Thereafter, an SUS mask having a thickness of 0.08 mm, which had been passed through 20 탆 larger than the diameter of the through-hole, was placed in close contact with the ceramic green sheet and then a via electrode paste (first electrode paste) Respectively. The first electrode paste was prepared by mixing 86 g of molybdenum (average particle diameter (D ₅₀ ): 1.7 μm), 3 g of 2- (butoxyethoxy) ethanol acetate, 2 g of ethylcellulose 400,000 g / mol) and 9 g of alpha terpinol were mixed and used. Thereafter, the ceramic green sheet having the via electrode formed was dried at 50 DEG C for 10 minutes.

Thereafter, the transparent protective film was removed and the first electrode paste was screen printed using a printing machine to form an internal electrode, a heater electrode, and a temperature sensing electrode, followed by drying at 50 DEG C for 10 minutes. The first electrode paste was prepared by mixing 85 g of molybdenum (average particle diameter (D ₅₀ ): 1.7 μm), 7 g of 2- (butoxyethoxy) ethanol acetate and 2 g of ethylcellulose (weight average molecular weight: 400,000 g / mol ) And 15 g of alpha terpinol.

Three dried ceramic green sheets were laminated, and then an insulating layer paste was printed on one side of the laminate using a 325 mesh screen mask and dried at 120 DEG C for 60 minutes. Then, an insulating layer paste was printed using a 400 mesh screen mask and dried at 120 DEG C for 60 minutes to form an insulating layer having a thickness of 20 mu m.

The first electrode paste was screen-printed on the insulating layer so as to have a line width of 45 ± 5 μm, a pattern interval of 50 ± 10 μm and a thickness of 20 μm to form an external sensor electrode, followed by drying at 50 ° C. for 10 minutes .

1-3: Co-firing and coating of external sensor electrodes

The laminate of Example 1-2 was heated and pressurized to 20 MPa and 55 캜 to be unified, and degreased at 900 캜 for 120 minutes to remove the binder. After baking at 1500 캜 for 60 minutes, palladium (Pd) was plated with a thickness of 2 ㎛ by an electroless plating process to produce a particulate matter sensor.

Comparative Example  One.

Except that palladium plating of Example 1-3 was performed after nickel (Ni) was subjected to a base plating of 5.5 탆 thickness by an electroless plating process on the external sensor electrode of the fired laminate of Example 1-3 , A particulate matter sensor was produced in the same manner as in Example 1.

Comparative Example  2.

A particulate matter sensor was prepared in the same manner as in Comparative Example 1, except that nickel plating was performed and then heat treatment was conducted at 1500 占 폚 for 60 minutes.

Experimental Example  One.

The discoloration test and peeling of the plated coating layer were measured for the particulate matter sensor of Example 1 and Comparative Examples 1 and 2, and the measurement results are shown in Table 1.

(1) Discoloration test

After heat treatment at 400 ° C, 500 ° C, 600 ° C, 700 ° C and 800 ° C for 15 minutes, the external sensor electrode was evaluated for discoloration.

(2) Peeling of the coating layer

A pressure sensitive adhesive tape (product name: 9713XYZ) of 3M company was adhered to the plated coating layer, and when the tape was peeled off, the presence or absence of peeling was judged.

Comparative Example 1 Comparative Example 2 Example 1 Discoloration test Discoloration at 400 ° C Discoloration at 600 ° C Discoloration at 800 ° C Peeling of plating coating layer Palladium coating layer peeling Palladium coating layer peeling X

As shown in Table 1, the particulate matter sensor of Example 1 exhibited discoloration at a high temperature of 800 ° C or higher, and it was confirmed that the palladium coating layer was not peeled off. On the other hand, in the particulate matter sensors of Comparative Examples 1 and 2, discoloration occurred at a low temperature of less than 800 占 폚, and the palladium coating layer was peeled off.

Example  2. External sensor

The laminate including the insulating layer of Example 1-2 was integrated by heating and pressing at 20 MPa and 55 占 폚. Thereafter, a second electrode paste was screen-printed on one surface of the laminate such that the line width was 45 +/- 5 mu m, the pattern spacing was 50 +/- 10 mu m, and the thickness was 20 mu m to form an external sensor electrode. Thereafter, the particulate matter sensor was prepared by degreasing at 900 DEG C for 120 minutes to remove the binder, and firing at 1,500 DEG C for 60 minutes.

The second electrode paste was prepared by mixing 85 g of platinum (Pt), 7 g of 2- (butoxyethoxy) acetate acetate, 2 g of ethylcellulose (weight average molecular weight: 400,000 g / mol) And terpinol.

Example  3.

The laminate including the insulating layer of Example 1-2 was integrated by heating and pressing at 20 MPa and 55 占 폚. Thereafter, the second electrode paste was printed on the entire surface of the laminate at a thickness of 20 μm, and a pattern (line width: 45 ± 5 μm, pattern interval: 50 ± 10 μm) of the external sensor electrodes was formed by laser trimming A particulate matter sensor was prepared in the same manner as in Example 2. [

Example  4.

The laminate including the insulating layer of Example 1-2 was integrated by heating and pressing at 20 MPa and 55 占 폚. Then, the second electrode paste was completely printed on one surface of the laminate to a thickness of 20 탆, and degreased and fired at 900 캜 for 120 minutes. Then, a particle sensor was fabricated by forming a pattern (line width: 45 ± 5 ㎛, pattern interval: 50 ± 10 ㎛) of the external sensor electrode on the fired second electrode paste by a laser trimming method.

At this time, the second electrode paste was prepared by the same method and composition as in Example 2.

100: particulate matter sensor 101: insulating layer
102, 103: ceramic substrate 210: external sensor electrode
221: inner electrode 222: heater electrode
223: Temperature sensing electrode 310: Via electrode
W: Line width of external sensor electrode D: Pattern interval of external sensor electrode

Claims (15)

A particulate matter sensor including a ceramic substrate, an insulating layer, an inner electrode, a via electrode, a heater electrode, a temperature sensing electrode, and an outer sensor electrode,
Wherein the inner electrode, the via electrode, the heater electrode and the temperature sensing electrode comprise at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ) and molybdenum and,
Wherein the external sensor electrode comprises at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ) and molybdenum (MoMn) Pt), and palladium (Pd).
A particulate matter sensor including a ceramic substrate, an insulating layer, an inner electrode, a via electrode, a heater electrode, a temperature sensing electrode, and an outer sensor electrode,
Wherein the inner electrode, the via electrode, the heater electrode and the temperature sensing electrode comprise at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ) and molybdenum and,
Wherein the external sensor electrode comprises at least one second metal selected from the group consisting of platinum (Pt) and palladium (Pd).
The method according to claim 1,
Wherein the average thickness of the coating layer comprising the second metal is 1 占 퐉 or more.
3. The method according to claim 1 or 2,
Wherein the first metal has an average particle diameter (D ₅₀ ) of 0.5 to 2 μm.
3. The method according to claim 1 or 2,
And the second metal has an average particle diameter (D ₅₀ ) of 0.5 to 2.5 μm.
3. The method according to claim 1 or 2,
Wherein the insulating layer has an average thickness of 20 to 40 mu m.
3. The method according to claim 1 or 2,
Wherein the external sensor electrode has a line width of 30 to 80 占 퐉 and a pattern interval of 30 to 80 占 퐉.
3. The method according to claim 1 or 2,
Wherein the ceramic substrate comprises at least one selected from the group consisting of alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), talc, silica (SiO ₂ ), manganese dioxide (MnO ₂ ) and calcium carbonate (CaCO ₃ ) Particulate matter sensor.
(1) providing a plurality of ceramic green sheets having at least one through hole;
(2) forming an internal electrode, a via electrode, a heater electrode and a temperature sensing electrode as a first electrode paste on the ceramic green sheet;
(3) stacking a plurality of ceramic green sheets having the electrodes formed thereon, and then forming an insulating layer on one surface of the stacked body;
(4) co-firing the electrodes, the ceramic green sheet and the insulating layer after forming the external sensor electrode with the first electrode paste on the insulating layer; And
(5) forming a coating layer on the outer sensor electrode of the fired laminate,
Wherein the first electrode paste includes at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ), and molybdenum (MoMn)
Wherein the coating layer comprises at least one second metal selected from the group consisting of platinum (Pt) and palladium (Pd).
(A) providing a plurality of ceramic green sheets having at least one through hole;
(B) forming an internal electrode, a via electrode, a heater electrode and a temperature sensing electrode as a first electrode paste on the ceramic green sheet;
(C) depositing a plurality of ceramic green sheets on which the electrodes are formed, and then forming an insulating layer on one surface of the stacked body;
(D) forming an external sensor electrode with a second electrode paste on the insulating layer; And
(E) co-firing the electrodes, the ceramic green sheet and the insulating layer,
Wherein the first electrode paste includes at least one first metal selected from the group consisting of molybdenum (Mo), tungsten (W), molybdenum molybdenum (MoSi ₂ ), and molybdenum (MoMn)
Wherein the second electrode paste comprises at least one second metal selected from the group consisting of platinum (Pt) and palladium (Pd).
11. The method according to claim 9 or 10,
Wherein the first electrode paste has a viscosity at 25 캜 of 35,000 to 140,000 cps.
11. The method according to claim 9 or 10,
Wherein the first electrode paste comprises 70 to 90 weight percent of the first metal and 10 to 30 weight percent of the organic solvent based on the total weight of the paste.
13. The method of claim 12,
Wherein the organic solvent comprises at least one selected from the group consisting of alpha-terpineol, ethylcellulose, and 2-buthoxy ethoxyethanol acetate. .
11. The method according to claim 9 or 10,
Wherein the co-firing is performed at 1,300 to 1,600 占 폚.
11. The method according to claim 9 or 10,
The ceramic green sheet containing alumina (Al ₂ O _3), zirconia (ZrO _2), talc, silica (SiO _2), manganese dioxide (MnO ₂₎ and at least one selected from the group consisting of calcium carbonate (CaCO ₃₎ , A method for manufacturing a particulate matter sensor.

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