JPH10324574A - Method for firing ceramic element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the cracking, warping, etc., of a ceramic element by arranging an unsintered ceramic having the same sintered contraction characteristic as the contraction characteristic of the ceramic element being calcined around the element as a strut. SOLUTION: A ceramic element 1 formed by mixing PZT ceramic powder with PVA as a binder, granulating the mixture and press-forming the grain at 1 ton/cm<2> pressure, a ceramic strut 2a obtained by press-forming the same PZT ceramic powder in the same way as the element 1, a magnesia porous setter 3 having 18% porosity and carrying the element directly and a dense magnesia setter 4 having 0% porosity and used in combination with the porous setter 3 to control the atmosphere are set. The spacing S between the element 1 and magnesia setter 4 positioned thereabove is controlled to 0-120 μm, and the element is calcined at 1,200 deg.C.

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 a ceramic element, and more particularly, to a method for firing a ceramic element which requires a high degree of dimensional accuracy.

[0002]

2. Description of the Related Art In a conventional method of firing a ceramic element, a ceramic sheet 1 punched into a predetermined shape is pressed to obtain a ceramic element 1, and then a setter 4 made of magnesium, zirconia, or alumina porcelain as shown in FIG. The ceramic element 1 was mounted thereon, and if necessary, the setters 4 were stacked using the columns 2b and fired at a temperature of a thousand and several hundred degrees Celsius.

[0003] Japanese Patent Application Laid-Open No. 1-282157 discloses a method in which a ceramic element 1 is surrounded by columns 2b having a frame shape and made of ceramics such as the same material as the setter 4 and fired.

Japanese Patent Application Laid-Open No. 62-128973 discloses that as shown in FIG. 3, a ceramic column 2c having a sintering shrinkage greater than the sintering shrinkage of a ceramic element 1 is shrunk, so that a weight plate is formed. 5 discloses a method for applying a load to the ceramic element 1 to improve the warpage of the ceramic element 1.

[0005]

In the conventional firing method,
Since the atmosphere is different between the lower surface side (setter surface side) and the upper surface side of the ceramic element, the ceramic element is warped. Since the warpage becomes more remarkable as the size of the ceramic element increases, the dimensions of the ceramic element that can be manufactured are limited.

As a method of improving the warpage, a method of firing with a weight plate placed on the ceramic element has been studied. However, a plate having a weight necessary to sufficiently suppress the warpage of the ceramic element is considered. When mounted, uniform shrinkage during sintering is hindered, which causes a problem in that the shape of the ceramic element is poor, that is, the dimensional accuracy is poor.

As a method for avoiding this drawback, Japanese Patent Application Laid-Open No. 62-128973 discloses a method of using a ceramic column 2c having a shrinkage ratio larger than that of the ceramic element 1 and a shrinkage start temperature higher than that of the ceramic element 1 as shown in FIG. A method of adjusting the timing of applying a load by the weight plate 5 is disclosed.

However, in these methods, since the warp is forcibly forced by placing the weight plate 5 on the ceramic element 1 once hardened in the sintering process, cracks are generated in the ceramic element 1 or the ceramic element 1 is uniformly deformed. There is a problem that the shape and dimensional accuracy of the ceramic element are hardly obtained without shrinkage.

An object of the present invention is to provide a firing method without a ceramic element, which eliminates element deformation such as generation of cracks and warpage.

[0010]

In order to achieve the above object, a method of firing a ceramic element according to the present invention is a method of firing a ceramic element in which ceramic elements are mounted on a setter in multiple stages and fired. Unsintered ceramic having the same sintering shrinkage characteristic as that of the ceramic element in the firing process is disposed around the ceramic element as a support, and a certain gap is formed by the ceramic support between the ceramic element and an upper setter. And firing the ceramic element.

The gap between the ceramic element and the upper setter is set in the range of 0 <(gap gap) ≦ 100 μm.

As a setter for mounting a ceramic element, a combination of a porous setter and a dense setter is used.

[0013]

By using a ceramic support having the same characteristics as the firing shrinkage characteristics of the ceramic element, the gap between the ceramic element and the setter located above the element is kept constant during firing. In addition, the gap is 100
μm or less, and by adopting a porous material as the material of the setter on which the element is mounted,
The difference between the setter surface side and the ceramic element upper surface side of the ceramic element can be reduced, and as a result, the warpage of the ceramic element can be improved. Also, since the upper setter is not in direct contact with the ceramic element, the upper setter does not hinder sintering shrinkage and does not cause deformation of the ceramic element.

[0014]

Next, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a configuration diagram showing a method for firing a ceramic element according to an embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes a ceramic element (length L50 mm × width W10 mm × thickness T1.5 m) formed by mixing and granulating PZT-based ceramic powder with polyvinyl alcohol as a binder, and then molding the mixture under a press pressure of 1 ton / cm ^2.
m). Reference numeral 2a denotes a ceramic pillar formed by pressing the same PZT-based ceramic powder as the ceramic element 1 in the same manner as the ceramic element 1. Reference numeral 3 denotes a porous magnesia setter having a porosity of 18% on which a ceramic element is directly mounted. Reference numeral 4 denotes a dense magnesia setter having a porosity of 0% and used in combination with the porous magnesia setter 3 for controlling the atmosphere.

In FIG. 1, a porous magnesia setter 3 is stacked on a magnesia setter 4 and the ceramic element 1 is set on the porous magnesia setter 3. Further, a ceramic support 2a is provided around the porous magnesia setter 3.
And the upper magnesia setter 4 is supported by the ceramic pillar 2a. Similarly, the ceramic element 1 is set.

The gap S between the ceramic element 1 and the dense magnesia setter 4 located above the ceramic element 1 is changed in the range of 0 to 120 μm by changing the height of the ceramic support 2a. Element 1
Is fired at 1200 ° C., and the value of the warpage generated in the ceramic element 1 is shown in Table 1. For comparison, the results of firing by a conventional method using a magnesia material that does not shrink during firing as a support, and the results when a dense magnesia setter with a porosity of 0% is used as a setter on which a ceramic element is mounted are also shown.

When the external electrode is formed on the surface of the ceramic element 1 by a printing method, if the warpage exceeds 50 μm, a stable printing thickness cannot be obtained.
The research was conducted on the condition that the following conditions were satisfied. The air gap S is
Larger than specified range according to the present invention (air gap> 100 μ)
m), the target value of the warpage of the ceramic element 1 is 50
μm or less could not be satisfied. In addition, when the air gap S was set to 0, the sintering shrinkage became uneven, and the ceramic element 1 was deformed.

Next, when the non-shrinking ceramic pillar was used, the effect of improving the warpage of the ceramic element was smaller than that of the sintering shrinking pillar. Further, when a dense setter was used for mounting the ceramic element, the effect of suppressing the warpage of the ceramic element was small.

In the first embodiment, the distance between the ceramic pillar and the ceramic element does not affect the warpage.

[0021]

[Table 1]

(Embodiment 2) Pb (Mg1 / 2W1 /
2) Ceramic element 1 (L50 mm × W1) as in Embodiment 1 using 03-PbTiO3 ceramic powder
0 mm × T1.5 mm) and the ceramic column 2 a were obtained by press molding, and then the ceramic element 1 was formed in the same manner as in the first embodiment.
The ceramic element 1 is fired at 1000 ° C. using a porous magnesia setter 3 having a porosity of 22% and a dense magnesia setter 4 having a porosity of 0% laid below the porous setter 3 immediately after the sintering. Table 2 shows the values of the warpage that occurred in the ceramic element 1 of FIG.

When the air gap S is set to 0, the sintering shrinkage becomes non-uniform and the ceramic element is deformed. When the air gap S exceeds 100 μm, the effect of suppressing the warpage of the ceramic element 1 is small and exceeds 50 μm. You can see that

If the material of the setter 4 is made porous, the direction and size of the warpage of the ceramic element 1 become unstable, so that the porous setter 3 is combined with the dense setter 4 as shown in FIG. It is better to use.

[0025]

[Table 2]

[0026]

As described above, according to the present invention, when a ceramic element is fired, a non-sintered ceramic column made of the same material as that of the ceramic element is used. Can be kept constant during firing, and the sintered body having less warpage, cracks and deformation can be obtained by setting the gap between 0 and 100 μm or less and firing.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a method for firing a ceramic element according to an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a conventional method of firing a ceramic element.

FIG. 3 is a configuration diagram illustrating a conventional method of firing a ceramic element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic element 2a Ceramic support 2b Ceramic support 2c Ceramic support 3 Porous setter 4 Dense setter 5 Weight plate

Claims (3)

[Claims] 1. A method for firing a ceramic element in which ceramic elements are mounted on a setter in a multi-stage stack and fired, comprising: supporting a non-sintered ceramic having the same sintering shrinkage characteristic as that of a ceramic element in a firing process. A method for firing a ceramic element, comprising: disposing the ceramic element around a ceramic element; and providing a certain gap between the ceramic element and an upper setter by the ceramic support to fire the ceramic element. 2. The method of firing a ceramic element according to claim 1, wherein a gap between the ceramic element and a setter located above is set in a range of 0 <(gap) ≦ 100 μm. 3. The method for firing a ceramic element according to claim 1, wherein a combination of a porous setter and a dense setter is used as the setter on which the ceramic element is mounted.