TWI719252B - Fixer for firing - Google Patents

Abstract

The fixing device 10 for firing is made of ceramics, and includes a surface layer 2, an intermediate layer 4 and a back layer 6. The middle layer 4 has a honeycomb structure, and the density is lower than that of the surface layer and the back layer. In addition, the surface layer 2 has a flat plate shape, and the thickness is 50 μm or more and 2000 μm or less. Furthermore, the open porosity of the surface layer 2 is 5% or more and 50% or less.

Description

Fixer for firing

The present invention discloses a technology related to a setter for firing. In particular, it discloses a technique related to a fixing device for firing made of ceramics.

When firing the fired object, the fired object is placed on a ceramic holder, and the holder is placed in the firing furnace. The holder and the burned object are heated in the burning furnace. In order to track the temperature change in the furnace well, a holder with a small heat capacity is required. Japanese Unexamined Patent Publication No. 1-167600 (hereinafter referred to as Patent Document 1) discloses a technique for reducing the heat capacity of the holder by setting the holder in a honeycomb structure. In Patent Document 1, the use of a honeycomb-structured fixture suppresses uneven heating of the upper surface (the surface not in contact with the fixture) and the lower surface (the surface in contact with the fixture) of the burned object.

As described above, when the holder is provided in a honeycomb structure, the density of the holder becomes smaller, and the heat capacity of the holder can be reduced. However, in general, when the density decreases, the strength decreases. Therefore, due to repeated use of the holder, the holder may be deformed or damaged. Merely setting the fixator into a honeycomb structure will reduce the durability of the fixator. It can be said that there is a trade off relationship between the decrease in heat capacity and the increase in durability. It is necessary to seek a fixer with a small heat capacity and high durability. This manual provides techniques for realizing a fixture with high durability while maintaining a small heat capacity.

The fixing device for firing disclosed in this specification is made of ceramics and includes a surface layer, an intermediate layer, and a back layer. The middle layer has a honeycomb structure, and the density is lower than that of the surface layer and the back layer. Furthermore, in the above-mentioned fixing device for firing, the surface layer is a flat plate with a thickness of 50 μm or more and 2000 μm or less, and the open porosity of the surface layer is 5% or more and 50% or less.

First, the "surface layer" and "back layer" mentioned in this manual will be described. The term "surface layer" refers to a layered portion that includes the surface on which the fired object is placed, is adjacent to the intermediate layer, and is formed with a density higher than that of the intermediate layer. The term "back layer" refers to a layered portion formed adjacent to the intermediate layer so as to be on the opposite side of the intermediate layer from the surface layer and formed at a density higher than that of the intermediate layer. In addition, when the front and back surfaces of the firing holder are used as the mounting surface of the fired object, the expressions of "surface layer" and "back layer" only indicate relative positions during firing. In this case, both the "surface layer" and the "back layer" have the same structural features as the above-mentioned "surface layer".

In the above-mentioned fixing device for firing, the density of the intermediate layer is lower than that of the surface layer and the back layer. In other words, the density of the surface layer and the back layer is higher than that of the intermediate layer. By providing a low-density intermediate layer, the heat capacity of the entire firing fixture is reduced. By providing a high-density surface layer and a back layer, the strength of the entire sintering fixture can be maintained.

Furthermore, by adjusting the thickness of the surface layer to 50 μm or more and 2000 μm or less, the strength of the surface layer can be ensured to support the weight of the fired object. Furthermore, by ensuring the strength of the surface layer, it is possible to prevent the surface layer from being cracked or broken due to impact when loading or taking out the burned object, and at the same time, it also suppresses the deformation of the fixture during the firing process. As a result, the burned object can be held firmly on the surface of the holder. For example, in the case of firing a burned object with a relatively small size, the loss of the burned object can be prevented by suppressing cracks or breakage of the surface layer. Furthermore, in the case of firing a burned object with a relatively large size, deformation of the burned object can be prevented by suppressing deformation of the holder. Furthermore, by adjusting the surface layer to the above-mentioned thickness, the heat capacity of the surface layer is suppressed from becoming too large, and the temperature difference between the holder and the fired object during temperature increase and decrease can be reduced.

In addition, when the density of the surface layer generally increases, the open porosity of the surface layer decreases. When the pores of the surface layer (especially the open porosity) decrease, the gas generated from the sintered object at the contact part of the sintered object and the surface layer becomes difficult to escape, or the atmosphere gas in the furnace becomes difficult to penetrate into The surface layer causes the temperature difference between the burned object and the holder to increase. In the above-mentioned fixing device for firing, by setting the open porosity of the surface layer to 5% or more, it is possible to prevent the gas generated from the fired object from becoming difficult to escape, and because the atmosphere gas in the furnace becomes easy to permeate To the surface layer, the temperature difference between the temperature in the furnace and the holder can be reduced. Furthermore, by setting the open porosity to 50% or less, it is also possible to prevent the strength of the surface layer from decreasing. In addition, the "open porosity" refers to the pores (open pores) connected to the outer space of the porous body among the pores of the porous body divided by the volume of the porous body.

2: Surface layer

4: middle layer

6: Back layer

10: Fixer

Fig. 1 is a perspective view showing the fixing device for firing of the first embodiment.

Fig. 2 is a partial enlarged view showing a cross section along the line II-II in Fig. 1.

Fig. 3 shows a modified example of the fixing device for firing of the first embodiment.

Fig. 4 shows a modified example of the fixing device for firing of the first embodiment.

Fig. 5 shows a modified example of the fixing device for firing of the first embodiment.

Fig. 6 shows a modified example of the fixing device for firing of the first embodiment.

Fig. 7 shows a modified example of the fixing device for firing of the first embodiment.

Fig. 8 is a perspective view showing the fixing device for firing of the second embodiment.

Fig. 9 is a partially enlarged view showing a section along the line IX-IX in Fig. 8.

Fig. 10 is a schematic diagram illustrating the manufacturing process of the fixing device for firing of the second embodiment.

Fig. 11 shows a modified example of the fixing device for firing of the second embodiment.

Fig. 12 shows a modified example of the fixing device for firing of the second embodiment.

Fig. 13 is a perspective view showing the fixing device for firing of the third embodiment.

Fig. 14 is a perspective view showing the fixing device for firing of the fourth embodiment.

Fig. 15 is a partial enlarged view showing a cross-section of the firing fixture of the fifth embodiment.

Fig. 16 is a partial plan view showing the firing fixture of the fifth embodiment.

Hereinafter, the characteristics of the technology disclosed in this specification are summarized. In addition, the items described below each have technical utility individually.

The holder disclosed in this specification is used for placing the burned object when the burned object is fired. The holder disclosed in this specification is made of ceramics. Although not particularly limited, the material of the holder can be cordierite, mullite, alumina, zirconia, silicon nitride, or silicon carbide. From the viewpoint of relatively low density of the material itself and low thermal expansion coefficient, the material of the fixture is preferably cordierite.

The holder includes a surface layer, a middle layer and a back layer. The burned object is placed on the surface layer. The surface layer is flat. Specifically, the surface layer does not include openings such as a mesh structure, a honeycomb structure, etc., the surface layer is solid, and the surface layer part is flat. By setting the surface layer in a flat plate shape, a relatively small object to be fired (for example, electronic components, etc.) can be stably placed on the holder.

The thickness of the surface layer is 50 μm or more and 2000 μm or less. By setting the thickness of the surface layer to 50 μm or more, the strength of the surface layer can be ensured to support the weight of the fired object. By ensuring the strength of the surface layer, it is possible to suppress cracks or breakage of the surface layer due to impact when loading or taking out the burned object. Furthermore, by ensuring the strength of the surface layer, the deformation of the fixture during the firing process is also suppressed. As a result, the burned object can be held firmly on the surface of the holder. For example, in the case of firing a burned object with a relatively small size, the loss of the burned object can be prevented by suppressing cracks or breakage of the surface layer. In the case of firing a fired object with a relatively large size, the deformation of the fired object can be prevented by suppressing the deformation of the holder. Furthermore, by setting the thickness of the surface layer to 2000 μm or less, the heat capacity of the surface layer is suppressed from becoming too large, and the heat of the furnace atmosphere gas flowing through the intermediate layer is easily transferred to the surface layer to be fired. Things. As a result, it is possible to reduce the temperature difference between the holder and the burned object when the temperature is raised and lowered. Although not particularly limited, the thickness of the surface layer is preferably 100 μm or more, and more preferably 150 μm or more. Furthermore, the thickness of the surface layer is preferably 1000 μm or less, preferably 500 μm or less, more preferably 250 μm or less, and particularly preferably 200 μm or less.

The open porosity of the surface layer is 5% or more and 50% or less. By setting the open porosity of the surface layer to 5% or more, it is possible to prevent the gas generated from the burned object from becoming difficult to escape. Furthermore, the atmosphere gas in the furnace becomes easy to penetrate into the surface layer, and the temperature difference between the temperature in the furnace and the holder can be reduced. The temperature of the surface of the fired object in contact with the holder is very close to the temperature in the furnace, and the entire fired object can be heated uniformly. Furthermore, by setting the open porosity to 50% or less, it is possible to prevent the strength of the surface layer from decreasing. Although not particularly limited, the open porosity of the surface layer is preferably 10% or more, more preferably 20% or more, and particularly preferably 30% or more. The open porosity of the surface layer is preferably 45% or less, preferably 40% or less, and particularly preferably 35% or less.

The back layer may be flat like the surface layer. Therefore, the surface of the back layer can also be used as the surface on which the fired object is placed. In this case, the thickness of the back layer may be the same as the thickness of the surface layer. Furthermore, the thickness of the back layer may be set thicker than the thickness of the surface layer, and the back layer may be used as a film layer that ensures the strength of the anchor. In this case, the thickness of the back layer may be 100 μm or more and 2000 μm or less. By setting the thickness to 100 μm or more, it is possible to prevent warpage of the fixture due to the load of the fired object and the fixture itself. That is, it is possible to obtain a fixture with high durability. If the thickness of the surface layer and the back surface layer is set to 100 μm or more, the surface layer and the back surface layer can be used as the mounting surface of the fired object, and at the same time, a high-durability anchor can be realized. From the viewpoint of achieving high durability, the thickness of the back layer is preferably 200 μm or more, and more preferably 300 μm or more. Furthermore, the thickness of the back layer is preferably 1000 μm or less, preferably 500 μm or less, more preferably 400 μm or less, and particularly preferably 350 μm or less.

The open porosity of the back layer can be the same as that of the surface layer, which is 5% or more and 50% or less. The surface layer and the back layer may be composed of the same material. By setting the open porosity of the back layer to 5% or more, when the back layer is used as a mounting surface of the burned object, it is possible to prevent the gas generated from the burned object from becoming difficult to escape. Furthermore, by setting the open porosity to 50% or less, the strength of the back layer can be ensured. Although not particularly limited, the open porosity of the back layer is preferably 10% or more, more preferably 20% or more, and particularly preferably 30% or more. The open porosity of the back layer is preferably 45% or less, preferably 40% or less, and particularly preferably 35% or less.

Furthermore, when the back layer is used as a film layer to ensure the strength of the fixture, the back layer can also be immersed in finely ground cordierite, mullite particles, alumina particles, zirconia particles, nitrogen Silicon carbide particles, silicon carbide particles, etc., are fired to increase the strength of the back layer. The strength of the back layer can be ensured without increasing the thickness of the back layer, and a lightweight and high-strength anchor can be obtained.

The density of the middle layer is lower than that of the surface layer and the back layer. In addition, the surface layer and the back layer may have the same density or different densities. The middle layer has a honeycomb structure. The aperture ratio of the honeycomb structure constituting the intermediate layer may be 50% or more and 95% or less. That is, in the cross-section orthogonal to the extending direction of the opening, the area of the partition wall defining the opening is 5% or more and 50% or less, and the portion (void) other than the partition wall may be 50% or more and 95% or less. In addition, the open porosity of the partition wall may be the same as that of the surface layer and/or the back layer, being 5% or more and 50% or less. The same reason as the surface layer and/or back layer, the open porosity of the partition wall is 10 % Or more is preferable, 20% or more is more preferable, and 30% or more is particularly preferable. Furthermore, the open porosity of the partition wall is preferably 45% or less, preferably 40% or less, and particularly preferably 35% or less.

The thickness of the partition wall defining the opening of the honeycomb structure may be 50 μm or more and 2000 μm or less. By setting the thickness of the partition wall to 50 μm or more, the strength of the partition wall can be ensured, and the strength as a honeycomb structure can be ensured. By setting the thickness of the partition wall to 2000 μm or less, it is possible to suppress an increase in the heat capacity of the holder. From the viewpoint of ensuring the strength of the honeycomb structure while suppressing the increase in heat capacity, the thickness of the partition wall is preferably 60 μm or more, and more preferably 80 μm or more. Furthermore, the thickness of the partition wall is preferably 1000 μm or less, preferably 500 μm or less, more preferably 200 μm or less, and particularly preferably 100 μm or less. In addition, the thickness of the partition wall may be the same as the thickness of the surface layer and/or the back layer. If the thickness of the partition wall is the same as the thickness of the surface layer and the back layer, all parts constituting the fixture have the same thickness, which can be easily manufactured.

The hydraulic diameter of the opening defined by the partition wall may be 0.3 mm or more and 7 mm or less. By setting the hydraulic diameter to 0.3 mm or more, the atmospheric gas can easily pass through the inside of the intermediate layer. With the atmosphere gas, the holder is heated or cooled from the inside, so the temperature change of the holder easily follows the temperature change of the atmosphere in the furnace, and the temperature rise and fall speed during firing can be quickly set. By setting the hydraulic diameter to 7 mm or less, the high strength of the structure as the intermediate layer can be maintained. The hydraulic diameter is preferably 0.4 mm or more, preferably 0.5 mm or more, and particularly preferably 0.6 mm or more. The hydraulic diameter is preferably 3 mm or less, preferably 2 mm or less, and particularly preferably 1.5 mm or less.

The intermediate layer is arranged between the surface layer and the back layer. In other words, the surface layer and the back layer are joined through the intermediate layer. The surface layer, the middle layer and the back layer may also be integrally formed. Specifically, the partition wall between the surface layer and the intermediate layer is continuous, the partition wall between the back layer and the intermediate layer is continuous, and the surface layer, the intermediate layer, and the back layer may be integrated. In this case, the surface layer, the intermediate layer, and the back layer are composed of the same material. The holder of this structure can be manufactured by, for example, extrusion molding.

The opening of the intermediate layer may extend in the direction connecting the surface layer and the back layer (that is, the thickness direction). Alternatively, the opening may extend in a direction orthogonal to the direction connecting the surface layer and the back layer (that is, a direction parallel to the surface or the back surface). Hereinafter, the thickness direction may be referred to as the first direction, or the direction orthogonal to the first direction may be referred to as the second direction.

The form in which the opening extends in the first direction can increase the strength (compressive strength) in the thickness direction, and is suitable as a holder for firing a heavy fired object. Furthermore, the form in which the opening extends in the second direction can easily control the thickness of the surface layer and the back layer during extrusion molding, which is advantageous for easy integral molding. In addition, in the form in which the opening extends in the second direction, the opening may appear only once in the first direction, or may appear multiple times. That is, between the surface layer and the back layer, one or more honeycomb cells (openings surrounded by partition walls) may appear. In this case, the honeycomb unit may be 1 unit or more and 6 units or less. The number of honeycomb units can be appropriately adjusted based on the required thickness, hydraulic diameter, etc. of the fixture.

The thermal expansion coefficient of the holder disclosed in this specification may be 2.0 ppm/°C or less, preferably 1.5 ppm/°C or less, and preferably 1.0 ppm/°C or less. In addition, the "thermal expansion coefficient of the fixture" refers to a sample containing a surface layer, a middle layer (honeycomb structure layer), and a back layer, and the middle layer contains one or more honeycomb units. The temperature is from room temperature to 800°C. The measured value. In addition, even in the case of using a material with a thermal expansion coefficient of more than 2.0 ppm/°C for bulk parts formed by compression molding, etc., a honeycomb structure layer (intermediate layer) is formed by using extrusion molding. The fixer can also get a fixer with a thermal expansion coefficient of 2.0 ppm/℃ or less.

The fixer disclosed in this specification may be a flat plate as a whole, or ribs may be provided at the ends in the plane. The flat plate-shaped fixture can be easily manufactured. By providing ribs on the fixture, the strength of the fixture can be compensated. Furthermore, by providing the ribs, when a plurality of holders are stacked in the firing furnace, a spacer for ensuring a gap between the respective holders can be eliminated.

Furthermore, the fixer disclosed in this specification may also be provided with a coating layer on the surface and/or the back surface. With the coating layer, it is possible to prevent a chemical reaction between the fired object and the holder. By applying coating, it is possible to increase the selectivity of the material of the fixture or the type of the fired object. Furthermore, by applying coating, the smoothness of the surface of the fixture can also be improved (surface roughness can be reduced).

In addition, the coating layer preferably has open pores. It can prevent the gas generated from the burned object from becoming difficult to escape. Although not particularly limited, for the same reason as the above-mentioned surface layer and back layer, the open porosity of the coating layer can be 5% or more and 70% or less, preferably 20% or more, preferably 30% or more. More than 40% is particularly good. Furthermore, the open porosity of the coating layer is preferably 50% or less, preferably 45% or less, more preferably 40% or less, and particularly preferably 35% or less.

In the case of providing the coating layer, the thickness of the coating layer may be 500 μm or less. If the coating layer is too thick, peeling of the coating layer may occur due to repeated firing. Furthermore, if the coating layer is too thick, the cost of the fixture will increase. From the viewpoint of suppressing peeling and suppressing cost increase, the thickness of the coating layer may be 500 μm or less, 400 μm or less, 300 μm or less, 250 μm or less, or 200 μm or less. m or less, may be 150 μm or less, may be 100 μm or less, or may be 50 μm or less.

Furthermore, in the case of providing the coating layer, the thickness of the coating layer may be 5 μm or more from the viewpoint of effectively preventing the chemical reaction between the fired object and the holder. In addition, from the viewpoint of continuing to prevent the chemical reaction between the fired object and the holder for a long time, the thickness of the coating layer is preferably 10 μm or more, preferably 20 μm or more, and 50 μm or more. More than μm is particularly preferred.

The coating layer can be formed by methods such as gas plasma spraying, hydroplasma spraying, spray coating, casting and the like. From the viewpoint of obtaining a good open porosity, it is better to form the coating layer by spray coating or casting. Various materials can be selected for the coating layer according to the material of the holder and the method of forming the coating layer. As an example, the material of the coating layer can be mullite, alumina, alumina-zirconia, Y ₂ O ₃ stabilized zirconia, CaO stabilized zirconia, CaO/Y ₂ O ₃ stabilization zirconia material, spinel (spinel) material. From the viewpoint of obtaining good open porosity and suppressing chemical reaction with the fired object, the material of the coating layer is preferably alumina material or alumina-zirconia material.

As an example of the holder disclosed in this specification, a ceramic holder for firing electronic parts can be cited. The holder disclosed in this specification can be applied to the firing of electronic parts whose contact surface with the holder is approximately 0.1mm×0.2mm. Although not particularly limited, the technology disclosed in this specification can be applied as an example to ceramic holders with a width of 50 to 500 mm, a length of 50 to 250 mm, and a thickness of 0.5 to 10 mm.

[Example]

(First embodiment)

The anchor 10 will be described with reference to Figs. 1 and 2. As shown in FIG. 1, the anchor 10 includes a surface layer 2, an intermediate layer 4 and a back layer 6. The intermediate layer 4 is provided between the surface layer 2 and the back layer 6. The material of the surface layer 2, the middle layer 4 and the back layer 6 is cordierite. The surface of the surface layer 2 and the surface (back surface) of the back surface layer 6 are flat. That is, the surface layer 2 and the back surface layer 6 are in the shape of a flat plate. Therefore, the holder 10 itself has a flat plate shape.

The middle layer 4 has a honeycomb structure and has a lower density than the surface layer 2 and the back layer 6. The details will be described later. The opening of the intermediate layer 4 extends in a direction orthogonal to the thickness direction (the direction of the arrow 20 in Figure 1). The opening of the intermediate layer 4 extends in the direction of the arrow 20 and communicates from one end of the holder 10 to the other end. On the side of the holder 10, a side wall 8 is provided. The side wall 8 is not provided in the direction in which the opening of the intermediate layer 4 extends. That is, the side walls 8 are provided on two surfaces orthogonal to the direction of the arrow 20 among the side surfaces of the holder 10. The side wall 8 extends in the thickness direction of the holder 10 (perpendicular to the surface layer 2 and the back layer 6).

As shown in FIG. 2, the intermediate layer 4 includes a partition wall 14 and a space (opening portion) 12 surrounded by the partition wall 14. Therefore, the density of the intermediate layer 4 is lower than that of the surface layer 2 and the back surface layer 6. The thickness t2 of the surface layer 2 is 100 μm , the thickness t4 of the intermediate layer 4 is 800 μm , and the thickness t6 of the back layer 6 is 100 μm . The thickness t10 of the holder 10 is 1 mm.

In the intermediate layer 4, the partition wall 14 constitutes a truss structure 16. The truss structure 16 is an example of a honeycomb structure. In the holder 10, a one-step honeycomb unit is provided between the surface layer 2 and the back surface layer 6. As shown in FIG. The length D16 of one side of the opening 12 of the truss structure 16 is 0.92 mm. The thickness t14 of the partition wall 14 is 100 μm . That is, in the holder 10, the thickness t2 of the surface layer 2, the thickness t6 of the back layer 6, and the thickness t14 of the partition wall 14 are equal. The aperture ratio of the fixture 10 is 70%, and the hydraulic diameter is 0.53 mm. In addition, at the end of the intermediate layer 4 (a part of the opening 12 defined by the side wall 8 ), the area of the opening 12 is about half of the area of the other openings 12.

The partition wall 14 is continuous with the surface layer 2, the back layer 6 and the side wall 8. In the holder 10, the surface layer 2, the intermediate layer 4, the back layer 6, and the side wall 8 are integrally formed of the same material (cordierite). The surface layer 2, the middle layer 4, the back layer 6, and the side wall 8 have open pores, and the open porosity is 35%. Furthermore, the thermal expansion coefficient of the holder 10 is 0.9 ppm/°C. In addition, the thermal expansion coefficient of the cordierite of the bulk material (in a state where the structure is not oriented) is 2.2 to 2.8 ppm/°C. Since the anchor 10 has a honeycomb structure by extrusion molding, the thermal expansion coefficient can be greatly reduced compared with a solid anchor.

As described above, the anchor 10 includes a planar surface layer 2 and a back layer 6 and a honeycomb-shaped intermediate layer 4 provided between the surface layer 2 and the back layer 6. The fixing device 10 has a honeycomb-shaped intermediate layer 4, so that the weight can be reduced compared with a solid fixing device. The holder 10 can reduce the heat capacity and can well follow the temperature change in the furnace. Furthermore, the hydraulic diameter of the opening 12 of the intermediate layer 4 is 0.53 mm, and the furnace gas can move in the intermediate layer 4 well. The fixture 10 can be heated from the outside and the inside (in the middle layer 4), and can better follow the temperature change in the furnace.

Furthermore, the thickness (100 μm ) of the surface layer 2 and the back layer 6 is sufficiently ensured, and sufficient strength can still be exhibited regardless of whether it has a honeycomb structure. Generally, when the thickness of the surface layer increases, the movement of the gas generated from the burned article is hindered in the portion where the burned article is in contact with the surface layer. However, in the fixture 10, the surface layer 2 has open pores, and the open porosity is adjusted to 35%. Therefore, even in the portion where the fired object is in contact with the holder 10, the gas generated from the fired object can surely move to the outside of the fired object, and the fired object can be fired well. Furthermore, the gas in the furnace penetrates into the surface layer 2 from the outside of the holder 10 and the opening 12 (intermediate layer 4), and the temperature of the surface layer 2 follows the temperature in the furnace well. Furthermore, since the side wall 8 is orthogonal to the surface layer 2 and the back surface layer 6, it is possible to ensure sufficient compressive strength at the end of the fixture 10.

The fixer 10 is an example of the technology disclosed in this specification, and various variations can be obtained. Hereinafter, several modified examples of the holder 10 will be explained.

In the anchor 10a shown in FIG. 3, the thickness t6a of the back layer 6a is different from that of the anchor 10. Refer to Figure 1 for the rough appearance. Regarding the holder 10a, the same structure as the holder 10 uses the same reference numerals as the holder 10, and the description thereof is omitted.

In the holder 10a, the thickness t6a of the back layer 6a is 300 μm . The anchor 10a can increase the strength more than the anchor 10. In addition, in the anchor 10, in addition to the back layer 6, the strength can be improved even if the thickness of the surface layer 2 or the intermediate layer 4 is increased. Alternatively, the thickness of the back layer 6 is not increased, and the strength can be improved even if the thickness of the surface layer 2 or the intermediate layer 4 is increased. However, increasing the thickness of each layer 2, 4, and 6 increases the weight of the fixture. The anchor 10a can increase the strength while suppressing the increase in weight by increasing only the thickness of the back layer that is most helpful for increasing the strength.

In the holder 10a, the structure of the surface layer 2 and the partition wall 14 in contact with the object to be fired is the same as that of the holder 10. In the anchor 10a, the heat capacity of the surface layer 2 and the intermediate layer 4 near the surface layer 2 does not increase relative to the anchor 10. Therefore, the anchor 10a can reduce the heat capacity like the anchor 10 while increasing the strength.

In the anchor 10b shown in FIG. 4, the thickness t14a of the partition wall 14a is different from that of the anchor 10. Refer to Figure 1 for the rough appearance. For the holder 10b, the same structure as the holder 10 uses the same reference numerals as the holder 10, and the description thereof is omitted.

In the holder 10b, the thickness t14a of the partition wall 14a is 60 μm . The anchor 10b can be lighter than the anchor 10 in weight. Furthermore, by making the thickness of the partition wall 14 thinner than the holder 10, the aperture ratio of the intermediate layer 4 increases (the density of the intermediate layer 4 decreases), and therefore the heat capacity is further reduced. As mentioned above, the back layer contributes most to the strength of the fixture. Therefore, even if the thickness of the partition wall is thinned, the strength of the fixture will not be significantly reduced. The anchor 10b can reduce the weight and heat capacity while suppressing the decrease in strength.

In addition, in the anchor 10b, the thickness of the back layer 6 may be the same as that of the anchor 10a (Figure 2). In other words, in the holder 10, the thickness of the back layer 6 may be thicker than the thickness of the surface layer 2, or the thickness of the partition wall 14 may be thinner than the thickness of the surface layer 2.

In the holder 10c shown in FIG. 5, the shape of the side wall 8a is different from that of the holder 10. Refer to Figure 1 for the rough appearance. For the holder 10c, the same structure as the holder 10 uses the same reference numerals as the holder 10, and the description thereof is omitted. In the holder 10c, the side wall 8a is inclined with respect to the thickness direction. Specifically, the size of the opening 12 is the same at the center part and the end part of the intermediate layer 4. As a result, the furnace gas can pass through the entire intermediate layer 4 evenly. The holder 10c can suppress the occurrence of temperature unevenness in the plane.

In addition, the feature that the side walls are inclined so that the size of the opening 12 is equal at the center portion and the end portion of the intermediate layer 4 can also be applied to the above-mentioned anchors 10a and 10b.

In the anchor 10d shown in FIG. 6, the structure of the intermediate layer 4 is different from that of the anchor 10. For the holder 10d, the same structure as the holder 10 uses the same reference numerals as the holder 10, and the description thereof is omitted. In the anchor 10d, the intermediate layer 4 is provided with a two-step truss structure (honeycomb unit) 16a, 16b. That is, the opening 12 appeared twice in the direction (thickness direction) connecting the surface layer 2 and the back surface layer 6. In addition, the side wall 8 extends in the thickness direction of the holder 10d (orthogonal to the surface layer 2 and the back layer 6).

The anchor 10d can increase the thickness of the anchor without increasing the size of each truss structure. If the size of the truss structure is increased too much, the strength of the anchor may decrease. By forming a two-step truss structure, the thickness of the anchor can be ensured while suppressing the decrease in strength. Alternatively, the anchor 10d can be said to ensure the thickness of the anchor without increasing the thickness of the surface layer 2 and the back layer 6. That is, the anchor 10d can ensure the thickness while suppressing the increase in weight.

In addition, Fig. 6 shows a fixture 10d including two-step truss structures 16a and 16b. However, the order of the truss structure may be two or more steps. The order of the truss structure can be 2 or more and 6 or less. Furthermore, in the anchor 10d, the thickness of the back layer 6 may be thicker than the thickness of the surface layer 2 and/or the thickness of the partition wall 14 may be thinner than the thickness of the surface layer 2.

The anchor 10e shown in FIG. 7 can be said to be a modified example of the anchor 10d. For the holder 10e, the same reference numerals as those of the holder 10d are used for the same structure as the holder 10d, and the description thereof will be omitted. In the holder 10e, the structure of the side wall 8b is different from that of the holder 10d. The outer surface of the side wall 8b has a curve. By having the side wall 8b, it is possible to make the end of the holder 10e less likely to break.

(Second embodiment)

The anchor 210 will be described with reference to FIGS. 8 and 9. The holder 210 is a modified example of the holder 10, and the same reference numerals as those of the holder 10 are used for the points in common with the holder 10, and the description thereof is omitted.

In the holder 210, a rib 30 is provided at the end 34 on the side of the surface layer 2. In other words, the thickness of the central portion 32 of the holder 210 is thinner than the end portion 34. The rib 30 extends along the arrow 20 extending from the opening 12 (parallel to the direction in which the opening 12 extends). The ribs 30 are provided at both ends of the surface layer 2 in a direction orthogonal to the direction in which the opening 12 extends. By providing the rib 30, when the to-be-fired object is fired, a plurality of holders 210 can be stacked and fired. The burned object is set in the space formed by the rib 30 (the space formed between the stacked holders 210 and 210).

As shown in Figure 9, the end 34 of the holder 210 includes 4 steps The truss structures 16a, 16b, 16c and 16d. In contrast, the central portion 32 includes two-step truss structures 16c and 16d. In this way, by forming the rib 30 with the truss structure, it is possible to suppress the increase in the weight of the anchor 210. In addition, the wall surface 30a connecting the end portion 34 and the center portion 32 is inclined with respect to the thickness direction. The gas in the furnace can evenly pass through the entire rib 30.

In addition, a flat plate including the four-step truss structures 16a, 16b, 16c, and 16d shown in Figure 10 is prepared, and the truss structures 16a, 16b that form the central portion 32 are removed along the dotted line 36 to easily form a fixed器210. That is, in the holder 210, the central portion 32 where the burned object is placed is integrated with the rib 30.

Figure 11 shows the holder 210a. The holder 210a is a modified example of the holder 210. Regarding the holder 210a, the same structure as the holder 210 uses the same reference numerals as the holder 210, and the description thereof is omitted. The central portion 32 of the holder 210a is provided with a coating layer 40. The coating layer 40 is made of aluminum oxide and is formed on the surface of the surface layer 2 by spray coating. The open porosity of the coating layer 40 is 30%, and the thickness is 50 microns.

In addition, like the holder 210b shown in FIG. 12, the coating layer 40a may be provided on the central portion 32 and the wall surface 30a of the holder 210b. In addition, the coating layer 40a may be provided on the surface layer of a flat plate-shaped holder. That is, the coating layer 40a may be provided on the surface of the surface layer 2 of the above-mentioned holders 10, 10a, 10b, 10c, 10d, and 10e.

(Third embodiment)

With reference to Fig. 13, the anchor 310 will be described. The holder 310 is a modified example of the holders 10 and 210, and for those common to the holders 10 and 210 Here, the same reference numerals as those of the holders 10 and 210 are used, and the description thereof is omitted.

The holder 310 is the same as the holder 210, and in a direction orthogonal to the direction in which the opening 12 extends (the direction of the arrow 20), both ends of the surface layer 2 are provided with ribs 330a. Furthermore, the holder 310 is provided with a rib 330b at one end of the direction in which the opening 12 extends. The rib 330a and the rib 330b are integrated. Therefore, the anchor 310 can be said to be that the ribs 330 (ribs 330a and 330b) are provided on three sides of the end of the surface layer 2. The holder 310, compared to the holder 210, when a plurality of holders 310 are stacked, the holders 310 and 310 are in contact with each other on three sides. Therefore, the anchors 310 and 310 can be stably supported on each other. Furthermore, it is also possible to prevent the burned object from falling off the surface of the holder 310.

In addition, in the holder 310, a coating layer may be provided on the wall surface of the surface layer 2 and/or the rib 330 (see FIGS. 11 and 12 together). When the rib 330 is provided with a coating layer, the coating layer may be provided on the wall surface of the rib 330a instead of the wall surface of the rib 330b. Alternatively, a coating layer may be provided on both the wall surface of the rib 330a and the wall surface of the rib 330b. When the coating layer is provided on the wall surface of the rib 330b, the coating layer is provided on the end surface of the partition wall 14 while ensuring the opening 12. Thereby, while preventing the reaction between the fired object and the surface of the holder, since the furnace gas passes through the opening 14 of the rib 330b, the temperature of the surface layer 2 can well follow the furnace atmosphere.

(Fourth embodiment)

With reference to Fig. 14, the anchor 410 will be described. The holder 410 is a modification of the holders 10, 210, and 310. For the common features with the holders 10, 210, and 310, the same reference numerals as the holders 10, 210, and 310 are used, and The description is omitted.

In the holder 410, the entire periphery of the end of the surface layer 2 is surrounded by the rib 430. In other words, in the holder 410, the central portion 32 is recessed. In detail, in the direction orthogonal to the direction in which the opening 12 extends (the direction of the arrow 20), both ends of the surface layer 2 are provided with ribs 430a. Furthermore, ribs 430b are provided at both ends of the direction in which the opening 12 extends. The rib 430a and the rib 430b are integrated. In the holder 410, a coating layer may be provided on the surface layer 2 and/or the wall surface of the rib 430. When the rib 430 is provided with a coating layer, the coating layer may be provided only on the wall surface of the rib 430a, and the coating layer may not be provided on the wall surface of the rib 430b. Alternatively, a coating layer may be provided on both the wall surface of the rib 430a and the wall surface of the rib 430b. When the coating layer is provided on the wall surface of the rib 430b, the coating layer is provided on the end surface of the partition wall 14 while ensuring the opening 12. Thereby, while preventing the reaction between the fired object and the surface of the holder, since the furnace gas passes through the opening 14 of the rib 430b, the temperature of the surface layer 2 can well follow the furnace atmosphere.

(Fifth embodiment)

The anchor 510 will be described with reference to Figs. 15 and 16. FIG. 15 shows a part of the cross section of the holder 310, which is equivalent to the part shown in FIG. 2 in the holder 10. As shown in FIG. Furthermore, Fig. 16 is a view of the anchor 310 viewed from the side of the surface layer 2, and the shape of the intermediate layer is shown by a broken line.

In the holder 510, the opening 12 of the middle layer 4 (truss structure) extends in the direction connecting the surface layer 2 and the back layer 6 (the direction of the arrow 50). That is, in the holder 510, the partition wall 14 extends in a direction parallel to the arrow 50. Therefore, the anchor 510 can increase the compressive strength in the thickness direction. Furthermore, like the holders 10, 210, etc. (refer to Figures 1 and 8), in the case where the opening 12 extends in the direction of the arrow 20, in order to ensure that the hydraulic diameter of the opening 12 is large, it is necessary to increase the size of the intermediate layer 4 Thicker. However, in the case of the holder 510, while the thickness of the intermediate layer 4 is thinned (that is, the thickness of the holder 510 is thinned), the hydraulic diameter of the opening 12 can be increased.

The holder 510 can be manufactured by separately forming the surface layer 2, the intermediate layer 4, and the back layer 6, and bonding the layers 2, 4, and 6 using a ceramic paste, and firing them at a predetermined temperature. Specifically, for example, by extrusion molding, an intermediate layer 4 including a honeycomb structure and openings 12 appearing on the surface and the back surface is formed. Furthermore, separately from the intermediate layer 4, a sheet-like surface layer 2 and a back surface layer 6 are formed by, for example, extrusion molding. After that, the surface layer 2 and the back layer 6 are bonded to the intermediate layer 4, and the anchor 510 can be formed by firing. By forming the surface layer 2, the intermediate layer 4, and the back layer 6 separately, the materials and/or open porosity of the layers 2, 4, and 6 can be different. For example, the open porosity of the partition wall 14 of the intermediate layer 4 may be smaller than the open porosity of the surface layer 2. It can ensure that the surface layer 2 maintains the original open porosity, and further enhance the strength of the intermediate layer 4. In addition, in the holder 510, a coating layer may be provided on the surface of the surface layer 2.

(Research on the thickness of the coating layer)

A coating layer was formed on the surface of the holder 10 (refer to FIG. 1), and a heating experiment of the holder 10 itself and a reactivity experiment with the fired object were performed. In addition, cordierite is used as the material of the fixture 10. The coating material is: 0.5 parts of hydrophilic organic binder (binder) is added to 100 parts of granular ceramics with an average particle size of 20-100μm, and 60 parts of ion exchange water are added and the mixture is added to the placed ceramic The jade container is ground and mixed with a pot mill to produce a slurry. In addition, ion exchange water is used to adjust the coating material (slurry) to a viscosity that is easy to coat. Furthermore, as the ceramic jade, for example, alumina jade can be used. A trommel can also be used instead of a pot mill. A spray gun is used to apply the prepared coating material (raw slurry) on the surface of the holder 10 to form a coating layer. In addition, the coating time was adjusted to form a coating layer of 5 to 600 μm on the surface of the holder 10 (sample 1-12). Furthermore, a plasma sprayer was used to spray granular ceramics with an average particle size of 20-100 μm on the surface of the holder 10 to form a 100 μm coating layer on the surface of the holder 10 (Sample 13). Furthermore, the above-mentioned coating material (raw slurry) was poured on the surface of the holder 10, and a coating layer of 100 μm was formed on the surface of the holder 10 (sample 14). As the aforementioned granular ceramics, for example, zirconia, mullite, alumina, etc. can be used. In addition, a heating experiment and a reactivity experiment (Sample 15) were also performed on the holder 10 without the coating layer. The experimental conditions and results are shown in Table 1.

The heating experiment was performed on the holder 10 (for the holder 10 itself) on which the heated part was not placed in a nitrogen atmosphere under atmospheric pressure. In the heating experiment, a cycle of heating to 1350°C at a temperature increase rate of 100°C/hour, holding at 1350°C for 2 hours, and then naturally cooling to room temperature was one cycle, and five cycles were performed. In Table 1, samples with no abnormalities in the coating layer after each cycle are marked as "A", samples with no peeling but confirmed deterioration (swelling, etc.) are marked as "B", and samples with peeling confirmed are marked as "C".

In the reactivity experiment, 100 parts to be heated (ceramic capacitors (condenser)) were placed on the holder 10 under atmospheric pressure in a nitrogen atmosphere, and heated to 1200°C at a temperature increase rate of 100°C/hour. At 1200 The cycle of maintaining the temperature for 10 minutes and then cooling to room temperature is regarded as 1 cycle, and 5 cycles are performed. In Table 1, after each cycle, samples with 0 to 2 heated parts with uneven firing are marked as "A", and samples with 3 to 4 heated parts with uneven firing are marked as "B". Samples with more than 5 samples of heated parts that have uneven firing are marked as "C".

As shown in Table 1, in the heating experiment, it was confirmed that if the thickness of the coating layer is 500 μm or less, the abnormality (peeling, swelling) of the coating layer can be suppressed. However, if the thickness of the coating layer exceeds 250 μm , as the number of cycles of the heating experiment increases, a sample with an abnormality in the coating layer is found. However, it can be confirmed that if the thickness of the coating layer is 250 μm or less, even if the heating experiment is repeated, no abnormality occurs in the coating layer. Furthermore, in the reactivity experiment, it was confirmed that by providing the coating layer, the occurrence of uneven firing accompanied by the reaction between the holder and the non-heated part was improved (Sample 1, 15). In particular, it can be confirmed that if the thickness of the coating layer is 20 μm or more, even if the number of cycles is increased, uneven firing of the heated member does not occur (all evaluations are "A"). In addition, in this experiment, it was confirmed that even though the reactivity experiment was performed for 5 cycles, there was no sample evaluated as "C". From the above results, it can be confirmed that it is better to adjust the thickness of the coating layer to 5 to 500 μm. In particular, by adjusting the thickness to 20 to 250 μm, it is possible to prevent abnormalities in the coating layer and prevent the heated parts from being burnt. Evenly. In addition, in this experiment, it was confirmed that the method of forming the coating layer did not cause a difference (Sample 5, 13, 14).

It should be noted that the aforementioned evaluations "A", "B", and "C" are marked as "○", "△" and "X" in Table 1.

In the above-mentioned embodiment, the fixer including the truss shape (triangle) as the honeycomb structure has been described. However, the shape of the honeycomb structure may also be quadrilateral (square, rectangular), hexagon, or the like.

Above, specific examples of the present invention have been described in detail, but they are only examples and do not limit the scope of the patent application. The technology described in the scope of the patent application includes various changes and modifications of the specific examples listed above. Furthermore, the technical elements described in this specification or the drawings can exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the scope of the patent application at the time of application. Furthermore, the technologies listed in this specification or the drawings can achieve multiple goals at the same time, and achieving one of the goals is technically practical in itself.

2‧‧‧Surface layer

4‧‧‧Middle layer

6‧‧‧Back layer

8‧‧‧Sidewall

10‧‧‧Fixer

20‧‧‧Arrow

Claims (11)

A fixer for firing, which is a fixer for firing made of ceramics, comprising a surface layer, a middle layer and a back layer. The middle layer has a honeycomb structure, and the density is lower than that of the surface layer and the back layer. It is 50 μm or more and 2000 μm or less, and the open porosity is 5% or more and 50% or less. The fixing device for firing described in the first item of the scope of patent application, wherein the back layer is a flat plate with a thickness of 100 μm or more and 2000 μm or less. The fixing device for firing as described in item 1 or 2 of the scope of patent application, wherein the thickness of the partition wall defining the opening of the honeycomb structure of the intermediate layer is 50 μm or more and 2000 μm or less. The fixing device for firing as described in item 3 of the scope of patent application, wherein the hydraulic diameter of the opening is 0.3 mm or more and 7 mm or less. The fixing device for firing as described in the third item of the scope of patent application, wherein the opening ratio of the above-mentioned opening is 50% or more and 95% or less. The fixing device for firing described in the scope of patent application 3, wherein the opening is opened in a second direction orthogonal to the first direction connecting the surface layer and the back layer. The fixing device for firing as described in item 1 of the scope of patent application, wherein the strength of the back layer is higher than that of the surface layer and the middle layer. The fixing device for firing as described in item 1 of the scope of patent application, wherein the coefficient of thermal expansion is 2.0 ppm/°C or less. The fixing device for firing as described in item 1 of the scope of patent application, wherein the honeycomb structure of the intermediate layer has partition walls, The partition wall between the surface layer and the intermediate layer is continuous, the partition wall between the back layer and the intermediate layer is continuous, and the surface layer, the intermediate layer and the back layer are integrally formed. The fixing device for firing as described in item 1 of the scope of patent application, wherein a coating layer is provided on the surface layer. The fixing device for firing as described in item 10 of the scope of patent application, wherein the thickness of the coating layer is 5 μm or more and 500 μm or less.

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