JPH10236878A - Ceramic parts and their production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent trouble such as cracking and chipping when plural unfired ceramic sheets are laminated, fired in one body and separated and to obtain ceramic parts having satisfactory surface quality in a high yield by forming many spot-shaped recesses in at least one face of each of the unfired ceramic sheets. SOLUTION: Many spot-shaped recesses are formed in at least one face of an unfired ceramic sheet. A plurality of such sheets are laminated so that the recessed faces do not confront each other and they are fired to obtain a laminated ceramic sintered compact 2. Ceramic sintered compacts 21 -2n are then separated from the sintered compact 2. The spot-shaped recesses are remarkably easily formed by adopting blasting with a shot material such as shot blasting, sand blasting or glass bead blasting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic component used as an electronic component, an acoustic component, a mechanical component, an automobile component, and the like, and a method of manufacturing the same.

[0002]

2. Description of the Related Art A piezoelectric element used as a ceramic component, for example, an electronic component, an acoustic component, or the like, is exemplified by BaTi, which is a main component of the piezoelectric element 11, as shown in FIG.
The ceramic sintered body 12 includes O ₃ , PbTiO ₃ , PbZrO _3, etc. as main components, and electrodes 13A and 13B provided on the front and back surfaces of the ceramic sintered body 12.

When manufacturing such a piezoelectric element 11, in order to increase productivity, usually, a plurality of unfired ceramic sheets (ceramic green sheets) formed by a press forming method or the like are stacked to form, for example, 100 sheets.
After sintering at a temperature of 0 to 1300 ° C. to obtain a laminated ceramic sintered body in a plurality of layers, the laminated ceramic sintered body is separated into respective ceramic sintered bodies. In some cases, the electrodes 13A and 13B are provided on the front and back surfaces of the substrate 12.

Then, as shown in FIG. 5, for example, as shown in FIG. 5, a plurality of unsintered ceramic sheets are fired in a stacked state to be easily separated from each other from a laminated ceramic sintered body. Ceramic unfired sheet 12G
There is also a concept that the convex lines (or concave lines) 12a are formed side by side on the front and back surfaces to prevent the ceramic unsintered sheets 12G from being strongly bonded to each other and the bonding between the ceramic sintered bodies after sintering from becoming strong. (See, for example,
No. 117152).

[0005]

However, in the conventional case, the ceramics are so formed as to be easily separated into respective ceramic sintered bodies from a laminated ceramic sintered body obtained by firing a plurality of stacked ceramic unsintered sheets. Unfired sheet 12
Although the convex lines 12a are formed in advance on G, since the interval between the convex lines 12a is wide, when a plurality of unfired ceramic sheets 12G are stacked, the state of surface contact between the convex lines 12a is reduced. Because of the increased number of contact portions, the bonding strength between the laminated ceramic sintered bodies increases after sintering, and it is necessary to separate the laminated ceramic sintered bodies into respective ceramic sintered bodies (12). There has been a problem that it may not be easy.

When it is attempted to separate the ceramic sintered bodies (12) in a state where the bonding strength between the laminated ceramic sintered bodies is increased, each of the ceramic sintered bodies (12) is convex. There has been a problem that the production yield may be significantly reduced due to cracking, chipping, or inability to completely separate along the shape line 12a.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and a plurality of unsintered ceramic sheets are fired by stacking to obtain a stacked ceramic sintered body having a plurality of stacked sheets. After that, when separating from the laminated ceramic sintered body into respective ceramic sintered bodies, the ceramic sintered bodies are prevented from being strongly bonded after sintering, and each ceramic from the laminated ceramic sintered body is separated. To be able to satisfactorily separate a sintered body, to prevent defects such as cracks and chips from occurring during separation, and to provide a ceramic part having a high production yield and a small number of surface defects. It is an object.

[0008]

According to a first aspect of the present invention, there is provided a ceramic component having at least a part (or at least one) surface having a large number of dot-shaped concave portions formed thereon. It is characterized in that it has a configuration using a union.

In the embodiment of the ceramic component according to the present invention, as described in claim 2, the surface on which the dot-shaped concave portions are formed has a higher surface density by blasting using a shot material. Can be used.

According to a third aspect of the present invention, there is provided a method for manufacturing a ceramic component, comprising the steps of forming a large number of dot-shaped recesses on at least a part (or at least one) of a surface of an unfired ceramic sheet. A plurality of ceramic unsintered sheets were fired by stacking a plurality of ceramic unsintered sheets with the dot-shaped concave portions of the ceramic unsintered sheets interposed therebetween to obtain a stacked ceramic sintered body in a stacked state. It is characterized in that it is separated into ceramic sintered bodies.

In the embodiment of the method of manufacturing a ceramic component according to the present invention, as described in claim 4, the dot-shaped concave portions are formed by a shot material such as a shot blast, a sand blast, or a glass bead blast. It can be formed by the blasting used.

Similarly, in an embodiment of the method for manufacturing a ceramic component according to the present invention, as described in claim 5, the surface of the surface on which the point-shaped concave portions are formed by blasting using a shot material. It can be made to increase the density.

[0013] Similarly, in an embodiment of the method of manufacturing a ceramic component according to the present invention, as described in claim 6, a plurality of laminated ceramic sintered bodies are converted into respective ceramic sintered bodies. Ultrasonic waves can be used for separation.

Similarly, in an embodiment of the method for manufacturing a ceramic component according to the present invention, as described in claim 7, an extrusion molding method is used for forming a ceramic unsintered sheet. , A doctor blade method may be used for forming a green ceramic sheet.

[0015]

According to the ceramic component of the present invention, a ceramic sintered body having a large number of dot-shaped concave portions formed on at least a part of its surface is used. Since the ceramic sintered body is not cracked, chipped, or not completely separated, a ceramic component having a good surface quality and a high yield, for example, a piezoelectric element having excellent electric-vibration characteristics when it is a piezoelectric element. A remarkably excellent effect that it can be provided at low cost is provided.

And, as described in claim 2,
The surface on which the point-shaped concave portions are formed should be such that the density of the surface is increased by blasting using a shot material, so that defects such as cracks and chips on the surface are unlikely to occur. In addition, a remarkably excellent effect that, for example, the electric-vibration characteristics of a piezoelectric element can be further improved can be obtained.

According to the method for manufacturing a ceramic component of the present invention, after forming a large number of dot-shaped concave portions on at least a part of the surface of the unfired ceramic sheet, the dotted concave portions of the unfired ceramic sheet are interposed. A plurality of ceramic unsintered sheets were stacked and fired to obtain a stacked ceramic sintered body in a stacked state, and then separated from the stacked ceramic sintered body into respective ceramic sintered bodies. It is possible to prevent each ceramic sintered body from cracking, chipping or not being able to be completely separated in the separation process after firing, and it is possible to produce ceramic parts with good surface quality with good yield In the case of a piezoelectric element, for example, it is possible to produce a ceramic component having excellent electric-vibration characteristics at a low cost. That.

And, as described in claim 4,
The dot-like concave portions are formed by blasting using a shot material such as shot blast, sand blast, glass bead ball blast, etc., so that at least a part or at least one surface of the unfired ceramic sheet is formed. Has a remarkable effect that the formation of the concave portion can be performed extremely easily by a mass production method.

According to the fifth aspect of the present invention, the surface density of the surface where the point-like concave portions are formed by blasting using a shot material is increased, so that cracks or chipping on the surface are achieved. It is possible to manufacture a ceramic component that is unlikely to cause defects such as a piezoelectric element, and it is possible to manufacture a ceramic component having more excellent electric-vibration characteristics in the case of a piezoelectric element. It is. Further, as described in claim 6, ultrasonic waves are used when separating the plurality of stacked ceramic sintered bodies into the respective ceramic sintered bodies, so that each of the sintered ceramic bodies after integral firing is separated. When the ceramic sintered body is separated into ceramic sintered bodies, the ceramic sintered bodies can be separated more easily without causing problems such as cracking or chipping.

Further, as described in claim 7, an extrusion molding method is used for forming the unsintered ceramic sheet, and as described in claim 8, a doctor is used for forming the unsintered ceramic sheet. By using the blade method or the like, a remarkably excellent effect that a ceramic unsintered sheet can be formed by an extremely simple method is obtained.

[0021]

FIG. 1 shows an embodiment of a ceramic part and a method of manufacturing the same according to the present invention.
The case where a ceramic component is applied to a piezoelectric element which is a dielectric element is shown.

The ceramic component (piezoelectric element) 1 shown in FIG. 1 uses a disc-shaped ceramic sintered body 2 and has a large number of dot-shaped recesses 2a formed on one side thereof. The electrodes 3A and 3B are provided on the surface having the concave portion 2a and the smooth surface on the opposite side, respectively.

In manufacturing the ceramic component (rolling element) 1 having such a configuration, first, a ceramic powder is used as a raw material, and in some cases, the ceramic powder is calcined and then pulverized into a powder. The mixture is kneaded by adding an agent, a dispersant, a dispersion medium, and the like, and then formed into an unfired ceramic sheet by an extrusion molding method, a doctor blade molding method, or the like.

Next, blasting is performed by blasting a shot such as a steel shot, a sand or a glass bead ball on a part of the surface of the unfired ceramic sheet, or one surface, or the front and back surfaces. A large number of dot-shaped concave portions are formed on the surface of the unfired sheet.

Next, after stacking a plurality of ceramic unsintered sheets with the dot-shaped recesses formed in the ceramic unsintered sheets therebetween, the sheets are fired, for example, at a temperature of 1000 to 1300 ° C. A laminated ceramic sintered body is obtained.

The laminated ceramic sintered body obtained here is
As shown in FIG. 2, each of the ceramic sintered body 2 _1,
2 ₂ ,..., 2 _n−1 , 2 _n
a, the ceramic sintered bodies 2 are in contact with each other in a very small area or a small area, so that the entire contact area is small, and each ceramic sintered body 2 Are integrated with an appropriate bonding force.

Then, subsequently, the laminated ceramic sintered bodies in a plurality of stacked states are immersed in water and subjected to ultrasonic vibration to be separated into respective ceramic sintered bodies 2.

At this time, since each ceramic sintered body 2 is subjected to blasting for hitting a shot such as a steel shot, a sand or a glass bead ball when forming the dot-shaped concave portion 2a, the surface of the blasting is performed. Of the piezoelectric element 1 manufactured by providing the electrodes 3A and 3B on the surface of the sintered ceramic body 2 after sintering and separation, the electric-vibration characteristics are further improved. It will be.

FIG. 3 shows another embodiment of the present invention, in which a large number of dot-shaped recesses 2a are formed on both surfaces of a ceramic sintered body 2 (therefore, a ceramic unfired sheet 2G before firing). As electrode 3 after sintering and separation
A and 3B may be provided.

[0030]

EXAMPLE 1 To a raw material powder mainly composed of barium titanate (BaTiO ₃ ), a binder containing methylcellulose as a main component was added and mixed well, and then extruded to a thickness of 500 μm. (Green) sheet was formed.

Next, this ceramic unsintered sheet was stamped and formed into 100 disks using a mold having a diameter of 15 mm.

Subsequently, a glass bead shot having a diameter of 30 μm was blasted on one main surface of each disk for 2 minutes to form a large number of minute concave portions on one surface of each disk.

Next, the unsintered disks after the formation of the minute recesses are stacked every 20 sheets and stacked to form five unsintered laminates, and then sintered at a temperature of 1150 to 1220 ° C. As a result, a laminated ceramic sintered body in a state of being stacked on each of 20 sheets was obtained.

Next, each laminated ceramic sintered body was immersed in ethyl alcohol and subjected to ultrasonic treatment at 500 W for 1 minute to try to separate each ceramic sintered body.

As a result, there were no ceramic sintered bodies that did not separate, the separation rate was 100%, and no cracks or chips occurred on the surface of each ceramic sintered body, and the non-defective rate was 100%. Met.

COMPARATIVE EXAMPLE 1 After forming the same unfired ceramic (green) sheet as in Example 1, 3
300 kgf / c mold with 50 mesh convex line
By pressing with a pressure of m ² , a concave line having a depth of 8 μm is formed, and a concave line having a diameter of 15 mm is formed.
Punching was performed on 0 disks.

Subsequently, the unsintered disks on which the concave lines are formed are stacked every 20 sheets and stacked to form five unsintered laminates, and then sintered at a temperature of 1150 to 1220 ° C. A laminated ceramic sintered body was obtained in a state where each of the laminated ceramic sintered bodies was 20 sheets.

Next, each laminated ceramic sintered body was immersed in ethyl alcohol in the same manner as in Example 1, and subjected to ultrasonic treatment at 500 W for 1 minute to try to separate each ceramic sintered body.

As a result, 92 pieces out of 100 pieces were separated into each ceramic sintered body, and three of the separated pieces had cracks along the concave line. 89%.

[Brief description of the drawings]

1A and 1B show an embodiment of a ceramic component according to the present invention, wherein FIG. 1A is an explanatory plan view of a ceramic sintered body constituting the ceramic component, and FIG. 1B is an explanatory sectional view of the ceramic component.

FIG. 2 is an explanatory sectional view of a laminated ceramic sintered body.

3A and 3B show another embodiment of a ceramic component according to the present invention, wherein FIG. 3A is a plan view of a ceramic sintered body constituting the ceramic component, and FIG. 3B is a cross-sectional view of the ceramic component. .

4A and 4B show a ceramic part according to a conventional example, wherein FIG. 4A is an explanatory plan view of a ceramic sintered body constituting the ceramic part, and FIG. 4B is a sectional explanatory view of the ceramic part.

5A and 5B show a ceramic sintered body according to a conventional example, wherein FIG. 5A is a plan view and FIG. 5B is a cross-sectional view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic component 2 Ceramic sintered compact 2a Point-shaped recess 3A, 3B Electrode

Claims (8)

[Claims] 1. A ceramic component comprising a ceramic sintered body having a large number of dot-shaped recesses formed on at least a part of its surface. 2. The ceramic component according to claim 1, wherein the surface on which the point-shaped concave portions are formed has its surface density increased by blasting using a shot material. 3. After forming a large number of dot-shaped recesses on at least a part of the surface of the unfired ceramic sheet, a plurality of unfired ceramic sheets are stacked and fired with the dot-shaped recesses of the unfired ceramic sheet interposed therebetween. A method for manufacturing a ceramic component, comprising: obtaining a plurality of stacked ceramic sintered bodies in a stacked state; and separating the ceramic sintered bodies from the stacked ceramic sintered bodies into respective ceramic sintered bodies. 4. The method for manufacturing a ceramic component according to claim 3, wherein the point-like concave portions are formed by blasting using a shot material such as shot blast, sand blast, or glass bead blast. 5. The method of manufacturing a ceramic component according to claim 4, wherein the surface density of the surface on which the point-shaped concave portions are formed by blasting using a shot material is increased. 6. The method of manufacturing a ceramic component according to claim 3, wherein ultrasonic waves are used to separate each of the plurality of stacked ceramic sintered bodies from the stacked ceramic sintered bodies. 7. The method for manufacturing a ceramic component according to claim 3, wherein an extrusion molding method is used for forming the unsintered ceramic sheet. 8. The method for producing a ceramic component according to claim 3, wherein a doctor blade method is used for forming the unsintered ceramic sheet.