JPH07237975A - Method for burning ceramics - Google Patents

Abstract

PURPOSE:To a provide a method for burning ceramics by which the deformation can be avoided; the dispersion in shrinkage factor is extremely small and the resultant sintered compacts are excellent in smoothness and good in density thereof and the dispersion in various characteristics is slight without a deviation of composition by arranging a frame provided with a lid placed on a specific plank having many honeycombed through pores, etc., spreading powder for suppressing the fluctuation in the composition on the plank, placing compacts of the ceramics thereon and baking the ceramics. CONSTITUTION:This method for baking ceramics is to use three kinds of planks respectively having many through pores and the many pores assuming a honeycombed form or bottomed pores assuming the honeycombed form or transverse or vertical grooves as a specific plank and powder having a content of ZnO increased from that of the same composition by, e.g. 0-3mol% as powder for suppressing the fluctuation in composition. This figure is one example of the plank having the many through pores. The plank 2 for baking made of zirconia is used and the many through pores 5 are arranged in the honeycombed form. Furthermore, the powder 13 having the same composition as that of an Mn-Zn-based ferrite is piled up on a bed plate 4 made of zirconia and compacts 10 having the same composition are placed thereon. A frame 11 and a lid 12 are placed to bake the ceramics in an atmosphere of oxygen.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for firing ceramics.

[0002]

2. Description of the Related Art Soft ferrites such as Mn-Zn type ferrites are used for coil transformers, various small coils for communication, antenna coils, communication transformers, intermediate frequency transformers, rotary transformers, pulse transformers, switching transformers for power supplies, It is used in flyback transformers, magnetic heads for heads, deflection yokes for deflection, magnetostrictive vibrators for vibration, temperature-sensitive switches for sensors, etc., and its applications are wide-ranging. Of these Mn-Zn system soft ferrite is a magnetic material that is conventionally employed in the electronics ferrite core or the like, the Mn-Zn ferrite is mixed Fe ₂ O _3, MnO, the powders of ZnO, which Is added with a binder and compression-molded into, for example, a ring shape, an E-shape, an I-shape, a U-shape, and the like, and then the molded body is fired in a firing furnace. When the molded body of Mn-Zn ferrite is fired, plate-like alumina (Al ₂ O ₃ ) that withstands high temperatures and magnesia (M
gO) and zirconia (ZrO ₂ ) are placed on a floor plate and inserted into the firing furnace. However, in the method of firing the ferrite containing Zn by placing it on the plate-shaped floor plate, the ferrite in the ferrite comes into contact with and abuts the plate-shaped floor plate, and Zn in ferrite is alumina of the floor plate,
Ferrite that forms a solid solution in magnesia, zirconia, etc., reduces the amount of Zn in the ferrite, causes a composition shift, and contains Zn, for example, Mn-Mg-Zn-based ferrite, Mg-
Cu-Zn based ferrite, Ni-Zn based ferrite, N
It can be said that a ferrite material containing ZnO, such as an i-Cu-Zn-based ferrite, is likely to have a different Zn composition. As a result, the above Mn-Zn ferrite, Mn
-Mg-Zn-based ferrite, Mg-Cu-Zn-based ferrite, Ni-Zn-based ferrite, Ni-Cu-Zn-based ferrite and the like have a problem that magnetic properties such as initial magnetic permeability, relative loss coefficient and hysteresis loss coefficient deteriorate. Occurs.

As shown in FIG. 7, the conventional firing method of ferrite containing Zn is as follows: width 295 × length 295 × thickness 1
For example, a powder 13 having the same composition as Mn—Zn ferrite is spread on a spread plate 17 having a thickness of 5 tmm with a thickness of 2 to 3 mm, and an external diameter φ25 is applied on the spread same powder.
mm × inner diameter φ15mm × thickness of 4.5tmm Mn of the product
This is a method of arranging the Zn-based ferrite compacts 10 and further burying and burying the compacts 10 with a powder 13 having the same composition for 10 mm or more and firing. When the molded body 10 is buried, a step of covering the powder for firing is required, and since the powder adheres during this firing, the deposit must be removed. Therefore, extra work is required and efficiency is low. Further, since it was buried, 10% or more of cracks due to the organic binder were generated.

On the other hand, ceramic capacitors have made remarkable progress toward miniaturization and large capacity, and various consumer appliances, exchanges, power supplies, etc., and piezoelectric ceramics include ultrasonic vibrators, actuators, ultrasonic motors, ceramic filters, and piezoelectric buzzers. It is applied to a wide range of applications. For example, as an example,
As a method for manufacturing a ceramic capacitor, a sheet molding technology, an extrusion molding technology, a doctor blade method, or a molding machine for thin materials is used to manufacture a green sheet of a ceramic capacitor, and then an internal electrode is formed on the sheet and punched, After that, they are laminated to produce a chip-shaped molded body. A common method is to arrange a predetermined number of these on a baking base and fire them. Speaking of the above-mentioned baking base, naturally, it has a weak affinity for the components to be baked (difficult to react), good releasability from the baked product after baking, low impurities, etc. Required. Therefore, as the material of this kind of baking base used for conventional baking, alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), magnesia (MgO), etc., which satisfy the above conditions to some extent, are used. A ceramic plate having a main component is known. As shown in FIG. 12, for example, a dielectric ceramic capacitor is provided on a plate-like base plate 15 as shown in FIG.
The green chip molded body 1 was mounted and fired.
Further, they may be loaded and buried on the same powder. However, when the molded product of the chip-shaped ceramic capacitor is directly placed on the baking base plate using the baking base plate made of the above-mentioned material and fired, it may be slightly different depending on the purity and the denseness of the main components of the baking base plate. In the contact surface portion between the molded body of the ceramic capacitor and the firing base plate, a partial reaction is caused to cause welding or shrinkage during the firing process of the molded body of the ceramic capacitor is not made smooth and uniform. However, there is a problem in quality such that the fired body of the ceramic capacitor is deformed or cracked, or the fired body of the ceramic capacitor is varied in size or composition, resulting in large variations in various characteristics. From the above, in firing the above-mentioned chip-shaped dielectric, a suitable firing floor plate has been desired.

[0005]

DISCLOSURE OF THE INVENTION In the present invention, when a ferrite- and dielectric-containing compact containing Zn is placed on a plate and fired, it is not covered with powder, has good working efficiency, and is fired after firing. There is no fusion of the powder for firing with the floor plate, deformation can be avoided, variation in shrinkage is extremely small, smoothness is excellent, composition does not shift, density of sintered body is good, variation in various characteristics An object of the present invention is to provide a method for firing a ferrite and a dielectric material using a small baking sheet.

[0006]

According to the present invention, a floor plate has a honeycomb-like through-hole, a frame having a lid is placed on the floor plate, and the floor plate is used to suppress composition fluctuation. It is a method of firing a ceramic, which comprises laying a powder, placing a ceramic molded body, and firing the molded body.

In the present invention, the floor plate has a honeycomb-like bottomed porosity, a frame with a lid is placed on the floor plate, and the floor plate is used to spread powder for suppressing composition fluctuation, A ceramic firing method is characterized in that a ceramic compact is placed and the compact is fired.

According to the present invention, a base plate has a concave groove, a frame with a lid is placed on the base plate, and a powder for suppressing composition variation is spread using the base plate to form a ceramic. A ceramic firing method is characterized in that a body is placed and the molded body is fired.

The present invention is the above-described method for firing ferrite containing Zn, characterized in that a powder containing 0 to 3 mol% of ZnO increased from the same composition is used as the powder for suppressing compositional fluctuation. .

The present invention is a method for firing a ferrite containing Zn, characterized in that a ferrite firing powder having the same composition is used.

The present invention is a method for firing a ceramic capacitor, characterized in that a powder for firing a ceramic capacitor having the same composition is used.

The present invention is a method for firing a piezoelectric ceramic, characterized in that firing powder of the piezoelectric ceramic having the same composition is used.

[0013]

When the shaped body of ferrite and dielectric is fired, when the shaped body is fired into a fired body after firing, the fired body and the firing base plate react with each other by welding. The condition is that it can be avoided. When firing,
When the reaction between the fired body and the firing base plate occurs, the composition of the fired body shifts. Not only that, the shrinkage of the fired body is not smooth and uniform, and as a result, the fired body is deformed or cracked, which is exposed to high temperatures at the firing temperature to cause discoloration or a large variation in various characteristics. Become. In order to avoid these defects, the following three types of baking sheets are used. The firing floor plate of the present invention has a plate-like shape and has a porosity penetrating in the thickness direction, and the porosity forms a honeycomb shape.
The baking slab of the present invention has a plate-like shape and has bottomed porosity in the thickness direction, and the bottomed porosity forms a honeycomb shape. The baking sheet of the present invention has a plate shape and has horizontal or vertical grooves. The floor plate of the present invention, all through porosity,
A powder having a bottomed porosity and horizontal or vertical grooves and having the same composition is used as a firing powder, and the porosity having a bottom, a bottomed porosity, a horizontal or vertical groove is filled with the firing powder. Further, in order to cover the molded product on the floor plate, a frame and lid having the same width and the same length as the floor plate are manufactured and used to suppress factors such as welding and compositional deviation, and deterioration of various characteristics. is there. It has also been found that ceramics are effective in preventing deterioration in quality such as welding, composition shift, and deformation cracking.

In the case of ferrite, the one having the same composition as the firing powder and the one having the same composition as the firing powder do not have the same composition as the firing powder because the zinc oxide content of the molded body is easily worn during the firing of the ferrite. 1, 2, 2.5, 3,
Experiments were carried out using seven types of firing powders with the amount of zinc oxide increased to 4,5 mol%. As a result, it was found that the amount of zinc oxide depletion was the smallest in the case where the powder having the increased amount of 2.5 mol% zinc oxide was used and the frame and the lid were covered, and the amount of zinc oxide depletion was the smallest. Powder and 2.5
An effect could be obtained using a powder with an increased amount of mol% zinc oxide. In order to suppress the wear of the zinc oxide content of the fired ferrite product, a laying plate, a laying plate, and a laying plate are used, and in each case, a frame and a lid are used, and a calcination powder in which the amount of zinc oxide is increased by 2.5 mol% is used. When used, the wear of the zinc oxide amount can be avoided in the ferrite containing Zn.

[0015]

EXAMPLES Examples of the case where the present invention is a Mn-Zn type ferrite will be described below. FIG. 1 is an explanatory diagram showing a method of firing Mn—Zn-based ferrite using a firing base plate that has a honeycomb-shaped porosity that penetrates in the thickness direction and that uses a frame and a lid. FIG. 2 is an explanatory diagram showing a method for firing Mn—Zn-based ferrite using a firing base plate having a honeycomb-shaped bottomed porosity in the thickness direction and using a frame and a lid. FIG. 3 is an explanatory diagram showing a method for firing Mn—Zn-based ferrite using a firing base plate having a horizontal groove or a vertical groove in the thickness direction and using a frame and a lid.

First, a method of manufacturing a baking sheet will be described.
A zirconia (ZrO ₂ ) raw material having a chemical purity of 99% or more was mixed, calcinated at 1250 ° C. to 1300 ° C. for several hours, pulverized and classified by a pulverizer, and the particle size was adjusted to about 60 to 100 μm. An appropriate amount of an organic binder was added to the powder obtained by mixing and pulverizing as described above, the mixture was granulated, pressure-molded at a pressure of 1.5 t / cm ² , and fired at a temperature of 1230 ° C. to 1260 ° C. for several hours. . From the obtained fired body, a floor board having a width of 295 mm × a length of 295 mm × 5 tmm and 10 tmm is prepared,
Furthermore, the following three types of floor boards were produced. The zirconia base plate is finished to have a honeycomb-like base plate having a perforation of φ5 mm with a width of 295 mm, a length of 295 mm, and a length of 5 tmm and 5 m intervals. The floorboard is 295 mm wide x 295 mm long x 10
Honeycomb-shaped outer diameter φ5 mm × depth 5 at intervals of 5 m in tmm
Finish into a floor plate having a bottomed perforation of mm. The floor plate is finished to have a width of 295 mm × length of 295 mm × 10 tmm and lateral grooves of 5 mm width × 5 mm depth at 5 mm intervals.

By the same method as the zirconia base plate, an alumina (Al ₂ O ₃ ) base plate, a plate-like plate having no holes or grooves, width 295 mm × length 295 mm × thickness 10 tmm.
The floor board of was produced.

A magnesia (MgO) floor plate, a plate-like floor plate having no holes or grooves and having a width of 295 mm, a length of 295 mm, and a thickness of 10 tmm was prepared in the same manner as the above-mentioned zirconia floor plate.

The frame is made of zirconia and has a width of 295 mm and a length of 2.
The one used was 95 mm × height 10 mm, and the lid was made of zirconia and had a width of 295 mm × a length of 295 mm × a thickness of 5 mm.

Above, the floor plate and frame 11 and lid 12
The method that led to confirming the effect of adopting and
And the result is demonstrated below.

First, a method of manufacturing the Mn-Zn type ferrite adopted in this embodiment will be described. The composition is Fe ₂ O ₃
Powders of 52 mol%, MnO 25 mol% and ZnO 23 mol% were mixed by a ball mill for 40 hours, and 900 ° C. × 2
Temporarily bake in time. Next, the obtained powder was added with CaCO ₃ and SiO ₂ as a property improving agent at 0.06, 0.
Add 01 wt% and crush with a ball mill for 24 hours. Thereafter, 5 wt% of a binder is added and further mixed by a ball mill for 4 hours. Further, the obtained mixture was treated with a spray dryer to regulate the particle size to a predetermined particle size, and this was compressed into a compression molding machine at a pressure of 2000 Kg / cm ² to give a ring-shaped Mn as shown in FIG. A Zn-based ferrite compact 10 was obtained. This molded body 10 has an outer diameter of 25 mm x
The inner diameter is 15 mm and the thickness is 4.5 tmm.

As shown in FIG. 7, the conventional firing is a method of arranging compacts on a plate-like base plate in order to prevent the wear of zinc oxide, and covering the compacts with a powder having the same composition. Was adopted. Specifically, in order to completely prevent the wear of zinc oxide, the molded body was covered with a thickness of 10 mm or more. When the burning method of burying in such a manner is adopted, cracks and cracks occur because the removal of the organic binder such as the ring-shaped pot core, the E-shaped core, and the co-shaped core in the step of removing the organic binder is insufficient. Furthermore, when the above-mentioned burial firing method is used, the burial firing powder adheres to the sintered body, and the deposits of this powder must be removed.
ineffective. Therefore, first, in order to prevent the wear of zinc oxide in the fired body of Mn-Zn ferrite and to produce a method with good working efficiency, the following examples were preceded.

There are seven types of examples for confirming the amount of depletion of zinc oxide. In all of these seven types of examples, a floor plate 7 is used, and similarly, a frame and a lid are used for all of them and Ten compacts were lined up on the floor plate with the powder for firing packed. The firing powder used for the floorboard is the same powder as that of the molded body, which is obtained by increasing the amount of zinc oxide by 1 mol%, 2 mol%, 2.5 mol%, 3 mol%, 4 mol% or 5 mol%. Further, one kind of the same powder was added to the above condition to obtain seven kinds. That is, in Example 1, as shown in FIG. 2, the frame 11 and the lid 12 were used, and the firing powder used for the floorboard increased the zinc oxide content by 1 mol% with respect to the same composition as the molded body. Powder was used to fill the bottomed perforations 6 of the floor plate 7, and ten molded bodies 10 were arranged on the floor plate 7 and fired. Example 2 was fired in exactly the same manner as in Example 1, but the firing powder used was a powder in which the zinc oxide content was increased by 2 mol% with respect to the same composition as the molded body. Example 3 was fired by the same method as in Example 1, but the firing powder used was a powder in which the zinc oxide content was increased by 2.5 mol% with respect to the same composition as the molded body. Example 4 was fired in exactly the same way as Example 1, but
The firing powder used was a powder in which the zinc oxide content was increased by 3.0 mol% with respect to the same composition as the molded body. Example 5 was fired in exactly the same manner as in Example 1, but the firing powder used was a powder in which the zinc oxide content was increased by 4.0 mol% with respect to the same composition as the molded body. Example 6 was fired in exactly the same manner as in Example 1, but the firing powder used was a powder in which the zinc oxide content was increased by 5.0 mol% with respect to the same composition as the molded body. Example 7 was fired in exactly the same manner as in Example 1, but the firing powder used was the same powder as the compact. The laying board is a zirconia laying board, which is a 295 mm wide x 295 mm long x 10 tmm thick honeycomb-like outer diameter φ5 mm x depth 5 m.
It has a bottomed porosity of m. Also, the frame is 295 mm wide x 29 long
The dimensions are 5 mm × height 10 mm and wall thickness 5 tmm, and the lid has the same dimensions as the frame and has a thickness 5 tmm. The samples of Examples 1 to 7 described above were taken, and the surface of the fired body was measured with an X-ray microanalyzer to examine the wear of zinc oxide. The results are shown in Table 1.

[0024]

[Table 1]

From the results shown in Table 1, it is preferable to use a powder having an increased zinc oxide content of 2.0 mol% to 3.0 mol% with respect to the same composition as that of the molded body as the powder for firing. As a result, when using a powder with an increased zinc oxide content of 2.5 mol% relative to the same composition as the molded body, the most desirable composition of zinc oxide is the case where the floor plate is covered with a frame and the lid is baked. It was found that the composition shift was small in the vicinity.

(Embodiment 8) As shown in FIG.
A zirconia laying plate 2 having a size of mm × length 295 mm × thickness 5 tmm was used. The through-holes 5 of the floorboard 2 are
Holes having an outer diameter of 5 mm are arranged in a honeycomb shape at intervals of 5 mm. Width 295 mm x length 295 mm x thickness 10 tm
The powder 13 having the same composition as the Mn—Zn-based ferrite is spread over the zirconia base plate 4 of m so as to rise, and the zirconia baking plate 2 is pressed against the powder 13 having the same composition as the spread compact. Floor plate 2 is powder 1
When pressed against 3, the powder 13 of the same composition rises from the honeycomb-shaped through-holes 5 and protrudes upward, so that the floor plate 2 is leveled and flattened to fill the through-holes 5. After confirming, the molded body 10 of Mn—Zn ferrite was applied to the zirconia base plate 2 for burning 30 times.
I put them individually. After this, width 295 mm x length 295 mm x
Frame 11 with a height of 10 mm and a wall thickness of 5 tmm and a width of 295 mm
× Prepare a lid 12 of 295 mm in length × 5 tmm in thickness and 3
It was placed on the baking base plate 2 so as not to touch 0 molded bodies 10. After that, 30 on the floor plate 2 as described above.
The individual compact was held and inserted into a firing furnace in a predetermined oxygen atmosphere, and the compact was fired at 1350 ° C. for 2 hours to prepare 30 fired bodies 10 as samples.

(Embodiment 9) Embodiment 9 is exactly the same experiment as Embodiment 8, as shown in FIG. However, although the powder for firing had the same composition as that of the molded body 10 in Example 8, in Example 9 the firing was performed by increasing the zinc oxide content by 2.5 mol% with respect to the same composition as that of the molded body. The powder for use was used.

(Embodiment 10) As shown in FIG. 2, a baking base plate 7 made of zirconia has a width of 295 mm and a length of 295.
mm × thickness 10 tmm. Floor board 7 is 5m
This is a plate having honeycomb-shaped perforated bottoms 6 having an outer diameter of φ5 mm and a depth of 5 mm at m intervals. A powder 13 having the same composition as that of the Mn-Zn ferrite is filled so as to rise into the bottomed pores 6 of the zirconia baking sheet 7 and flattened to flatten the zirconia baking sheet 7. Thirty compacts 10 were placed on the floor plate 7. After that, width 295m
m × length 295 mm × height 10 mm, wall thickness 5 tmm frame 11, width 295 mm × length 295 mm × thickness 5 tmm
The lid 12 was put on the firing floor plate so as not to touch the molded body 10. After that, keeping the above-mentioned state, insert it in a firing furnace in a predetermined oxygen atmosphere,
The molded body 10 was fired at 1350 ° C. for 2 hours to prepare 30 fired bodies as samples.

Example 11 As shown in FIG. 2, Example 11 is an experiment exactly the same as Example 10. However, as the powder for firing, a powder in which the zinc oxide content is increased by 2.5 mol% with respect to the same composition as the molded body is used.

(Embodiment 12) A zirconia base plate 9 for firing shown in FIG. 3 has a width of 295 mm × a length of 295 mm × a thickness of 10 tmm and has lateral grooves 8 having a groove width of 5 mm at intervals of 5 mm. . A powder 13 having the same composition as that of the Mn-Zn ferrite is filled in the groove 8 of the zirconia baking base plate 9 so as to be raised, and then flattened to flatten the Mn-Zn base plate Mn. -Z
A molded body 10 of n-type ferrite was placed. Then width 2
95mm x Length 295mm x Height 10mm, Wall Thickness 5tm
m frame 11 and width 295 mm x length 295 mm x thickness 5
A tmm lid 12 was prepared and placed on the firing floor plate 9 so as not to touch the compact 10. After that, this state was maintained, this was inserted into a firing furnace in a predetermined oxygen atmosphere, the molded body 10 was fired at 1350 ° C. × 2 hours, and 30 fired bodies were prepared as samples.

(Embodiment 13) As shown in FIG. 3, Embodiment 13 is an experiment exactly the same as Embodiment 12. However, instead of the powder having the same composition, a powder 13 in which the zinc oxide content was increased by 2.5 mol% with respect to the same composition as the molded body was used.

(Comparative Example 1) As Comparative Example 1, as shown in FIG. 5, the unbaked zirconia baking sheet 17 had a width of 295 mm, a length of 295 mm, and a thickness of 10 tm.
A plate with a size of m. A powder 13 having the same composition as that of the Mn-Zn-based ferrite is flatly spread thereon so as to have a thickness of 2 to 3 mm, and the Mn-Zn-based ferrite compact 10 is placed thereon. The outer circumference and the inner circumference were covered with powder having the same composition. After that, keep this state,
Insert this in a firing furnace in a prescribed oxygen atmosphere,
The molded body 10 was fired at 0 ° C. for 2 hours to prepare 30 fired bodies as samples.

(Comparative Example 2) In Comparative Example 2, as shown in FIG. 6, a zirconia laying board 17 made of unprocessed zirconia.
The molded body 10 was placed directly on the top, and the same treatment as in Comparative Example 1 was performed to prepare 30 fired bodies as samples.

(Comparative Example 3) In Comparative Example 3, as shown in FIG. 7, 2 to 3 are formed on the unprocessed zirconia base plate 17.
The powder 13 having a thickness of 3 mm, which is the same as that of the molded body, is spread, the molded body 10 is further placed, and the powder having the same composition as the molded body is covered on the floor plate so as to be buried by 10 mm or more. The same treatment as in Comparative Example 1 was performed to prepare 30 fired bodies as samples.

The conditions and results of Examples 8 to 13 and Comparative Examples 1 to 3 are shown in Tables 2 and 3.

[0036]

[Table 2]

[0037]

[Table 3]

Tables 2 and 3 show the initial magnetic permeability (μ _i ), relative loss coefficient (tan δ / μ) and hysteresis loss coefficient (for each of 30 samples in Examples 8 to 13 and Comparative Examples 1 to 3). h ₁₀ ) is measured with an LCR meter, and the results of inspections such as powder adhesion, cracks and cracks are shown.

From Tables 2 and 3, the best results were obtained in Comparative Example 3 in which the molded body was embedded with the powder having the same composition as the molded body and the molded body was covered with a thickness of about 10 mm.
However, Comparative Example 3 has disadvantages such as the number of steps for burying the molded body, the adhesion of the powder, which must be removed, and the fact that the powder is cracked by about 10% due to debinding. There is. In Examples 8 to 13, there were no powder deposits, and the magnetic properties were of great significance for practical use, and the results of Comparative Example 3 could be supplemented. Further, the effect of using the frame and the lid is that the zinc oxide evaporated from the powder filled in the perforated holes, the bottomed holes, the grooves, etc. of the floor plate used in the present invention is not directly exposed to the high temperature of the baking furnace and the atmosphere in the furnace is It is considered that the zinc oxide is prevented from coming off from the molded body by being trapped inside the frame and the lid without escaping inside. In particular, the firing powder used for through-hole porosity, bottom-end porosity, grooves, etc., has a zinc oxide content of 2.5 from the molded body.
The effect of using the one that has been increased by mol% is shown. In Comparative Example 1, the inner and outer peripheral surfaces except the upper surface of the molded body were covered with powder, but the frame and the lid were not used, so it is considered that zinc oxide was evaporated into the furnace. Comparative example 2
Since it was placed directly on the floor plate and baked without using a frame and a lid, the magnetic properties deteriorated significantly.

Example 14 As a composition of a green chip-shaped ceramic capacitor, PbO, MnO ₂ , Nb ₂ O ₅ , WO ₃ and Ti were used as the main raw materials of the ceramic capacitor.
At least four kinds or more of O ₂ and Fe ₂ O ₃ are selected, and in Examples 14 to 16, starting materials PbO, MnO ₂ , Nb ₂ O ₅ , and TiO ₂ having a chemical purity of 99% or more are blended in a predetermined composition. Weigh accurately and mix to obtain a ratio, and then 850 ° C-9
It was calcined at 00 ° C. An appropriate amount of an organic binder plasticizer and the like is added to the powder obtained by pulverizing the calcined powder with a ball mill, and the mixture is kneaded to have a thickness of 15 using a doctor blade method.
A green sheet of -30 μm was prepared. A green chip of a multilayer ceramic capacitor having a plurality of internal electrodes formed by printing a mixed paste of Ag and Pd to be internal electrodes on a green sheet by a screen printing method to form internal electrodes A shaped body was obtained. 30 pieces of 2 mm × 5 mm × 2 tmm rectangular parallelepiped shaped bodies were prepared as samples.

As shown in FIG. 8, a through-hole zirconia base plate 2 is used, the through-hole 5 is filled with powder having the same composition as the molded body 1, and the base plate 4 is filled with powder 3 having the same composition as the molded body 1. It was sprayed, and the floor plate 2 was placed on it. The through-holes 5 were filled with powder, and when they were swelled, the floor plate was flattened. In this state, the frame 11 and the lid 12 were placed on the floor plate 2, and 30 compacts 1 were placed and fired at a temperature of 1200 ° C to 1230 ° C for several hours.

(Example 15) As shown in FIG. 9, a zirconia base plate 7 having a bottomed perforation 6 was used, the bottomed porosity 6 was filled with a powder 3 having the same composition as that of the molded body 1, and the bottomed porosity 6 was formed. When the powder was filled and swelled, the floor plate 7 was leveled and flattened. In this state, the frame 11 and the lid 12 were placed on the floor plate 7, and 30 compacts 1 were placed and fired at a temperature of 1200 ° C to 1230 ° C for several hours.

(Example 16) As shown in FIG. 10, a zirconia base plate 9 having a lateral groove was used, and the lateral groove 8 was filled with powder 3 having the same composition as that of the molded body 1. The lateral groove 8 was filled with the powder and swelled. In some cases, the floor plate 9 was leveled and flattened. In this state, the frame 11 and the lid 12 are placed on the base plate 9 to set the molded body 1 to 3
Zero pieces were placed and baked at a temperature of 1200 ° C to 1230 ° C for several hours.

(Comparative Example 4) As shown in FIG. 12, a floor board 15 made of an alumina floor board having no perforations and grooves was used. Thirty compacts 1 were fired at a temperature of 1200 ° C to 1230 ° C for several hours without using a powder having the same composition as that of the compact and using the same frame and lid.

(Comparative Example 5) As shown in FIG. 12, a magnesia plate-shaped floor plate having no perforations and grooves like the floor plate was used. Thirty compacts 1 were fired at a temperature of 1200 ° C. to 1230 ° C. for several hours without using a powder having the same composition as that of the compact and using the same frame and lid.

(Comparative Example 6) As shown in FIG. 12, a zirconia plate-shaped floor plate having no perforations and grooves like the floor plate was used. Without using the powder of the same composition as the compact, and without using the same frame and lid
Zero molded bodies 1 were fired at a temperature of 1200 ° C to 1230 ° C for several hours.

Examples 14 to 16 described above and Comparative Example 4
The results up to 6 are shown in Table 4.

[0048]

[Table 4]

The pass / fail judgment results can be passed in Examples 14 to 16. Comparative Examples 4 to 6 are disqualified because of discoloration or welding.

[0050]

As described above, according to the present invention, after firing, there is no welding of the fired body, the floor plate and the firing powder,
It is possible to obtain a method for firing a dielectric material such as a ferrite and a ceramic capacitor, which has good working efficiency and little variation in various characteristics.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a method for firing Mn—Zn-based ferrite of the present invention using a floor plate having a through-hole, a frame and a lid, and a firing powder. FIG. 1A is a perspective view showing a method for firing Mn—Zn based ferrite according to Examples 8 and 9 of the present invention. FIG. 1B is a partially enlarged view of FIG.

FIG. 2 is an explanatory diagram showing a method of firing Mn—Zn-based ferrite of the present invention using a floor plate having a bottomed porous structure, a frame and a lid, and a firing powder. FIG. 2A shows a first embodiment of the present invention.
The perspective view which shows the baking method of 0,11 Mn-Zn type | system | group ferrite. FIG. 2B is a partially enlarged view of FIG.

FIG. 3 is an explanatory diagram showing a method for firing Mn—Zn-based ferrite of the present invention using a floorboard having lateral grooves, a frame and a lid, and a firing powder. FIG. 3A shows a twelfth embodiment of the present invention.
13 is a perspective view showing a method of firing Mn—Zn based ferrite of No. 13. FIG. 3B is a partially enlarged view of FIG.

FIG. 4 is a perspective view of a molded body of Mn—Zn ferrite.

5 is a perspective view showing a method of firing Mn—Zn-based ferrite showing Comparative Example 1. FIG.

FIG. 6 is a perspective view showing a firing method of Mn—Zn ferrite showing Comparative Example 2.

FIG. 7 is a cross-sectional view showing a method for firing Mn—Zn-based ferrite showing Comparative Example 3.

FIG. 8 is an explanatory view showing a firing method for a ceramic capacitor of the present invention using a floor plate having a through-hole, a frame and a lid, and a firing powder. FIG. 8A is a perspective view showing a method for firing a ceramic capacitor of Example 14 of the present invention. Figure 8
8B is a partially enlarged view of FIG.

FIG. 9 is an explanatory view showing a firing method for a ceramic capacitor of the present invention using a floor plate having a bottomed porous structure, a frame and a lid, and a firing powder. FIG. 9A shows a fifteenth embodiment of the present invention.
FIG. 6 is a perspective view showing a method of firing the ceramic capacitor of FIG. Figure 9
FIG. 9B is a partially enlarged view of FIG.

FIG. 10 is an explanatory view showing a method for firing a ceramic capacitor of the present invention using a floor plate having lateral grooves, a frame and a lid, and a firing powder. FIG. 10A shows a sixteenth embodiment of the present invention.
FIG. 6 is a perspective view showing a method of firing the ceramic capacitor of FIG. Figure 1
0 (b) is a partially enlarged view of FIG. 10 (a).

FIG. 11 is a perspective view showing a green chip molded body of a laminated ceramic capacitor.

FIG. 12 is a perspective view in which a green chip molded body of a laminated ceramic capacitor is placed on a plate-shaped floor plate.

[Explanation of symbols]

1 (green chip) molded body 2 floor plate 3 powder of the same composition as the molded body (ceramic capacitor) 4 base plate 5 through-hole porous 6 bottomed porous 7 floor plate 8 lateral groove 9 floor plate 10 (Mn-Zn-based ferrite) molded body 11 frame 12 Lid 13 Powder (Ferrite Powder) with the Same Composition as the Molded Body 15 Conventional Floorboard (Alumina) 16 Conventional Floorboard (Magnesia) 17 Conventional Floorboard (Zirconia)

Claims (7)

[Claims] 1. A ceramic molding, wherein a floor plate has a honeycomb-shaped through-hole, a frame with a lid is placed on the floor plate, and a powder for suppressing a composition variation is spread using the floor plate. A method for firing a ceramic, comprising placing a body and firing the formed body. 2. The base plate has a honeycomb-like bottomed porosity, a frame with a lid is placed on the base plate, and the base plate is used to spread a powder for suppressing compositional variation, and a ceramic A ceramic firing method, comprising placing a compact and firing the compact. 3. A ceramic molding is obtained by laying a frame having a lid on the floor plate, laying a powder for suppressing compositional variation on the floor plate, and laying a powder on the floor plate. A method for firing a ceramic, which comprises placing and firing the adult body. 4. A powder for suppressing composition fluctuation,
The method for calcination of ferrite containing Zn according to claim 1, wherein a powder containing 0 to 3 mol% of ZnO increased from the same composition is used. 5. The method for firing a ferrite containing Zn according to claim 1, wherein powders for firing ferrite having the same composition are used. 6. The method for firing a ceramic capacitor according to claim 1, wherein powders for firing a ceramic capacitor having the same composition are used. 7. The method for firing a piezoelectric ceramic according to claim 1, wherein powders for firing the piezoelectric ceramic having the same composition are used.