JP4808977B2 - Ceramic heater, gas sensor element and electrode pattern, ceramic heater, gas sensor element manufacturing method - Google Patents

Description

The present invention, Se la Mick heaters relates to gas sensor element and a process for their production, details ceramic heater inherent suitable electrode pattern on a plate-shaped oxygen sensor element used in the oxygen concentration detection, etc. in the automobile exhaust gas, the The present invention relates to a gas sensor element provided with a ceramic heater, an electrode pattern, a ceramic heater, and a method for manufacturing the gas sensor element .

In recent years, environmental issues have been highlighted, and efforts are being made to put the global environment as a top priority in each industry. In particular, in the automobile industry, as represented by the exhaust gas regulations of California in the United States, reducing the amount of CO ₂ , CO, HC and NOx in exhaust gas year by year has become a trend of the world. . In order to reduce the above gas in the exhaust gas, it is important how efficiently the fuel is burned. For that purpose, the amount of residual oxygen in the exhaust gas is instantaneously measured and the information is fed back quickly to the combustion system. There is a growing demand for gas sensors such as oxygen sensors.

  Up to now, gas sensors have used the heat of exhaust gas to raise the temperature of a cup-shaped sensor and develop the sensor function. However, until the sensor function appeared, the exhaust gas was flowing down, and it has become impossible to meet the recent strict exhaust gas regulations. Therefore, a gas sensor that actively heats the cup-shaped sensor with a heater was developed. By using such a gas sensor, the sensor function can be expressed quickly, and information can be fed back with good response.

  However, in the cup-shaped sensor as described above, the size is increased and the distance between the heater and the sensor is increased, so that the speed of the sensor function is limited. Therefore, recently, the sensor part has a plate-like sensor element that has a plate-like shape and is made smaller, and the sensor part and the heater are integrally molded to increase the rate of temperature rise so that the sensor function can be expressed more quickly. Gas sensors (plate gas sensors) are being developed.

  Patent Document 1 describes a ceramic heater in which a predetermined refractory metal heating element pattern is embedded in a ceramic sintered body mainly composed of alumina. In this ceramic heater, a metal paste is printed on a first green sheet in a thick film pattern having a predetermined shape to form a heating element pattern, and the second green sheet is formed on the surface of the green sheet on which the heating element pattern is formed. The heating element pattern is covered by overlapping and pressure-bonding, and is simultaneously fired. And it is described that this ceramic heater can be used for a plate-like oxygen sensor element.

  Patent Document 2 includes at least one measurement cell and at least one heating element, and the measurement cell and the heating element are connected to each other through a predetermined electrical insulating layer. A plate-like sensor element for measuring the oxygen content is described. This sensor element is formed by laminating a measurement cell and a heating element.

  FIG. 7 is a schematic cross-sectional view showing a conventional (plate-like) oxygen sensor element as described in Patent Document 1 and Patent Document 2. As shown in FIG. 7, the oxygen sensor element 41 includes a sensor unit 48 in which a detection electrode 46 and a reference electrode 47 are formed on both surfaces of a solid electrolyte layer 45, and a heater electrode pattern 42 for heating the sensor unit 48. Is formed of a heater portion 44 embedded in the heater base 43, and these are integrated by firing to form a hollow portion 49 that is hollow so as to be in contact with the reference atmosphere.

  Generally, the heater electrode pattern 42 is formed by printing a heater electrode pattern printing paste on a green sheet (not shown) by a predetermined method. The oxygen sensor element 41 is formed by laminating and heating a heater unit 44 formed by laminating a plurality of green sheets including a green sheet on which the electrode pattern 42 is formed, and a sensor unit 48, and simultaneously firing them. I am making it.

  However, it is not easy to select a lamination adhesion condition, a degreasing firing condition, and the like, and there is a problem of a lamination failure in which a ceramic layer is peeled off on a lamination surface on which an electrode pattern is formed during lamination adhesion and after a degreasing firing. Furthermore, with this stacking failure, the manufacturing yield of ceramic heaters and gas sensor elements is reduced, and ceramic materials and electrode materials are wasted, leading to an increase in cost.

JP-A-5-315055 Special Table 2000-507359

An object of the present invention, Rousset La Mick heater can suppress separation of the laminated adhesion during and ceramic layer of the laminate faces the electrode patterns are formed after the degreasing firing, gas sensor element and the electrode pattern, a ceramic heater, a gas sensor It is providing the manufacturing method of an element .

  As a result of intensive studies to solve the above problems, the present inventors have improved the peel strength when the cross section of the electrode pattern contained in the laminate has a shape including a plurality of convex portions. The inventors have found a new finding that it is possible to suppress peeling of the ceramic layer at the time of stacking adhesion and after degreasing firing, and have completed the present invention.

That is, the ceramic heater, gas sensor element and electrode pattern, ceramic heater, and gas sensor element manufacturing method according to the present invention have the following configurations.
(1) A ceramic heater having a laminate as a heater base and a heater electrode pattern embedded in the laminate, wherein the heater electrode pattern has a shape including a plurality of convex portions in a cross section in the width direction . The ceramic heater is characterized in that the height of the plurality of projections from the recesses between the plurality of projections is 5 μm or more.
(2) The ceramic heater according to (1), wherein the cross section has two convex portions.
(3) A gas sensor element comprising the ceramic heater according to (1) or (2).
(4) The gas sensor element according to (3), which is an oxygen sensor element.
(5) forming an electrode pattern on a green sheet, pressing a mold on the surface of the electrode pattern, forming the electrode pattern in a shape in which a cross section of the electrode pattern includes a plurality of convex portions, A method for producing an electrode pattern, comprising: a step of laminating a green sheet and another green sheet to form a laminate; and a step of simultaneously firing the laminate.
(6) A step of forming a heater electrode pattern on a green sheet, a step of forming the heater electrode pattern in a shape in which a cross section of the heater electrode pattern includes a plurality of convex portions, the green sheet and another green sheet, A method of manufacturing a ceramic heater, comprising: a step of forming a laminated body by laminating layers; and a step of simultaneously firing the laminated body.
(7) A step of forming a heater electrode pattern on a green sheet, a step of forming the heater electrode pattern in a shape in which a cross section of the heater electrode pattern includes a plurality of convex portions, and detecting the green sheet and gas concentration A method for producing a gas sensor element, comprising: a step of laminating a green sheet on which a sensor portion having a function is formed to form a laminate; and a step of simultaneously firing the laminate.

Se la Mick heater of the present invention, the gas sensor element and the electrode pattern, a ceramic heater, according to the method of manufacturing a gas sensor element, since the cross section of the electrode pattern inherent in the laminated body with a predetermined shape, the peel strength is improved There is an effect that it is possible to suppress peeling of the ceramic layer on the laminated surface on which the electrode pattern is formed at the time of adhesion and after degreasing and firing. Furthermore, the manufacturing yield is improved and a plurality of green sheets are fired at the same time, so that the number of times of firing is one and the cost can be reduced.

Hereinafter, an electrode pattern, a ceramic heater, a gas sensor element, and a manufacturing method thereof according to the present invention will be described in detail with reference to the drawings.
<Electrode pattern / ceramic heater>
FIG. 1 is a schematic cross-sectional view showing a ceramic heater according to an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of a heater electrode pattern in the ceramic heater. FIG. 4 is an exploded view of the ceramic heater. As shown in FIG. 1, a ceramic heater 1 includes a heater electrode pattern 2 and a heater base 3 in which the heater electrode pattern 2 is interposed between green sheets (ceramic layers) 3a and 3b and integrated by firing. Has been.

  As shown in FIG. 4, the heater electrode pattern 2 is composed of a heater electrode 2a and a heater electrode lead 2b, and the cross section has a shape including a plurality of convex portions. Thereby, peeling strength improves and peeling of the green sheets (ceramic layers) 3a and 3b at the time of lamination | stacking adhesion | attachment and after degreasing baking can be suppressed. This improvement in peel strength is due to the fact that the electrode pattern 2 has the above-described shape, thereby increasing the contact area between the electrode pattern 2 and the green sheets (ceramic layers) 3a and 3b in which the electrode pattern 2 is contained. This is presumed to be due to an increase in bonding strength. Only one of the heater electrode 2a and the heater electrode lead 2b may have a shape including the convex portion.

  The number of the convex portions of the electrode pattern 2 is not particularly limited, and may be arbitrarily selected according to the use. In the present invention, however, in terms of the ease of forming the convex portions, FIG. And as shown in FIG. 2, it is preferable that it is a shape containing two convex parts.

  As shown in FIG. 2, the thickness H1 of the protrusions on the electrode pattern 2 is preferably 10 to 50 μm, the thickness H2 of the recesses is preferably 4 to 48 μm, and the heater lead width W is preferably 100 to 1500 μm. The electrode pattern 2 is preferably formed so as to have the shape described above. In particular, it is more preferable that the difference ΔH (= H1−H2) between the thickness H1 of the convex portion and the thickness H2 of the concave portion is larger.

  The heater electrode pattern 2 is made of a conductive material and a ceramic material. As the conductive material, various known conductive metal materials can be used. For example, platinum, tungsten, or an alloy of platinum and one kind selected from the group consisting of rhodium, palladium, lutetium, and gold is used. Is possible. In the present invention, platinum, tungsten, or the like can be preferably used because it can be sintered simultaneously with the ceramic material such as the heater base 3. Examples of the ceramic co-material include alumina, forsterite, magnesia, zirconia, mullite, titania, silicon nitride, silicon carbide and the like. The ceramic common material is preferably contained in the electrode pattern 2 at a ratio of 20 to 60% by volume with respect to the total amount of the conductive material and the ceramic common material. The average particle size of the conductive material and the ceramic co-material is preferably 0.1 to 2.0 μm.

  The material of the heater base 3 that is a ceramic insulating layer is not particularly limited as long as it is an insulating ceramic. For example, alumina, forsterite, or the like can be used. The average particle size of the material is preferably 0.1 to 2.0 μm. Moreover, the base 3 may use a co-material together with the material. As this common material, various ceramics useful in reducing the difference in thermal expansion coefficient from the base 3 can be used, and it is particularly preferable to use a material having substantially the same composition as the base 3. Specific examples of the common material include the ceramic common material described above.

  The ceramic heater in the present invention is integrated with other members in order to heat various elements such as a (plate-like) oxygen sensor, a NOx sensor, and a CO sensor, which will be described later, in addition to heating means in various structural parts. It can be suitably used as a gas sensor (ceramic heater structure).

<Gas sensor element (oxygen sensor element)>
FIG. 3 is a schematic cross-sectional view showing a plate-like oxygen sensor element according to another embodiment of the present invention. As shown in FIG. 3, the plate-like oxygen sensor element 10 includes a sensor unit 11 having a function of detecting the oxygen concentration and a heater unit 12 for heating the sensor unit 11. A hollow portion 19 is formed which is integrated and made hollow so as to be in contact with the reference atmosphere.

  The sensor unit 11 includes a solid electrolyte layer 13 having oxygen ion conductivity, a detection electrode 14 provided on the upper surface of the solid electrolyte layer 13, and a reference electrode 15 provided on the lower surface of the solid electrolyte layer 13. Yes. A protective layer 16 is provided on the surface of the detection electrode 14 as an electrode protection layer from the viewpoint of preventing poisoning of the detection electrode 14 by exhaust gas.

  The heater unit 12 is the same as the ceramic heater described above except that the heater base 17 is integrally formed in contact with the solid electrolyte layer 13 on the reference electrode 15 side. Omitted.

As a material constituting the solid electrolyte layer 13, a solid electrolyte such as zirconia or titania ceramics can be used. The average particle diameter of the solid electrolyte is preferably 0.1 to 2.0 μm. As the solid electrolyte, rare earth oxides such as Y ₂ O ₃ , Yb ₂ O ₃ , Sc ₂ O ₃ , Sm ₂ O ₃ , Nd ₂ O ₃ , and Dy ₂ O ₃ are used as stabilizers in terms of oxides. partially stabilized ZrO ₂ or stabilized ZrO ₂ containing 15 mol%, or the like may be used ZrO ₂ which was a solid solution of alkaline earth elements.

  As an electrode material constituting the detection electrode 14 and the reference electrode 15, the same conductive material as that of the heater electrode pattern 2 can be used. In particular, platinum, tungsten, and the like are preferable because they can be fired simultaneously with the solid electrolyte layer 13 and the substrate 17. The average particle size of the conductive material is preferably 0.1 to 2.0 μm. Examples of the protective layer 16 include a ceramic porous layer made of zirconia, alumina, magnesia, spinel, and the like.

  In the oxygen sensor element 10, the heater electrode pattern 2 is energized and the solid electrolyte layer 13 is heated to about 400 to 1000 ° C., the reference atmosphere (oxygen) is introduced into the cavity 19 and the detection electrode 14 is made of exhaust gas or the like. Arranged in the measurement atmosphere. Then, the electromotive force generated between the detection electrode 14 and the reference electrode 15 is measured, and the oxygen concentration in the exhaust gas is measured. As a measurement method, for example, a concentration cell type in which an electromotive force generated between the detection electrode 14 and the reference electrode 15 is measured to measure an oxygen concentration in the exhaust gas, a current is detected by applying a constant voltage. For example, a limiting current type for measuring the oxygen concentration may be used.

<Electrode pattern / ceramic heater manufacturing method>
Next, the manufacturing method of the ceramic heater concerning one Embodiment of this invention is demonstrated based on the lamination | stacking exploded view of FIG. 4, and the schematic of FIG. In FIG. 4, through holes for electrode connection and the like are omitted.

  First, a ceramic material constituting the heater base and an organic binder such as a butyral resin, an organic solvent, a medium, and the like are mixed to prepare a slurry, and the slurry is formed by, for example, tape molding using a doctor blade method. Green sheets 21 and 22 are obtained by molding and drying by a known molding method. The thickness of the green sheets 21 and 22 is preferably 50 to 500 μm.

  Next, the conductive material constituting the heater electrode pattern and the ceramic co-material are mixed to produce a print paste for the heater electrode pattern. When preparing this paste, it is preferable to use an organic binder such as butyral resin and an organic solvent such as terpineol. Further, the mixing method is not particularly limited, and for example, roll mixing such as three rolls, mill mixing using a mill, or the like can be used.

  The heater electrode pattern printing paste prepared above is printed on one side of the green sheet 22 by a method such as screen printing to form the heater electrode pattern 2 including the heater electrode 2a and the heater electrode lead 2b. Next, as shown in FIG. 5, the mold 24 is pressed against the surface of the heater electrode pattern 2 to form the heater electrode pattern 2 in a shape in which the cross section includes two convex portions. At this time, a concave portion corresponding to the convex portion of the heater electrode pattern 2 is formed in a portion of the mold 24 that presses the surface of the heater electrode pattern 2. By using the mold 24 having such a shape, the electrode pattern 2 can be formed in a predetermined shape. The pressing force at the time of pressing the mold 24 is not particularly limited. For example, the pressing force may be pressed with a pressing force of about 0.1 to 20 MPa, and the material of the mold 24 is not particularly limited. A mold, a resin mold, etc. are mentioned.

  In the mold 24, it is needless to say that a recess may be formed in addition to the portion corresponding to the heater electrode pattern 2. In this case, accurate alignment is not necessary, and various forms are possible. It can be used for the electrode pattern 2. Furthermore, since a convex part can be formed also in a heater base | substrate, when laminating | stacking another member on this heater base | substrate, adhesiveness can further be improved.

  The method for forming the electrode pattern 2 in a predetermined shape is not particularly limited as long as it has a shape including a plurality of convex portions as the cross-sectional shape of the electrode pattern. In addition to forming using the mold 24, for example, a method of forming by optimizing the printing conditions can be used.

  Then, an electrode pad 25 for the extraction electrode is formed on the other surface of the green sheet 22 through a through hole by a known method. Next, the green sheet 21 is adhered and laminated on the surface of the green sheet 22 on which the electrode pattern 2 is formed to obtain a green body (green sheet laminate). In addition, it is preferable to carry out the pressure bonding at about 30 to 50 MPa, and the adhesion lamination may be heated while being pressure-bonded. Thereby, generation | occurrence | production of the joining defect of ceramics can be suppressed. In order to adjust the thickness of the ceramic heater, a green sheet on which no electrode pattern is printed may be further laminated on the green body.

  After the green body is cut into a predetermined size with a hot knife or the like, the green body is simultaneously fired to obtain a ceramic heater. Thereby, a baking process can be carried out once and cost reduction can be aimed at. The firing temperature can be appropriately selected depending on the relationship with the ceramic material, the electrode material, and the like.

<Method for manufacturing gas sensor element (oxygen sensor element)>
Next, a method for manufacturing an oxygen sensor element according to another embodiment of the present invention will be described with reference to the exploded view of FIG. In FIG. 6, through holes for electrode connection and the like are omitted.
(Sensor part)
The green sheet 31 for a solid electrolyte layer is obtained by using the ceramic material constituting the solid electrolyte layer by a molding method similar to the method for manufacturing the ceramic heater described above. The thickness of the solid electrolyte layer green sheet 31 is preferably 50 to 500 μm. In addition, an electrode paste and a protective layer paste are prepared by the same preparation method as the heater electrode pattern printing paste, using the detection electrode, the conductive material constituting the reference electrode, and the material constituting the protective layer. To do.

  Using the electrode paste prepared above, the sensor electrode pattern 32 is formed on one surface of the green sheet 31 and the reference electrode pattern 33 is formed on the other surface in the same manner as the above-described ceramic heater manufacturing method. Can be obtained. A protective layer 34 is formed on the surface of the detection electrode pattern 32 of the sensor unit using a protective layer paste. In order to adjust the thickness of the sensor part, a plurality of solid electrolyte layer green sheets 31 are laminated to a predetermined thickness, and a detection electrode pattern or the like is formed on the green sheet, and the sensor part is It may be configured.

(Heater part)
Three green sheets are obtained in the same manner as the ceramic heater manufacturing method described above. Among these green sheets, the green sheet 35 is formed into a grooved green sheet by punching with a die into a shape that is in contact with the reference atmosphere.
Since it is the same as that of an above described ceramic heater except having mentioned above, the same code | symbol is attached | subjected and description is abbreviate | omitted.

(Oxygen sensor element)
The oxygen sensor green body (laminated body) can be formed by laminating the heater part on the solid electrolyte layer green sheet 31 on the side of the reference electrode pattern 33 forming the sensor part. In addition, you may use contact | adherence liquid in the case of the said lamination | stacking, As this contact | adherence liquid, the adhesive agent etc. which consist of various well-known organic solvents are mentioned, for example. Moreover, you may contain ceramic powder in contact | adherence liquid. Further, for the purpose of adjusting the thickness of the oxygen sensor element, there is no problem even if another green sheet on which various patterns are not printed is further interposed between the green sheets, and the present invention is not limited to FIG.

Then, the oxygen sensor green body is simultaneously fired to obtain an oxygen sensor element (gas sensor element). Thereby, a baking process can be carried out once and cost reduction can be aimed at. The firing temperature can be appropriately selected depending on the relationship with the ceramic material, the electrode material, and the like.
The gas sensor element according to the present invention is not intended to be limited to the oxygen sensor element, for example NOx sensor, it is also applicable to a gas sensor element of similar structure, such as a CO ₂ sensor.

  Hereinafter, the electrode pattern, the ceramic heater, the gas sensor element and the manufacturing method thereof according to the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples. .

[Examples 1 to 4]
<Production of ceramic heater>
(Green sheet)
A butyral binder, solvent and media were mixed with alumina powder having an average particle size of 0.3 μm and stirred for 48 hours to obtain a slurry. Thereafter, the slurry was molded by doctor blade molding and dried to prepare a green sheet having a thickness of 200 μm.

(Heater electrode pattern)
Butylal binder and terpineol were mixed into a mixture of 60% by volume of platinum powder having an average particle size of 1 μm and 40% by volume of alumina powder having an average particle size of 0.3 μm, and this mixture was passed 10 times with 3 rolls. Then, the mixture was diluted with terpineol to obtain a heater electrode pattern printing paste with viscosity adjusted. This paste was formed on the green sheet obtained above by screen printing and dried to obtain a green sheet on which a heater electrode pattern was formed. The shape of the cross section of the formed heater electrode pattern was a shape having one convex portion.

  Next, as the cross-sectional shape of the heater electrode pattern, the cross-sectional shape of the heater lead portion is the cross-sectional shape shown in Table 1 (the convex portion thickness H1, the concave portion thickness H2 and the heater lead width W), and two convex portions can be formed. The mold was pressed against the surface of the heater electrode pattern formed above with a pressing force of 0.5 MPa to form a heater electrode pattern whose cross-sectional shape had two convex portions.

(Ceramic heater)
Various green sheets having a total number of laminated layers of 6 including the green sheet on which the heater electrode was formed were positioned and heated and pressed by thermocompression to obtain a heater green body (laminated body). Then, it cut with the hot knife, the said heater green body was baked at 1450 degreeC for 2 hours, and the ceramic heater was produced.

<Peel strength>
Since all the ceramic heaters obtained by firing were difficult to peel off, the front and back surfaces of the heater green body (laminated body) obtained above were pulled and the peel strength was measured. The results are also shown in Table 1. In addition, evaluation was performed with 10 heater green bodies and represented by the average value.

[Comparative Example 1]
Ceramic heaters were produced in the same manner as in Examples 1 to 4, except that the surface of the heater electrode pattern was not pressed with the mold. Next, the peel strength was evaluated in the same manner as in Examples 1 to 4 for 10 heater green bodies as in Examples 1 to 4. The results are also shown in Table 1.

[Examples 5 to 8]
<Production of gas sensor element>
(Sensor part)
A butyral binder, solvent and media were mixed with partially stabilized zirconia powder (5 mol of Y ₂ O ₃ added, average particle size 0.3 μm) and stirred for 48 hours to obtain a slurry. Then, the said slurry was shape | molded and dried by doctor blade shaping | molding, and the green sheet for solid electrolyte layers of thickness 180 micrometers was produced.

  Next, butyral binder and terpineol are mixed with platinum powder having an average particle diameter of 1 μm, mixed with ten rolls by three rolls, diluted with terpineol, viscosity adjusted, and printing paste for electrodes. Got. Using this printing paste, various electrode patterns are formed by screen printing on the solid electrolyte layer green sheet, and then dried to obtain a solid electrolyte layer green sheet (sensor part) on which the electrode pattern is formed. It was.

(Heater part)
A green sheet having a thickness of 200 μm was produced in the same manner as in Examples 1 to 4. A grooved green sheet forming a cavity in contact with the reference atmosphere was produced by punching the green sheet into a groove shape having a width of 1.6 mm using a mold. Next, a green sheet on which a heater electrode pattern was formed was obtained in the same manner as in Examples 1 and 2.

  And as a cross-sectional shape of a heater electrode pattern, the cross-sectional shape of a heater lead part can form two convex parts by the cross-sectional shape (thickness H1 of a convex part, thickness H2 of a recessed part, and heater lead width W) shown in Table 1. The mold was pressed against the surface of the heater electrode pattern with a pressing force of 0.5 MPa to form a heater electrode pattern whose cross-sectional shape had two convex portions. Then, together with the green sheet on which the heater electrode was formed and the green sheet with a groove, various green sheets were positioned and thermocompression bonded to obtain a heater green body (laminated body) in which the heater electrode was embedded.

(Gas sensor element)
The sensor part and the heater part obtained above were positioned, adhered and laminated using an adhesion liquid, and pressed to obtain a sensor green body (laminate). The sensor green body was cut with a hot knife and baked at 1450 ° C. for 2 hours to produce a gas sensor element having a heater.

<Peel strength>
Since all the gas sensor elements obtained by firing were difficult to peel, the peel strength was evaluated in the same manner as in Examples 1 to 4 for 10 sensor green bodies (laminated bodies) obtained above. The results are also shown in Table 1.

[Comparative Example 2]
Gas sensor elements were produced in the same manner as in Examples 5 to 8, except that the surface of the heater electrode pattern was not pressed with the mold. Then, peel strength was evaluated for 10 sensor green bodies in the same manner as in Examples 5 to 8 in the same manner as in Examples 5 to 8. The results are also shown in Table 1.

表１から、実施例１〜４は、比較例１に対して、剥離強度が高いのがわかる。また、実施例５〜８は、比較例２に対して、剥離強度が高いのがわかる。

From Table 1, it can be seen that Examples 1 to 4 have higher peel strength than Comparative Example 1. In addition, it can be seen that Examples 5 to 8 have higher peel strength than Comparative Example 2.

It is a schematic sectional drawing which shows the ceramic heater concerning one Embodiment of this invention. It is an expanded sectional view of the heater electrode pattern in the ceramic heater concerning one Embodiment of this invention. It is a schematic sectional drawing which shows the plate-shaped oxygen sensor element concerning other embodiment of this invention. It is a lamination | stacking exploded view which shows the manufacturing method of the ceramic heater concerning one Embodiment of this invention. It is the schematic which shows the method of forming the heater electrode pattern of the ceramic heater concerning one Embodiment of this invention in a defined shape. It is a lamination | stacking exploded view which shows the manufacturing method of the oxygen sensor element concerning other embodiment of this invention. It is a schematic sectional drawing which shows the conventional oxygen sensor element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ceramic heater 2,42 Heater electrode pattern 2a Heater electrode 2b Heater electrode lead 3,17 Heater base | substrate 3a, 3b, 21,22,35 Green sheet 10,41 Oxygen sensor element 11,48 Sensor part 12,44 Heater part 13,44 45 Solid Electrolyte Layer 14, 46 Sensing Electrode 15, 47 Reference Electrode 16, 34 Protective Layer 19, 49 Cavity 24 Type 25 Electrode Pad 31 Green Sheet for Solid Electrolyte Layer 32 Sensing Electrode Pattern 33 Reference Electrode Pattern

Claims (7)

A ceramic heater having a laminate as a heater base and a heater electrode pattern contained in the laminate,
The heater electrode pattern has a shape in which a cross section in the width direction includes a plurality of protrusions, and the height of the plurality of protrusions from the recesses between the plurality of protrusions is 5 μm or more. Ceramic heater to do.   The ceramic heater according to claim 1, wherein the cross section has two convex portions.   A gas sensor element comprising the ceramic heater according to claim 1.   The gas sensor element according to claim 3, which is an oxygen sensor element.   A step of forming an electrode pattern on a green sheet, a step of pressing a mold against the surface of the electrode pattern, and forming the electrode pattern into a shape in which a cross section of the electrode pattern includes a plurality of convex portions; and the green sheet; A method for producing an electrode pattern, comprising: a step of laminating other green sheets to form a laminate; and a step of simultaneously firing the laminate.   A step of forming a heater electrode pattern on a green sheet, a step of forming the heater electrode pattern in a shape in which a cross section of the heater electrode pattern includes a plurality of convex portions, and laminating the green sheet and another green sheet. A method of manufacturing a ceramic heater, comprising: a step of forming a laminated body; and a step of simultaneously firing the laminated body.   A step of forming a heater electrode pattern on a green sheet; a step of forming the heater electrode pattern in a shape in which a cross section of the heater electrode pattern includes a plurality of convex portions; and a function of detecting the green sheet and a gas concentration. A method for producing a gas sensor element, comprising: a step of laminating a green sheet on which a sensor portion is formed to form a laminate; and a step of simultaneously firing the laminate.

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