JP2001322875A - Implement for calcination of electronic parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve peeling resistance and strength against stress between the base body and a zirconia surface layer of a conventional implement for calcination of electronic parts manufactured by applying the zirconia layer on the surface of the base body. SOLUTION: A partially molten intermediate layer consisting of two or more kinds of metal oxides is formed between the base body and the zirconia surface layer of the implement for calcination of electronic parts. Unlike a conventional implement for calcination of electronic parts, the partially molten intermediate layer is formed by using two or more kinds of metal oxides and partially molten, therefore, the molten oxide as a liquid phase improves the adhesion property between the zirconia surface layer and the base body and gives good peeling resistance to the zirconia surface layer. Further, the sintering property of the partially molten intermediate layer is improved, which improves the strength against stress.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a setter, a shelf, and the like used for firing electronic components such as dielectrics, multilayer capacitors, ceramic capacitors, piezoelectric elements, and thermistors.
The present invention relates to a jig for firing electronic components such as a sagger.

[0002]

2. Description of the Related Art A jig for firing electronic parts is required to not react with ceramic electronic parts to be fired in addition to heat resistance and mechanical strength. When an electronic component work such as a dielectric material comes into contact with and reacts with a firing jig, there are problems such as fusing or a change in the composition of the work resulting in deterioration of characteristics. Usually, an alumina-mullite base material having a high hot strength and a good thermal spalling property is frequently used as a base material for these electronic component firing jigs. However, this alumina-mullite base material easily reacts with the electronic component work, and in order to prevent this reaction, a method of coating the surface of the base material with zirconia has been adopted.

[0003]

Although zirconia has low reactivity with a substrate, the zirconia has a large difference in coefficient of thermal expansion with the substrate, so that cracks may occur in the coating of the jig in a use environment in which repeated thermal cycles occur. There is a problem that it occurs or peels off. Furthermore, zirconia undergoes a phase change from monoclinic to tetragonal at around 1100 ° C. As a result, there is a problem that the zirconia coating layer is easily detached due to a change in the thermal expansion coefficient accompanying the phase transformation due to repeated thermal cycling. When unstabilized zirconia is used as the surface layer, there is a problem that powdering occurs due to phase transformation.

In order to solve such problems, there has been proposed a jig for firing electronic parts in which an intermediate layer made of alumina is present between a zirconia surface layer and a substrate. However, this electronic component firing jig has the disadvantage that the sinterability of alumina is poor, the adhesive does not have sufficient adhesion as an intermediate layer between the zirconia surface layer and the substrate, and peeling cannot be prevented at a satisfactory level. Accordingly, an object of the present invention is to provide an electronic component firing jig having an intermediate layer having various properties, particularly excellent peeling resistance and strength, instead of the conventional intermediate layer made of alumina alone.

[0005]

SUMMARY OF THE INVENTION The present invention provides a substrate, a partially molten intermediate layer comprising two or more metal oxides coated on the surface of the substrate, and zirconia formed on the partially molten intermediate layer. An electronic component firing jig comprising a surface layer.

Hereinafter, the present invention will be described in detail. The jig for firing an electronic component of the present invention comprises a
It is characterized by having a partially molten intermediate layer composed of more than one kind of metal oxide (in this specification, the layer before firing is simply referred to as “intermediate layer”, and the layer after firing is referred to as “partially molten intermediate layer”). And The material of the substrate of the electronic component firing jig according to the present invention may be the same as the conventional one, for example, alumina-based material, alumina-mullite-based material, alumina-magnesia-based spinel material, alumina-mullite-cordierite-based material,
Alternatively, a material based on a combination thereof is used.

The partially molten intermediate layer formed on the substrate is obtained by firing a mixture of two or more metal oxides at a high temperature. Aluminum oxide (alumina, Al
₂ O ₃ ), zirconium oxide (zirconia, Zr
O ₂ ), yttrium oxide (yttria, Y ₂ O ₃ ),
There are calcium oxide (calcia, CaO), magnesium oxide (MgO, magnesia), strontium oxide (strontia, SrO) and alumina-magnesia spinel composite oxide (Al ₂ O ₃ .MgO, hereinafter referred to as “spinel oxide”). Two or more types are selected from these. Specifically, it is desirable to combine alumina with another metal oxide. For example, a combination of alumina-spinel oxide-magnesia or alumina-calcia-yttria can provide a partially melted intermediate layer having excellent properties.

The mixing ratio of the metal oxide is not particularly limited. However, when the content of one type of metal oxide exceeds 90% by weight, the effect of using a mixture of two or more types of metal oxides is reduced, which is preferable. Absent. The particle size of the metal oxide constituting the partial melt intermediate layer is not particularly limited, and the partial melt intermediate layer or the intermediate layer may be formed of a metal oxide having a random particle size. The average particle size
When a mixture of coarse particles of 30 to 500 μm and fine particles of an average particle diameter of 0.1 to 10 μm is present, voids are formed in the partially molten intermediate layer by the coarse metal oxide having a high porosity, and the zirconia surface layer and the It can absorb and reduce the difference in the coefficient of thermal expansion between the molten intermediate layer, and the partially molten intermediate layer and the base material, and can be used in a thermal cycle environment where rapid heating and rapid cooling are repeated.
Can be used without peeling for a relatively long time. However, the amount of the coarse particles with respect to the entire partially melted intermediate layer is 90% by weight or less. If the content exceeds 90% by weight, the effect of partial melting cannot be obtained, and the film may not be densified, which may cause a problem in strength.

The intermediate layer can be formed on the surface of the substrate by a coating-pyrolysis method, a spray method, a dip coating method, or the like.
The coating-thermal decomposition method is a method in which an aqueous solution of a metal salt such as a nitrate of a corresponding metal is applied to the surface of a substrate, converted to a corresponding metal oxide by thermal decomposition, and coated on the surface of the substrate. The spray method is a method in which metal oxide particles having a predetermined particle size are suspended in a solvent, the solvent is sprayed on the surface of the substrate, and the solvent is scattered to coat the metal oxide on the surface of the substrate. In the dip coating method, the substrate is immersed in a solution in which the corresponding metal oxide is dissolved or suspended, a liquid layer containing the metal oxide is formed on the substrate surface, and the solvent is removed by drying to remove the metal oxide. This is a method of forming a layer. The coating-pyrolysis method and the dip coating method make it difficult to control the particle size of the generated metal oxide particles, and form a metal oxide having a desired particle size distribution, for example, an intermediate layer of the above-described metal oxide composed of coarse particles and fine particles. In the case of forming, it is desirable to use a spray method of directly spraying metal oxide particles having a predetermined particle size.

[0010] The thickness of the partially molten intermediate layer is not particularly limited.
μm is preferable, and in consideration of the spray amount of the metal or the metal compound on the substrate or the coating amount of the solution of the metal or the metal compound and the amount of the solvent to be removed in each production method, the thickness of the formed intermediate layer is reduced. Can be adjusted arbitrarily. The intermediate layer thus formed is converted into a partially molten intermediate layer by firing at a high temperature. It is desirable that the firing temperature be higher than the temperature at which the electronic component is actually fired so that the electronic component firing jig of the present invention does not deteriorate during use. Since the firing temperature of a normal electronic component is 1200 to 1400 ° C., the firing temperature of the intermediate layer is preferably about 1300 to 1600 ° C. The firing of the intermediate layer may be performed simultaneously with the firing of the zirconia surface layer after the formation of the zirconia surface layer, whereby the number of firing steps can be reduced.

A zirconia surface layer is formed on the partially molten intermediate layer (or the intermediate layer) thus formed. Similar to the above-mentioned intermediate layer, the production method includes a coating-pyrolysis method, a spray method, a dip coating method and the like. This zirconia layer may be formed by firing zirconia having a random particle size.However, as in the case of the intermediate layer, coarse particles and fine particles are mixed, for example, zirconia coarse particles having an average particle size of 30 to 500 μm. When particles and zirconia fine particles having an average particle size of 0.1 to 10 μm are mixed and present, voids are formed in the surface layer by the zirconia coarse particles having a high porosity, and in addition to the void forming ability of the partially molten intermediate layer, the zirconia surface layer has The difference in thermal expansion coefficient between the zirconia surface layer and the partially molten intermediate layer can be more completely absorbed and reduced by the void forming ability. In the case of the zirconia surface layer as well, the amount of the coarse particles is desirably 90% by weight or less based on the whole.

As the material of the zirconia surface layer, specifically, unstabilized zirconia, partially stabilized zirconia, stabilized zirconia, and the like can be used. It should not be detrimental, and it is therefore desirable to use zirconia partially stabilized or stabilized with yttria, calcia and magnesia, or mixtures thereof. Zirconia is monoclinic at room temperature, and monoclinic → (~ 1170 ° C) → tetragonal → (~ 2370
℃) → The cubic phase transformation occurs, but the solid-state binder (stabilizer) such as yttria or magnesia is dissolved in zirconia to form a high-temperature phase of tetragonal or cubic at room temperature. Stabilization ".

[0013] The electronic component firing jig of the present invention manufactured as described above has an intermediate layer made of two or more kinds of metal oxides, and a partially melted intermediate layer formed by melting part of the intermediate layer during heating and firing. The liquid phase formed by partial melting reacts with both the zirconia surface layer and the base material, thereby significantly improving the adhesion between each layer and the base material, in other words, the zirconia surface layer is separated from the base material. It becomes difficult. If the amount of the liquid phase is too large, the film and the substrate may be deformed due to shrinkage when the liquid phase is solidified. Therefore, it is desirable to appropriately set the heating and firing conditions. Furthermore, 2
Since one kind of metal oxide is used, even if one kind of metal oxide is inferior in sinterability, it is complemented by the sinterability of other metal oxides, and the sinterability as a whole is improved. The strength as a molten intermediate layer is improved. In addition, by using two types of metal oxides, the melting point is lower than that of a metal oxide alone (for example, the melting point of alumina is about 2000 ° C.), and firing at a preferable firing temperature of 1300 to 1600 ° C. is easy. Become. Therefore, separation prevention due to a reduction in the difference in the coefficient of thermal expansion between the substrate and the zirconia surface layer, which could not be substantially achieved by the conventional electronic component firing jig having the intermediate layer formed of only one type of metal oxide, was not achieved. , And the strength of the partially molten intermediate layer can be improved.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment relating to the production of a jig for firing an electronic component according to the present invention will be described, but the present invention is not limited to the embodiment.

Example 1 As a substrate, alumina containing up to about 10% by weight of a silica component
A mullite substrate was used. Alumina (70% by weight), calcia (28% by weight) and magnesia (3% by weight), each of which was finely divided, were uniformly mixed in a ball mill, and water and polyvinyl alcohol as a binder were added to form a slurry. The slurry was spray-coated on the surface of the substrate and dried at about 100 ° C. The thickness of the obtained intermediate layer is about 100 μ
m. Next, the surface of this intermediate layer is coated with yttria (Y ₂
The zirconia surface layer stabilized with O ₃ ) was spray-coated and dried at about 100 ° C. The thickness of the zirconia surface layer is about 100
μm. This laminate was kept at 1400 to 1600 ° C. for 2 hours, and the intermediate layer was converted into a partially melted intermediate layer to prepare a jig for firing electronic parts.

In order to examine the separation of the electronic component firing jig from the zirconia surface layer, the partially melted intermediate layer, and the substrate, the jig was heated rapidly from 500 ° C. to 1300 ° C. over 3 hours, and then heated from 1300 ° C. to 500 ° C. The rapid cooling to 3 ° C. over 3 hours was repeated, and the number of heat cycles until peeling was examined. as a result,
No delamination occurred after 150 cycles. The results are shown in Table 1.

Examples 2 to 14 The procedure of Example 1 was repeated except that 40% by weight of the alumina in the partially molten intermediate layer was in the form of coarse particles (Example 2), and 80% by weight of the alumina in the partially molten intermediate layer. Was made in the same manner as in Example 1 (Example 3) except that the zirconia surface layer was made of a mixture of yttria-stabilized zirconia and unstabilized zirconia (Example 3), and the weight of alumina, calcia, and magnesia was changed. 66% by weight and 30% by weight, respectively
And 4% by weight as in Example 1 (Example 4), except that alumina, calcia and magnesia were 69%, 13% and 18% by weight, respectively. An electronic component firing jig was produced in the same manner as in Example 1 (Example 5).

Further, spinel oxide (Al ₂ O ₃ .MgO or MgAl ₂ O ₄ ) was used in place of magnesia, and alumina, spinel oxide and calcia were 55% by weight, 15% by weight and 30% by weight, respectively. Except for this, the same as Example 1 (Example 6), and the same as Example 6 except that the proportions of coarse particles of alumina and spinel oxide were 50% and 20%, respectively (Example 7). The same procedure as in Example 1 was repeated except that alumina, spinel oxide and calcia were 24%, 63% and 13% by weight, respectively, and the material of the zirconia surface layer was zirconia partially stabilized with yttria. 8) Same as Example 8 except that the proportion of coarse particles of spinel oxide was 50% and the material of the zirconia surface layer was a mixture of yttria-stabilized zirconia and unstabilized zirconia. It was manufactured (Example 9) electronic components firing jig.

Yttria was used in place of the spinel oxide, and the weight percentages of alumina, calcia and magnesia were 56%, 23% and 21%, respectively, and the material of the zirconia surface layer was yttria-stabilized zirconia. And a mixture of unstabilized zirconia and the same as in Example 1 (Example 10), and also as in Example 10 except that 60% by weight of the alumina in the partially molten intermediate layer was made into coarse particles. (Example 11) Also, the weight percentages of alumina, calcia and yttria were 54%, 5% and 41%, respectively.
(Example 2)
12) A jig for firing electronic components was manufactured. Example 12 was repeated except that 47% by weight of alumina and 53% by weight of strontia were used as the partially molten intermediate layer (Example 1).
3) A jig for firing electronic parts, in the same manner as in Example 1 (Example 14) except that 29% by weight of alumina, 19% by weight of calcia, and 52% by weight of strontia were used as the partially molten intermediate layer. Was prepared.

A thermal cycle test was performed in the same manner as in Example 1 for the electronic component firing jig including the partially melted intermediate layers produced in Examples 2 to 14. The number of heat cycles until peeling occurred in the electronic component firing jig of each example was examined. The results are shown in Table 1. From Table 1, it can be seen that the jig for baking electronic components was resistant to peeling when the partially molten intermediate layer was made of alumina-calcia-magnesia (Examples 1 to 5) and alumina-calcia-yttria (Examples 10 to 12). The properties were particularly good, and other compositions were found to be able to withstand more than 100 thermal cycles. In addition, it was also found that when a part of the constituent oxide of the partially melted intermediate layer was formed into coarse particles (see Examples 6 and 7), the peeling resistance was improved.

[0021]

[Table 1]

Comparative Examples 1 to 5 The procedure of Example 1 was repeated except that the single intermediate layer corresponding to the partially melted intermediate layer of Example 1 was made of 100% alumina (Comparative Example 1). The same as Comparative Example 1 except that coarse particles were used (Comparative Example 2), and the same as Comparative Example 2 except that the material of the zirconia surface layer was a mixture of yttria-stabilized zirconia and unstabilized zirconia. Comparative Example 3 An electronic component firing jig was manufactured. The same as Comparative Example 1 except that the single intermediate layer was 100% spinel oxide (Comparative Example 4), and the same as Comparative Example 4 except that 50% by weight of the spinel oxide was coarse. (Comparative Example 5) An electronic component firing jig was manufactured. The number of heat cycles until peeling occurred in the electronic component firing jig having the intermediate layer of each comparative example was examined. Table 2 shows the results. Table 2 shows that when the intermediate layer is a single oxide or spinel oxide, it can withstand less than 50 thermal cycles.

[0023]

[Table 2]

[0024]

The present invention includes a substrate, a partially molten intermediate layer composed of two or more metal oxides coated on the surface of the substrate, and a zirconia surface layer formed on the partially molten intermediate layer. An electronic component firing jig (claim 1) characterized by the following. Unlike the conventional alumina-only intermediate layer, this electronic component firing jig uses two or more types of metal oxides and partially melts them. It improves the adhesion to both the layer and the substrate, and imparts good peel resistance to the zirconia surface layer. In addition, sintering at a high temperature during the formation of the partially molten intermediate layer improves the sinterability of the partially molten intermediate layer and improves the strength against stress. Therefore, it can be used as an electronic component firing jig for a considerably long time even in a thermal cycle environment in which rapid heating and rapid cooling are repeated.

The metal oxide forming the partially molten intermediate layer is
Two or more metal oxides selected from the group consisting of aluminum oxide, zirconium oxide, yttrium oxide, calcium oxide, magnesium oxide, strontium oxide, and aluminum oxide / magnesium oxide spinel composite oxide (claim 2), particularly The combination of alumina-spinel oxide-magnesia and the combination of alumina-calcia-yttria provide a partially molten intermediate layer having excellent properties. The metal oxide forming the partially molten intermediate layer is composed of coarse particles having an average particle size of 30 to 500 μm and average particles of 0.1 to 10 μm.
In the case of fine particles having a particle diameter of μm (claim 3), voids are formed in the intermediate layer by the coarse metal oxide having a high porosity, and the thermal expansion between the zirconia surface layer and the intermediate layer and between the intermediate layer and the substrate. The rate difference can be absorbed and mitigated.

Claims (3)

[Claims] 1. A method comprising: a substrate; a partially molten intermediate layer comprising two or more metal oxides coated on the surface of the substrate; and a zirconia surface layer formed on the partially molten intermediate layer. Characteristic jig for firing electronic components. 2. The metal oxide forming the partially molten intermediate layer is selected from the group consisting of aluminum oxide, zirconium oxide, yttrium oxide, calcium oxide, magnesium oxide, strontium oxide and alumina / magnesia spinel composite oxide. The electronic component firing jig according to claim 1, wherein the jig is at least one kind of metal oxide. 3. The method according to claim 1, wherein the metal oxide forming the partially molten intermediate layer comprises coarse particles having an average particle size of 30 to 500 μm and coarse particles having an average particle size of 0.1 to 10 μm.
The electronic component firing jig according to claim 1, further comprising: μm fine particles.