JP2020189785A - Ceramic structure - Google Patents

Abstract

To provide a ceramic structure having higher strength than conventionally and excellent in thermal shock resistance.SOLUTION: A plate-like ceramic structure has: a plurality of first ceramic-made line parts 10 extending toward one direction; a plurality of second ceramic-made line parts 20 extending toward a direction crossing with the first line parts; and a third ceramic-made line part 30 passing through a diagonal line of a quadrilateral formed by the first and second line parts crossing with each other, wherein: the first, second and third line parts cross at one crossing section 2; at any crossing section, the second line part is arranged on the third line part; and at any crossing section, the first line part is arranged on the second line part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a structure formed by combining ceramic streaks.

Applicants first have a plurality of first lines of ceramics extending in one direction and a plurality of second lines of ceramics extending in a direction intersecting the first streaks. A ceramic lattice body having a strip is proposed (see Patent Documents 1 and 2). At the intersection of the first streak and the second streak in this ceramic lattice, the second streak is arranged on the first streak at any of the intersections. It is in a state and has a rectangular through hole in a plan view.

JP-A-2018-184304 JP-A-2018-193274

The ceramic lattice bodies described in Patent Documents 1 and 2 have high strength and excellent spalling resistance due to the lattice structure. In particular, the strength along the direction parallel to the lattice is extremely high. However, in the diagonal direction of the lattice, further improvement in strength may be required.

Therefore, an object of the present invention is to improve a structure composed of a plurality of lines made of ceramics, and more specifically, to make the structure have higher strength and higher thermal shock resistance. ..

The present invention includes a plurality of first streaks made of ceramics extending in one direction and a plurality of second streaks made of ceramics extending in a direction intersecting the first streaks. It has a third line made of ceramics that passes on the diagonal of a quadrilateral defined by the intersection of the first line and the second line.
The above-mentioned by providing a plate-shaped ceramic structure in which a plurality of triangular through holes defined by a first streak, a second streak and a third streak are formed. It is a solution to the problem.

FIG. 1 is a plan view showing an embodiment of the ceramic structure of the present invention. FIG. 2 is a perspective view of the ceramic structure shown in FIG. 1 as viewed from the upper surface side. FIG. 3 is a perspective view of the ceramic structure shown in FIG. 1 as viewed from the lower surface side. FIG. 4 is a cross-sectional view taken along the line AA in FIG. FIG. 5 is a cross-sectional view taken along the line BB in FIG. FIG. 6 is a cross-sectional view of the third streak portion in the ceramic structure shown in FIG. 7 (a) and 7 (b) are cross-sectional views of a first line portion and a second line portion in the ceramic structure shown in FIG. 1, respectively. 8 (a) is a plan view showing another embodiment of the ceramic structure of the present invention, and FIG. 8 (b) is a sectional view taken along line AA in FIG. 8 (a). 9 (a) is a plan view showing still another embodiment of the ceramic structure of the present invention, and FIG. 9 (b) is a sectional view taken along line AA in FIG. 9 (a).

Hereinafter, the present invention will be described based on the preferred embodiment with reference to the drawings. 1 to 7 show an embodiment of the ceramic structure of the present invention. The ceramic structure (hereinafter, also simply referred to as “structure”) 1 shown in these figures is a flat plate, and has a first surface 1a and a second surface 1b facing the first surface 1a.

The structure 1 of the present embodiment has a plurality of first linear portions 10 made of ceramics extending in one direction X. Each of the first streaks 10 is substantially straight and extends parallel to each other. The spacing between the adjacent first streaks 10 is approximately equal.

The structure 1 has a plurality of second linear portions 20 made of ceramics extending in the Y direction, which is a direction different from the X direction. Each of the second streaks 20 has a straight line and extends parallel to each other. The spacing between the adjacent second streaks 20 is approximately equal. Since the X direction and the Y direction are different directions, the first streak portion 10 and the second streak portion 20 intersect. The crossing angles of the streaks 10 and 20 can be set according to the specific use of the ceramic structure 1. For example, the crossing angle of the second streak portion 20 with respect to the first streak portion 10 can be 90 degrees. Alternatively, as shown in FIG. 1, when viewed in a counterclockwise direction with respect to the first streak portion 10, the intersection angle formed by the first streak portion 10 and the second streak portion 20 is formed. θ can be changed in the range of 60 degrees ± 40 degrees or 90 degrees ± 40 degrees. The intersection of the plurality of first streaks 10 and the plurality of second streaks 20 forms a lattice having quadrilateral openings in the plan view of the structure 1. .. FIG. 1 shows a state in which a lattice having a diamond-shaped opening is formed by the intersection of the first line portion 10 and the second line portion 20, but the shape is rhombic. Other quadrilaterals, such as rectangles and squares (not shown), are also possible.

The structure 1 also has a plurality of third streaks 30 made of ceramics. Each of the third streaks 30 has a straight line and extends parallel to each other. The third strip 30 extends along the Z direction, which is a direction different from both the extending direction X of the first strip 10 and the extending direction Y of the second strip 20. Each of the third streaks 30 is arranged so as to pass on the diagonal line of the quadrilateral defined by the intersection of the first streaks and the second streaks. As a result, in the structure 1 of the present embodiment, a plurality of triangular through holes 3 defined by the first line portion 10, the second line portion 20, and the third line portion 30 are formed. Has been done. FIG. 1 shows a state in which a substantially equilateral triangular through hole 3 is formed.

As described above, in the structure 1, the third line portion 30 passes on the diagonal line of the quadrilateral defined by the intersection of the first line portion and the second line portion. It is preferable that the first to third streaks 10, 20, and 30 always intersect at one intersection 2 in the plan view of the structure 1. In other words, it is preferable that, of the three striations 10, 20, and 30, the intersection in which only two striae intersect is substantially nonexistent in the structure 1.

As in the present embodiment, the structure 1 in which the triangular through holes are formed by using three types of streaks in combination has high strength along the three directions of the X direction, the Y direction, and the Z direction. .. Therefore, the anisotropy of the strength decrease is less than that of the lattice bodies described in Patent Documents 1 and 2 having high strength along the two directions. In particular, when the through hole 3 is a substantially equilateral triangle as shown in FIG. 1, each side of the equilateral triangle has substantially the same length, and among the first to third streaks 10, 20, 30. Since it is formed of any one of the above, it is almost equivalent in strength. Therefore, the anisotropy of the strength decrease is further reduced, and the strength is almost the same in all directions.

Moreover, according to the structure of the present embodiment, it is possible to easily form a small through hole as compared with the lattice body described in Patent Documents 1 and 2. Therefore, when the structure of the present embodiment is used as a setter, which is also called a shelf board or a floor board, which is used when firing a fired body, for example, a smaller size fired body is placed on the structure. It is possible to place it. This is particularly advantageous when manufacturing chip monolithic ceramic capacitors (MLCCs) by firing.

Moreover, the structure of the present embodiment can be lighter in mass than the lattice body when exhibiting the same strength as the lattice body described in Patent Documents 1 and 2. As a result, when the structure of the present embodiment is used as a setter, there is an advantage that the temperature unevenness in the structure is reduced and the thermal shock resistance is improved at the time of firing.

As shown in FIGS. 4 and 5, in the structure 1, the third linear portion 30 is located on the first surface 1a side, and the first linear portion 10 is located on the second surface 1b side. ing. Then, the second line portion 20 is arranged on the third line portion 30, and the first line portion 10 is arranged on the second line portion 20. Further, as shown in FIGS. 1 to 5, the third line portion 30 and the second line portion 20 have a second line on the third line portion 30 at any intersection 2. Article 20 is arranged. That is, in the intersection 2, of the two surfaces 1a and 1b of the structure 1, the second surface 1b side is relatively on the third linear portion 30 located relatively on the first surface 1a side. A second streak portion 20 located at is arranged. In addition to this, at any intersection 2, the second streak 20 and the first streak 10 have the first streak 10 arranged on the second streak 20. ing. That is, in the intersection 2, of the two surfaces 1a and 1b of the structure 1, the second surface 1b side is relatively on the second linear portion 20 located relatively on the first surface 1a side. The first streak portion 10 located at is arranged.

The thickness at the intersection 2 is larger than the sum of the thickness of the first streak portion 10, the thickness of the second streak portion 20, and the thickness of the third streak portion 30 at a portion other than the intersection. You may. Alternatively, the thickness at the intersection 2 is the same as the sum of the thickness of the first streak portion 10, the thickness of the second streak portion 20, and the thickness of the third streak portion 30 at a portion other than the intersection. It may be present or smaller than the sum. Therefore, the maximum thickness portion of the structure 1 exists at the intersection 2 or at a portion other than the intersection.

As shown in FIG. 6, the third streak portion 30 has a constant width W3 in a plan view at a position other than the intersection portion 2. As shown in FIG. 6, the third linear portion 30 has a cross-sectional shape along the thickness direction in the direction orthogonal to the longitudinal direction thereof, and is located on the first surface 1a side of the ceramic structure 1 as the first surface 30a. And the second surface 30b located on the second surface 1b side of the ceramic structure 1. Specifically, the third streak portion 30 has a cross section along the thickness direction in the direction orthogonal to the longitudinal direction thereof, at a portion other than the intersection 2, a straight portion 30A and both ends of the straight portion 30A. It has a shape composed of a convex curved portion 30B having an end portion thereof. As a result, the first surface 30a of the third linear portion 30 has a flat cross section in the thickness direction of the linear portion 30. The flat surface is substantially parallel to the in-plane direction of the ceramic structure 1. On the other hand, the second surface 30b of the third linear portion 30 has a convex curved surface shape in which the cross section of the linear portion 30 in the thickness direction is from the first surface 1a to the second surface 1b of the ceramic structure 1. I am doing.

Similar to the third line portion 30, as shown in FIGS. 7A and 7B, the first line portion 10 and the second line portion 20 are also flat at positions other than the intersection 2. It has a certain width W1 and W2 when viewed. The widths W1 and W2 may be the same as or different from each other. Further, the widths W1 and W2 may be the same as or different from the width W3 of the third line portion 30. In manufacturing the structure 1, it is convenient that W1, W2, and W3 are the same. The first striated portion 10 and the second striated portion 20 have a ceramic structure as shown in FIGS. 7A and 7B, in which the cross-sectional shape along the thickness direction in the direction orthogonal to the longitudinal direction thereof is shown. It is defined by the first surfaces 10a and 20a located on the first surface 1a side of the body 1 and the second surfaces 10b and 20b located on the second surface 1b side of the ceramic structure 1. The first surfaces 10a and 20a of the first linear portion 10 and the second linear portion 20 have a convex cross section in the thickness direction from the second surface 1b to the first surface 1a of the ceramic structure 1. It has a curved shape. On the other hand, the second surfaces 10b and 20b of the first linear portion 10 and the second linear portion 20 have a cross section in the thickness direction directed from the first surface 1a to the second surface 1b of the ceramic structure 1. It has a convex curved shape. The curved surface shape may be the same as or different from the curved surface shape of the third line portion 30. In the present embodiment, the first surfaces 10a and 20a and the second surfaces 10b and 20b of the first line portion 10 and the second line portion 20 have a symmetrical shape, and as a result, the first surface is symmetrical. The linear portion 10 and the second linear portion 20 have a circular or elliptical cross-sectional shape along the thickness direction in a direction orthogonal to the longitudinal direction thereof.

As shown in FIG. 5, when the straight line portion 30A in the third streak portion 30, that is, the first surface 10a is placed on the plane P as the mounting surface, all the first surfaces 30a are located on the plane P. .. Since the first surface 30a forms the first surface 1a of the ceramic structure 1, the fact that all the first surfaces 30a are located on the plane P means that the first surface 1a of the structure 1 becomes a flat surface. It means that it has become. Therefore, when the structure 1 is placed so that its first surface 1a is in contact with the flat mounting surface, the entire area of the first surface 1a is in contact with the mounting surface.

As shown in FIG. 5, when the straight portion 30A in the third linear portion 30, that is, the first surface 30a is placed on the plane P as the mounting surface, the first linear portion 10 and the second linear portion 30 are placed. The portion 20 has a shape that is separated from the plane P between two adjacent intersecting portions 2. Therefore, a space S is formed between the first line portion 10 and the second line portion 20 and the plane P between the two adjacent intersections 2.

On the other hand, the second surface 1b of the structure 1 is composed of the second surface 10b of the first line portion 10 having a convex curved surface shape as shown in FIG. 7A, so that the second surface 1b is a flat surface. There is no uneven surface.

At the intersection 2 in the structure 1, the three types of streaks 10, 20, and 30 are integrated. "Integrated" means that when observing the cross section of the intersection 2, the three types of streaks 10, 20, and 30 form a continuous structure as ceramics. Each through hole 3 formed in the structure 1 by the intersection of the three types of streaks 10, 20, and 30 has the same size and the same shape. The through holes 3 are regularly arranged.

In the third line portion 30, the highest position of the second surface 30b on the third line portion 30, that is, the position of the top, extends from the third line portion 30 at a portion other than the intersection 2. It is the same along the direction.
Regarding the second streak portion 20, at a portion other than the intersection 2, the highest position of the second surface 20b on the second streak portion 20 is along the extending direction of the second striation portion 20. They are in the same position as each other. The lowest position of the first surface 20a in the second streak portion 20 is at the same position as each other along the extending direction of the second striation portion 20 at a portion other than the intersection 2.
Further, with respect to the first streak portion 10, the highest position of the second surface 10b in the first streak portion 10 is the first position at both the position of the intersection 2 and the position other than the intersection 2. They are in the same position as each other along the extending direction of the streaks 10. The lowest positions of the first surface 10a of the first streak portion 10 are at the same positions as each other along the extending direction of the first streak portion 10 at a portion other than the intersection 2.

As shown in FIGS. 4 and 5, when the intersection 2 of the structure 1 is viewed in a vertical cross section, the third line portion 30 and the second line portion 20 are in the third line portion 30. Only the top of the convex curved portion 30B is in contact with the top of the downwardly convex curve in the circular or elliptical shape of the second strip 20, that is, the top of the first surface 20a. In other words, the third line portion 30 and the second line portion 20 are in a state of point contact or surface contact close to point contact. The second streak 20 and the first streak 10 are the top of a circular or elliptical upwardly convex curve in the second streak 20, that is, the top of the second surface 20b and the first. Only the top of the downwardly convex curve in the circular or elliptical shape of the line portion 10, that is, the top of the first surface 10a is in contact. As a result of the study by the present inventor, it has been found that the structure 1 has improved spalling resistance when the three types of streaks 10, 20, and 30 are in such a contact state. The reason for this is that the three types of streaks 10, 20, and 30 are connected by point contact or surface contact close to them, and these streaks 10, 20, and 30 are excessively tightly bonded. It is considered that this is because the volume change that occurs during rapid heating and / or cooling can be alleviated due to this. From this point of view, the thickness Tc of the intersection 2 is the thickness T1 of the first line portion 10 at a position other than the intersection 2 and the thickness T2 of the second line portion 20 at a position other than the intersection 2. Is the sum of (T1 + T2 + T3) with the thickness T3 of the third streak portion 30 at a position other than the intersection 2, preferably 0.5 or more and 1.0 or less, and more preferably 0.8 or more and 1 The point contact state is such that it is 0.0 or less, more preferably 0.9 or more and 1.0 or less.

In order to bring the first linear portion 10, the second linear portion 20, and the third linear portion 30 into a state of point contact or surface contact close to point contact, for example, a structure described later is used. The body 1 may be manufactured.

When the ceramic structure 1 having the above structure is used, for example, as a setter for firing the body to be fired, if the body to be fired is placed on the first surface 1a of the structure 1, the first surface 1a Since is a flat surface, it is suitable for placing a fired body that is required to be flat. Examples of the body to be fired that are required to have flatness include small chip-shaped electronic components such as multilayer ceramic capacitors. Since these small electronic components are required not to be caught by the setter in the firing step, it is advantageous that the first surface 1a of the structure 1 is flat. Further, since the body to be fired comes into contact with only the first streak portion 10 which is a member constituting the first surface 1a, the contact area between the structure 1 and the body to be fired is significantly reduced, thereby being fired. It facilitates rapid heating and cooling of the body. Further, since the structure 1 is formed by the intersection of three types of linear portions 10, 20, and 30, and a plurality of through holes 3 are formed, the heat capacity is small, and from this point as well, the fired body is abrupt. Easy to heat and cool. Further, since the structure 1 has good air permeability due to the existence of the plurality of through holes 3, it is easy to rapidly cool the body to be fired. Good breathability is further pronounced by the floating of the second streak 20 between the adjacent intersections 2. Moreover, in the structure 1, since the three types of streak portions 10, 20, and 30 are integrated at the intersection 2, the structure 1 has sufficient strength.

On the other hand, it is advantageous to place a mm-order fired body on the second surface 1b of the structure 1. The second surface 1b is an uneven surface caused by the curved surface of the first streak portion 10, and an electronic component of this order size has an uneven surface on which it is placed, which is degreasing. This is because it is advantageous from the viewpoint of enhancing the sex.

As described above, in the structure 1 of the present embodiment, one surface is flat and the other surface is an uneven surface, so that the mounting surface can be properly used according to the type of the body to be fired. It is advantageous in that.

From the viewpoint of making the various advantageous effects described above more remarkable, the value of T3 is preferably 50 μm or more and 5 mm or less, and more preferably 200 μm or more and 2 mm or less. On the other hand, the values of T1 and T2 are preferably 50 μm or more and 5 mm or less, and more preferably 200 μm or more and 2 mm or less, respectively. There is no particular limitation on the magnitude relationship between the values of T1, T2 and T3.

From the same viewpoint, the thickness Tc at the intersection 2 is preferably 20 μm or more and 5 mm or less, preferably 50 μm or more and 2 mm, provided that it is preferably 0.5 or more and 1.0 or less with respect to (T1 + T2 + T3). The following is more preferable.

Further, when the cross-sectional shape (see FIGS. 7A and 7B) of the first line portion 10 and the second line portion 20 in the thickness direction is elliptical, the elliptical minor axis is the structure. It is preferable that the elliptical long axis coincides with the thickness direction of the body 1 and coincides with the plane direction of the structure 1 from the viewpoint that the object to be fired can be placed successfully. In this case, the ratio of the major axis to the minor axis is preferably 1 or more and 5 or less, and more preferably 1 or more and 3 or less. Further, the fact that the cross-sectional shapes of the first streak portion 10 and the second streak portion 20 in the thickness direction are elliptical or circular also contributes to the improvement of the strength of the structure 1.

The triangular through hole 3 formed in the ceramic structure 1 has an area of 100 μm ² or more and 100 mm ² or less, particularly 2500 μm ² or more and 1 mm ² or less, which reduces the heat capacity of the structure 1 and has air permeability. Is preferable from the viewpoint of improving the strength of the structure 1 and maintaining the strength of the structure 1. Further, the ratio of the total area of the through holes 3 to the apparent area of the ceramic structure 1 in a plan view is preferably 1% or more and 80% or less, and more preferably 3% or more and 70% or less. It is more preferably 10% or more and 70% or less. This ratio is calculated by cutting the ceramic structure 1 into a rectangle of an arbitrary size in a plan view, calculating the total area of the through holes 3 included in the rectangle, and dividing the total by the rectangular area to 100. It is calculated by multiplying by. Further, the area of each through hole 3 can be measured by image analysis of the microscopic observation image of the structure 1.

In relation to the area of the through hole 3, the width W3 of the third streak portion 30 is preferably 50 μm or more and 10 mm or less, and more preferably 75 μm or more and 1 mm or less. On the other hand, the widths W1 and W2 of the first line portion 10 and the second line portion 20 are preferably 50 μm or more and 10 mm or less, and more preferably 75 μm or more and 1 mm or less, respectively. There is no particular limitation on the magnitude relationship between the values of W1, W2 and W3.

In relation to the widths W1, W2, and W3 of the first, second, and third streaks 10, 20, and 30, the distance D3 between adjacent third streaks 30 is 100 μm or more and 10 mm or less. It is preferable, and more preferably 150 μm or more and 5 mm or less. On the other hand, the distance D1 between the adjacent first streaks 10 and the distance D2 between the second streaks 20 are preferably 100 μm or more and 10 mm or less, and 150 μm or more and 5 mm or less, respectively. Is more preferable. D1, D2 and D3 may be the same as or different from each other. In manufacturing the structure 1, it is convenient that D1, D2 and D3 are the same.

Various materials can be used as the ceramic material constituting the ceramic structure 1. For example, alumina, silicon carbide, silicon nitride, zirconia, mulite, zircon, cordierite, aluminum titanate, magnesium titanate, magnesia, titanium diboronet, boron nitride and the like can be mentioned. These ceramic materials may be used alone or in combination of two or more. In particular, it is preferably made of ceramics containing alumina, mullite, cordierite, zirconia or silicon carbide. When ceramics containing zirconia are used, in order to make the structure 1 more suitable for use in high-temperature firing, zirconia or the like completely stabilized by the addition of yttria can be used. When the ceramic structure 1 is subjected to rapid heating and cooling, it is particularly preferable to use silicon carbide as the ceramic material. Since silicon carbide may react with the object to be fired, when silicon carbide is used as the ceramic material, it is preferable to coat the surface with a ceramic material having low reactivity such as zirconia. As the raw material powder of the ceramic material constituting the structure 1, it is preferable to use a powder having a particle size of 0.1 μm or more and 200 μm or less in consideration of viscosity and ease of sintering when made into a paste. The ceramic materials constituting the three types of streaks 10, 20, and 30 may be the same or different. From the viewpoint of increasing the integrity of the three types of streak portions 10, 20 and 30 at the intersection 2, it is preferable that the ceramic materials constituting the streak portions 10, 20 and 30 are the same.

Next, a suitable manufacturing method of the ceramic structure 1 of the present embodiment will be described. In this production method, first, a raw material powder of a ceramic material is prepared, and the raw material powder is mixed with a medium such as water and a binder to prepare a paste for producing a streak.

As the binder, the same binders conventionally used for this type of paste can be used. Examples include polyvinyl alcohol, polyethylene glycol, polyethylene oxide, dextrin, sodium lignin sulfonate and ammonium, carboxymethyl cellulose, ethyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, sodium alginate and ammonium, epoxy resins, phenols. Resins, gum arabic, polyvinyl butyral, acrylic polymers such as polyacrylic acid and polyacrylamide, thickening polysaccharides such as xanthan gum and guagam, gelling agents such as gelatin, agar and pectin, vinyl acetate resin emulsions, wax emulsions, In addition, inorganic binders such as alumina sol and silica sol can be mentioned. Two or more of these may be mixed and used.

The viscosity of the paste is preferably high at the temperature at the time of coating, from the viewpoint that the structure 1 having the structure of the present embodiment can be successfully produced. Specifically, the viscosity of the paste is preferably 1.5 MPa · s or more and 5.0 MPa · s or less, and further preferably 1.7 MPa · s or more and 3.0 MPa · s or less at the temperature at the time of coating. preferable. For the viscosity of the paste, a cone plate type rotary viscometer or a rheometer was used, and the measured value at 4 minutes after the start of measurement at a rotation speed of 0.3 rpm was used.

The ratio of the raw material powder of the ceramic material in the paste is preferably 20% by mass or more and 85% by mass or less, and more preferably 35% by mass or more and 75% by mass or less. The proportion of the medium in the paste is preferably 15% by mass or more and 60% by mass or less, and more preferably 20% by mass or more and 55% by mass or less. The proportion of the binder in the paste is preferably 1% by mass or more and 40% by mass or less, and more preferably 5% by mass or more and 25% by mass or less.

The paste can contain a thickener, a flocculant, a thixotropic agent and the like as a viscosity modifier. Examples of thickeners include proteins such as polyethylene glycol fatty acid ester, alkylallyl sulfonic acid, alkylammonium salt, ethyl vinyl ether / maleic anhydride copolymer, fumed silica, and albumin. In many cases, the binder may be classified as a thickener because of its thickening effect, but if more strict viscosity adjustment is required, the binder is not separately classified as a thickener. Agents can be used. Examples of the flocculant include polyacrylamide, polyacrylic acid ester, aluminum sulfate, polyaluminum chloride and the like. Examples of thixotropic agents include fatty acid amides, polyolefin oxides, and polyether ester-type surfactants. As the solvent for preparing the paste, alcohol, acetone, ethyl acetate and the like are used in addition to water, and two or more kinds of these may be mixed. Further, in order to stabilize the discharge amount, a plasticizer, a lubricant, a dispersant, a sedimentation inhibitor, a pH adjuster and the like may be added. Examples of the plasticizer include glycol-based plasticizers such as trimethylene glycol and tetramethylene glycol, glycerin, butanediol, phthalic acid-based, adipic acid-based, and phosphoric acid-based plasticizers. Examples of the lubricant include hydrocarbons such as liquid paraffin, microwax and synthetic paraffin, higher fatty acids, fatty acid amides and the like. Examples of the dispersant include sodium or ammonium salt of polycarboxylic acid, acrylic acid type, polyacetylene imine, phosphoric acid type and the like. Examples of the sedimentation inhibitor include polyamideamine salts, bentonite, aluminum stearate and the like. Examples of the PH adjusting agent include sodium hydroxide, aqueous ammonia, oxalic acid, acetic acid, hydrochloric acid and the like.

Using the obtained paste, a plurality of linear third coated bodies are formed on a flat substrate in parallel and linearly with each other. The third line coating body corresponds to the third line portion 30 in the target structure 1. The third paste, which is a paste used for forming the linear third coated body, contains the above-mentioned third raw material powder of the ceramic material, a medium, and a binder. Various coating devices such as a small extruder and a printing machine can be used to form the linear third coated body using the third paste.

Once the medium has been removed from the 3rd strip coating, then the 2nd paste is used to parallel the 2nd strip coatings to intersect the 3rd strip coating. And it is formed linearly. The second line coating body corresponds to the second line portion 20 in the target structure 1. As the second paste, a paste having the same composition as the third paste can be used, and includes a second raw material powder of a ceramic material, a medium, and a binder. A coating device similar to that of the linear third coated body can be used for forming the linear second coated body. After the linear second coated body is formed, the medium is then removed from the linear second coated body and dried to further increase the viscosity of the linear second coated body. This operation can be performed in the same manner as the operation performed on the line third coated body.

Once the medium has been removed from the second line coating, then the first paste is used to intersect the second line coating and the third line coating so that the first multiple lines intersect. The coated bodies are formed parallel to each other and linearly. The first line coating body corresponds to the first line portion 10 in the target structure 1. As the first paste, a paste having the same composition as the second paste and / or the third paste can be used, and contains the first raw material powder, the medium and the binder of the ceramic material. For the formation of the first line coating body, the same coating device as the second line coating body and the third line coating body can be used. After the linear first coated body is formed, the medium is then removed from the linear first coated body and dried to further increase the viscosity of the linear first coated body. This operation can be performed in the same manner as the operation performed on the second line coating body and / or the third line coating body. In this way, the formation of the third line coating body and the removal of the medium, the formation of the second line coating body and the removal of the medium, and the formation of the first line coating body and the removal of the medium are sequentially performed. By doing so, the structure 1 in which the second striae 20 is located on the third striae 30 and the first striae 10 is located on the second striae 20 is successfully performed. can get.

The pre-firing structure thus obtained is peeled from the substrate and placed in a firing furnace for firing. The target ceramic structure 1 is obtained by this firing. Baking can generally be carried out in the atmosphere. As the firing temperature, an appropriate temperature may be selected according to the type of raw material powder of the ceramic material. The same applies to the firing time.

By the above method, the target ceramic structure 1 can be obtained. This ceramic structure 1 is suitably used as a setter for degreasing or firing ceramic products such as shelf boards and floor boards, and can also be used as a kiln tool other than the setter, for example, a box or a beam. Further, it can be used for applications other than kiln tools, such as various jigs such as filters and catalyst carriers, and various structural materials. In this case, it is common to place the body to be fired on the second surface 1b, which is the uneven surface of the structure 1, but depending on the type of the body to be fired, it is placed on the first surface 1a, which is a flat surface. The body to be fired may be placed. For example, when performing a firing step in the manufacturing process of electronic components such as chip multilayer ceramic capacitors (MLCCs) and multilayer ceramic inductors, it is preferable to place the object to be fired on the first surface 1a, which is a flat surface. The setter on which the fired body is placed may fire the fired body, or another ceramic structure 1 or another structure that can be a lid is placed on the setter so that the fired body does not scatter. It may be placed and fired. Further, in order to improve the efficiency of the firing process, the ceramic structure 1 on which the object to be fired is placed may be stacked in a plurality of stages and fired, or a block-shaped ceramic structure 1 may be stacked between the ceramic structures 1 stacked in a plurality of stages. A spacer may be placed and fired. In addition, as for the ceramic structure 1, the ceramic structure 1 is placed on a mounting portion of another ceramic tray, and the fired body is placed on the ceramic structure 1 to form one unit with the ceramic structure 1. It can also be applied to a mode in which the units of the above are fired in a stacked state.

Next, another embodiment of the ceramic structure of the present invention will be described with reference to FIGS. 8 (a) and 8 (b) and FIGS. 9 (a) and 9 (b). Regarding these embodiments, only the points different from the above-described embodiments will be described, and the description of the above-described embodiments will be appropriately applied to the points not particularly described. Further, in FIGS. 8 (a) and 8 (b) and 9 (a) and 9 (b), the same members as those in FIGS. 1 to 7 are designated by the same reference numerals.

In the ceramic structure 1A of the embodiment shown in FIGS. 8A and 8B, the method of laminating the first, second and third streaks 10, 20, and 30 is the same as that of the embodiment shown in FIG. It is different. Specifically, the second line portion 20 is arranged on the first line portion 10, and the third line portion 30 is arranged on the second line portion 20. The third line portion 30 is arranged so as to pass on the diagonal line of the quadrilateral defined by the intersection of the first line portion and the second line portion.

The first line portion 10, the second line portion 20, and the third line portion 30 intersect at one intersection 2. At any of the intersections 2, the second line portion 20 is arranged on the first line portion 10. Further, at any of the intersections 2, a third line portion 30 is arranged on the second line portion 20.

As shown in FIG. 8B, the first linear portion 10 has a cross-sectional shape along the thickness direction in the direction orthogonal to the longitudinal direction thereof, and is located on the first surface 1a side of the ceramic structure 1. It is defined by one surface 10a and a second surface 10b located on the second surface 1b side of the ceramic structure 1. Specifically, the first linear portion 10 has a cross section along the thickness direction in the direction orthogonal to the longitudinal direction thereof, at a portion other than the intersection 2, the straight portion 10A and both ends of the straight portion 10A. It has a shape composed of a convex curved portion 10B having an end portion. As a result, the first surface 10a of the first linear portion 10 has a flat cross section in the thickness direction of the linear portion 10. The flat surface is substantially parallel to the in-plane direction of the ceramic structure 1. On the other hand, the second surface 10b of the first linear portion 10 has a convex curved surface shape in which the cross section of the linear portion 10 in the thickness direction is from the first surface 1a to the second surface 1b of the ceramic structure 1. I am doing. On the other hand, with respect to the second streak portion 20 and the third streak portion 30, their cross sections have a circular or elliptical shape at a portion other than the intersection 2.

The ceramic structure 1B of the embodiment shown in FIGS. 9A and 9B also has the same first, second and third parts as the ceramic structure 1A of the embodiment shown in FIGS. 8A and 8B. The method of laminating the streaks 10, 20, and 30 is different from that of the embodiment shown in FIG. Specifically, the third line portion 30 is arranged on the second line portion 20, and the first line portion 10 is arranged on the third line portion 30. The third line portion 30 is arranged so as to pass on the diagonal line of the quadrilateral defined by the intersection of the first line portion and the second line portion.

The first line portion 10, the second line portion 20, and the third line portion 30 intersect at one intersection 2. At any of the intersections 2, a third line portion 30 is arranged on the second line portion 20. Further, at any of the intersections 2, the first line portion 10 is arranged on the third line portion 30.

As shown in FIG. 9B, the second linear portion 20 has a cross-sectional shape along the thickness direction in the direction orthogonal to the longitudinal direction thereof, and is located on the first surface 1a side of the ceramic structure 1. It is defined by one surface 20a and a second surface 20b located on the second surface 1b side of the ceramic structure 1. Specifically, the second linear portion 20 has a cross section along the thickness direction in the direction orthogonal to the longitudinal direction thereof, at a portion other than the intersection 2, the straight portion 20A and both ends of the straight portion 20A. It has a shape composed of a convex curved portion 20B having an end portion thereof. As a result, the first surface 20a of the second streak portion 20 has a flat cross section in the thickness direction of the streak portion 20. The flat surface is substantially parallel to the in-plane direction of the ceramic structure 1. On the other hand, the second surface 20b of the second linear portion 20 has a convex curved surface shape in which the cross section of the linear portion 20 in the thickness direction is from the first surface 1a to the second surface 1b of the ceramic structure 1. I am doing. With respect to the second streak portion 30 and the first streak portion 10, their cross sections have a circular or elliptical shape at a portion other than the intersection 2.

The embodiments shown in FIGS. 8 (a) and 8 (b) and 9 (a) and 9 (b) also have the same effects as those shown in FIGS. 1 to 7.

Next, matters common to each of the above-described embodiments will be described. The ceramic structure of each of the above-described embodiments is not particularly limited in shape in a plan view, and may be, for example, a circle, an ellipse, or a rectangle. Alternatively, it may have a contour that is a combination of a straight line and a curved line. When the ceramic structure has a straight side portion at least a part of its contour, any one of the first, second and third streaks 10, 20, and 30 is a straight line. It is preferable that the ceramic structure is arranged parallel to the side portion from the viewpoint of more firmly maintaining the impact resistance in the vicinity of the straight side portion of the ceramic structure. Further, it is preferable that the straight side portion intersects the intersection at any position of the straight side portion from the viewpoint of preventing chipping due to chipping at the end portion of the ceramic structure.

In particular, in the case of the ceramic structure 1 of the embodiment shown in FIG. 1, it is preferable that the first line portion 10 or the third line portion 30 is arranged parallel to the straight side portion. In this case, the second streak portion 20 is 10 degrees or more and 80 degrees or less or 100 degrees or more and 170 degrees or less, particularly 20 degrees or more and 70 degrees or less or 110 degrees or more and 160 degrees or less, particularly 30 degrees or more and 60 degrees or less with the straight side portion. It is preferable that they intersect at an angle of 105 degrees or more or 150 degrees or less from the viewpoint of effectively preventing the propagation of defects such as cracks generated in the ceramic structure 1.
In the case of the ceramic structure 1A of the embodiment shown in FIG. 8A, it is preferable that the first streak portion 10 or the third streak portion 30 is arranged parallel to the straight side portion. In this case, it is more preferable that the second streak portion 20 intersects the straight side portion at the above-mentioned angle from the viewpoint of effectively preventing the propagation of defects such as cracks generated in the ceramic structure 1A.
In the case of the ceramic structure 1B of the embodiment shown in FIG. 9A, it is preferable that the third streak portion 30 is arranged parallel to the straight side portion. In this case, it is preferable that the second strip portion intersects the straight side portion at the above-mentioned angle from the viewpoint of effectively preventing the propagation of defects such as cracks generated in the ceramic structure 1B.

In addition, the ceramic structure of each of the above-described embodiments may be provided with an outer frame (not shown) on the outer periphery of the structure for the purpose of improving its strength. The outer frame may be integrally formed from the same material as the structure, or may be manufactured separately from the structure and joined by a predetermined joining means. The outer frame may have a constant width, or may have a wide portion and a narrow portion. When the width of the outer frame is constant, the width is preferably 0.4 mm or more and 10 mm or less. When the width of the outer frame is not constant, the width is preferably 1 mm or more and 10 mm or less in the widest part, and preferably 0.5 mm or more and 1 mm or less in the narrowest part.

Although the present invention has been described above based on the preferred embodiment, the present invention is not limited to the above embodiment. For example, in each of the above-described embodiments, a structure in which three layers are used as one unit using three types of linear portions composed of the first, second, and third linear portions 10, 20, and 30. However, instead of this, two or more repeating units composed of the first, second and third streak portions 10, 20 and 30 may be laminated to form a structure. ..

Further, in the embodiment shown in FIG. 1, the first line portion 10 is arranged under the third line portion 30, or the third line portion is arranged on the first line portion 10. You may do it. Similarly, in the embodiment shown in FIG. 8A, the third line portion 30 is arranged below the first line portion 10, or the first line is placed on the third line portion 30. The strip 10 may be arranged. Similarly, in the embodiment shown in FIG. 9A, the first streak portion 10 is arranged below the second streak portion 20, or the second streak portion 10 is placed on the first streak portion 10. The streak portion 20 may be arranged.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the scope of the present invention is not limited to such examples. Unless otherwise specified, "part" means "part by mass". The morphology of the ceramic structure, the number of stacked striatum, the distance between the striatum, the mass, etc. are as shown in Table 1.

[Example 1]
In this embodiment, the flat ceramic structure 1 shown in FIG. 1 was manufactured.
(1) Preparation of paste for forming a linear coating body 65.3 parts of fully stabilized zirconia powder containing 8 mol% yttria with an average particle size of 0.8 μm, 5.0 parts of a methylcellulose binder as an aqueous binder, and As a plasticizer, 2.5 parts of glycerin, 1.1 parts of a polycarboxylic acid-based dispersant (molecular weight 12000), and 26.1 parts of water were mixed and defoamed to prepare a paste. The viscosity of the paste was 2.0 MPa · s at 25 ° C.
(2) Formation of a linear coating body Using the above paste as a raw material, a linear third coating body is formed on a resin substrate in an environment of 25 ° C. using a small extruder having a nozzle with a diameter of 0.8 mm. Then, a second line coating body and a first line line coating body intersecting the same were formed. The intersection angle between the second line coating body and the first line coating body was set to 60 degrees so that a diamond-shaped lattice was formed. The third line coating body was made to pass on the shorter diagonal line of the diagonal lines of the rhombus. In this way, a pre-baking structure was obtained.
(3) Baking step The pre-baking structure after drying was peeled off from the resin substrate and then placed in an atmospheric firing furnace. Degreasing and firing were performed in this firing furnace to obtain a rectangular ceramic structure having the shape shown in FIG. The firing temperature was 1600 ° C. and the firing time was 3 hours. The specifications of the obtained structure are shown in Table 1 below. In this structure, the third streak was parallel to the straight side.
The first line portion 10 in the structure thus obtained has a width W1 of 425 μm and a thickness T1 of 400 μm, and the second line portion 20 in the structure has a width W2 of 420 μm and a thickness T2 of 410 μm. The third linear portion 30 in the structure had a width W3 of 425 μm and a thickness T3 of 410 μm. The thickness Tc of the intersection 2 was 1160 μm.

[Example 2]
In this embodiment, the flat plate-shaped ceramic structure 1A shown in FIG. 8A was manufactured.
Using the same paste as in Example 1 as a raw material, a first linear coating body is formed on a resin substrate in an environment of 25 ° C. using a small extruder having a nozzle with a diameter of 0.8 mm, and subsequently intersects the paste. The second line coating body and the third line coating body were formed. The intersection angle between the second line coating body and the first line coating body was set to 60 degrees so that a diamond-shaped lattice was formed. The third line coating body was made to pass on the shorter diagonal line of the diagonal lines of the rhombus. A rectangular ceramic structure having the shape shown in FIG. 8A was obtained in the same manner as in Example 1 except for the above. The specifications of the obtained structure are shown in Table 1 below. In this structure, the third streak was parallel to the straight side.

[Example 3]
In this embodiment, the flat plate-shaped ceramic structure 1B shown in FIG. 9A was manufactured.
Using the same paste as in Example 1 as a raw material, a second linear coating body is formed on a resin substrate in an environment of 25 ° C. using a small extruder having a nozzle with a diameter of 0.8 mm, and subsequently intersects the paste. A third line coating body and a first line line coating body were formed. The intersection angle between the second line coating body and the first line coating body was set to 60 degrees so that a diamond-shaped lattice was formed. The third line coating body was made to pass on the shorter diagonal line of the diagonal lines of the rhombus. A rectangular ceramic structure having the shape shown in FIG. 9A was obtained in the same manner as in Example 1 except for the above. The specifications of the obtained structure are shown in Table 1 below. In this structure, the third streak was parallel to the straight side.

[Comparative Example 1]
In this comparative example, a lattice-shaped ceramic structure was manufactured.
Using the same paste as in Example 1 as a raw material, a linear first coated body is formed on a resin substrate in an environment of 25 ° C. using a small extruder having a nozzle with a diameter of 0.8 mm, and is subsequently orthogonal to it. The second line coating body was formed. A linear first coated body and a second linear coated body were formed on the coating body to obtain a grid-like pre-baking structure composed of a total of four layers of coated bodies. The first streak and the second streak were arranged so as to be orthogonal to each other at 90 °, and the intersection angle between the straight side and each streak was 0 ° (parallel) to 90 ° (orthogonal). .. A rectangular ceramic structure was obtained in the same manner as in Example 1 except for the above. The specifications of the obtained structure are shown in Table 1 below.

[Comparative Example 2]
In this comparative example, a lattice-shaped ceramic structure was manufactured.
Using the same paste as in Example 1 as a raw material, a first linear coating body is formed on a resin substrate in an environment of 25 ° C. using a small extruder having a nozzle with a diameter of 0.8 mm, and continues to be orthogonal to it. The second line coating body was formed. A first linear coating body was formed on the coating body to obtain a grid-like pre-firing structure composed of a total of three layers of the coated body. The first streak and the second streak were arranged so as to be orthogonal at 90 °, and the intersection angle between the side and each streak was 0 ° (parallel) to 90 ° (orthogonal). A rectangular ceramic structure was obtained in the same manner as in Example 1 except for the above. The specifications of the obtained structure are shown in Table 1 below.

[Examples 4 to 6 and Comparative Examples 3 and 4]
Ceramic structures were obtained in the same manner as in Examples 1 to 3 and Comparative Example 2 except that the width of the striatum and the distance between the striatum were as shown in Table 1.

[Evaluation]
The heat-resistant impact temperature and strength of the ceramic structures obtained in Examples and Comparative Examples were measured by the following methods. The results are shown in Table 1.

[Heat-resistant impact temperature]
The ceramic structure is placed in a firing furnace, held for 1 hour, then taken out into the atmosphere at once and rapidly cooled. Check for cracks after the ceramic structure has returned to room temperature. The evaluation is started from 200 ° C., and if there are no cracks, the set temperature of the firing furnace is further raised by 25 ° C., and the test is repeated again. The thermal shock temperature is defined as the upper temperature limit of the furnace that maintains durability without cracking.

[Strength evaluation 1]
The strength of the obtained ceramic structure was evaluated. For the ceramic structure obtained in the examples, the strength when bent in a direction parallel to the straight side portion where the third streak portion intersects was determined. For the ceramic structure obtained in the comparative example, the strength when bent in the direction orthogonal to the first streak portion provided with two layers was determined. A 4-point bending test was adopted for the strength evaluation. The 4-point bending test was based on the room temperature bending strength test method of JIS R1601: 2008 fine ceramics. At this time, the cross-sectional area was calculated from the width and thickness of the structure.

[Strength evaluation 2]
For the obtained ceramic structure, the strength in the direction orthogonal to the strength evaluation 1 was also measured for Example 1 and Comparative Example 2.

As is clear from the results shown in Table 1, it can be seen that the area of the through hole can be made smaller in the example even though the width and spacing of the striatum are the same in the example and the comparative example. It can also be seen that although the width and spacing of the striatum are the same in the examples and the comparative examples, the mass can be lighter in the examples. Moreover, it can be seen that the examples are superior in thermal shock resistance and strength to the comparative examples, even though the mass is lighter.
Further, in Example 1, the strength of the strength evaluation 2 was slightly reduced by -35% with respect to the strength in the strength evaluation 1, but in Comparative Example 2, it was reduced by -35%, and a large anisotropy was observed. Was done. Therefore, it was found that the examples were also excellent in strength anisotropy.

According to the present invention, a ceramic structure having higher strength than the conventional one can be obtained. Further, according to the present invention, a ceramic structure having higher thermal shock resistance than the conventional one can be obtained.

Claims (5)

A plurality of ceramic first streaks extending in one direction, a plurality of ceramic second streaks extending in a direction intersecting the first streaks, and a first. It has a third line made of ceramics that runs on the diagonal of a quadrilateral defined by the intersection of the line part and the second line part.
The first streak, the second streak and the third streak intersect at one intersection,
At any of the intersections, a second streak is arranged on the third streak.
A plate-shaped ceramic structure in which a first streak is arranged on a second streak at any of the intersections. The cross section of the second streak portion has a circular or elliptical shape at a portion other than the intersection.
The ceramic structure according to claim 1, wherein the first linear portion has a circular or elliptical shape at a portion other than the intersection. It has straight sides at least part of the contour in plan view.
The invention according to claim 1 or 2, wherein any one of the first line portion, the second line portion, and the third line portion is arranged in parallel with the straight side portion. Ceramic structure. The ceramic structure according to claim 3, wherein the first linear portion or the third linear portion is arranged in parallel with the straight side portion. The ceramic structure according to any one of claims 1 to 4, wherein two or more repeating units composed of a first linear portion, a second linear portion, and a third linear portion are laminated. ..

Images