JPH1117242A - Manufacturing method of fired ceramic plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the warp of a burned ceramic board for electric components to enhance the flatness by baking a ceramic compact sandwiched between backing sheet jigs made of a ceramic powder with an organic binder. SOLUTION: The manufacturing method comprises laying a good-smoothness magnesia ceramic bottom board 2 on a burning magnesia sagger, the backing box, laying a backing sheet-like jig 3 thereon, placing a ceramic green compact 4 thereon, similarly alternately stacking the baking jigs 3 and ceramic compacts 4 up to specified height, placing a heavy stone composed of the same baked body as the compact 4 on the jig 3, debindering and burning the stack with the sagger covered with a cap 6 under specified burning condition, cooling and taking out resultant burned ceramic board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fired ceramic plate suitable for producing plate-like ceramics such as piezoelectric ceramics and dielectric ceramics used as one of electric components by firing.

[0002]

2. Description of the Related Art In recent years, as a material for piezoelectric ceramics,
Composite perovskite compounds containing lead are widely used and commercialized in various technical fields. Among them, research using piezoelectric ceramics as an actuator is being advanced. As this actuator, an actuator having a large displacement under a constant voltage is suitable, and as a means for increasing the displacement, a thin piezoelectric ceramic plate and a conductor are laminated in layers to shorten the distance between the electrodes. Structure is adopted.

[0003] In the case of such a structure,
Since the piezoelectric ceramic plates are to be laminated, it is necessary that these piezoelectric ceramic plates have good flatness. For example, in Japanese Patent Application Laid-Open No. 2-164883, an aluminum oxide plate having good smoothness is provided on the bottom in a mortar. Laying, laying zirconium oxide powder thereon to a predetermined thickness, placing the ceramic laminate to be fired thereon, and further filling the zirconium oxide powder in the mortar until the ceramic laminate is completely covered. Japanese Patent Application Laid-Open No. 6-53076 discloses a method in which a ceramic green sheet is sandwiched between substrates of magnesia or the like and fired.

[0004]

However, a method of laying zirconium oxide powder to a predetermined thickness as described in Japanese Patent Application Laid-Open No. 2-164083, placing a ceramic laminate thereon, and further filling the zirconium oxide powder. Then, the amount of zirconium oxide powder between the ceramic laminates is too large to be able to control the thickness because the powder is only laid by gravity, so in particular, to avoid the reaction between the ceramic molded bodies, For example, when the zirconium oxide powder has to be spread, there is a problem that the thickness of the zirconium oxide powder may be uneven and the flatness of the piezoelectric ceramic plate may be deteriorated.

In the method of firing a ceramic green sheet sandwiched between substrates of magnesia or the like as disclosed in Japanese Patent Application Laid-Open No. Hei 6-53076, the substrate of magnesia or the like has poor air permeability and the atmosphere is difficult to be uniform. There has been a problem that the composition of the plate may be uneven, or the piezoelectric ceramic plate may be broken due to insufficient binder removal.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem. For example, a fired ceramic plate for electric parts such as piezoelectric ceramics and dielectric ceramics is free from warpage. It is an object of the present invention to make it possible to increase its flatness and to apply it without machining.

[0007]

According to a first aspect of the present invention, there is provided a method for manufacturing a fired ceramic plate, comprising the steps of: forming a fired sheet jig consisting essentially of a ceramic powder and an organic binder; Further, the ceramic molded body to be fired is sandwiched and fired.

In the embodiment of the method for manufacturing a fired ceramic plate according to the present invention, as described in claim 2, the bottom of the firing mortar, which is a firing box, has good smoothness. It is possible to lay a ceramic base plate, place a laminated body of a ceramic molded body to be fired and a firing jig on the ceramic base plate, and fire the laminate.

Similarly, in an embodiment of the method for manufacturing a fired ceramic plate according to the present invention, as described in claim 3, the firing sheet jig comprises a green sheet,
It can be formed from a press molded article or a slip cast.

Similarly, in an embodiment of the method for manufacturing a fired ceramic plate according to the present invention, as described in claim 4, the ceramic compact to be fired is made of a piezoelectric ceramic powder or a dielectric ceramic powder. It can be composed of a green sheet, a powder press molded body, or an extruded molded body.

[0011] Similarly, in an embodiment of the method for manufacturing a fired ceramic plate according to the present invention, as described in claim 5, the ceramic powder of the firing sheet jig is:
It may be MgO.

Similarly, in an embodiment of the method of manufacturing a fired ceramic plate according to the present invention, as described in claim 6, the ceramic powder of the firing sheet jig is:
It may be ZrO ₂ .

[0013] Similarly, in an embodiment of the method for manufacturing a fired ceramic plate according to the present invention, as set forth in claim 7, the outer diameter of the firing sheet jig and the ceramic molded body to be fired. Can have substantially the same outer diameter.

[0014]

The method for manufacturing a fired ceramic plate according to the present invention has the above-mentioned structure, and this fired ceramic plate is applied as a piezoelectric ceramic or a dielectric ceramic used as one of electric components. Things.

[0015] Of these, piezoelectric ceramics include P
Lead zirconate titanate (PbZrO) represented by ZT
₃ -PbTiO ₃ system) ceramics and lead titanate (P
bTiO ₃ ) ceramics and the like, and there is no particular limitation on the added element.

As the dielectric ceramic, a ceramic capacitor for temperature compensation (MgTiO ₃ , La ₂ O)
_{3 · 2TiO 2, Bi 2 O} 3 · 2TiO 2, SrTiO
₃ ) and high dielectric constant ceramic capacitors (BaTi
O _3, etc.) and, semiconductor ceramic capacitor (BaTi
O _3, etc.) and, or a laminated ceramic capacitor, there are so microwave dielectric ceramics (such as BaO-TiO ₂ system) is not particularly limited.

In forming a ceramic molded body composed of such a component system and to be fired, a doctor blade method, a press molding method, an extrusion molding method, or the like can be selected, and the green sheet molded by these methods can be selected. , A powder press molded body, and an extruded molded body.

The firing sheet jig used in the present invention can be substantially composed of magnesium oxide (magnesia; MgO) or zirconium oxide (zirconia; ZrO ₂ ) powder and an organic binder.

It is more desirable that the organic binder in this case decompose before the firing temperature of the ceramic molded body to be fired. And the decomposition temperature of the organic binder may be higher than the decomposition temperature of the binder contained in the ceramic molded body to be fired, but in this case, after performing the binder removal in the ceramic molded body to be fired, It is necessary to decompose (de-binder) the binder contained in the firing sheet jig.

This firing sheet jig has an outer diameter of
It is desirable that the outer diameter of the ceramic molded body to be fired is substantially the same as that of the ceramic molded body. This makes it possible to align the ceramic molded body to be fired and the sheet jig for firing alternately. It can be done easily.

It is more desirable that the firing sheet jig used here has a powder filling density and a composition that does not allow firing under the firing conditions of the ceramic molded body to be fired. MgO or Z
From a mixture having a composition such as rO _2, a green sheet, a press-formed body, a slip cast, or the like, which is formed with good flatness by a method such as a green sheet forming method, a press forming method, or a slip casting method, is used.

The firing jig may be in the form of a powder or a very brittle porous body before firing of the ceramic compact to be fired. However, since the distance between the ceramic molded bodies to be fired is kept uniform until the completion of sintering, the fired ceramic plate after the completion of sintering can be fired with the flatness kept high. Further, this firing sheet jig is
After debinding, there is always air permeability during firing, so that the atmosphere inside the firing mortar, which is the firing box, is constant, and the composition and structure of the fired ceramic plate (element) do not vary.

After firing, the firing jig is in the form of a powder or a very brittle porous body, so that a firing ceramic plate (element) can be removed. Is not an obstacle.

[0024]

According to the method for manufacturing a fired ceramic plate according to the present invention, as described in claim 1, the firing is performed between the firing jigs substantially made of ceramic powder and an organic binder. The ceramic body to be fired is sandwiched and fired, making it possible to greatly improve the flatness of the fired ceramic plate used as a piezoelectric ceramic element or a dielectric ceramic element, without machining. An extremely excellent effect that it can be commercialized or applied as an electric component such as a piezoelectric ceramic or a dielectric ceramic is provided.

And, as described in claim 2,
Lay a ceramic flooring plate with good smoothness on the bottom of the firing bowl, place the laminated body of the ceramic molded body to be fired and the firing jig on the ceramic flooring plate, and fire. By doing so, there is an extremely excellent effect that the flatness of the fired ceramic plate can be further stably and greatly improved.

According to a third aspect of the present invention, the baking sheet jig is made of a green sheet, a press-formed body or a slip cast, so that the baking sheet has a good flatness. A remarkably excellent effect that a sheet-shaped jig can be efficiently and stably formed can be obtained.

Furthermore, as described in claim 4, the ceramic compact to be fired comprises a green sheet, a powder press compact, or an extruded compact of piezoelectric ceramic powder or dielectric ceramic powder. By doing so, a remarkably excellent effect that a ceramic molded body having high flatness can be efficiently and stably molded in the ceramic molded body to be fired is brought about.

Furthermore, as described in claim 5, the ceramic powder of the firing sheet jig is made of MgO, so that no reaction occurs with the ceramic molded body to be fired. As a result, a remarkably excellent effect that a fired ceramic plate having a high flatness can be produced is provided.

Furthermore, as described in claim 6, the ceramic powder of the firing sheet jig is made of ZrO _2.
By doing so, a remarkably excellent effect that a fired ceramic plate having a high flatness can be manufactured without causing a reaction with the ceramic molded body to be fired is brought about.

Further, as set forth in claim 7, the outer diameter of the firing sheet jig and the outer diameter of the ceramic molded body to be fired are substantially the same. Accordingly, a remarkably excellent effect is obtained that the positioning can be easily performed when the firing sheet-shaped jig and the ceramic molded body to be fired are alternately laminated.

[0031]

EXAMPLES Next, examples of the method for producing a fired ceramic plate according to the present invention will be described, but it goes without saying that the present invention is not limited to only such examples.

Example 1 In Example 1, lead zirconate titanate (PZT) was used as a raw material of a ceramic molded body to be fired, and this calcined powder was prepared. Then, the calcined powder, a small amount of an organic binder and a small amount of a plasticizer are mixed in an organic solvent to prepare a slurry, and a slurry having a thickness of 200 mm is formed by a doctor blade method.
A green sheet having a thickness of μm was prepared, and the green sheet was punched into a predetermined shape to obtain a ceramic (element) molded body to be fired.

On the other hand, when preparing a sheet jig for firing, powder of zirconium oxide (zirconia: ZrO ₂ ) is prepared, mixed with a phenol resin which is a thermosetting resin, and pressed to a thickness of 500 μm. Then, a firing sheet-like jig having the same outer diameter as the ceramic molded body to be fired was prepared.

Next, as a firing setup, as shown in FIG. 1, a magnesia ceramic plate 2 having good smoothness was laid on a firing bowl 1 made of magnesia (MgO) as a firing box. On top of this, a firing sheet jig 3
Then, the ceramic molded body 4 to be fired was placed. Then, the firing sheet jig 3 and the ceramic molded body 4 to be fired are alternately stacked, and when a predetermined height is reached, the firing is performed on the firing sheet jig 3. A weight 5 made of the same fired body as the ceramic molded body 4 was placed. After the binder was removed, firing was performed with the lid 6 of the mortar closed.
The firing at this time was performed in the atmosphere at a temperature of 1190 ° C. and a time of 2 hours. After cooling, the fired ceramic plate was taken out, and the fired ceramic plate obtained in Example 1 was cracked and fixed. Warpage was investigated.

(Example 2) In Example 2, the manufacturing process of the ceramic molded body to be fired is the same as that in Example 1. On the other hand, when preparing a sheet jig for firing, powder of magnesium oxide (magnesia: MgO) is prepared, a phenol resin which is a thermosetting resin is mixed with a solvent, and the mixture is poured into a mold by slip casting. A firing sheet jig having a thickness of 300 μm and the same outer diameter as the ceramic molded body to be fired was prepared.

Next, as a firing setup, as shown in FIG. 1, a magnesia (MgO)
A ceramic slab 2 made of zirconia having good smoothness is laid on a firing mortar 1 made of zirconia, and a sheet jig 3 for firing is placed thereon.
Was put. Then, the firing sheet jig 3 and the ceramic molded body 4 to be fired are alternately stacked,
At a predetermined height, a weight 5 made of the same fired body as the ceramic molded body 4 to be fired was placed on the fired sheet jig 3. Thereafter, firing was performed in the same manner as in Example 1, thereby obtaining a fired ceramic plate of Example 2.

Example 3 In Example 3, as a raw material of a ceramic molded body to be fired, lead zirconate titanate (PZT) was added to Pb (Ni _1/3 Nb).
_2/3 ) A calcined powder in which O ₃ was dissolved was prepared. And
A sheet having a thickness of 500 μm was prepared from the kneaded body obtained by mixing the calcined powder and the water-soluble binder by an extrusion molding method, and the sheet was punched into a predetermined size to obtain a ceramic molded body to be fired. . on the other hand,
Preparation of the sheet jig for firing was performed in the same manner as in Example 1.

Next, as a firing setup, as shown in FIG. 1, a zirconia ceramic having good smoothness was placed in an alumina (aluminum oxide: Al ₂ O ₃ ) mortar 1 as a firing box. A laying plate 2 was laid, and a firing sheet jig 3 was placed thereon, and then a ceramic molded body 4 to be fired was placed thereon. Then, the firing sheet jig 3 and the ceramic molded body 4 to be fired are alternately stacked, and when a predetermined height is reached, the firing is performed on the firing sheet jig 3. A weight 5 made of the same fired body as the ceramic molded body 4 was placed. Hereinafter, it is basically the same as Example 1, but the firing temperature is 1170 ° C.
As a result, a fired ceramic plate of Example 3 was obtained.

Example 4 In Example 4, as a raw material of a ceramic molded body to be fired, lead zirconate titanate (PZT) was added to Pb (Zn _1/3 Nb).
_2/3 ) A calcined powder in which O ₃ was dissolved was prepared. And
A sheet having a thickness of 500 μm was prepared from the kneaded body obtained by mixing the calcined powder and the water-soluble binder by an extrusion molding method, and the sheet was punched into a predetermined size to obtain a ceramic molded body to be fired. . on the other hand,
When preparing a firing jig, a powder of zirconium oxide (zirconia: ZrO ₂ ) is prepared, a green sheet is prepared by a doctor blade method using a water-soluble binder, and a ceramic molded body to be fired is prepared. It was punched out to the same outer diameter as in Example 1 to obtain a firing sheet jig. The following was basically the same as in Example 1, except that the firing temperature was 1165 ° C. to obtain a fired ceramic plate of Example 4.

(Comparative Example 1) In Comparative Example 1, the steps of manufacturing a ceramic molded body to be fired are the same as those in Example 1. And as the setup for the next firing,
As shown in FIG. 2, magnesia (Mg)
A magnesia ceramic plate 12 having good smoothness is laid on a firing mortar 11 made of O), and zirconia (zirconium oxide: ZrO ₂ ) of 100 mesh or less is placed thereon.
, And then a ceramic compact 14 to be fired was placed. And after that,
The ceramic powder 13 made of zirconia and the ceramic molded body 14 to be fired are alternately stacked,
At a predetermined height, a weight 15 made of the same fired body as the ceramic molded body 14 to be fired was placed on the ceramic powder 13 made of zirconia. Then, the firing and the subsequent steps were the same as in Example 1 to obtain a fired ceramic plate of Comparative Example 1.

(Comparative Example 2) In Comparative Example 2, the manufacturing process of the ceramic molded body to be fired is the same as that in Example 4. And as the setup for the next firing,
As shown in FIG. 2, a ceramic floor plate 12 made of zirconia having good smoothness is laid on a firing bowl 11 made of magnesia, which is a firing box body, and zirconia (zirconium oxide) of 100 mesh or less is placed thereon. , And then a ceramic compact 14 to be fired was placed. Thereafter, the ceramic powder 13 made of zirconia and the ceramic molded body 14 to be fired are alternately stacked, and when a predetermined height is reached, the ceramic powder 13 made of zirconia is fired. A weight 15 made of the same fired body as the ceramic molded body 14 was placed. Then, the firing and the subsequent steps were the same as in Example 4 to obtain a fired ceramic plate of Comparative Example 2.

(Comparative Example 3) In Comparative Example 3, the manufacturing process of the ceramic molded body to be fired is the same as that in Example 4. And as the setup for the next firing,
As shown in FIG. 2, a magnesia ceramic mortar 12 having good smoothness is laid on a magnesia mortar 11 serving as a calcination box, and a ceramic molded body 14 to be fired is placed thereon. The magnesia ceramic substrate (laying plate) 13 is placed thereon, and the ceramic molded body 14 to be fired and the ceramic substrate 13
Were alternately stacked, and at a predetermined height, a weight 15 made of the same fired body as the ceramic molded body 14 to be fired was placed on a magnesia ceramic substrate 13. Then, the firing and the subsequent steps were the same as in Example 4 to obtain a fired ceramic plate of Comparative Example 3.

(Evaluation Examples) Table 1 shows the evaluation results of the above Examples 1-4 and Comparative Examples 1-3 (evaluation results of the maximum warpage, cracking, sticking, and composition (characteristics) of the fired ceramic plate).

[0044]

[Table 1]

As is clear from Table 1, as in Comparative Examples 1 to 3, which are conventional examples, a case where only ceramic powder is laid or a ceramic substrate is sandwiched between ceramic compacts to be fired. In such a case, the fired ceramic plate was greatly warped, causing cracks, sticking, and poor characteristics (poor composition), resulting in poor product yield. On the other hand, in the fired ceramic substrate according to the present invention, the warpage was small, cracks and sticking did not occur, and characteristic failure (composition failure) did not occur, and the yield of non-defective products was high.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view showing a setup state of firing according to an embodiment of the present invention.

FIG. 2 is an explanatory cross-sectional view showing a sintering setup state according to a comparative example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 firing mortar 2 ceramic base plate 3 firing sheet-like jig 4 ceramic molded body to be fired 5 weight 6 mortar lid

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C04B 35/64 J H01L 41/18 101B

Claims (7)

[Claims] 1. A method for producing a fired ceramic plate, wherein a ceramic molded body to be fired is sandwiched between sheet firing jigs made of ceramic powder and an organic binder, and fired. 2. A state in which a ceramic floor plate having good smoothness is laid on the bottom of the firing bowl, and a laminated body of a ceramic molded body to be fired and a firing sheet jig is placed on the ceramic floor plate. The method for producing a fired ceramic plate according to claim 1, wherein the firing is performed. 3. The method for manufacturing a fired ceramic plate according to claim 1, wherein the firing sheet-shaped jig is formed from a green sheet, a press-formed body, or a slip cast. 4. A ceramic molded body to be fired,
The method for producing a fired ceramic plate according to any one of claims 1 to 3, comprising a green sheet, a powder press-formed body, or an extruded body of piezoelectric ceramic powder or dielectric ceramic powder. 5. The method for producing a fired ceramic plate according to claim 1, wherein the ceramic powder of the firing sheet jig is MgO. 6. The ceramic powder of the firing jig is ZrO _2.
The method for producing a fired ceramic plate according to any one of the above. 7. The method according to claim 1, wherein the outer diameter of the firing sheet jig is substantially the same as the outer diameter of the ceramic molded body to be fired. Manufacturing method of fired ceramic plate.