JP2003252677A - Ceramic-burning tool and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a burning tool which is not deformed when burning an object and does not change the properties of an alumina ceramic molding element when burning the object. <P>SOLUTION: The ceramic-burning tool comprises a first aggregate having a particle size of 10-300 μm made of an electro-fused alumina and/or a sintered alumina, a second aggregate having a particle size of 10-300 μm made of an electro-fused mullite and a binder having a particle size of less than 10 μm made of a low soda calcined alumina, and does not comprise clay. The Al<SB>2</SB>O<SB>3</SB>/ SiO<SB>2</SB>ratio by weight is in the range of 85/15-95/5, and the aggregate/binder ratio by weight is in the range of 80/20-60/40, in total. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of ceramic manufacturing, and in particular, the molding element body is placed in the firing for obtaining an alumina ceramic fired body from the molding element body made of alumina. TECHNICAL FIELD The present invention relates to a ceramic firing tool material used for manufacturing and a manufacturing method thereof.

The ceramic firing tool material of the present invention is suitably used, for example, for firing a molded body to obtain a colored alumina ceramic fired body such as a package base material for semiconductor devices.

[0003]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
As a package base material for a semiconductor device, one made of a colored alumina ceramic (for example, brown alumina) is used.

When the colored alumina ceramic is fired, the shaped body is placed on a ceramic mounting table called a firing tool material in order to reduce deformation of the shaped body due to firing as much as possible.

The firing tool material is composed of an aggregate and a binder. The binder is a mixture of alumina fine powder and clay fine powder, and mullite is formed by the reaction at the time of firing, which causes the binding force between the aggregates to be generated, and mechanical strength as a tool tool for firing is obtained. . Mullite has a characteristic that the strength does not decrease even at high temperatures as a characteristic of the material itself, and therefore has the effect of suppressing flexural deformation of the baking tool material at high temperatures. It is used as a binder for tool materials for firing electronic parts.

However, the mullite binder is liable to be decomposed into alumina (Al ₂ O ₃ ) and silica (SiO ₂ ) which are the oxides constituting the mullite binder at a high temperature, especially in a reducing atmosphere, and is formed by the decomposition. Silica is gradually deposited on the surface of the tool material for firing as the number of times the tool material is used increases, and in the case where the material to be fired is a colored alumina ceramic molded body, by reaction with this generated silica, There is a drawback that the surface of the object to be fired that comes into contact with the firing tool material is likely to be deteriorated at an early stage (that is, while the number of times the firing tool material is used is small). The alteration usually occurs in spots. When such deterioration occurs, the characteristics (for example, insulation) of the electronic component that is the molded product are changed from those required, and in extreme cases, the electronic component becomes a defective product due to characteristic deterioration.

In order to avoid the occurrence of such a problem, it is conceivable to use only alumina, which is unlikely to deteriorate during firing of the material to be fired, as both the aggregate and the binder in the firing tool material. Warpage is likely to occur as a result of high-temperature creep deformation during firing of the material to be fired, and the life as a tool material for firing electronic parts that requires flatness when firing the material to be fired becomes short.

[0008] Therefore, an object of the present invention is to provide a tool material for firing, which is less likely to be deformed when the article to be fired is burned, and which hardly changes the alumina-based ceramic molded body when firing the article to be fired. To do.

[0009]

According to the present invention, in order to achieve the above objects, a first aggregate made of fused alumina and / or sintered alumina and having a particle size of 10 to 300 μm, A second aggregate composed of fused mullite having a particle size of 10 to 300 μm and a particle size composed of low-soda calcined alumina 1
Al in the whole, including a binder of less than 0 μm
₂ O ₃ / SiO ₂ ratio [by weight] is 85/15 to 95
A ceramic firing tool material is provided which is in the range of / 5.

In one aspect of the invention, the ceramic firing tool material has an aggregate / binder ratio [by weight] of 80 /
It is in the range of 20 to 60/40. Here, the aggregate weight is the total of the weight of the first aggregate and the weight of the second aggregate.
In the present invention, the ceramic firing tool material preferably does not contain clay.

According to the present invention, in order to achieve the above-mentioned object, there is provided a method for producing the above-mentioned ceramic firing tool material, which is a first method comprising fused alumina and / or sintered alumina. Mixing the aggregate forming powder, the second aggregate forming powder made of fused mullite, the binder forming powder made of calcined alumina of low soda, the organic powder binder and the liquid binder. The mixture obtained by
Knead, dry, and 1700-1830 ° C under air atmosphere
A method for manufacturing a ceramic firing tool material is provided, which comprises firing at a temperature within the range.

In the present invention, it is preferable that the mixture does not contain clay.

The fused alumina used as the first aggregate is described in JIS-R2001 as refractory term 255, and is a high alumina raw material melted in an electric furnace. The sintered alumina used as the first aggregate is described as a refractory term 254 in JIS-R2001, and is a high-alumina raw material sintered in a kiln. Mullite is described in JIS-R2001 as refractory term 249, and is 3Al ₂ O ₃ / 2SiO.
It is an alumina silicate with a basic chemical formula of ₂ .
The electrofused mullite used as the second aggregate is obtained by melting a raw material having a mullite composition in an electric furnace.

The calcination is described in JIS-R2001 as refractory term 102, and is a preliminary heat treatment for physically or chemically changing the raw material. The calcined alumina is Al (OH) 2. ₃ is roasted in a kiln and Al ₂ O
_It was set to ₃ . The low-soda calcined alumina used as the binder is a calcined alumina having a Na ₂ O content of 0.1% by weight or less. In the present specification, a material having a Na ₂ O content of more than 0.1% by weight is referred to as high soda calcined alumina.

The ceramic firing tool material of the present invention is the first
Also, since the particle diameter of the second aggregate is 10 to 300 μm and the particle diameter of the binder is less than 10 μm, it is homogeneous and has sufficient strength and stability. If the particle diameters of the first and second aggregates are too small, the creep characteristics tend to be poor and the deformation during firing tends to increase. On the other hand, if the particle diameters of the first and second aggregates are too large, a smooth surface cannot be obtained, and scratches or pinholes tend to be easily generated in the material to be fired.

Since a binder made of calcined alumina of low soda having a particle size of less than 10 μm is used as the binder,
It does not form a low-melt material, and therefore, it is unlikely that the fired material is deteriorated due to the reaction with the fired material.

The binder made of calcined alumina of low soda is preferably one having a particle size of less than 10 μm and having a wide range of particle size distribution, since it can exhibit a high filling property and thus a high bonding force due to high density and a low firing shrinkage property. Here, the wide range of particle size distribution is 10 to 30 in the range of particle size less than 2 μm.
% By weight; 30 to 50% by weight in the range of particle size 2 μm or more and less than 4 μm; 10 to 30% by weight in the range of particle size 4 μm or more and less than 6 μm; particle size 6 μm or more and 8 μm
The range of less than m is 10 to 30% by weight; the range of particle size is 8 μm or more and less than 10 μm is 5 to 25% by weight. The highly-fillable alumina is 2.30.
It means a material exhibiting the above high density (bulk density).

In the present invention, the aggregate / binder ratio, which is the ratio of the total weight of the first and second aggregates to the weight of the binder, is in the range of 80/20 to 60/40. Is preferred. If the ratio of the weight of the binder to the total weight of the aggregate and the binder exceeds 40%, the firing shrinkage increases,
Therefore, warpage or deformation becomes large, and stable manufacturing cannot be performed. On the other hand, when the ratio of the weight of the binder to the total weight of the aggregate and the binder is less than 20%, a sufficient bonding force cannot be obtained and the required strength cannot be obtained.
The surface of the firing tool material tends to be rough and tends to shed particles.

Further, in the present invention, the whole firing tool material
Al in the body₂ O₃ Weight and SiO ₂ Is the ratio to the weight
Al₂ O₃ / SiO₂ Ratio is in the range of 85/15 to 95/5
Since it is inside, the spots on the baked object during baking
The occurrence of state change is prevented, and even at high temperatures during baking
Good creep resistance, preventing deformation of the material to be fired
It Al₂ O₃ / SiO₂ In terms of ratio SiO₂ Is excessive
In some cases, spot-like changes in the material to be fired during firing.
Quality is likely to occur. Also, Al₂ O₃ / SiO₂ ratio
At Al₂ O₃ If the amount is excessive, when firing the material to be fired
Creep resistance is reduced at high temperatures and tends to warp
As a result, the material to be fired is also easily deformed.

The tool material has, for example, a flat plate shape,
It is not limited to this. When the tool material has a flat plate shape, for example, the thickness is 5 to 12 mm, and the length and width are 100 to 3
The size is 00 × 100 to 300 mm.

The organic powder binder used in the method for producing a ceramic firing tool material of the present invention includes:
Examples are polyvinyl alcohol, dextrin, and methyl cellulose. Examples of the liquid binder used in the method for producing a ceramic firing tool material of the present invention include ammonium polycarboxylate aqueous solutions, wax emulsions, and diethylene glycol. A mixer is used for kneading the mixture, and a vibration molding machine or a hydraulic press is used for molding.

In the present invention, since mullite is not used as a binder, there is no problem of silica generation due to mullite decomposition even at high temperature during firing of the material to be fired.
Occurrence of speckled alteration in the material to be fired is prevented. Further, in the present invention, since the electromelting mullite is used for a part of the aggregate, the creep resistance is good even at a high temperature during firing of the object to be fired, and therefore, the occurrence of deformation in the object to be fired is prevented. . Further, since this electrofused mullite has coarse particles, the mullite is not decomposed so much that the material to be fired is not deteriorated.

In the method for manufacturing a ceramic firing tool material according to the present invention, firing is performed at a temperature within a range of 1700 to 1830 ° C. in an air atmosphere. If the firing temperature is lower than 1700 ° C., the firing will be insufficient, sufficient strength of the tool material will not be obtained, the bending resistance will be poor, and shedding from the surface tends to occur, tending to adversely affect the article to be fired. On the other hand, 18
If the firing temperature is higher than 30 ° C, the shrinkage during firing tends to be large, and the resulting tool material tends to be largely deformed. As described above, when the baking temperature of the tool material is less than 1700 ° C. or exceeds 1830 ° C., a stable tool material cannot be obtained.

[0024]

EXAMPLES The present invention will be described below with reference to examples.

Examples 1 to 8 : A first aggregate forming powder made of fused alumina having a particle size of 10 to 300 μm, and a particle size of 10
A second aggregate forming powder composed of electro-melting mullite having a particle size of up to 300 μm, and a wide particle size distribution with a particle size of less than 10 μm [particle size 2
18% by weight in the range of less than μm; 34% by weight in the range of particle size of 2 μm or more and less than 4 μm; 21% by weight in the range of particle size of 4 μm or more and less than 6 μm;
17% by weight in the range of m or more and less than 8 μm; 10% by weight in the range of particle size of 8 μm or more and less than 10 μm], and a binder forming powder made of a low-soda calcined alumina having a density of 2.4. An organic powder binder made of polyvinyl alcohol and a liquid binder made of an aqueous solution of ammonium polycarboxylate were mixed to obtain a mixture. No clay was included in this mixture.

This mixture was kneaded with a mixer, molded with a vibration molding machine into the shape of a plate having a size of 100 × 100 × 5 mm, dried, and calcined at a temperature shown in Table 1 below in an air atmosphere, and calcined. I got the tools. At the same time, in order to obtain a test piece for measuring flexural deformation, a sample having a size of 20 × 100 × 5 mm was cut out from the firing tool material.

The composition of the obtained firing tool material (first aggregate,
The weight of the second aggregate and the binder, the Al ₂ O ₃ / SiO ₂ ratio,
The aggregate / binder ratio) is shown in Table 1 below. No clay was contained in these firing tool materials.

Using the thus obtained firing tool material, a molded element made of brown alumina ceramic was placed thereon, fired at 1400 ° C. in the atmosphere, and cooled to room temperature. The obtained fired body was removed, and subsequently, a new molded body was placed in the same manner using the same firing tool material, and thereafter firing was repeated in the same manner.

[0029] It was examined how many times the fired body obtained by the firing had a speckled alteration on the contact surface with the firing tool material. The results are shown in Table 1 below. If spot-like alteration appears on the contact surface of the fired body with the tool material,
It has been confirmed that spot-like alteration appears even in the subsequent firing, and therefore, the number of firings in which the alteration first appears can be used as a measure of the tool life.

Using the above-described flexural deformation test piece, a span 9
It is supported from the lower surface side at 0 mm, a weight of 200 g is placed on the central portion of the upper surface, and it is held in an electric furnace at 1400 ° C. for 10 hours. The difference from the height) was measured. The results are shown in Table 1 below.

Table 1 shows the comprehensive evaluation. The judgment criteria for the comprehensive evaluation were as follows: ⊚: The number of firings until the occurrence of alteration exceeds 100, and
Deflection deformation of firing tool material is less than 1.5 mm; ◯: Number of firings before occurrence of alteration is 50 times or more, and deflection deformation of firing tool material is less than 3 mm (except ◎); ×: Until alteration occurrence The number of firings is 49 times or less, or the bending deformation of the firing tool material is 3 mm or more.

Comparative Examples 1-8 : Examples except that the weights shown in Table 2 were used as the first aggregate, the second aggregate and the binder shown in Table 2 below. It carried out like 1-8. The high soda calcined alumina had a density of 2.0. The results obtained were treated in the same manner as in Examples 1-8,
It shows in Table 2.

[0033]

[Table 1]

[0034]

[Table 2] Although fused alumina is used as the first aggregate in the above examples, in the present invention, sintered alumina can be used as the first aggregate instead of or in combination with fused alumina. . It was confirmed that in these cases, the same operational effect as in the case of using fused alumina as the first aggregate was obtained.

[0035]

As described above, according to the present invention,
Particle size 10 consisting of fused alumina and / or sintered alumina
.About.300 .mu.m of the first aggregate, a second aggregate of 10 to 300 .mu.m in particle size made of electrofused mullite, and a binder made of low-soda calcined alumina and having a particle size of less than 10 .mu.m. Since the Al ₂ O ₃ / SiO ₂ ratio is within the range of 85/15 to 95/5, the volatilization of silica due to the decomposition of mullite is sufficiently suppressed even at a high temperature at the time of firing the object to be fired. Provided is a firing tool material capable of suppressing the occurrence of speckled alteration.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenichiro Koga             Mitsui Kinzoku, 3-1 Asamu-cho, Omuta-shi, Fukuoka             Mining Co., Ltd. Ceramics Division F-term (reference) 4G030 AA36 AA37 BA25 GA11 GA13

Claims (5)

[Claims] 1. A first aggregate made of electrofused alumina and / or sintered alumina having a particle size of 10 to 300 μm, a second aggregate made of electrofused mullite having a particle size of 10 to 300 μm, and calcined low soda. Al ₂ O ₃ / SiO _{2 as} a whole, including a binder made of alumina and having a particle size of less than 10 μm.
The ratio [by weight] is in the range of 85/15 to 95/5. 2. An aggregate / binder ratio [by weight] of 80 /
The ceramic firing tool material according to claim 1, wherein the tool material is in the range of 20 to 60/40. 3. The tool material for firing ceramics according to claim 1, wherein the tool material does not contain clay. 4. A method for manufacturing a ceramic firing tool material according to any one of claims 1 to 3, comprising a first aggregate-forming powder made of fused alumina and / or sintered alumina.
A mixture obtained by mixing a second aggregate-forming powder made of electrofused mullite, a binder-forming powder made of low-soda calcined alumina, an organic powder binder, and a liquid binder is kneaded. Dried and dried in air at 1700
A method for producing a ceramic firing tool material, which comprises firing at a temperature within a range of -1830 ° C. 5. The method for manufacturing a ceramic firing tool material according to claim 4, wherein the mixture does not contain clay.