JP2004053147A - Sintering setter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sintering setter having superior dimensional accuracy and stability when superposed in a multistage state, and capable of easily manufacturing a ceramic substrate with high planarity. <P>SOLUTION: The sintering setter is for placing an object to be sintered thereon in a sintering furnace when manufacturing a ceramic electronic part by sintering an object. It is equipped with a placing plate 1 for placing the object thereon and struts 2 mounted on a surface of the placing plate 1. Protruded parts 2b are protrudedly provided on the bottom of the struts 2, and recessed parts 1b having a size fittable with the protruded parts 2b are provided recessed on a surface 1a on which the struts 2 are not mounted. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a firing setter used for placing a ceramic fired body when firing a ceramic fired body such as a green sheet to produce a ceramic electronic component such as a ceramic capacitor or a multilayer ceramic substrate, More specifically, the present invention relates to a firing setter capable of obtaining a flat ceramic electronic component having high flatness.
[0002]
[Prior art]
High flatness is required for a ceramic substrate used as a multilayer, such as a ceramic capacitor.
In addition, when a ceramic electronic component is manufactured by firing, it is desired to fire a large number of objects to be fired at once from the viewpoint of productivity. In order to fire many objects to be fired at once in a firing furnace, the objects to be fired are usually stacked and fired in multiple stages, but the stacked objects to be fired are not sintered or reacted. A firing setter is used which can be stacked separately at a distance.
[0003]
Conventionally, firing setters as shown in FIG. 3 are used in a state of being stacked in multiple stages as shown in FIG.
The firing setter shown in FIG. 3 has a mounting portion on a mounting surface (hereinafter, sometimes referred to as an “upper surface”) side of a rectangular mounting portion 11 on which an object to be fired 10 such as a green sheet is mounted. A side wall 12 is provided along the edge of the base 11, and a leg 13 similar in shape to the mounting portion 11 is provided on the lower surface side so as to leave an interval slightly larger than the thickness of the side wall 12 on the periphery. It is a ceramic molded product.
[0004]
In such a firing setter, the four corners 12a of the side wall 12 of the second setter to be stacked are respectively provided on the outer peripheral corners 14 where the legs 13 on the lower surface of the mounting portion 11 are not provided. By engaging, the firing setters can be stacked in multiple stages.
[0005]
At the center of each side of the side wall 12, a window 12b formed by lowering the height of the wall is cut so that the mounting space formed when the setters are stacked in multiple stages and the outer space are formed. A gas port 15 through which air can pass through the space is formed. Through the gas port 15, gases such as a binder and a solvent released when the body 10 is fired can be discharged to the outside without accumulating in the mounting space.
[0006]
[Problems to be solved by the invention]
With a setter having such a configuration, it is difficult to obtain a ceramic substrate with high flatness for the following reasons. That is, the fired body 10 such as a green sheet is soft and can be deformed so as to reflect the flatness of the mounting portion 11 when mounted on the mounting portion 11. Therefore, the hard ceramic substrate obtained by firing has a flatness similar to the flatness of the upper surface of the mounting portion 11. Therefore, it is desired to increase the flatness of the mounting portion 11. However, only the upper surface of the mounting portion 11 of the setter in which complicated portions such as the legs 13 and the side walls 12 are integrally formed is polished to flatness. It is difficult to raise. That is, when the mounting portion 11 is warped as shown in FIGS. 5A to 5C, in order to increase the flatness of the mounting surface, the mounting surface is polished as indicated by a dashed line, and the mounting surface is polished. However, it is difficult to perform such an operation substantially without damaging the side wall 12.
[0007]
In addition, since the conventional setters have poor stability when stacked in multiple stages, if the setters are to be carried in a stacked state in which the setters are stacked, the set may be distorted, resulting in poor workability. In addition, since the baking is performed in 30 to 40 shelves in the baking furnace, if any vibration occurs during the baking, the state of the shelving collapses, and all the baking products of the lot become defective. And productivity was not good either.
[0008]
Further, the gas port 15 is preferably as large as possible so that the gas released from the object 10 during firing does not accumulate in the mounting space. However, if the gas port 15 is to be enlarged with the configuration of the setter shown in FIG. The only way to increase the cut length of the window portion 12b is that the corner portion 12a becomes smaller and the strength of the side wall 12 is reduced. Increasing the notch of the window 12b means that when the setters are stacked in multiple stages, the corners 12a of the portions that become the pillars become smaller, and this leads to a decrease in stability. Furthermore, since the firing setter itself is made of ceramics, the dimensional accuracy is inferior immediately after firing at the time of manufacturing the setter. Conventionally, the height of the side wall 12 is adjusted by polishing or the like in order to stack and use such firing setters. However, when the area of the corner 12a is reduced, the strength of the corner 12a is reduced. Therefore, the side wall 12 may be damaged.
[0009]
Further, since the dimensional accuracy of the window 12b is related to the opening area of the gas port 15 when the windows 12b are stacked in multiple stages, if the dimensional accuracy of the window 12b varies, the opening area of the gas port 15 varies, Ease of release of the gas released from the fired body 10 during firing is not constant, which affects the dimensional variation of the finally obtained ceramic substrate.
[0010]
As a method of obtaining a flat ceramic substrate having a high degree of flatness, for example, in JP-A-2001-19562, a flat mounting plate for mounting an object to be fired is shelf-assembled via a support, and at the end of firing, There has been proposed a method in which the pillars shrink to a thickness equal to or less than the thickness of the fired ceramic substrate and a surface pressure is applied to the fired body after firing, thereby correcting warpage and increasing flatness. However, in this method, the support is used only for one-time firing, and a cumbersome assembling operation of disposing a new support between the mounting plates for each firing must be performed.
[0011]
The present invention has been made in view of such circumstances, and it is an object of the present invention to easily produce a ceramic substrate having high dimensional accuracy, excellent stability when stacked in multiple stages, and high flatness. It is to provide a firing setter that can be manufactured.
[0012]
[Means for Solving the Problems]
The firing setter of the present invention is a firing setter in which the firing target is placed in a firing furnace when firing the firing target to produce a ceramic electronic component, wherein the firing target is A mounting plate on which the mounting plate is to be mounted, and a support attached to one surface of the mounting plate, wherein a protrusion is provided on the bottom surface of the support, and the support of the mounting plate is mounted. A concave portion having a size into which the convex portion can be inserted is formed in the surface on the side where no protrusion is provided.
[0013]
It is preferable that the support is formed separately from the mounting plate, and is attached to one surface of the mounting plate with an inorganic adhesive.
[0014]
It is preferable that the mounting plate has a square shape, the support is attached to each corner of the mounting plate, and the recess is mounted at a position corresponding to the support on the mounting plate. . In addition, the depth of the concave portion is equal to or greater than the height of the convex portion, and the convex portion of the first firing setter is fitted into the concave portion of the second firing setter, thereby forming the second firing setter. When the first baking setter is stacked on the baking setter, it is preferable that the support bottom surface of the first baking setter is in contact with the mounting surface of the second baking setter. Further, it is preferable that the mounting plate has a square shape, and the length of one side of the support is 1/10 to 1/30 of the length of one side of the mounting plate to which the support is attached.
[0015]
The mounting plate and the support are preferably made of dense ceramics, and at least one surface of the mounting plate is preferably surface-treated with partially stabilized zirconia. When the mounting plate is subjected to a surface treatment with partially stabilized zirconia, the convex portion of the first firing setter is inserted into the concave portion of the second firing setter, so that the second firing setter has the second firing setter. (1) When the firing setters are stacked, a portion of the mounting plate of the second firing setter where the support bottom surface of the first firing setter abuts is not subjected to the partially stabilized zirconia surface treatment. Is preferred.
[0016]
The flatness of the mounting plate is preferably 100 μm or less.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
The firing setter of the present invention will be described with reference to FIGS.
FIG. 1 is a perspective view showing a configuration of an embodiment of the firing setter of the present invention, and FIG. 2 is a view showing a state in which the firing setters shown in FIG. 1 are stacked in multiple stages.
[0018]
In the firing setter shown in FIG. 1, columns 2 are attached to each corner of the surface of a rectangular flat mounting plate 1 on which an object to be fired such as a green sheet is mounted during firing. Each of the columns 2 includes a column-shaped column main body 2a and a columnar convex portion 2b protruding substantially at the center of the bottom surface of the column main body 2a.
[0019]
At the four corners of the upper surface 1a of the rectangular mounting plate 1, cylindrical concave portions 1b are formed coaxially with the convex portions 2b of the columns 2. The concave portion 1b has a size into which the convex portion 2b can be inserted, and preferably has an inner diameter slightly larger than the outer diameter of the convex portion 2b so that the convex portion 2b can be loosely fitted. Further, it is preferable that the height of the convex portion 2b is slightly larger than the depth of the concave portion 1b.
[0020]
The firing setter of the present invention is composed of a ceramic molded body in which the mounting plate 1 and the support 2 are separately fired and manufactured, the support 2 is attached to the four corners of the mounting plate 1 with an inorganic adhesive, and further mounted by firing. It is preferable that it is formed by being fixedly integrated with the placing plate 1. As the inorganic adhesive, it is preferable to use a slurry of ceramic powder having the same components as the ceramic material constituting the mounting plate 1 and the support 2. For example, when the mounting plate 1 and the support 2 are made of alumina, it is preferable to bond them with an alumina slurry.
[0021]
Further, the type of ceramics constituting the mounting plate 1 and the support columns 2 can be appropriately selected according to the type of ceramics constituting the object to be fired, but is made of dense ceramics so that there is no dimensional change due to repeated firing. It is preferable to use dense alumina because it is excellent in heat resistance and inexpensive.
[0022]
Further, the upper surface of the mounting plate 1 is preferably surface-treated with partially stabilized zirconia so as not to react with the object to be fired. More preferably, as shown in FIG. Are stacked with a partially stabilized zirconia film except for the portion 1c where the bottom surface of the support 2 abuts when stacked. The reason why it is preferable to remove the contact portion 1c of the support 2 is that it is difficult to obtain a partially stabilized zirconia film having a uniform and uniform thickness, so that the bottom contact portion 1c of the support 2 does not necessarily have the same thickness. However, when the height of the contact portion 1c of the bottom surface of the support 2 from the ground surface is different due to the variation of the film thickness, or when the bottom surface of the support 2 comes in contact with the zirconia film having poor smoothness, the setters are stacked. This is because the stability at the time decreases. In addition, every time the operation of stacking or removing the firing setter is performed, the zirconia film is repeatedly rubbed by the support 2 at the portion where the bottom surface of the support 2 of the mounting plate 1 abuts. This is because the formed zirconia film is further reduced in smoothness, and furthermore, the stability when the firing setters are stacked is reduced. On the other hand, the portion where the support 2 abuts upon stacking does not come into contact with the fired body 4 during firing, and thus there is no possibility that the chemical composition of the fired body 4 will be affected. In addition, as a method of forming the partially stabilized zirconia film, a spray method; a sol-gel method; a dry plating method such as CVD, PVD, thermal spraying, or the like; and the like can be adopted. In this case, the bottom surface of the column 2 comes into contact. If the portion is masked, a partially stabilized zirconia film can be formed on the portion of the column 2 except for the bottom contact portion 1c.
[0023]
The firing setter according to the present embodiment having the above-described configuration can be used alone, but is usually used by being stacked in multiple stages. What is necessary is just to insert | stack the convex part 2'b of the support | pillar 2 'of another mounting plate 1' in the recessed part 1b of the mounting plate 1, and to accumulate in multiple stages.
[0024]
In the firing setter of the present invention, since the mounting plate 1 is manufactured separately from the columns 2, even if warpage occurs as an inherent problem of ceramics, the flatness required by polishing or the like is reduced. It can be reserved in advance. In addition, the pillars 2 may have dimensional variations as an inevitable problem associated with firing the ceramics. However, by making the depths of the concave portions 1b at the four corners formed in the mounting plate 1 larger than the height of the convex portions 2b of the support columns 2, the entire convex portions 2b are stacked regardless of the height of the convex portions 2b. Since the bottom surface of the column 2 is in contact with the mounting surface 1a by being inserted into the concave portion 1'b of the setter, the influence of the height variation of the convex portion 2b can be eliminated. Therefore, even if the firing setters are stacked in multiple stages, it is possible to obtain a ceramic fired body in which the flatness secured by the mounting plate 1 is maintained and warpage caused by the mounting surface 1a of the setter used during firing is prevented. it can.
[0025]
Even if the flatness of the mounting plate upper surface 1a may be affected by a difference in the height of the column body 2a or a slight variation based on the smoothness of the bottom surface of the column 2, the state in which the columns are stacked in multiple stages The flatness can be secured again only by polishing the mounting plate upper surface 1a. This is because the dispersion of the upper surface of the mounting plate 1 due to the dispersion of the bottom surface of the support column 2 is minute, so that fine adjustment is sufficient. In addition, when the support 2 is attached by attaching an adhesive, there is a possibility that the flatness of the mounting plate 1 may be affected by the interposition of the adhesive layer. The problem can be solved by finely adjusting the flatness by polishing the upper surface 1a of the mounting plate 1.
[0026]
In the firing setter having the above-described configuration, the flatness of the mounting plate 1 can be increased, and specifically, can be set to 100 μm or less. That is, the firing setter is placed on the surface plate with the mounting surface 1 side down, and a load of about 600 g is applied to one side of about 60% of one side of the firing setter. In this state, the flatness can be achieved such that a gap gauge having a flatness standard size (0.1 mm in the present invention) does not enter between the surface plate and the mounting surface 1. Therefore, when the firing setter of the present invention is used, even when the object to be fired is soft, such as a green sheet, and the flatness of the mounting surface of the setter is reflected, the mounting surface 1 In this manner, a ceramic substrate having a high flatness can be obtained.
[0027]
In addition, since the firing setter of the present invention is stacked by fitting the concave portion 1b of the mounting plate 1 and the convex portion 2b of the support column 2, a more stable lamination state can be implemented than the conventional peripheral edge engagement. The entire protrusion 2b is inserted into the recess 1b, and the support 2 is stacked in a state where the bottom surface of the support 2 is in contact with the mounting surface of the mounting plate 1, so that a more stable lamination state can be achieved. The bodies 4 can be simultaneously fired in a separated state by a firing setter.
[0028]
When the firing setters of the present invention are stacked in multiple stages, only the support 2 is interposed between the first mounting plate 1 and the second mounting plate 1 ′, and the interval between the supports 2 and 2 ′ is reduced. The mounting space is substantially an open space because it serves as the gas port 3 for ventilating the mounting space of the fired body 4 and the external space. Therefore, the gas such as the binder and the solvent generated during firing from the fired body 4 does not accumulate in the mounting space and can be efficiently released to the outside. Even if it is desired to change the atmosphere in the furnace, the atmosphere in the mounting space can be changed evenly by securing a sufficient opening, so that the composition does not change and the composition does not vary during firing.
[0029]
As described above, by using the sintering setter of the present invention, in a state of being stably stacked in multiple stages, it is possible to provide a mounting surface excellent in flatness, and to reduce a composition change due to sintering and a variation in composition. it can.
[0030]
Therefore, the object to be fired to which the fired setter of the present invention can be applied is not particularly limited, but becomes a precursor of an electronic component having a high demand for flatness and uniformity of composition, for example, a ceramic substrate for a capacitor used in a multilayer structure. The plate-like object to be fired is easily affected by the flatness of the mounting plate, and is particularly effective in firing a green sheet in which gas is released during firing.
[0031]
In the firing setter of the present invention, the shape of the concave portion 1b provided on the upper surface of the mounting plate 1 and the convex portion 2b provided on the bottom surface of the support 2 are circular in cross section in FIG. It is not limited to this. Any shape may be used as long as the concave portion and the convex portion can be fitted, and may be a square, an ellipse, or another shape.
[0032]
The height of the column 2 may be appropriately set according to the mounting space and the required size of the gas port 3 on condition that the height of the column 2 is larger than the thickness of the body 4 to be fired. The cross-sectional size of the support may be any size as long as the mounting plate 1 can be stably supported. In the present invention, since the firing setters can be stably stacked by fitting the unevenness, the length of one side of the prism-shaped support 2 is set to 1/10 to 1/10 of the length of one side of the rectangular mounting plate 1. It can be reduced to about 1/30, whereby a substantially open mounting space can be realized.
[0033]
Although the mounting plate 1 has a square shape in FIG. 1, the present invention is not limited to this. A flat plate may be used, and the shape may be a polygon or a circle. When the mounting plate 1 has a shape other than a square, such as a polygon or a circle, the number of the pillars may be stably multi-layered, and may be mounted at an even position in a well-balanced manner.
[0034]
In the usage mode of FIG. 2, the object to be fired is mounted on the surface of the mounting plate on which the column is not attached. However, the firing setter of the present invention is not limited to this usage method. By securing flatness on both surfaces of the mounting plate 1, the object to be fired may be mounted on the surface on the side on which the columns 2 are attached, and the firing setters may be stacked and fired. When only one surface of the mounting plate has been subjected to the surface treatment of partially stabilized zirconia, the objects to be fired may be stacked so as to be mounted on the surface on the side on which the surface treatment has been performed.
[0035]
【The invention's effect】
Since the firing setter of the present invention can increase the flatness of the mounting surface of the fired body, it is suitable for producing a ceramic electronic component having a high flatness.
[0036]
In addition, since the firing setter of the present invention can be stacked in multiple stages by fitting the unevenness, a stable shelf assembly state can be realized. Therefore, the work can be transported in a shelved state, so that the workability is good, and even in a firing furnace, there is no fear that the shelves will collapse due to a slight vibration, so that the occurrence of defective products due to the collapse of the shelves can be prevented. .
[0037]
Furthermore, in the baking setter of the present invention, the gas port is enlarged, and the mounting space can be made substantially an open space that can freely ventilate the external space. Therefore, the gas generated during firing does not accumulate in the mounting space, and when the atmosphere in the firing furnace is to be changed, the atmosphere in all the mounting spaces on the shelf is the same as the atmosphere in the furnace. Therefore, it is possible to provide a fired ceramic product having less variation in composition within a lot.
[Brief description of the drawings]
FIG. 1 is a perspective view of a firing setter according to an embodiment of the present invention.
FIG. 2 is a view showing a state in which a plurality of firing setters shown in FIG. 1 are stacked.
FIG. 3 is a perspective view of a conventional firing setter.
FIG. 4 is a view showing a state where a plurality of conventional firing setters are stacked.
FIG. 5 is a schematic cross-sectional view of a setter for explaining a problem of a conventional firing setter.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 mounting plate 1a mounting surface 1b recess 1c abutting portion of support bottom surface 2 support 2a support body 2b convex portion 3 gas port 4 body to be fired

Claims (9)

When firing the object to be fired to produce a ceramic electronic component, a firing setter in which the object to be fired is placed in a firing furnace,
A mounting plate on which the object to be fired is mounted, and a support attached to one surface of the mounting plate,
A protrusion is provided on the bottom surface of the support,
A firing setter in which a concave portion having a size in which the convex portion can be inserted is recessed on a surface of the mounting plate on which the column is not attached. 2. The firing setter according to claim 1, wherein the support is configured separately from the mounting plate, and is attached to one surface of the mounting plate with an inorganic adhesive. 3. The placing plate is square in shape,
The support is attached to each corner of the placing plate,
The baking setter according to claim 1, wherein the recess is attached to the mounting plate at a position corresponding to the column. The depth of the concave portion is equal to or greater than the height of the convex portion, and the convex portion of the first calcining setter is fitted into the concave portion of the second calcining setter to thereby form the second calcining setter. The firing according to any one of claims 1 to 3, wherein when the first firing setters are stacked on each other, the support bottom surface of the first firing setter is in contact with the mounting surface of the second firing setter. For setter. The mounting plate has a square shape,
The firing setter according to any one of claims 1 to 4, wherein the support has a side having a length of 1/10 to 1/30 of a length of one side of the mounting plate to which the support is attached. The firing setter according to any one of claims 1 to 5, wherein the placing plate and the support are made of dense ceramics. The firing setter according to any one of claims 1 to 6, wherein the flatness of the mounting plate is 100 µm or less. The firing setter according to any one of claims 1 to 7, wherein at least one surface of the mounting plate is surface-treated with partially stabilized zirconia. When the first baking setter is stacked on the second baking setter by fitting the protrusion of the first baking setter into the recess of the second baking setter, 9. The firing setter according to claim 8, wherein a portion of the mounting plate of the first setter for abutting the bottom surface of the column of the first firing setter is not subjected to a partially stabilized zirconia surface treatment.

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