JP2015197950A - Manufacturing method of ceramic heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a ceramic heater capable of manufacturing a ceramic heater in a simple method without using a release film.SOLUTION: A manufacturing method of a ceramic heater includes the steps of: placing a flat plate-like mask in which a wiring pattern for screen printing is drawn on a side surface of a columnar or cylindrical core material, rotating a columnar or cylindrical shaft in a longitudinal direction of the core material as a rotating shaft, moving the mask at a rotational speed of the core material and in synchronization with a rotational direction of the core material, and printing wiring patterns serving as a heater unit and a power feeding unit by screen-printing a conductive paste on a side surface of the core material using a squeegee; drying the conductive paste; and forming an insulating material layer serving as an insulating layer on the core material so that the heater unit is covered by the insulating layer and a part of the power feeding unit is exposed from the insulating layer.

Description

The present invention relates to a method for manufacturing a ceramic heater.

A ceramic heater in which a resistance heating element made of a refractory metal is embedded between a core material and an insulating sheet covering the core material is used as a heat source in an oxygen sensor for automobiles, a glow system, etc. It is widely used as a heat source for oil vaporizers such as heaters and oil fan heaters.

Patent Document 1 describes a method for producing a ceramic heater used for such a purpose. Specifically, an adhesive green sheet is formed on a release film by screen printing, and a conductor is formed thereon. A method for producing a ceramic heater by forming a paste by screen printing and further forming an insulating green sheet by screen printing, peeling off a release film to produce a laminate, and winding the laminate on a core material is described. Has been.

JP 2002-75596 A

The structure of the ceramic heater to be manufactured is a structure in which most of the wiring is embedded in an insulating material, and only a portion serving as a power feeding portion is exposed. In order to achieve such a structure, in Patent Document 1, an adhesive green sheet is formed at a position corresponding to a portion to be a power feeding portion to provide a step, and a conductive paste is placed on the release film and the adhesive green sheet. Wiring is formed by printing so that an insulating green sheet is not formed on the wiring formed on the bonding green sheet.

In such a process, when the conductive paste is printed, the conductive paste may flow or break at the boundary due to a step existing at the boundary between the release film and the green sheet for adhesion. As a result, it is difficult to control the thickness, size, and cross-sectional shape of the conductor paste, and the characteristics of the ceramic heater may become unstable.

In addition, the above process requires at least three printing processes, namely, printing of the adhesive green sheet, printing of the conductive paste, and printing of the insulating green sheet. Since there are many printing processes, the number of processes is reduced, and the process is reduced. There was a need to simplify.
Moreover, since the release film becomes disposable and there is a problem that the waste increases, there has been a demand for a method that does not use the release film.

An object of this invention is to provide the manufacturing method of the ceramic heater which can manufacture a ceramic heater by a simple process, without using a release film.

In order to achieve the above object, a method for producing a ceramic heater according to the present invention includes placing a flat mask on which a wiring pattern for screen printing is drawn on a side surface of a columnar or cylindrical core material,
The core material is rotated using a columnar or cylindrical longitudinal axis as a rotation axis, the mask is moved in synchronization with the rotation speed and the rotation direction of the core material, and a squeegee is used to move the core material to the side surface. A wiring pattern printing process for screen printing the conductor paste and printing a wiring pattern to be a heater part and a power feeding part, a drying process for drying the conductor paste, and the heater part is covered with an insulating layer, And an insulating material layer forming step of forming an insulating material layer to be an insulating layer on the core material so that a part is exposed from the insulating layer.

In the method for producing a ceramic heater according to the present invention, since no release film is used in the process, waste does not increase. Moreover, since the printing process is only the process of directly printing the conductor paste on the side surface of the core material, the process can be simplified. Moreover, since the conductor paste is directly printed on the side surface of the core material, the effect of improving the adhesion between the wiring and the core material is also obtained.
Further, since there is no step in the core material that is the object to be printed with the conductor paste, it is easy to control the thickness, dimensions, and cross-sectional shape of the conductor paste, and the uniformity of the thickness of the wiring can be improved.

In the method for manufacturing a ceramic heater according to the present invention, the squeegee can move up and down with respect to the mask, and a position where the mask is in contact with the core material or a distance between the mask and the core material is closest. It is desirable that the position is set so as to be positioned on the uppermost side with respect to the mask.
In this way, the variation in pressure transmitted from the squeegee to the mask during screen printing is reduced, so that the uniformity of the wiring thickness can be further improved.

In the method for manufacturing a ceramic heater according to the present invention, in the wiring pattern printing step, the wiring pattern serving as the heater portion is printed using the heater portion printing mask, and the wiring pattern serving as the feeding portion is printed. It is desirable to use this.
By using the respective masks, wirings having different compositions can be formed by using conductive pastes having different compositions in the wiring patterns serving as the heater portion and the power feeding portion.

In the method for manufacturing a ceramic heater of the present invention, in the insulating material layer forming step, the insulating material layer to be the insulating layer is formed on a flat plate by printing, and then the insulating material layer is formed on the side surface of the core material. It is desirable.
According to the above method, the insulating material layer can be easily formed by winding it around the side surface of the core material.

In the method for manufacturing a ceramic heater of the present invention, in the insulating material layer forming step, the insulating material layer is formed by applying a paste-like raw material composition containing ceramic powder to be the insulating layer to the side surface of the core material. It is desirable.
If the said coating method is employ | adopted, an insulating material layer can be more easily formed in the side surface of a core material. As a coating method, a dipping method, a spray method, or the like can be employed.

In the method for manufacturing a ceramic heater according to the present invention, it is preferable that a degreasing step and a firing step are performed after the insulating material layer forming step to form the heater portion and the power feeding portion, and to form the insulating layer. .
When the core material is made of ceramic, the printed wiring pattern and insulating material layer can be made into a heater part, a power feeding part, and an insulating layer by firing.
When the core material is a molded body before firing formed using the same material as the material for forming the insulating material layer, it becomes a ceramic core material by firing.

In the method for producing a ceramic heater of the present invention, a ceramic heater having good characteristics can be produced by performing the degreasing step and the firing step.

In the method for manufacturing a ceramic heater of the present invention, it is desirable to further perform a passivating layer forming step of forming a passivating layer on the surface of the exposed power feeding portion.
By forming the passive layer, corrosion of the exposed power feeding portion is prevented, and a ceramic heater suitable for long-term use can be obtained.

FIG. 1A is a perspective view schematically showing a ceramic heater obtained by the method for producing a ceramic heater of the present invention, and FIG. 1B is a diagram of the ceramic heater shown in FIG. It is AA sectional view. FIG. 2 is a perspective view schematically showing another example of the ceramic heater obtained by the method for producing a ceramic heater of the present invention. FIG. 3A is a top view schematically showing the wiring pattern printing process, and FIGS. 3B to 3D are cross-sectional views taken along the line BB schematically showing the wiring pattern printing process. . FIG. 4A is a top view schematically showing an example of the heater portion print mask, and FIG. 4B is a top view schematically showing an example of the power supply portion print mask. FIG. 5 is a perspective view schematically showing a core material having a wiring pattern printed on a side surface after a drying process. FIG. 6A is a side view schematically showing a winding method in which an insulating material layer formed on the surface of a transfer member is wound around a core material, and FIG. 6B schematically shows the above method. It is a top view. 7A is a side view showing one manufacturing process of the ceramic heater according to Comparative Example 1, and FIG. 7B is a front view showing one manufacturing process of the ceramic heater according to Comparative Example 1. FIG. 8A is a side view showing one manufacturing process of the ceramic heater according to Comparative Example 1, and FIG. 8B is a front view showing one manufacturing process of the ceramic heater according to Comparative Example 1. FIG. FIG. 9A is a side view showing one manufacturing process of the ceramic heater according to Comparative Example 1, and FIG. 9B is a front view showing one manufacturing process of the ceramic heater according to Comparative Example 1. 10A is a side view showing one manufacturing process of the ceramic heater according to Comparative Example 1, and FIG. 10B is a front view showing one manufacturing process of the ceramic heater according to Comparative Example 1.

(Detailed description of the invention)
First, a ceramic heater obtained by the method for producing a ceramic heater of the present invention will be described first.
The ceramic heater obtained by the method for producing a ceramic heater according to the present invention includes a core material, an insulating layer formed on a side surface of the core material, and a heater having a predetermined pattern interposed between the core material and the insulating layer. And a power feeding unit.

FIG. 1A is a perspective view schematically showing a ceramic heater obtained by the method for producing a ceramic heater of the present invention, and FIG. 1B is a diagram of the ceramic heater shown in FIG. It is AA sectional view.

As shown in FIGS. 1 (a) and 1 (b), in the ceramic heater 10 obtained by the method for manufacturing a ceramic heater of the present invention, a heater portion 13 and a power feeding portion 14 are provided on a side surface of a cylindrical core material 11. And the insulating layer 12 is formed so as to cover all of the heater part 13 and a part other than a part of the power feeding part 14. In other words, the heater unit 13 and the power feeding unit 14 are interposed between the core material 11 and the insulating layer 12 while leaving a part of the power feeding unit 14. In addition, the core material 11 has an opening 19 formed at the center.

The power supply unit 14 includes a connection terminal unit 15 that is a part of the power supply unit 14 whose rightmost part is exposed to the outside in FIG. 1A, and connects the exposed connection terminal unit 15 to a power source. As a result, the heater unit 13 generates heat and functions as a heater. FIG. 2 is a perspective view schematically showing another example of the ceramic heater obtained by the method for manufacturing a ceramic heater of the present invention. As shown in FIG. 2, the exposed connection terminal portion 15 is interposed with a brazing material. The lead terminal 16 may be connected and fixed.

The insulating layer has a thickness of 100 to 500 μm after firing, and the composition of the insulating layer is not particularly limited, but 88 to 95% by weight of Al ₂ O ₃ and SiO ₂ as a sintering aid. It is preferably made of an alumina ceramic containing 3 to 10% by weight, MgO 0.4 to 1.0% by weight, and CaO 1.0 to 2.5% by weight.

The above-mentioned SiO ₂ or the like is contained as a sintering aid in the insulating layer because the above-mentioned amount of SiO ₂ is used to form a dense sintered body without increasing the sintering temperature of the alumina ceramic. This is because a sintering aid such as MgO is required.

Examples of the material constituting the core material include oxide ceramics, nitride ceramics, and carbide ceramics.
Examples of nitride ceramics include aluminum nitride, silicon nitride, boron nitride, and titanium nitride.Examples of carbide ceramics include silicon carbide, zirconium carbide, titanium carbide, tantalum carbide, and tungsten carbide. Examples of the oxide ceramic include alumina, zirconia, cordierite, and mullite. In these, the ceramic containing the alumina which is the same material as an insulating layer is preferable. Since the coefficient of thermal expansion is the same, cracks and the like are unlikely to occur even when the temperature changes. In FIG. 1, the shape of the core material 11 is a cylindrical shape with an opening 19 formed in the center portion, but the shape of the core material 11 may be either a columnar shape or a cylindrical shape. It is preferable that it is 5-4.0 mm.
Moreover, it is preferable that the opening 19 formed in the center of a cylindrical shape is between 0.5-1.5 mm in diameter.

Examples of the refractory metal constituting the resistance heating element of the heater section include W, Mo, Ta, Nb, Ti, Re, Ni, and Cr. These may be used alone or in combination of two or more. Of these, W and Re are preferable. Further, as a component other than the above, a small amount of ceramic such as Al ₂ O ₃ may be contained.

The members that make up the power supply section have the same composition as the members that make up the heater section. In the power supply section, the resistance is lowered by increasing the line width or connecting multiple wires in parallel. The calorific value is low.
In addition, the composition of the member constituting the power supply portion and the member constituting the heater portion may be different by using a conductive paste having a different composition between the wiring pattern serving as the heater portion and the wiring pattern serving as the power supply portion. .

Next, the manufacturing method of the ceramic heater of this invention is demonstrated.
In the method for manufacturing a ceramic heater according to the present invention, a flat mask on which a wiring pattern for screen printing is drawn is placed on a side surface of a columnar or cylindrical core material, and the core material is formed into a columnar or cylindrical shape. Rotate the longitudinal axis of the shape as a rotation axis, move the mask in synchronization with the rotation speed and rotation direction of the core material, screen print the conductor paste on the side surface of the core material using a squeegee, A wiring pattern printing process for printing a wiring pattern to be a heater part and a power feeding part, a drying process for drying the conductor paste, the heater part is covered with an insulating layer, and a part of the power feeding part is exposed from the insulating layer Thus, an insulating material layer forming step of forming an insulating material layer to be an insulating layer on the core material is included.

As an example of the manufacturing method of the ceramic heater of the present invention, the following (1) wiring pattern printing step, (2) drying step, (3) insulating material layer forming step, (4) degreasing step and firing step, (5) And a method of performing a passive layer forming step. Each step will be described in detail below.

(1) Wiring pattern printing process FIG. 3A is a top view schematically showing the wiring pattern printing process, and FIGS. 3B to 3D schematically show the wiring pattern printing process. It is a BB sectional view.
In the method for manufacturing a ceramic heater of the present invention, as a wiring pattern printing step, a conductor paste is screen-printed on the side surface of the core material, and a wiring pattern serving as a heater portion and a wiring pattern serving as a power feeding portion are printed.

In this wiring pattern printing step, a mask provided with a screen mesh and having a predetermined wiring pattern-like hole is used.
FIG. 3A shows a mask on a flat plate on which a wiring pattern for screen printing is drawn.
The mask 30 is provided with a mask portion 31 that is a portion through which the conductor paste does not pass, and a wiring pattern portion 32 that is a portion through which the conductor paste passes and in which a wiring pattern-like hole is formed.
The wiring pattern part 32 includes a heater part pattern 33 on which a wiring pattern serving as a heater part is drawn and a power feeding part pattern 34 on which a wiring pattern serving as a power feeding part is drawn.

In the wiring pattern printing process, the mask 30 is placed on the side surface 17 of the cylindrical core material.
The core material 11 has a longitudinal direction of the core material 11 (a direction indicated by a double arrow a in FIG. 3A) and a longitudinal direction of the wiring pattern portion 32 (a direction indicated by a double arrow b in FIG. 3A). So that they are in the same direction.
The longitudinal direction of the wiring pattern portion 32 is a direction from the heater portion pattern 33 toward the power feeding portion pattern 34 (and the opposite direction).
In FIG. 3A, the core material 11 disposed under the mask 30 is shown by a dotted line by transmitting a part of the mask. Moreover, the edge parts 18a and 18b of the longitudinal direction of the core material 11 are shown.

FIG. 3B shows an initial arrangement of the wiring pattern printing process.
A conductive paste 35 is applied on the mask 30, and a squeegee 36 is set beside the conductive paste 35.
The core member 11 is pivotally supported at its end portions 18a and 18b by pivotally supporting the core member 11 and abutting a rotatable shaft support member (not shown). The shaft support member is a jig that can rotate the core material 11 about the axis in the longitudinal direction as a rotation axis. It is not limited.
Further, the core material 11 may be a molded body before firing formed using the same material as that for forming the insulating material layer. In this case, a cylindrical molded body is produced by extrusion molding or the like and then dried to have a hardness that can be pivotally supported.
Further, the core material 11 may be made of a ceramic manufactured using the same material as that for forming the insulating material layer.

Subsequently, the core member is rotated with the longitudinal axis as a rotation axis.
3C and 3D schematically show the wiring pattern printing process. In FIGS. 3C and 3D, the core 11 is rotated counterclockwise.
The mask 30 is moved in synchronization with the rotation speed and rotation direction of the core material. The moving direction of the mask 30 in FIGS. 3C and 3D is leftward.
The movement of the mask 30 is performed in synchronization with the movement speed so that the movement distance of the mask 30 when the core 11 rotates once is the same as the circumference of the core 11.
The moving distance of the mask 30 when the core member 11 rotates once is determined to be larger than the width of the wiring pattern portion 32 drawn on the mask 30 (the width indicated by the double arrow c in FIG. 3A). Desirably, the wiring pattern is printed without overlapping on the side surface of the core material by setting in this way.
The squeegee 36 is fixed on the top of the mask 30 and the conductor paste 35 is filled into the wiring pattern portion 32.
A wiring pattern portion 32 shown in FIGS. 3B to 3D is a power feeding portion pattern 34.

In this specification, the rotation direction when “the mask is moved in synchronization with the rotation speed and the rotation direction of the core material” is the position where the mask is in contact with the core material or the distance between the mask and the core material is the shortest. The direction of the rotation vector of the core material at the position is a direction parallel to the plane of the flat mask. The rotation speed is a speed represented by the magnitude of the rotation vector of the core material at the position.
The FIG. 3 (c), the represents the rotation vector of the core material by the arrow V ₁ at a distance is closest position between the mask and the core material (mask is in contact with the core position), the direction of the rotation vector and size is the same as the direction and magnitude of the movement vector of the mask indicated by the arrow V ₂ in Figure 3 (c).

In the wiring pattern printing process, it is desirable that the squeegee is fixed, but the squeegee may be moved in the direction opposite to the moving direction of the mask.
The movement of the mask means that the position of the mask changes with respect to the position of the core material, and means a change in the relative position of the mask with respect to the core material. That is, the concept of “the mask moves” includes the case where the core material is moving and the mask is not moving. When the core material moves and the mask does not move, it is desirable that the squeegee moves in the same direction as the core material.
The moving speed of the mask is preferably 0.5 to 200 mm / second. The moving speed is a relative moving speed of the mask with respect to the core material.
A preferable form of the relationship in which the mask, the core material, and the squeegee move is a form in which only the mask moves and the core material and the squeegee do not move. Moreover, the core material and the squeegee move, and the mask does not move.

The squeegee can move up and down with respect to the mask, and is set so that it is located on the uppermost side with respect to the mask at the position where the mask is in contact with the core material or the distance between the mask and the core material is closest. It is desirable that
In this way, the variation in pressure transmitted from the squeegee to the mask during screen printing is reduced, so that the uniformity of the wiring thickness can be further improved.

By this operation, the conductor paste 35 filled in the wiring pattern portion 32 is printed on the side surface 17 of the core material. Since the core material 11 is rotating, the printed conductor paste 35 moves away from the mask 30 immediately after printing. The printed conductor paste becomes a wiring pattern to be a heater part and a wiring pattern to be a power feeding part.
FIG. 3C and FIG. 3D show a wiring pattern 24 that is printed on the side surface 17 of the core material and serves as a power feeding unit.

As described above, the conductive paste includes at least one selected from the group consisting of refractory metals such as W, Mo, Ta, Nb, Ti, Re, Ni, and Cr, a ceramic component such as Al ₂ O _3, and a binder. It is desirable to contain a resin and a solvent. Examples of the binder resin include acrylic resins and epoxy resins, and examples of the solvent include acetone and ethanol.
The average particle diameter of W contained in the conductor paste is preferably 0.5 to 10 μm, and the viscosity of the conductor paste is preferably 10 to 200 Pa · s. As for the thickness of the printed conductor paste layer, 10-50 micrometers is preferable.

FIG. 4A is a top view schematically showing an example of the heater portion print mask, and FIG. 4B is a top view schematically showing an example of the power supply portion print mask.
In the wiring pattern printing step, a heater part printing mask 50 and a power feeding part printing mask 60 as shown in FIGS. 4A and 4B are prepared, and wiring to be a heater part using each mask. Pattern printing and wiring pattern serving as a power feeding unit may be printed.
Only the heater part pattern 33 is drawn on the heater part printing mask 50, and only the power feeding part pattern 34 is drawn on the power feeding part print mask 60.
By using the respective masks, wiring layers having different compositions can be formed by using conductive pastes having different compositions for the wiring patterns serving as the heater portion and the power feeding portion.

(2) Drying step In this drying step, the conductor paste printed on the side surface of the core material is dried.
The drying conditions are preferably a drying temperature of 40 to 180 ° C. and a drying time of 1 to 30 minutes, and more preferably a drying temperature of 60 to 100 ° C. and a drying time of 1 to 5 minutes.

FIG. 5 is a perspective view schematically showing a core material having a wiring pattern printed on a side surface after a drying process.
The core material 11 is printed with a wiring pattern 23 serving as a heater unit and a wiring pattern 24 serving as a power feeding unit (hereinafter also referred to as wiring patterns 23 and 24) by screen printing.
By the drying step, the wiring patterns 23 and 24 are brought into close contact with the surface of the core material 11 and are not peeled off from the surface of the core material 11.

(3) Insulating material layer forming step In this insulating material layer forming step, the side surface of the core material is so formed that the portion that becomes the heater portion is embedded in the insulating layer, and a portion of the portion that becomes the power feeding portion is exposed from the insulating layer. Then, an insulating material layer to be an insulating layer is formed.
The method for forming the insulating material layer is not particularly limited. For example, after forming the insulating material layer to be the insulating layer on a flat plate by printing, the insulating material layer is formed on the side surface of the core material. A method of winding and forming the insulating material layer around the core material (hereinafter also referred to as a winding method) can be employed.

FIG. 6A is a side view schematically showing a winding method in which an insulating material layer formed on the surface of a transfer member is wound around a core material, and FIG. 6B schematically shows the above method. It is a top view.

As shown in FIGS. 6A and 6B, when the winding method is adopted, an insulating material layer 25 is formed on the surface of the transfer member 21, and the insulating material layer 25 is formed on the surface. By rolling the core material 11, the insulating material layer 25 is wound around the core material 11, and the insulating material layer is formed around the core material.
Specifically, the core member 11 is pivotally supported on both end faces of the core member 11 and a pivotal support member (not shown) that can be rotated is brought into contact therewith to be pivotally supported. After the side surface of the core material 11 is brought into contact with the core material 11, the core material 11 is rolled on the surface of the transfer member 21.
When the insulating material layer 25 is formed on the surface of the transfer member 21, a screen printing method can be used. Specifically, a mask having a mesh and having holes formed in the shape of the insulating material layer 25. Then, the insulating material layer 25 having a solid pattern is formed.
The transfer member 21 preferably has elasticity while having appropriate wettability, and the material thereof is preferably an elastomer such as rubber, and more preferably silicon rubber.

As a raw material composition for printing, 88 to 95% by weight of Al ₂ O ₃ particles, ₃ to 10% by weight of SiO ₂ particles and 0.4 to 1.0% by weight of MgO particles as a sintering aid, A paste-like material containing 1.0 to 2.5% by weight of CaO particles and further containing a binder resin and a solvent can be used. As the binder resin and the solvent, those used in preparing the conductor paste can be used. The thickness of the insulating material layer 25 is preferably a thickness of 100 to 500 μm after firing.
It is preferable to wrap the insulating material layer 25 after the insulating material layer 25 is formed on the surface of the transfer member 21 and before the solvent scatters so that the insulating material layer 25 is in close contact with the core material 11.

At this time, as shown in FIG. 6A and FIG. 6B, the insulating material layer 25 is wound so that a part of the wiring pattern 24 serving as the power feeding portion is exposed to the outside, and the above-described portion is wound around the core material. An insulating material layer is formed. At this time, both end surfaces of the core material 11 are pivotally supported by the shaft support member, and the insulating material layer 25 is wound around the side surface of the core material 11 by rolling the surface of the insulating material layer 25, so that the above insulation is provided around the core material. A method for forming a material layer can be used.

After forming an insulating material layer having a large area and cutting it into a predetermined shape, an adhesive or the like may be applied to the surface, wound around the side surface of the core material 11, and the insulating material layer may be formed around the core material. . Thereafter, the insulating material layer is dried if necessary.

(4) Degreasing step and firing step Thereafter, the wiring patterns 23 and 24 and the wound insulating material layer 25 are degreased and fired. By the degreasing and firing, the wiring pattern 23 serving as the heater unit becomes the heater unit 13, and the wiring pattern 24 serving as the power feeding unit becomes the power feeding unit 14.
Further, the insulating material layer 25 becomes the insulating layer 12.
When the core material 11 is made of ceramic, there is no change due to the degreasing and firing, but the core material is a molded body before firing formed using the same material as the material for forming the insulating material layer. A ceramic core material is obtained by the above degreasing and firing.
Degreasing conditions include 200 to 800 ° C. and 1 to 15 hours, and firing conditions include 1000 to 1600 ° C. and 1 to 40 hours. The degreasing step is preferably performed in an oxygen-containing atmosphere, and the firing step is preferably performed in an inert atmosphere.
By the above process, the heater part is embedded in the insulating layer, and an insulating layer is formed on the core material so that a part of the power feeding part is exposed from the insulating layer, thereby manufacturing a ceramic heater that functions as a heater. it can.

(5) Passive layer formation process In order to prevent the electrode constituting the power feeding portion from deteriorating in the power feeding portion exposed from the insulating layer, a method such as plating is used, and Ni, Cr, Au, Ag, Pd, etc. The passive layer to be formed is formed, and the production of the ceramic heater shown in FIG. 1 or FIG. 2 is finished.

When the manufactured ceramic heater is energized, the resistance heating element constituting the heater section generates heat, and the target member can be heated so that the target temperature is reached.

In the above case, the winding method is adopted, but the method of forming the insulating material layer on the side surface of the core material by applying the paste-like raw material composition containing the ceramic powder to be the insulating layer on the side surface of the core material. (Hereinafter referred to as a coating method) may be employed.

When the coating method is adopted, a paste-like raw material composition having a lower viscosity than that when an insulating material layer is formed by screen printing is used, and the paste-like raw material composition is directed from the spray nozzle toward the side surface of the core material. The insulating material layer is formed by spraying. At this time, the core material is rotated at a predetermined speed and moved up and down to form an insulating material layer having a uniform thickness. The thickness of the insulating material layer is preferably such that the thickness after firing is 100 to 500 μm.
When the dipping method is adopted, the insulating material layer is formed by immersing the core material on which the wiring pattern is printed in the paste-like raw material composition.

Thereafter, as in the case of winding the insulating material layer, the ceramic material can be manufactured by drying the insulating material layer as necessary, and then performing a degreasing step, a firing step, and a passive layer forming step.

(Example)
Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Example 1)
(1) Wiring pattern printing process 78 parts by weight of W as a conductor paste, 19 parts by weight of Re, ₃ parts by weight of Al ₂ O ₃ and 6 parts by weight of acrylic resin as a binder resin for 100 parts by weight of these conductor components And 7 parts by weight of acetone was used as a solvent.
As the core material, a cylindrical material having a diameter of 3.2 mm, a length of 90 mm, and an opening having a diameter of 1.0 mm in the center was used. The core material 11 is made of ceramic containing 92.5% by weight of Al ₂ O ₃ , 5.8% by weight of SiO ₂ , 0.5% by weight of MgO and 1.2% by weight of CaO. .
Using the mask 30 shown in FIG. 3 (a), as shown in FIGS. 3 (b) to 3 (d), the core is rotated about the longitudinal axis of the cylinder as the rotation axis, and the mask is rotated at the rotational speed of the core. The conductor paste was screen-printed on the side surface of the core using a squeegee, and the wiring pattern 23 serving as a heater part and the wiring pattern 24 serving as a power feeding part were printed using a squeegee. The printed conductor paste layer had a thickness of 25 μm and a good wiring pattern was formed.

(2) Drying process The core material on which the wiring pattern was printed was dried at 120 ° C. for 10 minutes.

(3) Insulating material layer forming step 92.5 parts by weight of Al ₂ O ₃ as ceramic particles, 5.8 parts by weight of SiO ₂ , 0.5 parts by weight of MgO, and 1. A paste-form raw material composition containing 2 parts by weight and further containing 10 parts by weight of an acrylic resin as a binder resin and 15 parts by weight of acetone as a solvent is used with respect to 100 parts by weight of the ceramic particles. As shown in FIG. 3, the insulating material layer 25 was formed on the surface of the transfer member 21 by screen printing so that the thickness of the insulating layer after firing was 250 μm.

Subsequently, after a shaft support member is brought into contact with both end faces of the core material 11, the shaft support member and the core material 11 supported by the shaft are supported in a freely rotatable state, and are brought into contact with the surface of the transfer member 21. The shaft support member and the core material 11 supported by the shaft are moved in a direction parallel to the surface of the transfer member 21, and the core material 11 is rotated on the surface of the transfer member 21 so that the insulating material layer 25 is formed on the wiring pattern 23. It was wound around the side surface of the core material 11 on which 24 was formed, formed, and dried at 120 ° C. for 30 minutes.

(4) Degreasing process and baking process The thing in which the wiring patterns 23 and 24 and the insulating-material layer 25 were formed in the side surface of the core material 11 was degreased by heating at 450 degreeC for 1 hour in oxygen atmosphere. Thereafter, it is baked at 1600 ° C. for 1 hour in an inert gas atmosphere to form a heater portion 13 having a thickness of 20 μm, a width of 0.25 mm, and a power feeding portion 14 having a width of 3.0 mm. An insulating layer 12 having a thickness of 250 μm was formed.

(5) Passive layer formation process After this, electroless Ni plating and electroless Cr plating were applied to the connection terminal portion constituting the power supply portion exposed to the outside to form a passive layer.

(Example 2)
In the wiring pattern printing process of the embodiment (1), a heater part printing mask 50 and a power feeding part printing mask 60 as shown in FIGS. 4A and 4B are prepared, and the respective masks are used. A wiring pattern serving as a heater part and a wiring pattern serving as a power feeding part were printed.
First, as a conductive paste, 97 parts by weight of W, ₃ parts by weight of Al ₂ O ₃ , 6 parts by weight of acrylic resin as a binder resin and 7 parts by weight of acetone as a solvent with respect to 100 parts by weight of these conductor components It was prepared as a conductor paste for the power feeding part.
As the core material, a cylindrical material having a diameter of 3.2 mm, a length of 90 mm, and an opening having a diameter of 1.0 mm in the center was used. The core material 11 is made of ceramic containing 92.5% by weight of Al ₂ O ₃ , 5.8% by weight of SiO ₂ , 0.5% by weight of MgO and 1.2% by weight of CaO. .
As shown in FIGS. 3B to 3D, the core material is rotated about the longitudinal axis of the cylinder as the rotation axis, and the power feeding portion print mask 60 is moved in synchronization with the rotation speed and the rotation direction of the core material. Then, using a squeegee, the conductor paste for the power feeding part was screen-printed on the side surface of the core material, and the wiring pattern 24 serving as the power feeding part was printed.
Next, as a conductive paste, 78 parts by weight of W, 19 parts by weight of Re, ₃ parts by weight of Al ₂ O ₃ , 6 parts by weight of acrylic resin as a binder resin with respect to 100 parts by weight of these conductor components, solvent As a conductor paste for a heater part containing 7 parts by weight of acetone.
The heater part print mask 50 is set according to the position of the wiring pattern 24 to be the power feeding part printed earlier, and the heater part print mask 50 is moved in synchronization with the rotation speed and direction of the core material, and the squeegee is moved. The conductor paste for the heater part was screen printed on the side surface of the core material, and the wiring pattern 23 to be the heater part was printed.
The printed conductor paste layer had a thickness of 25 μm.
Other processes were the same as in Example 1 to produce a ceramic heater.

(Comparative Example 1)
FIGS. 7A to 10A are side views showing one manufacturing process of the ceramic heater according to Comparative Example 1, and FIGS. 7B to 10B are ceramics according to Comparative Example 1. FIGS. It is a front view which shows one manufacturing process of a heater.

First, as shown in FIGS. 7 (a) and 7 (b), an adhesive green is formed on a plastic film 41 having releasability by screen printing using a paste containing alumina powder, a binder resin, and a solvent. A sheet layer 47 was formed. The composition of the adhesive green sheet layer 47 was the same as that of the raw material composition used in the step (3) insulating material layer forming step of Example 1, and the thickness thereof was 300 μm after firing.

After the bonding green sheet layer 47 is dried, as a conductor paste printing process, a conductor paste layer 43a serving as a heater part and a conductor paste layer 43b serving as a power feeding part (hereinafter also referred to as conductor paste layers 43a and 43b) are obtained by screen printing. It formed on the plastic film 41 and the green sheet layer 47 for adhesion. At this time, the printing direction of the conductor paste layers 43a and 43b, that is, the direction in which the squeegee runs was a direction parallel to the conductor paste layer 43ax in the longitudinal direction.
The conductive paste layers 43a and 43b were the same as the conductive paste used in Example 1.

Next, as shown in FIGS. 8A and 8B, as a green sheet printing process, the conductor paste layer 43a is formed in a region including the conductor paste layers 43a and 43b printed in the conductor paste printing process. , 43b, a paste for an insulating layer containing ceramic powder, a binder resin, and a solvent was stacked and screen-printed to form a green sheet layer 44. At this time, the portion of the conductive paste layer 430 exposed to the outside after firing was not covered with the green sheet layer 44 but exposed.
The composition of the green sheet layer 44 used at this time was also the same as the raw material composition used in the (3) insulating material layer forming step of Example 1. The green sheet layer 44 had a thickness of 300 μm after firing.

Thereafter, the green sheet layer 44 was dried. A laminate 40 is formed by laminating these adhesion green sheet layer 47, conductor paste layers 43 a and 43 b, and green sheet layer 44.

Next, as shown in FIG. 9A, the laminate 40 shown in FIG. 8A is inverted so that the green sheet layer 44 is on the lower side, and placed on a predetermined table 45. Thereafter, the plastic film 41 was peeled off by fixing to the base 45 using air suction force through a through hole (not shown) formed in the base 45. In addition, FIG.9 (b) represents the laminated body 40 after peeling the plastic film 41. FIG.

Subsequently, as shown in FIG. 10A and FIG. 10B, as the winding process, the generated shape 46 that becomes the cylindrical core material 11 is placed on the laminated body 40, and the generated shape 46 A raw material molded body for firing was produced by winding the laminate 40 around the side surface. The ratio of the ceramic particles and the sintering aid constituting the generated shape 46 is the same as that of the green sheet layer 44.

Thereafter, as a degreasing / firing step, degreasing is performed at a temperature of 450 ° C. in the presence of oxygen to remove organic substances in the adhesive green sheet layer 47, the generated form 46, the conductive paste layers 43a and 43b, and the green sheet layer 44. Subsequently, firing was performed at 1600 ° C. for 3 hours in an inert atmosphere to sinter ceramic powder, refractory metal, and the like.
Thus, a ceramic heater having substantially the same configuration as the ceramic heater 10 shown in FIG. 1 was manufactured, in which the heater portion and the terminal portion were embedded in the insulating layer except for the connection terminal portion. In the ceramic heater of Comparative Example 1, since the adhesive green sheet layer 47 is formed and the conductive paste layer serving as the connection terminal portion is formed thereon, the connection terminal portion is almost the same as the surface of the insulating layer. It is height.

(Evaluation)
Next, when the ceramic heater manufactured in Example 1, Example 2 and Comparative Example 1 was heated to 500 ° C. and then subjected to a heat cycle test in which a cooling cycle for cooling to room temperature was repeated, Example 1 and Example In No. 2, it was possible to repeat heating and cooling well up to 500 cycles. At the same time as this heat cycle test, the heat generation state of the heater part was observed using a thermoviewer, and heat was generated substantially uniformly over the entire area of the heater part.
However, it was confirmed that Comparative Example 1 was difficult to heat when the number of cycles exceeded 300. In addition, it was confirmed that the steps of Example 1 and Example 2 could be simplified and the production time was shorter than that of Comparative Example 1.

DESCRIPTION OF SYMBOLS 10 Ceramic heater 11 Core material 12 Insulating layer 13 Heater part 14 Electric power feeding part 23, 24 Wiring pattern 25 Insulating material layer 30 Mask 35 Conductive paste 36 Squeegee

Claims (7)

On the side surface of the columnar or cylindrical core, a flat mask on which a wiring pattern for screen printing is drawn is placed,
The core material is rotated using a columnar or cylindrical longitudinal axis as a rotation axis, the mask is moved in synchronism with the rotation speed and the rotation direction of the core material, and a squeegee is used on the side surface of the core material. A wiring pattern printing step for screen printing the conductor paste and printing a wiring pattern to be a heater part and a power feeding part;
A drying step of drying the conductor paste;
An insulating material layer forming step of forming an insulating material layer serving as an insulating layer on the core material so that the heater portion is covered with an insulating layer and a part of the power feeding portion is exposed from the insulating layer. A method for producing a ceramic heater. The squeegee can move up and down with respect to the mask, and the uppermost position relative to the mask at a position where the mask is in contact with the core material or a position where the distance between the mask and the core material is closest. The method for manufacturing a ceramic heater according to claim 1, wherein the ceramic heater is set so as to be positioned at a position. In the wiring pattern printing step, the wiring pattern serving as a heater unit is printed using a heater printing mask, and the wiring pattern serving as a power feeding unit is printed using the power feeding unit printing mask. The manufacturing method of the ceramic heater of description. The said insulating material layer formation process WHEREIN: After forming the said insulating material layer used as the said insulating layer on a flat plate by printing, the said insulating material layer is formed in the side surface of the said core material. Manufacturing method of ceramic heater. The said insulating material layer formation process WHEREIN: The said insulating material layer is formed by apply | coating the paste-form raw material composition containing the ceramic powder used as the said insulating layer to the side surface of the said core material. Manufacturing method of ceramic heater. Furthermore, after the insulating material layer forming step, a degreasing step and a firing step are performed,
The method for manufacturing a ceramic heater according to claim 1, wherein the heater part and the power feeding part are formed, and the insulating layer is formed. The manufacturing method of the ceramic heater of Claim 6 which further performs the passive layer formation process which forms a passive layer in the surface of the exposed electric power feeding part.

Images