JP2000074571A - Calcination jig - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable applications to a variety of kinds of matters to be calcined by providing a setter detachably fitted under eaves in protrusions of a tray integrally formed on at least three points of peripheral parts of an upper face of a plate material and made of a heat resistant metal having a surface coated with a material hardly reacting with the matters to be calcined. SOLUTION: A tray 1 comprises, for example, a rectangular bottom plate 2 and three or more, e.g. six, elongated protrusions 3 integrally formed on corner parts and center parts of an upper face of two opposing peripheral parts of the bottom plate 2. A setter 5 is provided with notches respectively corresponding to positions of the protrusions 3 of the tray 1 and are detachably fitted under eaves 4 in the protrusions 3 of the tray so as to be placed on the bottom plate 2 of the tray. The tray 1 is made of a refractory material having a good thermal shock resistance such as alumina, alumina-silica, or the like. The setter is preferably made of a heat resistant metal such as nickel, nickel alloy or the like coated with zirconia or zirconate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a jig used for firing functional ceramics such as electronic parts.

[0002]

2. Description of the Related Art Alumina, alumina-silica, and magnesia are used for firing functional ceramics such as electronic parts.
A tray made of at least one refractory having good thermal shock resistance selected from alumina-silica and silicon carbide; and alumina, silica,
A setter made of zirconia or zirconate having low reactivity with the material to be fired in order to prevent reaction with silicon carbide and impurities and the material to be fired or to prevent components of the material to be fired from diffusing into the tray; Is used.

In recent years, a jig integrating a tray and a setter has been required in order to automate a step of loading and unloading an object to be fired before and after firing. In addition to the integration of the tray and the setter, the jig is required to have the following performance.

(A) To have an excellent thermal shock resistance corresponding to a sharp heat curve which enables a shortening of a heat cycle for improving productivity. (B) Light weight and low heat capacity.

(C) Recycling is possible. (D) It can be used for various kinds of objects to be fired. By the way, as an integrated jig of the tray and the setter, the one having the following structure is conventionally known.

(1) A jig made of a tray itself made of zirconia or zirconate. (2) Japanese Patent No. 1712115 and Japanese Patent No. 1913732.
, A jig in which a zirconia layer is formed on the surface of a tray having good thermal shock resistance, such as alumina-silica, by coating or the like as disclosed in Japanese Patent No. 1735200.

(3) A jig in which a zirconia setter is adhered to a tray having good thermal shock resistance, such as alumina-silica. (4) A jig in which a zirconia setter is fixed to a tray having good thermal shock resistance such as alumina-silica.

However, the jigs (1) to (4) have the following problems. Jig (1) This jig has no problem in terms of reactivity with the object to be fired, but is inferior in thermal shock resistance, so that when the object to be fired is baked with a sharp heat curve, cracks and breakage are likely to occur. In addition, the cost is high from both sides of the material, and the material is heavy and has a large heat capacity.

Jig (2) When firing is repeated, the zirconia layer is peeled off and cannot be used. In addition, considering recycling when it becomes unusable, it becomes difficult to separate and collect the tray and the zirconia layer because the zirconia layer is integrated with the tray.

The jig (3) When the firing is repeated, the tray is cracked or warped due to a difference in thermal expansion between the tray and the setter, so that it cannot be used. In addition, considering recycling when it becomes unusable, since the tray and the setter are integrated, it becomes difficult to separate and collect them.

Jig (4) Although excellent in terms of recycling, manufacturing is difficult due to its shape. Since the zirconia-based setter needs to be made thicker in manufacturing, a temperature difference occurs between the inside and the outside of the tray during cooling, so that a large thermal stress is generated and the tray is easily broken.

[0012]

The present invention can be applied to various kinds of objects to be fired, has excellent recyclability,
Another object of the present invention is to provide a firing jig having a long life.

[0013]

According to the present invention, there is provided a firing jig made of a refractory having good thermal shock resistance in which projections having eaves are integrally formed at three or more locations on the upper surface periphery of a plate material. And a setter made of a heat-resistant metal whose surface is coated with a material that is hardly reactive with an object to be fired, which is removably fitted below the eaves portion in the protrusion of the tray. Things.

In another firing jig according to the present invention, a projection having an eaves portion is integrally formed at three or more places on a peripheral edge of an upper surface of a plate, and a slit is formed on the plate or the plate including the projection. A formed tray made of a refractory material having good thermal shock resistance, and a heat-resistant metal whose surface is coated with a material that is removably fitted under the eaves at the projection of the tray and hardly reacts with the object to be fired. And a setter comprising:

[0015] In the firing jig according to the present invention, the setter includes a base material made of a heat-resistant metal having a melting point higher than a firing temperature and a protective layer made of a material which is hardly reacted with a fired body. It is preferable that the tray has a thickness of about 2.0 mm and has a cutout on the outer edge corresponding to the position of the protrusion of the tray.

In the firing jig according to the present invention, the tray is made of at least one refractory having good thermal shock resistance selected from alumina, alumina-silica, magnesia-alumina-silica and silicon carbide. Preferably, the setter is made of a refractory metal selected from nickel, nickel alloy, molybdenum, molybdenum alloy, tungsten, tungsten alloy, chromium and chromium alloy coated with zirconia or zirconate.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a firing jig according to the present invention will be described in detail with reference to FIGS. FIG. 1 is a perspective view showing a firing jig according to the present invention, and FIG. 2 is an exploded perspective view of the jig of FIG. The tray 1 includes, for example, a rectangular bottom plate 2 and three or more, for example, six elongated projections 3 integrally formed at the corners and the center of the upper surfaces of two opposing edges of the bottom plate 2. It is configured. Each protruding portion 3 has an eaves portion 4 having a triangular cross section, for example, which is directed toward the center of the bottom plate 2, and the upper surface of the eaves portion 4 is flat for multi-tiering. Note that the height of the eaves portion 4 is slightly higher than the thickness of a setter described later.

The setter 5 has a notch 6 on the outer edge corresponding to the position of each projection 3 of the tray 1 and is removably fitted under the eaves 4 of each projection 3 of the tray 1. The tray 1 is placed on the bottom plate 2 of the tray 1.

The setting operation of the setter 5 is performed, for example, by the notch 6 located at the left edge of the setter 5 under the eaves 4 of the three projections 3 located at the left edge of the tray 1.
After the insertion, the setter 5 is bent along the arrangement direction of the cutouts 6, and the right side of the setter 5 is placed under the eaves 4 of the three protrusions 3 located at the right edge of the tray 1. The setter 5 is mounted on the bottom 2 of the tray 1 by inserting so that the notches 6 located at the edges of the tray 1 match. The operation of removing the setter is performed in the reverse order of the mounting operation.

The tray 1 is made of at least one refractory having good thermal shock resistance selected from, for example, alumina, alumina-silica, magnesia-alumina-silica and silicon carbide. Such a tray 1
Is manufactured, for example, by processing a thick rectangular refractory to form a projection having the eaves, or by casting.

The setter 5 has a firing temperature (1000-1000).
It has a thickness of 0.2 to 2.0 mm in a structure in which a surface of a base material made of a heat-resistant metal having a melting point higher than 1400 ° C.) is coated with a protective layer of a material that does not easily react with an object to be fired.

Examples of the heat-resistant metal as the base material include nickel, molybdenum, tungsten, chromium, and alloys or cermets thereof. The substrate has, for example, a thin plate shape or a net shape.

Materials that do not easily react with the object to be fired include:
Mention may be made, for example, zirconates such as zirconia or CaZrO _3. This protective layer is 30 to 5
It preferably has a thickness of 00 μm.

As a method for coating the protective layer, a thermal spraying method or the like is conceivable, and a protective layer formed by a water plasma thermal spraying method is particularly preferable because it has excellent peeling resistance. The protective layer may be coated on the surface of the base material before the setter is set on the tray, or after the setter is set on the tray. When re-coating the protective layer, it is preferable to remove the original protective layer by polishing or blasting in advance.

The reason why the thickness of the setter is specified is that if the thickness is less than 0.2 mm, the strength may be reduced. Not only becomes more difficult, but also increases heat capacity and cost.

The firing jig according to the present invention described above comprises a tray 1 and a setter 5 as shown in FIGS.
Are detachable by three or more protruding portions 3 having an eaves portion 4 integrally formed on the edge of the tray 1, so that the following operations and effects are achieved.

(1) By changing the material of the setter 5 (particularly, the material of the base material), the tray 1 can be used for firing various kinds of objects to be fired. (2) Tray 1 and setter 5 by repeating firing
In the case where any one of them has cracked or broken, the normal member can be continuously used by replacing only the broken member.

(3) The tray 1 and the setter 5 which have become unusable can be separated from each other, so that they can be separately processed and reproduced. (4) By using a heat-resistant metal that can be elastically and plastically deformed as the base material of the setter 5, it is possible to easily attach and detach the tray 1 to and from the tray 1.

Further, since the base material made of a heat-resistant metal is harder to break than ceramics, it is possible to increase the number of repetitive uses subjected to a heat cycle. Furthermore, even if the protective layer on the surface of the setter 5 is peeled off, it can be reused by the recoating process, so that the amount of waste can be reduced.

(5) Since the setter 5 has a structure in which a protective layer made of a material which is hardly reactive with the object to be fired is coated on the surface of the substrate made of a heat-resistant metal, the object to be fired such as a multilayer ceramic capacitor is used as the material. Sintering can be performed well without causing a reaction. In particular, if the protective layer is made of zirconate, it is possible to further improve the resistance to the object to be fired.

(6) The thickness of the setter 5 is 0.2 to
By setting the thickness to 2.0 mm, the plastic deformability is improved, so that the operation of attaching to the tray 1 can be performed more easily.

By setting the setter 5 to the above-mentioned thickness, the firing jig can be reduced in weight and heat capacity. Next, another firing jig according to the present invention will be described with reference to FIGS.

FIG. 3 is a perspective view showing another firing jig according to the present invention, and FIG. 4 is an exploded perspective view of the jig of FIG. The tray 11 includes, for example, a rectangular bottom plate 12 and the bottom plate 12.
For example, four slits 13 cut out at right angles to the four edges of the bottom plate 12 are respectively integrated with the corners of the upper surface of the edge of the bottom plate 12 and the center of the edge facing the edge. And three elongated projections 14 formed on the substrate. Each of the projections 14 has an eave portion 15 having a triangular cross section, for example, toward the center of the bottom plate 12, and the upper surface of the eave portion 15 is flat for stacking in multiple stages. The height of the eaves 15 is slightly higher than the thickness of a setter described later.

The setter 16 has a rectangular frame-like projection 1
7 and has a notch 18 at the outer edge corresponding to the position of each projection 14 of the tray 11, and is removably fitted under the eaves 15 of each projection 14 of the tray 11. Then, it is placed on the bottom plate 12 of the tray 11.

In the mounting operation of the setter 16, for example, the notch 18 located on the left edge of the setter 16 coincides with the lower part of the eaves 15 of the two projections 14 located on the left edge of the tray 11. After the insertion, the setter 16 is bent along the arrangement direction of the cutouts 17 so that one protrusion 1 located at the right edge of the tray 11 is formed.
A notch 18 located on the right edge under the eaves 15 of FIG.
Is inserted so that the
Is mounted on the bottom 12 of the tray 11. The operation of removing the setter is performed in the reverse order of the mounting operation.

The tray 11 is made of at least one refractory having good thermal shock resistance selected from, for example, alumina, alumina-silica, magnesia-alumina-silica and silicon carbide. Such a tray 1
1 is manufactured, for example, by processing a thick rectangular refractory material to form a projection having the eaves, and then forming a slit or casting.

The setter 16 has a firing temperature (1000).
(1400 ° C.), a structure in which a surface of a rectangular frame-shaped base material made of a heat-resistant metal having a melting point higher than that of a heat-resistant metal is coated with a protective layer made of a material that is difficult to react with an object to be fired. It is preferred to have.

Examples of the heat-resistant metal as the base material include nickel, molybdenum, tungsten, chromium, and alloys or cermets thereof. Examples of the material that does not easily react with the object to be fired include zirconia and zirconates such as CaZrO ₃ . This protective layer has a thickness of 30 to 500 μm.
It preferably has a thickness.

As a method for coating the protective layer, the same means as described with reference to the firing jig shown in FIGS. 1 and 2 is employed. The thickness of the setter is specified for the same reason as described with reference to the firing jig shown in FIGS. More preferably, the thickness of the setter is 0.2 to 0.6 mm.

In the firing jig according to the present invention described above, the tray 11 and the setter 16 have the eave portion 15 integrally formed at the edge of the tray 11 as shown in FIGS. Since the structure is detachable by one or more projections 14, the same operation and effect as those of the above-described (1) to (6) are obtained. In particular, the firing jig shown in FIGS. 3 and 4 has a structure in which the setter 16 has a rectangular frame-shaped protrusion 17 at the peripheral edge thereof for reinforcing, and has a structure in which the whole is thin, so that a further improvement is achieved. Lighter weight and lower heat capacity can be achieved. Further, by forming the plurality of slits 13 in the tray 11, the thermal stress applied to the tray 11 can be reduced, and the number of times the tray 11 can be used can be increased.

In the firing jig according to the present invention, when the trays are stacked and the object to be fired is fired, when abrasion debris is generated due to friction between the contact portions of the trays and adversely affects the product. The contact portion between the trays is allowed to be coated with a hardly reactive component such as zirconia.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. (Example 1) First, the amount of alumina shown in FIG.
Made of 0 wt% alumina-silica, 150m long
m, a width of 150 mm and a thickness of 4 mm, and a rectangular bottom plate 2 and six elongated projections 3 integrally formed at the corners and the center of the upper surfaces of two opposing edges of the bottom plate 2. Prepared tray 1 was prepared. Each of the projections 3 has a width of 16 mm, a height of 6 mm, and has an eaves portion 4 (extending length of 3 mm), for example, having a triangular cross section toward the center of the bottom plate 2. The upper surface is flat for multi-tiering.

As shown in FIG. 2, each of the projections 3 of the tray 1 has a width of 16 mm and a depth of 5 mm.
C on the surface of a rectangular nickel base having two notches 6
A protective layer of partially stabilized zirconia containing 4% by weight of aO was coated by a water plasma spraying method with a length of 150 mm and a width of 15 mm.
A setter 5 having a thickness of 0 mm and a thickness of 1.5 mm was prepared.

Next, after the notch 6 located on the left edge of the setter 5 is inserted under the eaves 4 of the three projections 3 located on the left edge of the tray 1 so as to match, The setter 5 is curved along the direction in which the notches 6 are arranged so that the notch 6 located at the right edge of the tray 1 is located below the eaves 4 of the three protrusions 3 located at the right edge of the tray 1. The setter 5 was attached to the bottom 2 of the tray 1 by inserting so as to match, and the firing jig shown in FIG. 1 was assembled.

On the setter of the obtained firing jig, a barium titanate 3 mm long, 3 mm wide, 1 mm thick
Is placed in an electric furnace at a temperature rising rate of about 300 ° C./hr in a nitrogen atmosphere at 1300 ° C.
, And rapidly cooled to 400 ° C. at a temperature lowering rate of about 300 ° C./hr, and then gradually cooled to room temperature to fire the object to be fired. By repeating the firing of the object to be fired, 1
At every 0 cycle, the firing jig was taken out of the electric furnace and checked for damage such as cracks.

As a result, at the 40th cycle, large stains were formed on the setter surface of the jig, and the object to be fired came to adhere. For this reason, the setter is detached from the tray,
After the protective layer was removed by blasting the surface, the protective layer made of the stabilized zirconia was coated again, and the setter was mounted on a tray to assemble a jig.

Using the jig after the setter exchange, the same firing of the object to be fired was repeated. As a result, similar stains occur on the setter surface at the 80th and 120th cycles in total, and the removal of the setter, the re-coating of the protective layer, and the re-attachment to the tray are performed in the same manner to continue firing the object to be fired did.

The firing operation was stopped because a large crack occurred in the tray at the 180th cycle in total. At this time,
The setter removed from the tray could be used by mounting it on another tray.

(Example 2) First, a rectangular bottom plate 12 made of silicon carbide having a silicon carbide content of 90 wt% and having a length of 150 mm, a width of 150 mm, and a thickness of 2 mm as shown in FIG. Four slits 13 respectively cut out at four edges of the four sides so as to be orthogonal to the side,
A tray 1 comprising a corner on the upper surface of the edge of the bottom plate 12 and three elongated projections 14 integrally formed at the center of the edge facing the edge was prepared. Each of the protrusions 14 has a width of 15 mm and a height of 5 mm.
The cross section toward the center of the bottom plate 12 has a triangular eave portion 15 (extended length 3 mm), and the upper surface of the eave portion 15 is flat for multi-tiering.

Also, as shown in FIG.
m, a rectangular frame-shaped protrusion 17 having a width of 6 mm, and a width 17 m corresponding to the position of each protrusion 14 of the tray 11 on the outer edge.
m, a surface of a rectangular molybdenum base material having three notches 18 with a depth of 3.5 mm covered with a protective layer of calcium zirconate by a water plasma spraying method and having a length of 150 m.
A setter 16 having an m, a width of 150 mm and a thickness of 0.5 mm was prepared.

Next, after the notch 18 located on the left edge of the setter 16 is inserted under the eaves 15 of the two projections 14 located on the left edge of the tray 11 so as to match, The setter 16 is curved along the arrangement direction of the cutouts 17, and a cutout 18 located at the right edge of the tray 11 is located below the eaves 15 of one protrusion 14 located at the right edge of the tray 11. The setter 16 was attached to the bottom 12 of the tray 11 by inserting so as to match, and a firing jig shown in FIG. 3 was assembled.

On the setter of the obtained firing jig, barium titanate, 3 mm long, 3 mm wide, 1 mm thick
Is placed in an electric furnace at a temperature rising rate of about 300 ° C./hr in a nitrogen atmosphere at 1300 ° C.
, And rapidly cooled to 400 ° C. at a temperature lowering rate of about 300 ° C./hr, and then gradually cooled to room temperature to fire the object to be fired. By repeating the firing of the object to be fired, 1
At every 0 cycle, the firing jig was taken out of the electric furnace and checked for damage such as cracks.

As a result, since the protective layer on the setter surface of the jig was partially peeled off at the 70th cycle, the setter was detached from the tray, and the protective layer was removed by blasting the surface. A protective layer made of zirconia fluoride was coated, and the setter was mounted on a tray to assemble a jig.

Using the jig after the replacement of the setter, similar firing of the object to be fired was repeated. As a result, since the protective layer was partially peeled on the setter surface at the 150th cycle in total, the setter was similarly detached, the protective layer was re-coated, and the tray was reattached, and the firing of the object to be fired was continued. .

Even after the firing operation at the 200th cycle in total, the tray could be used without further damage such as cracks. (Comparative Example 1) As shown in FIG.
Alumina-silica material, length 150mm, width 1
A rectangular bottom plate 21 having a thickness of 50 mm and a thickness of 5 mm, and six elongated projections 22 integrally formed at the corners and the center of the upper surfaces of two opposing edges of the bottom plate 21.
And a tray-shaped firing jig having a protective layer formed by spray coating and baking partially stabilized zirconia containing 4 wt% of CaO on the inner surface. Each of the projections 22 has a width of 16 mm and a height of 6 m.
m, and the upper surface is flat for stacking in multiple stages.

Using the obtained firing jig, barium titanate having a length of 3 mm, a width of 3 mm, and
A firing test was performed on an object to be fired having a thickness of 1 mm. As a result, a small crack occurred in the bottom plate portion at the fifth cycle. The use was continued as it was, but as the number of uses increased, the cracks spread and the use was stopped at the 18th cycle because the crack length became more than half of the bottom plate.

(Comparative Example 2) As shown in FIG. 6, a silicon carbide material having a silicon carbide content of 90 wt% and a length of 150 m
m, width 150 mm, thickness 4 mm, rectangular bottom plate 31,
Four slits 32, each of which is cut out at four edges of the bottom plate 31 so as to be orthogonal to the sides thereof, and a corner at an upper surface of an edge of the bottom plate 31 and a center of an edge facing the edge, respectively. A tray-like firing jig was prepared, which was composed of three integrally formed elongated projections 33 and had a protective layer made of calcium zirconate coated on the inner surface by water plasma spraying. Each of the protrusions 33 has a width of 15 mm and a height of 6 mm, and has a flat upper surface for stacking in multiple stages.

Using the obtained firing jig, barium titanate having a length of 3 mm, a width of 3 mm, and
A firing test was performed on an object to be fired having a thickness of 1 mm. As a result, at the fifteenth cycle, the protective layer began to be peeled off from the vicinity of the slit-shaped portion. The use was stopped at the 25th cycle because the protective layer became chipped at the turned-up portion. However, no particular damage was observed on the silicon carbide base material itself.

[0059]

As described above, according to the present invention, it is possible to provide a firing jig which can be applied to various kinds of objects to be fired, has excellent recyclability, and has a long life. .

[Brief description of the drawings]

FIG. 1 is a perspective view showing a firing jig according to the present invention.

FIG. 2 is an exploded perspective view of the jig of FIG.

FIG. 3 is a perspective view showing another firing jig according to the present invention.

FIG. 4 is an exploded perspective view of the jig of FIG. 3;

FIG. 5 is a perspective view showing a firing jig of Comparative Example 1.

FIG. 6 is a perspective view showing a firing jig of Comparative Example 2.

[Explanation of symbols]

 1,11: tray, 2,12: bottom plate, 3,14: projection, 4,15: eaves, 5,16: setter, 6,18: cutout, 13: slit.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Toshiyuki Suzuki, Inventor No. 1 Minamito, Ogakie-cho, Kariya-shi, Aichi Pref. Lamix Corporation Kariya Works F-term (reference) 4K055 AA08 HA02 HA12 HA25 HA27 5E082 BC40 FG26 FG54 LL40 MM24 PP06 PP09

Claims (4)

[Claims] 1. A tray made of a refractory material having good thermal shock resistance in which projections having an eaves portion are integrally formed at three or more locations on a peripheral edge of an upper surface of a plate material; And a setter made of a heat-resistant metal whose surface is coated with a material that is hardly reactive with an object to be fired. 2. A refractory with good thermal shock resistance, wherein projections having an eaves portion are integrally formed at three or more locations on the periphery of the upper surface of the plate, and slits are formed in the plate or the plate including the projection. And a setter made of a heat-resistant metal whose surface is coated with a material that does not easily react with the object to be fired, which is removably fitted under the eaves portion of the protrusion of the tray. Jig for firing. 3. The method according to claim 1, wherein the setter has a thickness of 0.2 to 2.0 mm in which a surface of a base material made of a refractory metal having a melting point higher than a firing temperature is coated with a protective layer of a material that is difficult to react with an object to be fired. The firing jig according to claim 1, further comprising a notch at an outer edge corresponding to a position of the protrusion of the tray. 4. The tray according to claim 1, wherein the tray is made of alumina, alumina,
The setter is made of at least one refractory having good thermal shock resistance selected from siliceous, magnesia-alumina-silicic and silicon carbide, and the setter is nickel or nickel alloy whose surface is coated with zirconia or zirconate. 4. The firing jig according to claim 1, wherein the firing jig is made of a heat-resistant metal selected from the group consisting of molybdenum, molybdenum alloy, tungsten, tungsten alloy, chromium, and chromium alloy.