JP2024004824A - ceramic structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic structure that realizes light weight, high rigidity, and a high natural frequency.

SOLUTION: A ceramic structure is configured so that, a plurality of ribs at least has: a first rib which is inclined for any of first to fourth side plates; a second rib which is parallel with the first rib, and provided apart from the first rib by a first distance; a third rib which is inclined for any of the first to fourth side plates, and crosses the first rib in a space partitioned by an upper plate and the first to fourth side plates; and a fourth rib which is parallel with the third rib, crosses the second rib in the space, and provided apart from the third rib by the first distance. At least two crossing parts out of a first crossing part between the first rib and the fourth rib, a second crossing part between the second rib and the third rib, a third crossing part between the third rib and the first rib, and a fourth crossing part between the fourth rib and the second rib are not connected to any of the first to fourth side plates, and are positioned in the space.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

Aspects of the present invention generally relate to ceramic structures.

With the miniaturization of semiconductor devices and FDPs (Flat Panel Displays), higher precision is required of their manufacturing equipment. For example, air slide stages, which are important elements in exposure equipment, are required to have high precision. Conventionally, high precision has been achieved by using ceramics, which are lighter and more rigid than metals, for the members constituting the air slide stage. In recent years, with the development of IoT, the performance of semiconductor devices and FDPs has been rapidly evolving, and in addition to further miniaturization, lower costs are required. Therefore, even higher precision and higher throughput are required in manufacturing equipment. In particular, the air slide stage can play an important role in achieving high precision and high throughput.

Japanese Patent Application Publication No. 2003-163257 JP 2016-509539 Publication

One way to achieve high throughput is to increase the acceleration of the air slide stage by increasing the output of the motor that drives it. However, when the acceleration is increased, the force applied to the members constituting the air slide stage increases, and there is a risk that the members will deform and it will become impossible to achieve the desired motion accuracy. Furthermore, high-frequency vibrations may occur due to high-speed movement of the stage, and if this frequency matches the natural frequency of the members constituting the air slide stage, resonance will occur. This resonance amplifies the vibrations of the members constituting the air slide stage, so there is a risk that desired motion accuracy may not be achieved. In order to solve this problem, it is possible to increase the rigidity of the member and improve the natural frequency. One way to increase the rigidity of a component is to simply increase the weight of the component, but reducing weight is effective in increasing the natural frequency. Conflicting. In addition, if the weight of the member increases, there is a concern that throughput will decrease.

The aspects of the present invention have been made based on the recognition of such problems, and an object thereof is to provide a ceramic structure that is lightweight, has high rigidity, and has a high natural frequency.

A first invention provides an upper plate on which an object to be processed is placed, first to fourth side plates provided to intersect with the upper plate, and partitioned by the upper plate and the first to fourth side plates. A plurality of ribs connected to the upper plate in a space, each of the plurality of ribs connecting to any one of the first to fourth side plates. A ceramic structure having a main component, wherein the first side plate and the second side plate are parallel to each other,
The third side plate and the fourth side plate are parallel to each other and perpendicular to the first side plate and the second side plate, and the plurality of ribs are not connected to any of the first to fourth side plates. a first rib that is inclined; a second rib that is parallel to the first rib and is provided a first distance from the first rib; and is inclined with respect to any of the first to fourth side plates; a third rib that intersects the first rib in the space; and a third rib that is parallel to the third rib, intersects the second rib in the space, and is spaced the first distance from the third rib. a first intersection between the first rib and the fourth rib, a second intersection between the second rib and the third rib, and a second intersection between the third rib and the third rib. At least two of the third intersection with the first rib and the fourth intersection between the fourth rib and the second rib do not connect to any of the first to fourth side plates, and A ceramic structure located in space.

In the first invention, the first to fourth ribs form a rhombus with each side inclined with respect to the first to fourth side plates, and each of the first to fourth intersections is formed by the first to fourth ribs. It is located at the apex of the rhombus formed by. Further, since each of the ribs is connected to one of the first to fourth side plates, the side plates can be supported by the ribs. According to the first invention, compared to the case where ribs are provided in a lattice pattern parallel to any one of the first to fourth side plates, the number of ribs is limited for weight reduction, and yet high rigidity and high natural vibration are achieved. numbers can be achieved.

In a second invention, in the first invention, all of the first intersection, the second intersection, the third intersection, and the fourth intersection are connected to any of the first to fourth side plates. The ceramic structure is unconnected and located within the space.

According to the second invention, the fact that the intersection portion is not connected to any of the first to fourth side plates means that the ends of different ribs are not connected at the same position on the side plate. This disperses stress and increases rigidity.

A third aspect of the present invention is that in the second aspect, in a plan view of the space, a first line of symmetry connecting the center of the first side plate and the center of the second side plate; When the space is divided into the first to fourth regions by the second line of symmetry connecting the centers of the four side plates,
Each of the first to fourth ribs is one of two areas located diagonally across the intersection of the first line of symmetry and the second line of symmetry among the first to fourth areas. a ceramic structure extending from one region to another.

According to the third invention, the ribs can be made stronger against twisting than when the ribs extend between adjacent regions without sandwiching the intersection between the first line of symmetry and the second line of symmetry.

A fourth invention is based on the third invention, wherein one end of the first rib is connected to the third side plate, the other end is connected to the first side plate, and one end of the second rib is connected to the second side plate, The other ends are connected to the fourth side plate, one end of the third rib is connected to the third side plate, the other end is connected to the second side plate, and one end of the fourth rib is connected to the first side plate, The other end is a ceramic structure connected to the fourth side plate, respectively.

According to the fourth invention, the extensions of the first to fourth ribs forming a rhombus are connected to the side plates and support the side plates, thereby suppressing twisting and deformation of the side plates.

A fifth invention is based on the third invention, wherein one end of the first rib is connected to a first corner formed by the second side plate and the third side plate, and the other end of the first rib is connected to the first side plate, one end of the second rib is connected to the second side plate, and the other end of the second rib is connected to a second corner formed by the first side plate and the fourth side plate. one end of the third rib is connected to a third corner formed by the first side plate and the third side plate, and the other end of the third rib is connected to the second side plate, One end of the fourth rib is connected to the first side plate, and the other end of the fourth rib is connected to a fourth corner formed by the second side plate and the fourth side plate. It is.

According to the fifth invention, the extensions of the first to fourth ribs forming a rhombus are connected to the side plates and support the side plates, thereby suppressing twisting and deformation of the side plates.

A sixth invention is based on the third invention, wherein the length of the first side plate and the length of the second side plate are longer than the length of the third side plate and the length of the fourth side plate, and the length of the first side plate is longer than the length of the third side plate and the length of the fourth side plate. One end of the rib is connected to the second side plate, the other end is connected to the first side plate, one end of the second rib is connected to the second side plate, the other end is connected to the first side plate, and the third One end of the rib is connected to the first side plate, the other end is connected to the second side plate, and one end of the fourth rib is connected to the first side plate, and the other end is connected to the second side plate. It is a ceramic structure.

According to the sixth invention, the extensions of the first to fourth ribs forming a rhombus are connected to the side plates and support the side plates, thereby suppressing twisting and deformation of the side plates.

In a seventh invention, in any one of the first to sixth inventions, a first imaginary line connecting the first intersection and the second intersection is connected to the third side plate and the fourth side plate. parallel, ceramic structures.

According to the seventh invention, it is possible to suppress a decrease in specific rigidity.

An eighth invention is a ceramic structure according to any one of the first to sixth inventions, wherein the plurality of ribs further includes a fifth rib connected to the first side plate and the second side plate. be.

According to the eighth invention, the rigidity can be increased particularly against vibrations in the first mode.

A ninth invention is a ceramic structure based on the eighth invention, wherein the fifth rib is parallel to the third side plate and the fourth side plate.

According to the ninth invention, the rigidity can be increased particularly against vibrations in the first mode.

A tenth invention is based on the ninth invention, wherein the fifth rib is a ceramic structure that intersects with the first intersection and the second intersection.

According to the tenth invention, the rigidity can be increased particularly against vibrations in the first mode.

An eleventh invention is based on the first or second invention, wherein the plurality of ribs include a fifth rib connected to the first side plate and the second side plate, and a fifth rib parallel to the first rib and the second rib. a sixth rib provided apart from the first rib and the second rib; and a seventh rib parallel to the sixth rib and provided a second distance away from the sixth rib. an eighth rib that is parallel to the third rib and the fourth rib and intersects the sixth rib and the seventh rib in the space; 6 ribs and a ninth rib intersecting the seventh rib and provided at the second distance from the eighth rib, one end of the first rib is connected to the third side plate and the other The ends of the second rib are connected to the first side plate, one end of the second rib is connected to the second side plate, the other end is connected to the fifth rib, one end of the third rib is connected to the third side plate, and the other end is connected to the third side plate. The ends of the fourth rib are connected to the second side plate, one end of the fourth rib is connected to the first side plate, the other end is connected to the fifth rib, one end of the sixth rib is connected to the fifth rib, and the other end is connected to the fifth rib. The ends of the seventh rib are connected to the first side plate, one end of the seventh rib is connected to the second side plate, the other end is connected to the fourth side plate, one end of the eighth rib is connected to the fifth rib, and the other end is connected to the fifth rib. The ceramic structure has ends connected to the second side plate, one end of the ninth rib connected to the first side plate, and the other end connected to the fourth side plate.

According to the eleventh invention, by increasing the number of ribs, the rigidity can be further increased.

In a twelfth invention, in any one of the first to sixth inventions, the thickness of the upper plate is the same as or greater than the thickness of the first to fourth side plates and the thickness of the plurality of ribs. This is a ceramic structure characterized by the following.

According to the twelfth invention, by making the thickness of the upper plate larger than the thickness of the first to fourth side plates and the thickness of the plurality of ribs, the rigidity of the upper plate to which force is directly applied is increased. can be increased. This increases the moment of inertia of area and makes it difficult to deform. Furthermore, compared to the case where the thickness of the first to fourth side plates and the thickness of the plurality of ribs are made larger than the thickness of the upper plate, the rigidity can be increased while suppressing an increase in weight. This makes it possible to achieve both high rigidity and light weight in a better balance.

According to aspects of the present invention, it is possible to provide a ceramic structure that is lightweight, has high rigidity, and has a high natural frequency.

FIG. 1 is a perspective view of the ceramic structure of the first embodiment. (a) is a plan view of the space side of the ceramic structure of the first embodiment, and (b) is a plan view of the upper surface of the ceramic structure of the first embodiment. (a) is a plan view of the space side of the ceramic structure of the second embodiment, and (b) is a plan view of the space side of the ceramic structure of the third embodiment. (a) is a plan view of the space side of the ceramic structure of the fourth embodiment, and (b) is a plan view of the space side of the ceramic structure of the fifth embodiment. (a) is a plan view of the space side of the ceramic structure of the first comparative example, and (b) is a plan view of the space side of the ceramic structure of the second comparative example. (a) is a plan view of the space side of the ceramic structure of the third comparative example, and (b) is a plan view of the space side of the ceramic structure of the fourth comparative example. (a) is a plan view of the space side of the ceramic structure of the tenth embodiment, and (b) is a plan view of the space side of the ceramic structure of the eleventh embodiment. (a) is a plan view of the space side of the ceramic structure of the twelfth embodiment, and (b) is a plan view of the space side of the ceramic structure of the thirteenth embodiment. (a) is a plan view of the space side of the ceramic structure of the fifth comparative example, and (b) is a plan view of the space side of the ceramic structure of the sixth comparative example. (a) is a plan view of the space side of the ceramic structure of a seventh comparative example, and (b) is a perspective view of the space side of the ceramic structure of the eighth comparative example. 12 is a table showing simulation results of the first to ninth embodiments and the first to fourth comparative examples. 12 is a table showing simulation results of the 12th to 13th embodiments and the 5th to 9th comparative examples. FIG. 7 is a plan view of the space side of the ceramic structures of the sixth to ninth embodiments.

Embodiments of the present invention will be described below with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components in each drawing are denoted by the same reference numerals as much as possible, and redundant description will be omitted.

[First embodiment]
The ceramic structure 1 of the first embodiment will be described with reference to FIGS. 1, 2(a) and 2(b). Note that the top view of the ceramic structure 1 shown in FIG. 2(b) is also applied to ceramic structures of other embodiments and structures of comparative examples, which will be described later.

The ceramic structure 1 has ceramic as a main component. The ceramic structure 1 is made of, for example, an oxide such as alumina (Al ₂ O ₃ ), cordierite (Mg ₂ Al ₃ (AlSi ₅ O ₁₈ )), a nitride such as aluminum nitride (AlN), silicon nitride (SiN), or , a mixture of silicon (Si) and silicon carbide (SiC) (SiSiC), and a carbide such as silicon carbide (SiC) as the main component.
Here, the main component is a compound that is contained in a relatively large amount compared to other compounds contained in the ceramic structure 1, for example, by quantitative or semi-quantitative analysis of the ceramic structure 1 by X-ray diffraction (XRD). A compound. For example, the main component is a compound that is most present in the ceramic structure, and the proportion of the main component in the ceramic structure is greater than 50% in volume or mass ratio. The proportion occupied by the main component is more preferably greater than 70%, and also preferably greater than 90%. The proportion occupied by the main component may be 100%.

The ceramic structure 1 includes an upper plate 10, first to fourth side plates 11 to 14 provided to intersect with the upper plate 10, and a space S defined by the upper plate 10 and the first to fourth side plates 11 to 14. It includes a plurality of ribs 21 to 24 arranged inside.
In this specification, a "rib" is a plate-shaped member disposed within the space S. The ribs are mainly made of ceramic. The material constituting the ribs is the same as that of the top plate and the first to fourth side plates. Alternatively, the material constituting the ribs may be different from that of the upper plate and the first to fourth side plates. For example, the thickness of the rib (the length in the direction perpendicular to the direction in which the rib extends) may be thinner than the thickness of the upper plate. For example, the thickness of the rib may be thinner than the thickness of any one of the first to fourth side plates.

The first side plate 11 and the second side plate 12 are parallel to each other. The third side plate 13 and the fourth side plate 14 are parallel to each other and perpendicular to the first side plate 11 and the second side plate 12. The direction in which the first side plate 11 and the second side plate 12 extend is defined as a first direction X. The direction in which the third side plate 13 and the fourth side plate 14 extend is defined as a second direction Y. A direction perpendicular to the first direction X and the second direction Y is defined as a third direction Z. The first to fourth side plates 11 to 14 have four corners 41 to 44.
In this specification, "parallel" and "perpendicular" mean not only strictly "parallel" and "perpendicular" but also allow for some deviation as long as it is usable in the application of the ceramic structure, for example, a stage. It is something to do. For example, the angles of the corners 41 to 44 are not limited to 90°, but may be ± several degrees.

The upper plate 10 has a first surface 10a shown in FIGS. 1 and 2(a), and a second surface 10b shown in FIG. 2(b) located on the opposite side of the first surface 10a in the third direction Z. . The third direction Z is perpendicular to the first surface 10a and the second surface 10b. The first surface 10a of the upper plate 10 serves as a mounting surface on which the object to be processed is mounted.

The space S is defined by the second surface 10b of the upper plate 10, the inner surface of the first side plate 11, the inner surface of the second side plate 12, the inner surface of the third side plate 13, and the inner surface of the fourth side plate 14. In plan view, the first side plate 11, the second side plate 12, the third side plate 13, and the fourth side plate 14 continuously surround the space S. The inner and outer surfaces of each side plate are parallel to the third direction Z.

In the first embodiment, the length of the first side plate 11 in the first direction X and the length of the second side plate 12 in the first direction X are the same. The length of the third side plate 13 in the second direction Y and the length of the fourth side plate 14 in the second direction Y are the same. The length of the first side plate 11 in the first direction X and the length of the second side plate 12 in the first direction longer than length. The first surface 10a and the second surface 10b of the upper plate 10 are, for example, rectangular. Note that the length of the first side plate 11 in the first direction X, the length of the second side plate 12 in the first direction X, the length of the third side plate 13 in the second direction Y, and the length of the fourth side plate 14 in the second direction The length of Y may be the same, and the first surface 10a and the second surface 10b of the upper plate 10 may be square. The length of the first side plate 11 in the first direction X, the length of the second side plate 12 in the first direction X, the length of the third side plate 13 in the second direction Y, and the length of the fourth side plate 14 in the second direction Y. Each length is, for example, 1000 mm or more. Each length may be 300 mm or more.

The plurality of ribs include a first rib 21, a second rib 22, a third rib 23, and a fourth rib 24. The side surfaces of each rib 21 to 24 are parallel to the third direction Z. Ends of each of the ribs 21 to 24 on the upper plate 10 side in the third direction Z are connected to the second surface 10b of the upper plate 10 within the space S.

The first rib 21 is inclined with respect to any of the first to fourth side plates 11 to 14. One end 21a of the first rib 21 is connected to a first corner 41 formed by the second side plate 12 and the third side plate 13. The other end 21b of the first rib 21 is connected to the first side plate 11.

The second rib 22 is parallel to the first rib 21 and is provided a first distance d1 from the first rib 21. In this specification, unless otherwise specified, "distance" refers to the shortest distance between two objects. One end 22a of the second rib 22 is connected to the second side plate 12. The other end 22b of the second rib 22 is connected to a second corner 42 formed by the first side plate 11 and the fourth side plate 14.

The third rib 23 is inclined with respect to any of the first to fourth side plates 11 to 14, and intersects with the first rib 21 within the space S. In the first embodiment, the third rib 23 also intersects the second rib 22 within the space S. One end 23a of the third rib 23 is connected to a third corner 43 formed by the first side plate 11 and the third side plate 13. The other end 23b of the third rib 23 is connected to the second side plate 12.

The fourth rib 24 is parallel to the third rib 23, intersects the second rib 22 in the space S, and is provided a first distance d1 from the third rib 23. In the first embodiment, the fourth rib 24 also intersects with the first rib 21 within the space S. One end 24a of the fourth rib 24 is connected to the first side plate 11. The other end 24b of the fourth rib 24 is connected to a fourth corner 44 formed by the second side plate 12 and the fourth side plate 14.

The intersection between the first rib 21 and the fourth rib 24 is called a first intersection 31, the intersection between the second rib 22 and the third rib 23 is called a second intersection 32, and the third rib 23 and the first rib 21. Let the intersection between the fourth rib 24 and the second rib 22 be the third intersection 33 and the fourth intersection 34. At least two of the first to fourth intersections 31 to 34 are located within the space S without connecting to any of the first to fourth side plates 11 to 14. In the first embodiment, all of the first intersection 31, the second intersection 32, the third intersection 33, and the fourth intersection 34 are not connected to any of the first to fourth side plates 11 to 14, Located within space S. The first to fourth intersections 31 to 34 are located at the apexes of the rhombus formed by the first to fourth ribs 21 to 24.

As shown in FIG. 2(a), in a plan view of the space S, a straight line connecting the center of the first side plate 11 in the first direction X and the center of the second side plate 12 in the first direction A straight line connecting the center of the third side plate 13 in the second direction Y and the center of the fourth side plate 14 in the second direction Y is defined as a second line of symmetry L2. The first line of symmetry L1 and the second line of symmetry L2 are orthogonal to each other. When the space S is divided into the first to fourth regions S1 to S4 by the first line of symmetry L1 and the second line of symmetry L2, each of the first to fourth ribs 21 to 24 corresponds to the first to fourth regions S1 to S4. It extends from one region to the other of two regions located diagonally across the intersection of the first line of symmetry L1 and the second line of symmetry L2. The first area S1 and the second area S2 are located diagonally across the intersection of the first line of symmetry L1 and the second line of symmetry L2, and the third area S3 and the fourth area S4 are located on the opposite sides of the intersection of the first line of symmetry L1 and the second line of symmetry L2. and the second line of symmetry L2.

The first rib 21 extends from the first region S1 to the second region S2. The second rib 22 extends from the first region S1 to the second region S2. The third rib 23 extends from the third region S3 to the fourth region S4. The fourth rib 24 extends from the third region S3 to the fourth region S4.

If the straight line connecting the first intersection 31 and the second intersection 32 is the first imaginary line L3, the first imaginary line L3 is parallel to the third side plate 13 and the fourth side plate 14. In the first embodiment, the first virtual line L3 coincides with the first line of symmetry L1.

Hereinafter, other embodiments will be mainly described with respect to configurations that are different from the first embodiment. Note that the matters described in the first embodiment are also applied to the other embodiments unless there is a contradiction with the description and drawings in each of the other embodiments.

[Second embodiment]
According to the ceramic structure 2 of the second embodiment shown in FIG. 3A, one end 21a of the first rib 21 is connected to the second side plate 12. The other end 22b of the second rib 22 is connected to the first side plate 11. One end 23a of the third rib 23 is connected to the first side plate 11. The other end 24b of the fourth rib 24 is connected to the second side plate 12.

[Third embodiment]
According to the ceramic structure 3 of the third embodiment shown in FIG. 3(b), the other end 21b of the first rib 21 and one end 24a of the fourth rib 24 are connected to each other at the first side plate 11. In other words, the first intersection 31 between the first rib 21 and the fourth rib 24 is connected to the first side plate 11 .

Further, the other end 23b of the third rib 23 and the one end 22a of the second rib 22 are connected to each other at the second side plate 12. In other words, the second intersection 32 between the second rib 22 and the third rib 23 is connected to the second side plate 12 .

[Fourth embodiment]
According to the ceramic structure 4 of the fourth embodiment shown in FIG. 4(a), one end 21a of the first rib 21 is connected to the third side plate 13. The other end 22b of the second rib 22 is connected to the fourth side plate 14. One end 23a of the third rib 23 is connected to the third side plate 13. The other end 24b of the fourth rib 24 is connected to the fourth side plate 14.

[Fifth embodiment]
According to the ceramic structure 5 of the fifth embodiment shown in FIG. 4(b), one end 21a of the first rib 21 is connected to the third side plate 13. The other end 21b of the first rib 21 is connected to the second corner 42 between the first side plate 11 and the fourth side plate 14. One end 22a of the second rib 22 is connected to a first corner 41 between the second side plate 12 and the third side plate 13. The other end 22b of the second rib 22 is connected to the fourth side plate 14. One end 23a of the third rib 23 is connected to the third side plate 13. The other end 23b of the third rib 23 is connected to a fourth corner 44 between the second side plate 12 and the fourth side plate 14. One end 24a of the fourth rib 24 is connected to a third corner 43 between the first side plate 11 and the third side plate 13. The other end 24b of the fourth rib 24 is connected to the fourth side plate 14.

[6th to 9th embodiments]
In the ceramic structures of the sixth to ninth embodiments, as shown in FIG. 13, in plan view, the first virtual line L3 connecting the first intersection 31 and the second intersection 32 is It differs from the ceramic structure 4 of the fourth embodiment in that it is inclined with respect to the fourth side plate 14.

In the sixth to ninth embodiments, a line L5 passing through the center of gravity of the rhombus formed by the four ribs 21 to 24 and perpendicular to the first side plate 11 and the second side plate 12 and the outermost side of the second side plate 12 in plan view. The intersection with the outer edge located at is defined as a first intersection P1. The intersection between the first imaginary line L3 connecting the first intersection 31 and the second intersection 32 and the outer edge of the second side plate 12 is defined as a second intersection P2. In the sixth to ninth embodiments, the first intersection point P1 and the second intersection point P2 do not coincide in the first direction X and are located apart.

In the sixth embodiment, the distance in the first direction X between the first intersection point P1 and the second intersection point P2 is 25 mm.
In the seventh embodiment, the distance in the first direction X between the first intersection point P1 and the second intersection point P2 is 50 mm.
In the eighth embodiment, the distance in the first direction X between the first intersection P1 and the second intersection P2 is 100 mm.
In the ninth embodiment, the distance in the first direction X between the first intersection point P1 and the second intersection point P2 is 135 mm.

Next, we will discuss the results of simulating the natural frequency, amount of deformation, and specific stiffness for the first to ninth embodiments and the first to fourth comparative examples shown in FIGS. 5(a) to 6(b). explain.

According to the ceramic structure 101 of the first comparative example shown in FIG. All of the intersection 32, the third intersection 33 between the third rib 23 and the first rib 21, and the fourth intersection 34 between the fourth rib 24 and the second rib 22 are not located within the space S. In the fourth comparative example shown in FIG. 6(b), there is no intersection between the ribs.

According to the ceramic structure 102 of the second comparative example shown in FIG. 5(b), the first intersection 31 and the second intersection 32 are located in the space S, but the third intersection and the fourth intersection are not exist. According to the ceramic structure 103 of the third comparative example shown in FIG. 6(a), the third intersection 33 and the fourth intersection 34 are located in the space S, but the first intersection and the second intersection are not exist.

In the first to ninth embodiments and the first to fourth comparative examples, the length of the first side plate 11 and the second side plate 12 in the first direction X is 2000 mm, and the length of the third side plate 13 and the fourth side plate 14 in the second direction The length of Y was 1000 mm. Further, the thickness of each side plate in the direction perpendicular to the extending direction was 10 mm, and the thickness of each rib in the direction perpendicular to the extending direction was 5 mm. Further, the thickness of each side plate and each rib in the third direction Z was 10 mm.

FIG. 11 shows the simulation results.

The natural frequency [Hz] represents the natural frequency of the first mode when the ceramic structure is not restrained in any of the first direction X, second direction Y, and third direction Z. The primary mode is a vibration mode that is bent at the first line of symmetry L1 or the second line of symmetry L2.

Specific stiffness [Hz/kg] in terms of natural frequency was calculated from natural frequency [Hz]/mass [kg].

The amount of deformation [μm] represents the amount of deformation due to its own weight in the third direction Z when the ceramic structure is supported at four points from the first to fourth corners.

The specific rigidity [1/(m·kg)] from the viewpoint of deformation was calculated by 1/(deformation amount [m]×mass [kg]).

The specific stiffness [Hz/(m·kg)] from the viewpoint of natural frequency and deformation was calculated by natural frequency [Hz]/{deformation amount [m]×mass [kg]}.

From the results in FIG. 11, the specific stiffnesses in terms of natural frequency and deformation of the first to ninth embodiments are higher than those of the first to fourth comparative examples in terms of natural frequency and deformation. That is, according to the ceramic structures of the first to ninth embodiments, even if only four ribs are used to reduce weight, high rigidity and high natural frequency can be achieved by carefully arranging the ribs.

The ceramic structures of the first to ninth embodiments have all of the following common features.
Feature 1. It has four intersections 31 to 34 located at the apexes of a rhombus formed by four ribs 21 to 24.
Feature 2. At least two of the four intersections 31 to 34 are located within the space S without connecting to any of the first to fourth side plates 11 to 14.

Among the first to fourth comparative examples, there is no one that has both feature 1 and feature 2 above. Therefore, by having both Features 1 and 2 above, it is possible to provide a ceramic structure that is lightweight, has high rigidity, and has a high natural frequency.

Further, according to the first to ninth embodiments, in each of the ribs 21 to 24, the portion (at least one end of each rib 21 to 24) extending from the portion forming the diamond shape beyond the intersection is It is connected to any one of the four side plates 11 to 14 (including the corners 41 to 44). By supporting the side plate with the extension of the diamond-shaped rib, twisting and deformation of the side plate can be suppressed.

Further, according to the first to ninth embodiments, each of the first to fourth ribs 21 to 24 is connected to the first line of symmetry L1 and the second line of symmetry L2 among the first to fourth regions S1 to S4. It extends from one of the two areas diagonally across the intersection of the two areas to the other area. As a result, compared to the case where the rib extends between adjacent regions in the first direction X or the second direction Y without sandwiching the intersection of the first symmetry line L1 and the second symmetry line L2, the I can make it stronger.

Further, according to the first to fifth embodiments, the first virtual line L3 connecting the first intersection 31 and the second intersection 32 is parallel to the third side plate 13 and the fourth side plate 14. As a result, compared to the sixth to ninth embodiments in which the first virtual line L3 is non-parallel to the third side plate 13 and the fourth side plate 14 and is inclined, the reduction in the natural frequency is particularly suppressed, and as a result, the Decrease in rigidity can be suppressed.

The fact that each of the intersections 31 to 34 is not connected to any of the first to fourth side plates 11 to 14 means that the ends of different ribs are not connected to each other at the same position on the side plates. This disperses stress and increases rigidity. Moreover, when the length of the first side plate 11 and the length of the second side plate 12 are longer than the length of the third side plate 13 and the length of the fourth side plate 14, the four intersections 31 to 34 are all located in the space S and the ends of each rib 21 to 24 are connected to the side plates 11 and 12 on the long side or the corners 41 to 44, or as in the second embodiment, By locating all of the two intersections 31 to 34 in the space S and connecting all the ends of the ribs 21 to 24 to the side plates 11 and 12 on the long side, the natural frequency and deformation are higher than in other embodiments. The specific stiffness of the viewpoint can be increased.

[Tenth embodiment]
According to the ceramic structure 6 of the tenth embodiment shown in FIG. 7(a), the plurality of ribs further include a fifth rib 25. One end 25a of the fifth rib 25 is connected to the first side plate 11, and the other end 25b of the fifth rib 25 is connected to the second side plate 12. The fifth rib 25 makes it possible to further increase the rigidity, especially against vibrations in the first mode.

In order to increase rigidity, the fifth rib 25 is preferably parallel to the third side plate 13 and the fourth side plate 14. Moreover, in order to increase rigidity, it is preferable that the fifth rib 25 intersects with the first intersection 31 and the second intersection 32.

[Eleventh embodiment]
According to the ceramic structure 7 of the eleventh embodiment shown in FIG. 7(b), the plurality of ribs include the sixth to ninth ribs 26 to 29 in addition to the first to fifth ribs 21 to 25 described above. It also has. The first to fourth ribs 21 to 24 are located in the first region S1 and third region S3, and the sixth to ninth ribs 26 to 29 are located in second region S2 and fourth region S4. The fifth rib 25 is located on the first line of symmetry L1.

One end 21a of the first rib 21 is connected to the third side plate 13, and the other end 21b is connected to the first side plate 11. One end 22a of the second rib 22 is connected to the second side plate 12, and the other end 22b is connected to the fifth rib 25. One end 23a of the third rib 23 is connected to the third side plate 13, and the other end 23b is connected to the second side plate 12. One end 24a of the fourth rib 24 is connected to the first side plate 11, and the other end 24b is connected to the fifth rib 25.

The sixth rib 26 is parallel to the first rib 21 and the second rib 22 and is provided apart from the first rib 21 and the second rib 22. One end 26a of the sixth rib 26 is connected to the fifth rib 25, and the other end 26b is connected to the first side plate 11, respectively.

The seventh rib 27 is parallel to the sixth rib 26 and is provided at a second distance d2 from the sixth rib 26. The second distance d2 is the same as the first distance d1 described above. One end 27a of the seventh rib 27 is connected to the second side plate 12, and the other end 27b is connected to the fourth side plate 14.

The eighth rib 28 is parallel to the third rib 23 and the fourth rib 24, and intersects the sixth rib 26 and the seventh rib 27 within the space S. One end 28a of the eighth rib 28 is connected to the fifth rib 25, and the other end 28b is connected to the second side plate 12.

The ninth rib 29 is parallel to the eighth rib 28, intersects the sixth rib 26 and the seventh rib 27 in the space S, and is provided at a second distance d2 from the eighth rib 28. One end 29a of the ninth rib 29 is connected to the first side plate 11, and the other end 29b is connected to the fourth side plate 14.

A fifth intersection 35 between the sixth rib 26 and the ninth rib 29, a sixth intersection 36 between the seventh rib 27 and the eighth rib 28, and a seventh intersection 37 between the eighth rib 28 and the sixth rib 26 , and the eighth intersection 38 between the ninth rib 29 and the seventh rib 27 are located in the space S without connecting to any of the first to fourth side plates 11 to 14. The fifth to eighth intersections 35 to 38 are located at the apexes of the rhombus formed by the sixth to ninth ribs 26 to 29. The third intersection 33, the fourth intersection 34, the seventh intersection 37, and the eighth intersection 38 are located on the second line of symmetry L2. The second imaginary line L4 connecting the fifth intersection 35 and the sixth intersection 36 is parallel to the first imaginary line L3 and the first line of symmetry L1.

According to the ceramic structure 7 of the eleventh embodiment, the rigidity can be further increased by increasing the number of ribs compared to the first to tenth embodiments.

The side plates 11 to 14 are not limited to being connected directly, but may be connected via protrusions 51 to 54, as shown in FIGS. 8(a) and 8(b). The second side plate 12 and the third side plate 13 are connected via the first protrusion 51 . The first side plate 11 and the fourth side plate 14 are connected via the second protrusion 52 . The first side plate 11 and the third side plate 13 are connected via the third protrusion 53. The second side plate 12 and the fourth side plate 14 are connected via the fourth protrusion 54 .

The first protrusion 51 protrudes from one end of the second side plate 12 in the second direction Y, and the fourth protrusion 54 protrudes from the other end of the second side plate 12 in the second direction Y. The third protrusion 53 protrudes from one end of the first side plate 11 in a direction opposite to the protrusion direction of the first protrusion 51, and the second protrusion 52 protrudes from the other end of the first side plate 11 in the protrusion direction of the fourth protrusion 54. protrude in the opposite direction.

[Twelfth embodiment]
According to the ceramic structure 8 of the twelfth embodiment shown in FIG. 8(a), the plurality of ribs include the first to fourth ribs 21 to 24 and the sixth to ninth ribs 26 to 29. This is common to the eleventh embodiment. Note that the ceramic structure 8 of the twelfth embodiment does not have the fifth rib 25.

Further, the second rib 22 extends from the first region S1 to the second region S2, the fourth rib 24 extends from the third region S3 to the fourth region S4, and the sixth rib 26 extends from the first region S1 to the second region S2. This embodiment differs from the eleventh embodiment in that the eighth rib 28 extends from S1 to the second region S2, and that the eighth rib 28 extends from the third region S3 to the fourth region S4. One end 22a of the second rib 22 is connected to the second side plate 12 in the first region S1, and the other end 22b of the second rib 22 is connected to the first side plate 11 in the second region S2. One end 24a of the fourth rib 24 is connected to the first side plate 11 in the third region S3, and the other end 24b of the fourth rib 24 is connected to the second side plate 12 in the fourth region S4. One end 26a of the sixth rib 26 is connected to the second side plate 12 in the first region S1, and the other end 26b of the sixth rib 26 is connected to the first side plate 11 in the second region S2. One end 28a of the eighth rib 28 is connected to the first side plate 11 in the third region S3, and the other end 28b of the eighth rib 28 is connected to the second side plate 12 in the fourth region S4.

[13th embodiment]
According to the ceramic structure 9 of the thirteenth embodiment shown in FIG. 8(b), the configuration of the plurality of ribs is the same as that of the eleventh embodiment.

Next, the results of simulating the natural frequency, deformation amount, and specific stiffness for the twelfth embodiment, the thirteenth embodiment, and the fifth to ninth comparative examples will be described.

According to the ceramic structure 105 of the fifth comparative example shown in FIG. 9A, the other end 22b of the second rib 22, the other end 24b of the fourth rib 24, one end 26a of the sixth rib 26, and One end 28a of 28 is not connected to any of the first to fourth side plates 11 to 14.

According to the ceramic structure 106 of the sixth comparative example shown in FIG. 9(b) and the ceramic structure 107 of the seventh comparative example shown in FIG. 10(a), both ends of the first rib 21 and both ends of the second rib 22 , the other end 24b of the fourth rib 24, one end 26a of the sixth rib 26, both ends of the eighth rib 28, and both ends of the ninth rib 29 are not connected to any of the first to fourth side plates 11 to 14. .

According to the ceramic structure 108 of the eighth comparative example shown in FIG. 10(b), a plurality of ribs 71 are provided in a grid pattern in the first direction X and the second direction Y.

The ceramic structure of the ninth comparative example does not have ribs and consists only of the top plate 10, first to fourth side plates 11 to 14, and first to fourth protrusions 51 to 54.

In the twelfth embodiment, the thirteenth embodiment, and the fifth to ninth comparative examples, the length of the first side plate 11 and the second side plate 12 in the first direction The length in the second direction Y was 1000 mm. Further, the thickness of each side plate in the direction perpendicular to the extending direction was 10 mm, and the thickness of each rib in the direction perpendicular to the extending direction was 10 mm. Further, the thickness of each side plate and each rib in the third direction Z was 10 mm.

FIG. 12 shows the simulation results.
Natural frequency [Hz], specific stiffness from the perspective of natural frequency [Hz/kg], amount of deformation [μm], specific stiffness from the perspective of deformation [1/(m・kg)], and ratio of natural frequency/deformation perspective The stiffness [Hz/(m·kg)] was calculated in the same manner as the simulation whose results are shown in FIG. 11 described above.

From the results in FIG. 12, it is possible to make the specific stiffness in terms of natural frequency and deformation of the twelfth and thirteenth embodiments higher than the specific stiffness in terms of natural frequency and deformation of the fifth to ninth comparative examples. can. According to the ceramic structures of the twelfth and thirteenth embodiments, the number of ribs is reduced and the weight is significantly reduced compared to the eighth comparative example shown in FIG. By devising this, high rigidity and high natural frequency can be achieved.

The ceramic structure of each embodiment described above can be used, for example, in an air slide stage included in a semiconductor device or FPD manufacturing apparatus (for example, an exposure apparatus). An object to be processed, such as a semiconductor wafer or a glass substrate, is placed on the first surface 10a of the upper plate 10 of the ceramic structure. According to the ceramic structure of each embodiment, it is possible to achieve light weight, high rigidity, and high natural frequency, so when the ceramic structure of each embodiment is used for an air slide stage, the positioning accuracy of the air slide stage can be improved. Can be made high.

The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited thereto, and various modifications can be made based on the technical idea of the present invention.

DESCRIPTION OF SYMBOLS 1-9... Ceramic structure, 10... Top plate, 10a... First surface, 10b... Second surface, 11... First side plate, 12... Second side plate, 13... Third side plate, 14... Fourth side plate, 21 ...first rib, 22...second rib, 23...third rib, 24...fourth rib, 25..., fifth rib, 26...sixth rib, 27...seventh rib, 28...eighth rib, 29... 9th rib, 31...first intersection, 32...second intersection, 33...third intersection, 34...fourth intersection, 35...fifth intersection, 36...sixth intersection, 37...seventh Intersection, 38...Eighth intersection, 41...First corner, 42...Second corner, 43...Third corner, 44...Fourth corner, 51...First protrusion, 52...Second protrusion Part, 53...Third protrusion, 54...Fourth protrusion, S...Space, S1...First region, S2...Second region, S3...Third region, S4...Fourth region, L1...First line of symmetry , L2...second line of symmetry, L3...first virtual line

Claims (12)

an upper plate on which the object to be processed is placed;
first to fourth side plates provided to intersect with the upper plate;
A plurality of ribs connected to the upper plate in a space defined by the upper plate and the first to fourth side plates, each of the plurality of ribs being connected to one of the first to fourth side plates. the plurality of ribs that connect;
A ceramic structure mainly composed of ceramic, comprising:
the first side plate and the second side plate are parallel to each other;
The third side plate and the fourth side plate are parallel to each other and perpendicular to the first side plate and the second side plate,
The plurality of ribs are
a first rib that is inclined with respect to any of the first to fourth side plates;
a second rib parallel to the first rib and provided a first distance apart from the first rib;
a third rib that is inclined with respect to any of the first to fourth side plates and intersects the first rib in the space;
a fourth rib that is parallel to the third rib, intersects the second rib in the space, and is provided at the first distance from the third rib;
have at least
a first intersection between the first rib and the fourth rib; a second intersection between the second rib and the third rib; a third intersection between the third rib and the first rib; At least two of the fourth intersections between the fourth rib and the second rib do not connect to any of the first to fourth side plates and are located within the space. The first intersection, the second intersection, the third intersection, and the fourth intersection are all located within the space without connecting to any of the first to fourth side plates. The ceramic structure according to item 1. In a plan view of the space, a first line of symmetry connecting the center of the first side plate and the center of the second side plate, and a second line of symmetry connecting the center of the third side plate and the center of the fourth side plate. When the space is divided into the first to fourth regions by
Each of the first to fourth ribs is one of two areas located diagonally across the intersection of the first line of symmetry and the second line of symmetry among the first to fourth areas. 3. The ceramic structure of claim 2, wherein the ceramic structure extends from one region to the other region. One end of the first rib is connected to the third side plate, and the other end is connected to the first side plate,
One end of the second rib is connected to the second side plate, and the other end is connected to the fourth side plate,
One end of the third rib is connected to the third side plate, and the other end is connected to the second side plate,
The ceramic structure according to claim 3, wherein one end of the fourth rib is connected to the first side plate, and the other end is connected to the fourth side plate. One end of the first rib is connected to a first corner formed by the second side plate and the third side plate,
The other end of the first rib is connected to the first side plate,
one end of the second rib is connected to the second side plate,
The other end of the second rib is connected to a second corner formed by the first side plate and the fourth side plate,
One end of the third rib is connected to a third corner formed by the first side plate and the third side plate,
The other end of the third rib is connected to the second side plate,
one end of the fourth rib is connected to the first side plate,
The ceramic structure according to claim 3, wherein the other end of the fourth rib is connected to a fourth corner formed by the second side plate and the fourth side plate. The length of the first side plate and the length of the second side plate are longer than the length of the third side plate and the length of the fourth side plate,
One end of the first rib is connected to the second side plate, and the other end is connected to the first side plate,
One end of the second rib is connected to the second side plate, and the other end is connected to the first side plate,
One end of the third rib is connected to the first side plate, and the other end is connected to the second side plate,
The ceramic structure according to claim 3, wherein one end of the fourth rib is connected to the first side plate, and the other end is connected to the second side plate. The ceramic structure according to any one of claims 1 to 6, wherein a first virtual line connecting the first intersection and the second intersection is parallel to the third side plate and the fourth side plate. . The ceramic structure according to any one of claims 1 to 6, wherein the plurality of ribs further includes a fifth rib connected to the first side plate and the second side plate. The ceramic structure according to claim 8, wherein the fifth rib is parallel to the third side plate and the fourth side plate. The ceramic structure according to claim 9, wherein the fifth rib intersects the first intersection and the second intersection. The plurality of ribs are
a fifth rib connected to the first side plate and the second side plate;
a sixth rib parallel to the first rib and the second rib and provided apart from the first rib and the second rib;
a seventh rib parallel to the sixth rib and provided a second distance apart from the sixth rib;
an eighth rib that is parallel to the third rib and the fourth rib and intersects the sixth rib and the seventh rib in the space;
a ninth rib that is parallel to the eighth rib, intersects the sixth rib and the seventh rib in the space, and is provided at a distance of the second distance from the eighth rib;
It further has
One end of the first rib is connected to the third side plate, and the other end is connected to the first side plate,
One end of the second rib is connected to the second side plate, and the other end is connected to the fifth rib,
One end of the third rib is connected to the third side plate, and the other end is connected to the second side plate,
One end of the fourth rib is connected to the first side plate, and the other end is connected to the fifth rib,
One end of the sixth rib is connected to the fifth rib, and the other end is connected to the first side plate,
One end of the seventh rib is connected to the second side plate, and the other end is connected to the fourth side plate,
One end of the eighth rib is connected to the fifth rib, and the other end is connected to the second side plate,
The ceramic structure according to claim 1 or 2, wherein one end of the ninth rib is connected to the first side plate, and the other end is connected to the fourth side plate. The thickness of the upper plate is the same as or larger than the thickness of the first to fourth side plates and the plurality of ribs, according to any one of claims 1 to 6. Ceramic structure.

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