JP2002340848A - Manufacturing method for gas sensor element and tool for vacuum chuck for use in it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a gas sensor element having superior durability and hard to be deformed, and a tool for a vacuum chuck used in it. SOLUTION: According to this manufacturing method, in manufacturing the gas sensor element 1 constituted by stacking a plurality of ceramic plates including a solid electrolyte plate 13 having an electrode, raw sheets for each ceramic plate are prepared, and every two raw sheets for each ceramic plate is positioned, and stacked and bonded with a vacuum chuck by an adhesive to manufacture an unburnt layered product formed by a desired number of raw sheets for the ceramic plates. After that, the unburnt layered product is burnt. The tool for a vacuum chuck is used in the method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing various gas sensor elements mounted on an exhaust system of an internal combustion engine and used for combustion control, and a jig for a vacuum chuck used for the method.

[0002]

2. Description of the Related Art A gas sensor for use in combustion control is provided in an exhaust system of an automobile engine. As a gas sensor element incorporated therein, an element having a structure as disclosed in JP-A-9-26409 is known. ing.

As shown in FIG. 10, a gas sensor element 9 is provided in a reference gas chamber with respect to a solid electrolyte plate 93 having a measured gas side electrode 11 in contact with a measured gas and a reference gas side electrode 12 in contact with a reference gas. Are formed by laminating a spacer plate 94 which constitutes the substrate with the alumina substrate 95. As shown in the figure, the spacer plate 94 has a U-shape and has a window 940 for forming a reference gas chamber.

One end of the reference gas chamber of the gas sensor element 9 is a closed end, and the other end is an open end open to the outside of the gas sensor element, and air or the like serving as a reference gas is introduced from the open end. It is configured to: In addition,
Although not shown, a heater substrate provided with a heating element is laminated on the alumina substrate 95.

[0005]

However, in the conventional gas sensor element 9 described above, the spacer plate 94 and the alumina substrate 95 may peel off during the manufacturing process or during use of the gas sensor element, causing defects and troubles. was there. For this reason, a strong bonding is realized by using a thermocompression press or the like so that the spacer plate 94 and the alumina substrate 95 are sufficiently adhered to each other. However, in this method, a gas sensor such as a deformed reference gas chamber is used. In many cases, the shape of each part of the element 9 is distorted, and improvement has been required.

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and has as its object to provide a method of manufacturing a gas sensor element which is excellent in durability and hardly deforms, and a jig for a vacuum chuck used in the method. is there.

[0007]

According to the first aspect of the present invention, a raw sheet for each ceramic plate is manufactured when manufacturing a gas sensor element constituted by laminating a plurality of ceramic plates including a solid electrolyte plate provided with electrodes. Are prepared, and each green sheet for ceramic plate is positioned every two sheets and laminated and bonded together with a vacuum chuck using an adhesive to form an unsintered laminate composed of a desired number of green sheets for ceramic plate. A method for manufacturing a gas sensor element, comprising manufacturing and thereafter firing the unfired laminate.

In the present invention, the raw sheets for each ceramic plate are positioned every two sheets and are laminated and bonded together with the vacuum chuck using an adhesive. Since the vacuum chuck is used, positional deviation during lamination and bonding is prevented, and two green sheets can be strongly bonded. In addition, since positioning is performed for every two sheets and bonding is performed, misalignment or the like hardly occurs between two raw sheets, and reliable bonding can be realized.

Further, since the adhesive is used, the two green sheets can be strongly bonded. In order to form the unfired laminate by firmly bonding the raw sheets in this way,
In the gas sensor element, peeling or falling off between the ceramic plates hardly occurs, so that the durability can be increased.

[0010] In addition, since an adhesive or a vacuum chuck is used for laminating and bonding each of the raw sheets, each of the raw sheets can be surely laminated and bonded without applying large pressure or heat. Is unlikely to occur.

As described above, according to the present invention, it is possible to provide a method of manufacturing a gas sensor element which is excellent in durability and hardly deforms.

The vacuum chuck is a method for fixing two raw sheets by decompression, and will be described later in detail. The ceramic plate is usually a solid electrolyte plate or an insulating plate, depending on the structure of the gas sensor element. Specifically, a solid electrolyte plate having an electrode, a lead portion, a terminal portion, etc., electrically connected to the electrode, or a solid electrolyte plate provided between the solid electrolyte plate and another solid electrolyte plate to electrically connect both. An insulating plate or the like to be separated can be given. An acrylic adhesive or the like can be used as the adhesive.

Each of the raw sheets can be manufactured in a size that can take one gas sensor element. However, from the viewpoint of manufacturing efficiency, each raw sheet is configured to have a size that can take a plurality of gas sensor elements. It is preferable to form a plurality of printing sections, stack them, and then cut them into one gas sensor element by cutting or the like (refer to the embodiment for details).

The gas sensor element according to the present invention is of a so-called laminated type, and can be used not only as an ordinary oxygen sensor element but also as an air-fuel ratio sensor element installed in an exhaust system of an automobile engine. In addition, it can be used as a NOx sensor element, a composite sensor element, or the like by increasing the number of electrodes.

Next, as in the second aspect of the present invention, it is preferable that the lamination is performed while applying a pressure of 0.1 to 0.5 MPa. This makes it difficult for the reference gas chamber to deform. If the pressure is less than 0.1 MPa, the bonded raw sheets for ceramic plates may peel off. If the pressure is greater than 0.5 MPa,
When the bonded raw sheet for ceramic plate is distorted, there is a possibility that a portion serving as a reference gas chamber (a groove portion 530 as shown in FIG. 3 described later) is deformed. In addition, the adhesive used for the lamination may be protruded.

Next, as in the third aspect of the present invention, it is preferable that the lamination is performed while maintaining the temperature at 5 to 80 ° C. Thereby, the lamination bonding can be performed at room temperature, so that the working efficiency can be improved. Further, when the temperature is lower than 5 ° C., it is necessary to perform the lamination bonding in a low temperature environment, so that the working efficiency may be reduced.
If the temperature is higher than 80 ° C., the work is performed in a high-temperature environment, and thus the work efficiency may be similarly reduced.
The temperature at the time of laminating and bonding is more preferably 10 to 40.
It is preferable to carry out the reaction while maintaining the temperature. Thereby, higher working efficiency can be obtained.

Next, it is preferable that the lamination be performed within a time period of 0.1 to 5 seconds. Thereby, it is possible to prevent peeling between the laminated ceramic sheet sheets. If the time is less than 0.1 second, peeling may occur between the raw sheets for ceramic plates. If the time is longer than 5 seconds, the time required for laminating and bonding becomes too long, and the productivity may be reduced.

Next, as in the fifth aspect of the present invention, the vacuum chuck is performed by using a vacuum chuck jig including an upper jig and a lower jig. A raw sheet for one ceramic plate is placed on the jig, a raw sheet for the other ceramic plate is placed on the lower jig, and an upper jig is placed on the lower jig so that the raw sheets abut each other. It is preferable to apply a reduced pressure from at least one of the upper jig and the lower jig and to perform vacuum chucking so that the amphibious sheets are brought into close contact with each other.

As a result, the two raw sheets can be reliably laminated and bonded without displacement. The vacuum chuck in this example uses a vacuum hole or the like provided in a jig, and a process in which the raw sheet is brought into close contact with the vacuum hole by reducing the pressure from an external pump connected thereto. As a result, the raw sheet can be securely fixed to a predetermined position of the jig and cannot be moved from the jig, so that the raw sheet can be laminated and bonded.

Next, it is preferable that each green sheet has a lamination reference hole. Thus, since the raw sheets are positioned and laminated and bonded using the lamination reference holes, the laminated sheets can be laminated and bonded without displacement.

According to a seventh aspect of the present invention, in manufacturing a gas sensor element constituted by laminating a plurality of ceramic plates including a solid electrolyte plate provided with electrodes, a raw sheet for each ceramic plate is laminated. A jig for a vacuum chuck, which is used for a vacuum chuck performed in bonding and includes an upper jig and a lower jig, wherein the upper jig has a mounting surface of a raw sheet for a ceramic plate and an outer periphery of the mounting surface. The lower surface has a recess corresponding to the projection of the lower jig, and the mounting surface has a lamination reference pin for positioning a lamination reference hole previously provided in the raw sheet for ceramic plate. The lower jig is open to the mounting surface, has a vacuum hole configured to be connectable to an external pump, and configured to be capable of vacuum chucking by driving the external pump. It has a mounting surface for the raw sheet for plate and a projection for fixing the upper jig provided on the outer periphery of the mounting surface. The mounting surface described above uses a lamination reference hole previously provided in the raw sheet for ceramic plate. A jig for a vacuum chuck, characterized in that the jig has a stacked reference pin for positioning.

By using the vacuum chuck jig having such a configuration, it is possible to prevent lamination displacement.

As described above, according to the present invention, it is possible to provide a vacuum chuck jig which is excellent in durability and can be used in a method of manufacturing a gas sensor element which is hardly deformed.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment A method of manufacturing a gas sensor element according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the gas sensor element 1 of the present embodiment is configured by laminating a plurality of ceramic plates including a solid electrolyte plate 13 having electrodes 11 and 12. To manufacture the element 1, as shown in FIGS. 2 to 8, raw sheets 53 to 55 for each ceramic plate are first prepared, and the raw sheets 53 to 55 for each ceramic plate are positioned every two sheets. And a desired number of raw sheets 53 for ceramic plates are laminated and bonded together with a vacuum chuck using an adhesive.
To produce an unfired laminated body consisting of No.-55. Thereafter, the unfired laminate is fired to form the gas sensor element 1.

This will be described in detail. Gas sensor element 1 of this example
Uses a solid electrolyte plate 13, a spacer plate 14, and a heater substrate 15 as ceramic plates. As shown in FIGS. 1A and 1B, the gas sensor element 1 of the present embodiment
A solid electrolyte plate 13 having a measured gas side electrode 11 in contact with the measured gas and a reference gas side electrode 12 in contact with the reference gas
And a spacer plate 14 provided with a reference gas chamber 10 facing the reference gas side electrode 11 and configured to introduce a reference gas, and a heater substrate 15 provided with a heating element 150 that generates heat when energized. It is composed.

The reference gas chamber 10 contains the reference gas side electrode 1.
2 is provided with one end as a closed end 102 and the other end as an open end 101 opened to the outside of the gas sensor element 1.

The gas sensor element 1 according to the present embodiment is incorporated in a gas sensor 2 and attached to an exhaust system of an automobile engine to be used for air-fuel ratio control. As shown in FIG. 9, the gas sensor 2 comprises a cylindrical housing 20 and a dual gas
1 and an atmosphere-side cover 22 provided on the base end side. A water-repellent filter 22 is provided on the base end side of the atmosphere side cover 22.
An outer cover 221 is provided through the “0”. Inside the housing 20, the gas sensor element 1 inserted through the distal insulator 241 is inserted and arranged.
At the base end side of the air-side cover, a base-side insulator 24 is provided.
2 are arranged.

A terminal 231 for taking out the output of the gas sensor element 1 is arranged inside the base-side insulator 242, and this terminal 231 is connected to a lead wire 233 led out of the gas sensor 1 via a connection fitting 232. ing. Further, an elastic insulating member 25 is provided inside the atmosphere-side cover 22 at the most proximal end side, and the lead wire 233 is inserted therethrough.

A method for manufacturing the gas sensor element 1 will be described. First, a raw sheet for each ceramic plate is prepared. Each raw sheet 535, 53, 54, 55 is prepared by an extrusion molding device (not shown). FIG. 2 shows, in order from the drawing, a raw sheet 535 for an electrode protection layer (alumina composition thickness 0.15 mm), a raw sheet 53 for a solid electrolyte plate (zirconia composition thickness 0.2 mm), and a raw sheet 5 for a spacer plate.
4 (alumina composition thickness: 1.5 mm) and a raw sheet 55 for a heater substrate (alumina composition thickness: 0.2 mm). At the four corners of each of the raw sheets 535 to 55, positioning holes 59 having a diameter of 5 mm are provided.

The size of the raw sheet 53 for the solid electrolyte plate, the raw sheet 54 for the spacer plate, and the raw sheet 55 for the heater substrate are 70 mm × 90 mm, and the raw sheet 535 for the protective layer is used.
Is 70 mm × 35 mm. The raw sheet 54 for the spacer plate is provided with the groove 4 for the reference gas chamber 100.
After forming 50, it is adjusted to the above dimensions.

Next, the measured gas side electrode 11 and the reference gas side electrode 12 are applied to the raw sheet 53 for solid electrolyte plate.
And a printed portion 530 for each terminal portion, a lead portion connecting the terminal portion and the electrode, and the like. The printing unit 530 was formed by screen printing a platinum paste, which is a conductive paste, on the raw sheet 53. Similarly, for the heater sheet raw sheet 55, the heating element 150,
A printed portion 550 for the lead portion and the terminal portion used when the heating element 150 is energized was formed by screen-printing a platinum paste, which is a conductive paste, on the raw sheet 55.

Each of the processed raw sheets 535, 5
3, 54 and 55 are laminated, and details thereof will be described. As shown in FIG. 3, the entire surface of the raw sheet 55 on which the printing section 550 is provided is coated with an adhesive by screen printing. Further, no adhesive is applied to the back surface 549 of the raw sheet 54 opposite to the surface on which the groove 540 is provided. In this state, both are positioned and laminated and integrated.

The above-mentioned lamination and integration will be described. The vacuum chuck jig 3 to be used will be described.
As shown in FIG. 8, the vacuum chuck jig 3 includes an upper jig 32 and a lower jig 31. The lower jig 31 has a mounting surface 310 on which the raw sheet 55 is mounted, and a projection 312 for fixing the upper jig 32 provided on the outer periphery of the mounting surface 310. The mounting surface 310 is a raw sheet. The reference pin 3 for positioning using the reference hole 59 provided in advance in the reference numeral 55
13 are provided.

As shown in FIGS. 7A, 7B and 8, the upper jig 32 includes a mounting surface 320 for the raw sheet 54 and the lower jig 31 provided on the outer periphery of the mounting surface 320. The above-mentioned projection 312 has a recess 322 corresponding to the above-mentioned projection 312, and the above-mentioned mounting surface 320 is provided with a lamination reference pin 323 for positioning a lamination reference hole 59 previously provided in the raw sheet 54. A vacuum hole 33 is provided so as to pass through the surface 320 and can be connected to an external pump.

As shown in FIG. 8, the vacuum hole 33 has an opening 331 in the mounting surface 320, and a number of suction holes 332 provided in the thickness direction of the upper jig 32.
2 are connected inside the upper jig 32 and finally formed with a communication hole 333 formed to penetrate outside the upper jig 32.
An external pump is connected through the opening 334 of the communication hole 333. The vacuum hole 33 is also provided on the lower jig 31.

As shown in FIG. 8, the raw sheets 55 and 54 according to the present embodiment are stacked on the mounting surfaces 320 and 310 of the upper jig 32 and the lower jig 31, respectively.
3 and placed. In this state, the external pump is driven. Next, the upper jig 3 is placed on the lower jig 31.
2 and the projection 312 for fixing the upper jig is fitted into the recess 322 for the lower jig, and the two raw sheets 55 and 54 are stacked.

Next, a load of 0.2 MPa is applied for 2 seconds. While the load is applied, the external pump is driven, and the raw sheets 54 and 55 are attracted to the upper jig 32 and the lower jig 31 through the vacuum holes 33. After a predetermined period of time, the external pump is stopped and the upper jig 32 and the lower jig 31 are separated, laminated and bonded, and the integrated raw sheets 54 and 55 are taken out.

Next, as shown in FIG. 4, the raw sheet 53 is laminated and bonded to the integrated raw sheets 55-54 in the same manner as described above. At the time of vacuum chuck, a load is applied at 0.2 MPa for 2 seconds. Finally, as shown in FIG. 5, the raw sheet 535 and the auxiliary dummy sheet 536 are laminated and bonded to the integrated raw sheet 55-54-53 in the same manner as described above. The dummy sheet 536 is a raw sheet 535.
After is adhered, it is removed.

Integrated raw sheet 55-54-53-
From 535, the portion provided with the positioning holes 39 is cut and removed to obtain the unfired laminate 5 as shown in FIG. Then, the green body 5 is cut to obtain individual pieces 501 for one gas sensor element as shown in FIG. 6B. The obtained individual pieces 501 were fired at 1470 ° C. for 2 hours, and FIG.
(C) As shown in FIG. 1 (or FIG. 1), the gas sensor element 1 is obtained.

The operation and effect of this embodiment will be described. The gas sensor element of this example is made of a raw sheet 55,5 for each ceramic plate.
4, 53 are positioned every two sheets, and are laminated and bonded together with the vacuum chuck using an adhesive. Since the vacuum chuck is used, misalignment at the time of lamination can be prevented, so that two green sheets can be strongly bonded. In addition, since positioning is performed for every two sheets and bonding is performed, positional displacement or the like is unlikely to occur between the two raw sheets, and reliable bonding can be realized. Further, since an adhesive made of an acrylic material is used, the two green sheets can be strongly bonded.

As described above, in this example, each raw sheet 5
Since 5, 54 and 53 are adhered, peeling, falling off, and the like are hardly generated between the ceramic plates, that is, the solid electrolyte plate 13, the spacer plate 14, and the heater substrate 15, and the durability of the gas sensor element can be increased. . In addition, since the adhesive and the vacuum chuck are used when laminating and bonding the raw sheets, the raw sheets can be laminated and bonded without applying large pressure or heat, so that the gas sensor element is unlikely to be deformed. .

As described above, according to the present embodiment, it is possible to provide a method for manufacturing a gas sensor element which is excellent in durability and free from deformation.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view of a gas sensor element according to an embodiment.

FIG. 2 is a perspective view of each raw sheet in the embodiment.

FIG. 3 is an explanatory view of laminating a raw sheet for a spacer plate and a raw sheet for a heater substrate 55 in the embodiment.

FIG. 4 is an explanatory view when stacking raw sheets for a solid electrolyte plate in the embodiment.

FIG. 5 is an explanatory view when laminating a raw sheet for an electrode protection layer in the embodiment.

6A is an explanatory view of an unfired laminate, FIG. 6B is an explanatory view of an individual gas sensor element, and FIG.
(C) Explanatory drawing of the fired gas sensor element.

FIG. 7 is a plan view of (a) a lower jig and (b) an upper jig in the embodiment.

FIG. 8 is an explanatory view of a vacuum chuck jig in the embodiment.

FIG. 9 is an explanatory diagram of a gas sensor in the embodiment.

FIG. 10 is an explanatory view of a conventional gas sensor element.

[Explanation of symbols]

 1. . . 9. gas sensor element, . . Reference gas chamber, 11. . . 11. Gas electrode to be measured, . . 12. reference gas side electrode; . . 13. solid electrolyte body; . . 14. spacer plate, . . Heater substrate, 150. . . Heating element, 3. . . Jig for vacuum chuck, 31. . . Lower jig, 32. . . Upper jig, 310, 320. . . Mounting surface, 33. . . Vacuum holes,

Claims (7)

[Claims] In producing a gas sensor element constituted by laminating a plurality of ceramic plates including a solid electrolyte plate provided with electrodes, a raw sheet for each ceramic plate is prepared, and a raw sheet for each ceramic plate is prepared. Every two sheets,
It is characterized in that an unsintered laminate composed of a desired number of raw sheets for a ceramic plate is produced by performing positioning and laminating and bonding using an adhesive together with a vacuum chuck, and thereafter, the unsintered laminate is fired. Of manufacturing a gas sensor element. 2. The method according to claim 1, wherein the lamination adhesion is 0.1.
A method for manufacturing a gas sensor element, wherein the method is performed while applying pressure at 1 to 0.5 MPa. 3. The method according to claim 1, wherein the lamination is performed while maintaining the temperature at 4 to 80 ° C. 4. The method according to claim 1, wherein:
The method of manufacturing a gas sensor element, wherein the lamination is performed within a time period of 0.1 to 5 seconds. 5. The method of manufacturing a gas sensor element according to claim 1, wherein the vacuum chuck is performed using a vacuum chuck jig including an upper jig and a lower jig. The raw sheet for one ceramic plate is placed on the upper jig, the raw sheet for the other ceramic plate is placed on the lower jig, and the upper jig is placed on the lower jig so that the raw sheets abut each other. A method for manufacturing a gas sensor element, comprising: disposing the amphibious sheets in close contact by applying pressure reduction from at least one of an upper jig and a lower jig and performing vacuum chucking, and laminating and adhering the amphibious sheets in this state. . 6. The method according to claim 1, wherein:
A method for manufacturing a gas sensor element, wherein each raw sheet has a laminated reference hole. 7. A method for manufacturing a gas sensor element comprising a plurality of ceramic plates including a solid electrolyte plate provided with electrodes, which is used for a vacuum chuck performed in laminating and bonding the raw sheets for each ceramic plate. A jig for a vacuum chuck comprising an upper jig and a lower jig, wherein the upper jig is a surface for mounting a raw sheet for a ceramic plate and the lower jig provided on an outer periphery of the mounting surface. The mounting surface has a recess corresponding to the protrusion, and the mounting surface has a stacking reference pin for positioning a stacking reference hole provided in advance in the raw sheet for a ceramic plate. The pump is configured to be connectable and has a vacuum hole configured to be capable of vacuum chucking by driving an external pump. The lower jig has a mounting surface for a raw sheet for a ceramic plate and the mounting surface. It shall have a projection for fixing the upper jig provided on the outer periphery of the mounting surface, and the mounting surface shall have a lamination reference pin for positioning using a lamination reference hole previously provided in the raw sheet for ceramic plate. A jig for a vacuum chuck, characterized in that: