JPS5832075A - Method of baking ceramic thin plate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for firing ceramic thin plates, and is intended to provide a method that can easily produce a fired ceramic body of a desired shape without cracks.

Conventionally, in the firing method of thin ceramic ceramics, in the case of large quantities, the ceramic ceramic plates were stacked one on top of the other, and a loading porcelain plate was placed on the top two to prevent warping. However, when the total thickness of the sintered body becomes too large, the weight of the loading porcelain plate prevents the shrinkage during sintering, and the sintered body does not shrink sufficiently, resulting in poor properties. There were cracks in the surface.If the load was lightened to alleviate this problem, warping would occur.

The present invention aims to eliminate the above-mentioned conventional drawbacks and provide a homogeneous ceramic thin plate without warping, regardless of the number of sintered bodies.

That is, in the manufacturing method of the present invention, in the pre-sintering stage (at the stage when shrinkage due to sintering has almost finished), a loading porcelain plate is separately formed to prevent warping of the stacked thin ceramic sheets. Support the thin ceramic molded body in a manner that no load is applied to the thin ceramic molded body in the second part [1], and then in the process of sintering the thin ceramic molded body for the above purpose, the amount of shrinkage of the supporting ceramic molded body is reduced. By setting the shrinkage amount to be larger than the amount of shrinkage of the target thin ceramic ceramic, sintering is performed by applying a load to the target thin ceramic ceramic.

According to the present invention, at the initial stage of sintering, no load is applied to the target thin plate ceramic, so sintering can be performed freely in the thickness direction and the lateral direction. Since the porcelain plate begins to apply a load to the target ceramic thin plate, the warpage is corrected and a high quality ceramic thin plate without distortion or cracking is obtained.

Next, the present invention will be explained by giving examples. Figure 1 shows an example of bamboo mounting for carrying out the ``Unexploded 11J'' method.
is a magnesia ring bottom plate of 6oTRRφ×5#1IIt, 3oNφ×4y of magnesia ring same as 21d bottom plate 3
The bottom plate of the AT serves to place the object to be fired and to create a difference in shrinkage rate. 1 is 601111φX 3 for load
m t is a magnesia ring porcelain plate, 4 is a PZT-based piezoelectric ceramic green sheet (2oNφ×0.3+u
t, 35 pieces), 6 is a cylindrical ceramic molded body (7Kl) made of the same material as ceramic green sheet 4.
lφX16Nt, 4 pieces). The total thickness of the piezoelectric ceramic and tag green sheets 1 and 4 is 1 (L511 g, but in reality it is very thin <!f'). There is about 11 degrees due to sheet 40 warping etc. -+, ta,
There is a very small gap between the piezoelectric ceramic green sheet 4 and the loading plate 1.

Fig. 2 Fig. 1: I5・Firing of molded product'+Ijf
It shows the transition of dimensional change over time i, but the change r due to the distance 1 between the load porcelain plate 1 and the underlay plate 3 (thickness dimension of the ceramic molded body 6) in Fig. 1 is shown. to solid line A,
Changes in the distance 1 between the top of the piezoelectric ceramic green sheet 4 and the bottom plate 3 are indicated by dotted lines. And 1
At 180''C culm degree 1, kJ solid line A is above the dotted line, that is, in Fig. 1, load porcelain plate 1 is 1 even when no load is applied to piezoelectric ceramic green sheet 4.
It contracts freely in the four directions as well as in the thickness direction (indicated by sections in Figure 2), but when the depth exceeds 11,800, the load starts to be applied to the loading porcelain plate 1 kl piezoelectric ceramic green sheet 4 (the 2), which exhibits the effect of preventing warping in the final stage of contraction. In this case, the first
Floor plate 2 in the figure. Piezoelectric ceramic green sheet 4.
The thickness setting of the ceramic molded body 5 is Green Sea 1-4.
and the shrinkage rate of the ceramic molded body 5. That is, the shrinkage rate of the piezoelectric ceramic green sheet 4 and the total thickness are respectively S11''il and the shrinkage rate of the ceramic molded body 5.

If the thickness is S21''2 and the thickness of the underboard plate 2 is t, then the relational expression O>β1-p2+t>51421-32β2 should be satisfied.However, in the shrinkage curve in FIG. The shrinking dimension at
Since it is preferable that the load be applied after the contraction of at least % or more is completed, the relational expression "-It2+t>')S(Sl"1 s2g,) is better.

1. The material of the ceramic molded body 5 shown in FIG. 1 is as follows:
Although it is preferable to use the same material as the piezoelectric ceramic green sheet 4 because the contraction temperature is almost the same, other ceramic materials that are sintered at about 1.1 the same temperature can also be used, even if they are not necessarily the same grade. At that time, the shrinkage rate of the ceramic molded body 6 should be selected depending on the material of the piezoelectric ceramic grid and the loading ceramic plate 1 as long as it is non-reactive with the piezoelectric ceramic green sheet 4 and the ceramic molded body 5. ,
) A sintered body made of the same material as the fir ceramic green sheets 4 and J2 and the ceramic molded body 5 can also be used.

FIG. 3 shows another embodiment of the present invention, including a curved loading porcelain plate 1' and ? By using the root 2', it becomes possible to fire a spherical thin plate ceramic having a desired curvature and no distortion.

The present invention is constructed as described above, and it is possible to obtain a ceramic molded body without distortion, warpage, or cracking by a simple method, and its industrial efficiency is great. .

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of an apparatus for carrying out the method of the present invention, Fig. 2 is an explanatory view showing the dimensional change during the firing process in Fig. 1, and Fig. 3 1 is a cross-sectional view showing another embodiment of an apparatus for carrying out the method of the present invention. 1.1'...Loading porcelain plate, 4...
・Thin ceramic, Tsuku (piezoelectric ceramic green sheet), 5, Ceramic molded body. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3 439

Claims (1)

[Claims] In the pre-firing stage, the load-bearing porcelain plates that hold the laminated ceramic sheets stacked for one purpose are not provided with lamic molded bodies. In the post-firing stage, the shrinkage of the ceramic molded body that supports the Ichikawa porcelain plate causes a load to be applied to the thin ceramic plate for the purpose described above. A method of firing ceramic thin plates.