WO2007074854A1

WO2007074854A1 - Non-contact delivery device

Info

Publication number: WO2007074854A1
Application number: PCT/JP2006/326019
Authority: WO
Inventors: Hitoshi Iwasaka; Hideyuki Tokunaga; Kotaro Kobayashi; Yuji Kasai
Original assignee: Harmotec Co., Ltd.
Priority date: 2005-12-27
Filing date: 2006-12-27
Publication date: 2007-07-05
Also published as: JP2007176637A; TW200804160A

Abstract

Attention is paid on a micro energy loss which has not been considered in a conventional non-contact delivery device so as to effectively utilize energy of a fluid to realize improvement of energy efficiency and energy saving. The non-contact delivery device holds a plate-shaped body in a non-contact way and delivers it. The non-contact delivery device includes a columnar body having an indented cylindrical chamber formed with a circumference-shaped inner circumferential surface; a flat end surface formed at the indented cylindrical chamber opening side of the body; a nozzle formed over the inner circumference of the indented cylindrical chamber for discharging a supply fluid into the indented cylindrical chamber; and a fluid path communicating with the nozzle for supplying a fluid via the nozzle into the indented cylindrical chamber. The nozzle is arranged at a position apart inwardly from the indented cylindrical chamber inner circumferential surface.

Description

Specification

Non-contact transfer device

Technical field

TECHNICAL FIELD [0001] The present invention relates to a non-contact conveyance device used for holding, conveying, rotating, etc. a plate-like body in a non-contact manner.

Background art

[0002] Conventionally, when a workpiece such as a semiconductor wafer glass substrate is transported or transferred, or at its process stage, the workpiece is held by vacuum suction, mechanical chucking, etc. with an end effector or vacuum stage. I went. Since these methods are in direct contact between the workpiece and the vacuum suction section or chucking section, problems such as particle transfer to the workpiece, metal contamination, scratches due to contact, and generation of static electricity due to peeling due to vacuum breakage may occur. There is.

In order to solve these problems, non-contact transfer devices using compressed air and the Bernoulli's theorem are now being put into practical use. According to this non-contact conveying apparatus, it is possible to hold a workpiece in a non-contact manner, but there is a problem that the holding force is generally weak. In the non-contact conveyance device disclosed in Patent Document 1, although the force for sucking and holding the plate-like body is improved by turning the fluid, the energy efficiency and consumption flow rate are seen from the viewpoint of hydrodynamic viewpoint. There is room for improvement in that regard.

Patent Document 1: JP 2005-51260 A

Disclosure of the invention

Problems to be solved by the invention

[0003] As described above, in the conventional non-contact conveyance device, the importance of cost and ease of handling is emphasized, and energy efficiency is considered little. However, in view of the fact that the consumption flow rate is increasing in order to transport and hold large-sized and thinned semiconductor wafers, the energy efficiency of devices in this technical field is improved. Energy conservation is a major issue.

From April 1999, the conventional energy conservation law was significantly strengthened, and the “Revised Energy Conservation Law” was enforced. . In addition, the introduction of a “domestic emissions trading system” in which domestic businesses trade greenhouse gas emissions is being considered as an additional measure. In addition, energy conservation is a global issue in light of the ongoing development of greenhouse gas emissions trading at the national level.

The present invention has been made in view of the above-mentioned circumstances, paying attention to microscopic energy loss that has not been paid attention to in the conventional non-contact transfer device, and effectively using the energy of the fluid, thereby improving the energy efficiency. The purpose is to improve and save energy.

Means for solving the problem

[0004] In order to solve the above-mentioned problems, the present invention is formed on a substantially columnar main body having a concave cylindrical chamber having an inner circumferential surface formed on the opening side of the concave cylindrical chamber. A flat end surface, a nozzle for discharging a supply fluid into the concave cylindrical chamber, and a nozzle that communicates with the nozzle, and is formed through the nozzle. And a fluid passage for supplying fluid into the chamber, wherein the nozzle is disposed at a position farther inward than the inner circumferential surface of the concave cylindrical chamber.

[0005] In the above configuration, two nozzles may be arranged at positions that are point-symmetric with respect to the center of the circumference of the concave cylindrical chamber.

[0006] In the above configuration, the nozzle may be disposed in the middle of the concave cylindrical chamber.

[0007] In the above configuration, the nozzle is provided so as to have a predetermined angle Θ with respect to a tangent that is in contact with the inner periphery at the discharge point P. The angle Θ is a fluid from the discharge point P. When the radius r 1 orthogonal to the line L 1 extending in the discharge direction is drawn, the distance between the intersection point P 2 of the radius r 1 and the line L 1, and the intersection point P 3 of the radius rl and the circumference of the concave cylindrical chamber δ may be set to satisfy δ Zrl = 5% to 25%!

[0008] In the above configuration, the opening edge of the concave cylindrical chamber may be smoothly curved from the inner peripheral surface of the concave cylindrical chamber and extend to the outer edge of the concave cylindrical chamber opening. Brief Description of Drawings

FIG. 1 is a perspective view showing a configuration of a non-contact transfer device 1 according to a first embodiment, and (a) is an oblique view From below, (b) is a perspective view of the oblique upward force.

FIG. 2 is a cross-sectional view of the non-contact transfer apparatus 1 according to the embodiment, (a) is a cross-sectional view taken along line II in FIG. 1 (a), and (b) is II II in FIG. 1 (a). It is line sectional drawing.

FIG. 3 is a diagram showing the relationship between the position of the short offset nozzle 5 and the suction force.

[FIG. 4] (a) is a diagram showing the pressure distribution when two short offset nozzles 5 are arranged point-symmetrically, and (b) is a diagram showing the velocity distribution.

[Fig. 5] (a) is a diagram showing a pressure distribution when only one short offset nozzle 5 is arranged, and (b) is a diagram showing a velocity distribution.

FIG. 6 is a diagram showing the relationship between the number of short offset nozzles 5 and the suction force.

FIG. 7 is a diagram showing energy efficiency of the non-contact conveyance device 1 according to the first embodiment with respect to the non-contact conveyance device according to the prior art using the concept of air power.

FIG. 8 is a view showing energy efficiency of the non-contact conveyance device 1 according to the first embodiment with respect to the non-contact conveyance device according to the prior art using the concept of air power.

FIG. 9 is a diagram showing the energy efficiency of the non-contact conveyance device 1 according to the first embodiment with respect to the non-contact conveyance device according to the prior art using the concept of air power.

FIG. 10 is a perspective view showing a configuration of a non-contact transfer device 10 according to a second embodiment.

FIG. 11 is a view showing the configuration of the non-contact transfer apparatus 10 according to the embodiment, wherein (a) is a top view, (b) is a side view, and (c) is a bottom view.

FIG. 12 is a drive explanatory diagram of a centering mechanism provided in the non-contact transfer apparatus 10 according to the embodiment.

FIG. 13 is a perspective view showing a configuration of a non-contact transfer device 20 according to a third embodiment.

FIG. 14 is a view showing a configuration of a non-contact transfer device 20 according to the embodiment, wherein (a) is a top view and (b) is a side view.

FIG. 15 is a drive explanatory diagram of a centering mechanism 22 provided in the non-contact transport apparatus 10 according to the same embodiment.

Explanation of symbols

1, 10, 20 ··· Non-contact transfer device, 2… Swirl flow forming body, 3… Recessed cylindrical chamber, 4… Flat facing surface, 5… Short offset nozzle, 6… Belmouth fluid passage, · · Open edge, 8 ... flow Body conductor Pl, 11 ········· Base 12, ^ ··· Centering mechanism, 121, 221 ··· Cylinder, 122 ··· Link arm, 222 ··· Zinc pre-clamp, 123, 213, 223 ··· ··· Centering guide ····································· Fluid supply port, 21 ·········································· •

BEST MODE FOR CARRYING OUT THE INVENTION

[0011] <First embodiment>

A first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a perspective view showing a configuration of a non-contact transport apparatus 1 according to the present embodiment. (A) is an oblique view from below, and (b) is a view of the oblique upward force. FIG. 2 is a cross-sectional view of the non-contact conveyance device 1. (A) is a cross-sectional view taken along line II in FIG. 1 (a), and (b) is a cross-sectional view taken along line II-II in FIG. 1 (a).

As shown in these drawings, the non-contact conveyance device 1 has a substantially columnar swirl flow forming body 2. A concave cylindrical chamber 3 is formed in the swirl flow forming body 2 so as to form a columnar space and its lower end is an opening. The opening side of the concave cylindrical chamber 3 faces a plate-like body (a plate-like workpiece such as a wafer) and is a flat facing surface 4 in which the facing surface is formed flat.

The opening edge 7 that forms the periphery of the opening of the concave cylindrical chamber 3 has a curved shape with a smooth cross section. That is, the cross-sectional shape of the opening edge 7 is a shape that smoothly curves from the inner peripheral surface of the recessed cylindrical chamber 3 and extends to the outer edge of the opening as shown in FIG. 2 (b). In this case, the curvature of the opening edge 7 is, for example, about R2.5, and the surface is preferably extremely smooth.

Next, reference numeral 5 in FIGS. 1 and 2 denotes a short offset nozzle that discharges fluid into the concave cylindrical chamber 3, and is formed so as to face the concave cylindrical chamber 3. The short offset nozzle 5 is connected to a bell mouth-like fluid passage 6 for supplying fluid into the concave cylindrical chamber 3 through the nozzle.

As shown in FIG. 2 (a), the short offset nozzle 5 is provided so as to have a predetermined angle Θ with respect to a tangent line that is in contact with the inner periphery at the discharge point P. This angle Θ is determined by subtracting the radius rl perpendicular to the line L1 extending in the fluid discharge direction and the point P2 between the radius rl and the line L1 and the point P3 between the radius rl and the circumference P3. Distance (hereinafter referred to as offset) δ is It is set to satisfy δ Zrl = 5% to 25%.

When the offset δ is provided in this way, the shear resistance force on the wall surface of the concave cylindrical chamber 3 when fluid is discharged from the short offset nozzle 5 into the concave cylindrical chamber 3 can be suppressed, and the entrainment effect can be increased. Therefore, the input energy can be more efficiently converted into rotational momentum.

[0013] Further, as shown in FIG. 2 (b), the short offset nozzle 5 is arranged so as to face the middle of the concave cylindrical chamber 3 in the vertical direction. In this case, the position of the short offset nozzle 5 is preferably set such that the distance hi from the upper surface of the concave cylindrical chamber 3 with respect to the height h of the concave cylindrical chamber 3 satisfies hlZ h = 35% to 75%. Masashi. When the short offset nozzle 5 is arranged above the concave cylindrical chamber 3, the fluid discharged into the concave cylindrical chamber 3 causes friction with the upper surface of the concave cylindrical chamber 3 due to its viscosity, and the boundary layer develops. However, if the nozzle position is located in the middle of the concave cylindrical chamber 3, friction between the upper surface of the concave cylindrical chamber 3 can be suppressed, and as a result, it can be efficiently converted into rotational force. Can reduce energy loss.

In this embodiment, two short offset nozzles 5 are arranged at positions that are point-symmetric with respect to the center 0 of the circumference as shown in FIG. 2 (a). The fluid discharged from the short-offset nozzle 5 facing the point symmetry into the concave cylindrical chamber 3 is a force that decelerates and gradually decelerates along the inner wall of the concave cylindrical chamber 3. Increase the mentament effect and centrifugal force. FIG. 4 (a) is a diagram showing the pressure distribution when two short offset nozzles 5 are arranged point-symmetrically, and FIG. 4 (b) is a diagram showing the velocity distribution.

On the other hand, FIG. 5 (a) is a diagram showing the pressure distribution when only one short offset nozzle 5 is arranged, and FIG. 5 (b) is a diagram showing the velocity distribution. As shown in these figures, when only one short offset nozzle 5 is arranged, the pressure distribution and velocity distribution are biased. This is because the wall flow that forms a swirling flow along the inner wall of the concave cylindrical chamber 3 causes friction due to the centrifugal force and the entrainment effect of the fluid with a high flow velocity discharged from the short offset nozzle 5 and the viscosity of the fluid. It happens because of the slowdown due to the development of the boundary layer. If the plate is sucked in this state, the plate will tilt. It will be sucked and held, resulting in an unstable state. When holding a semiconductor wafer that has been ultra-thin processed (50 m or less), the stress and bias in the pressure distribution can cause large stress on the wafer, which can lead to cracks and cracks. On the other hand, if two short-offset nozzles 5 are arranged point-symmetrically, the above problem is solved, and the flow rate per nozzle is the same as shown in FIG. However, by arranging two nozzles in a well-balanced manner, it is possible to achieve a suction force of 2.5 times or more, not twice.

In addition, the color drawings in Fig. 4 and Fig. 5 will be submitted for reference.

[0015] Further, the short offset nozzle 5 is shorter in length than the nozzles according to the prior art in order to minimize the pressure loss in the nozzle.

The bell mouth-like fluid passage 6 is drilled horizontally from the fluid inlet 8 formed on the side surface of the swirling flow forming body 2 to the closed end surface 7 and faces the inner peripheral surface of the concave cylindrical chamber 3. It communicates with offset nozzle 5. As shown in Fig. 2 (a), the bellmouth fluid passage 6 communicates with the short offset nozzle 5 with a smooth curved surface, so that loss due to separation when fluid flows into the nozzle Can be greatly reduced.

In the non-contact transfer device 1 having the above-described configuration, when a fluid is supplied from an air supply device (not shown) to the fluid introduction port 8, the fluid is short-circuited via the bell mouth fluid passage 6. It is blown into the concave cylindrical chamber 3 from the offset nozzle 5. The fluid blown into the concave cylindrical chamber 3 is rectified as a swirling flow in the internal space of the concave cylindrical chamber 3 and then flows out of the concave cylindrical chamber 3. At that time, if a plate-like body is arranged at a position facing the flat opposed surface 4 of the swirling flow forming body 2, the atmospheric pressure supply of the external force into the concave cylindrical chamber 3 is restricted, and the entrainment effect Due to the centrifugal force, the density of fluid molecules per unit area gradually decreases, and the pressure at the center of the swirling flow in the concave cylindrical chamber 3 decreases, generating negative pressure. As a result, the plate-like body is pressed by the ambient atmospheric pressure and sucked toward the flat opposing surface 4 side, while when the distance between the flat opposing surface 4 and the plate-like body approaches, the plate body is discharged from the concave cylindrical chamber 3. Since the fluid is restricted and the flow velocity of the fluid blown from the short offset nozzle 5 becomes slow, the pressure at the center of the swirl flow in the concave cylindrical chamber 3 rises and the plate-like body does not come into contact with the flat opposed surface 4 and the plate-like shape. Body distance is maintained. Further, the plate-like body is stably held in a non-contact state by the air interposed between the flat opposing surface 4 and the plate-like body. [0018] According to this non-contact conveyance device 1, it is possible to realize a significant improvement in energy efficiency and energy saving as compared with the conventional non-contact conveyance device. Before explaining this, the evaluation method will be explained.

Conventionally, the energy consumption of pneumatic equipment including the non-contact conveyance device as described above is expressed by air consumption, and has been evaluated by being converted into power consumption through the specific energy of the compressor used. However, since air consumption is not directly linked to energy, it is desirable to define and quantify energy flow with compressed air flow. Therefore, in this specification, we focus on the energy of compressed air flowing and introduce the concept of effective energy and air power in evaluating energy efficiency.

As is well known, in pneumatic equipment, compressed air exists as an energy 'transmission medium. The power carried by the compressed air is called air power. Air power is expressed in units of kw (kilowatts), as is electric power. Air power is defined as the effective energy flux of compressed air and is expressed as:

P- ^Jd = pQ In 丄 U In 丄 where p and p

a is the absolute pressure and atmospheric pressure of compressed air, Q and Q, respectively

a is the volumetric flow rate in the compressed state and the volumetric flow rate converted to the atmospheric pressure state. Even if the pressure is different, the energy consumption varies greatly even with the same consumption flow rate, and these must be handled appropriately.

By introducing this concept of air power, the compressed air can be handled in the same way as electric power in the energy quantification process.

FIGS. 7 to 9 show a non-contact conveyance device according to the prior art of the non-contact conveyance device 1 according to the present embodiment (specifically, a non-contact conveyance device disclosed in Japanese Patent Laid-Open No. 2005-51260). It is a figure which displays the energy efficiency with respect to using the concept of air power.

First, as shown in FIG. 7, the non-contact conveyance device 1 formed with a smooth curved surface at the opening ridge angle prevents non-contact conveyance according to the conventional technique in which the opening edge is chamfered as a result of suppressing the separation due to the ridge angle. An average 12% improvement in efficiency was seen compared to the equipment. Further, as an effect (not shown), the stability of holding the plate-like body is increased as compared with the non-contact transfer device according to the prior art. Further, as shown in FIG. 7, as a result of the short offset nozzle 5 being arranged so as to face the middle of the concave cylindrical chamber 3, it is generated by friction due to the viscosity of the fluid and the upper surface of the concave cylindrical chamber 3. As a result, energy loss was suppressed, and an average 21% improvement in efficiency was seen compared to the non-contact transfer device according to the prior art in which the nozzles are arranged on the bottom surface of the concave cylindrical chamber 3.

In addition, as shown in FIG. 8, the non-contact transfer device 1 in which the short offset nozzle 5 is disposed at a position farther inward than the inner peripheral surface of the concave cylindrical chamber 3 includes the inner peripheral surface of the concave cylindrical chamber 3 In the non-contact conveyance according to the prior art in which the nozzle is arranged along the inner wall of the recessed cylindrical chamber 3 as a result of energy attenuation due to the large shearing force in the cylinder being avoided, and the input energy is more efficiently converted into rotational momentum. An average improvement of 17% was seen compared to the equipment.

[0021] FIG. 9 shows a result obtained by integrating the efficiency improvements shown in FIGS. As shown in the figure, the non-contact conveyance device 1 showed a significant improvement in efficiency of 41% on average in comparison with the non-contact conveyance device according to the prior art.

In the above description, the force in which the two short offset nozzles 5 are arranged in a point-symmetrical position with respect to the center O of the circumference of the concave cylindrical chamber 3 The arrangement method of the two nozzles is limited to this. There is no need to be done. Further, the number of the short offset nozzles 5 is not limited to two as in the above example, and may be any number of two or more that allows the fluid to rotate efficiently and in a balanced manner.

[0023] <Second Embodiment>

A second embodiment of the present invention will be described with reference to FIGS.

FIG. 10 is a perspective view showing the configuration of the non-contact transport apparatus 10 according to the present embodiment. FIG. 11 is a view showing the configuration of the non-contact transfer apparatus 10, where (a) is a top view, (b) is a side view, and (c) is a bottom view. FIG. 12 is an explanatory view of driving of the centering mechanism 12 provided in the non-contact transport apparatus 10. In the following description, components that are substantially the same as those of the first embodiment are given the same reference numerals, and descriptions thereof are omitted. The non-contact transfer device 10 according to the present embodiment is configured by using a plurality of swirl flow forming bodies 2 according to the first embodiment. Specifically, the non-contact transfer device 10 is attached to the base 11 and the base 11. 6 swirl flow forming bodies 2 provided, and a centering mechanism 12 mounted on the base 11 to prevent the plate-like body from being detached.

[0024] The six swirling flow forming bodies 2 are supported so that the closed end surface side is attached to the inner surface of the base portion 11, and the flat opposing surfaces 4 are all the same surface. The outer surface of the base 11 The body supply port 13 is provided, and a base passage (not shown) that connects the fluid supply port 13 and the fluid introduction port 8 of the swirl flow forming body 2 corresponding to the fluid supply port 13 is provided in the wall body. Branching out. A centering mechanism 12 is mounted on the outer surface of the base 11 for positioning and preventing the plate-like body held in a non-contact manner. As shown in FIG. 12, the centering mechanism 12 includes six cylinders 121 whose one ends communicate with each other, and six link arms each having one end connected to the other end of each cylinder 121. 122 and six centering guides 123 suspended from the other end of each link arm 122. Since the six cylinders 121 communicate with each other at one end, they can be pressurized or depressurized by a single system of fluid. When the pressure inside the cylinder 121 is reduced by the fluid, the six centering guides 123 are driven in the center direction via the six link arms 122. Due to the movement in the center direction by the centering guide 123, the outer periphery of the plate-like body held in a non-contact manner by the non-contact conveying device 10 is regulated, and the center of the plate-like body is the center of the internal space of the base portion 11. Is positioned so as to match. On the other hand, when the inside of the cylinder 121 is pressurized by the fluid, the six centering guides 123 are driven through the six link arms 122 in a direction in which the central force is also separated. By the movement in the direction away from the center by the centering guide 123, the restriction on the plate-like body is released, and the plate-like body becomes free.

In the non-contact conveyance device 10 having the above-described configuration, when a fluid is supplied from an air supply device (not shown) to the fluid supply port 13, the fluid passes through a passage in the base portion 11 (not shown), and then passes through each passage. It is sent to the swirl flow forming body 2. The fluid sent to each swirl flow forming body 2 is blown into the concave cylindrical chamber 3 from the short offset nozzle 5 through the fluid inlet 8 and the bell mouth fluid passage 6. The fluid blown into the concave cylindrical chamber 3 is rectified as a swirling flow in the internal space of the concave cylindrical chamber 3 and then flows out of the concave cylindrical chamber 3. Here, the swirling flow formed by each swirling flow forming body 2 is adjusted in advance so that the swirling flow is not rotated when the plate-like body is held in a non-contact manner. In the case of the non-contact transfer device 10 according to the present embodiment, among the six swirl flow forming bodies 2, three swirl swirl flows clockwise, and the remaining three swirl counterclockwise. It has been adjusted.

When the fluid flows out from the concave cylindrical chamber 3 of each swirl flow forming body 2, each swirl flow forming body 2 If a plate-like body is arranged at a position facing the flat opposed surface 4, the atmospheric pressure supply from the outside to the inside of the recessed cylindrical chamber 3 is limited, and gradually per unit area due to the entrainment effect and centrifugal force. As a result, the density of the fluid molecules decreases, the pressure in the center of the swirling flow in the concave cylindrical chamber 3 decreases, and negative pressure is generated. As a result, the plate-like body is pressed by the ambient atmospheric pressure and sucked toward the flat opposed surface 4 side, while when the distance between the flat opposed surface 4 and the plate-like body approaches, the discharge from the concave cylindrical chamber 3 is performed. Since the fluid is restricted and the flow velocity of the fluid blown from the short offset nozzle 5 becomes slow, the pressure at the center of the swirl flow in the concave cylindrical chamber 3 rises and the plate-like body does not come into contact with the flat opposed surface 4 and the plate. The distance of the body is maintained. In addition, the plate-like body is stably held in a non-contact state by the air interposed between the flat opposed surface 4 and the plate-like body. When the base portion 11 is moved in this state, the plate-like body is moved while being guided by the centering guide 123 along with the movement.

[0026] In this non-contact transfer device 10, the plate-like body is sucked by the swirling flow formed by the six swirling flow forming bodies 2, so that the suction force can be made extremely strong. Further, in this non-contact conveyance device 10, since a swirling flow is formed at six locations, even a plate-like body having a large diameter is sucked throughout. Therefore, even if the plate-like body is warped, it is possible to correct the warp throughout. Furthermore, since the non-contact conveying apparatus 10 uses the swirl flow forming body 2 similar to the non-contact conveying apparatus 1 according to the first embodiment, it is the same as the non-contact conveying apparatus 1 according to the first embodiment. In addition, significant energy efficiency and energy savings can be realized.

In the above description, six swirl flow formations 2 are provided. However, it is not necessary to be limited to six, and an arbitrary number of two or more may be provided. The same applies to the centering guide 123.

[0027] <Third embodiment>

A third embodiment of the present invention will be described with reference to FIGS.

FIG. 13 is a perspective view showing a configuration of the non-contact transport device 20 according to the present embodiment. FIG. 14 is a diagram showing the configuration of the non-contact transport device 20, where (a) is a top view and (b) is a side view. FIG. 15 is an explanatory view of driving of the centering mechanism 22 provided in the non-contact transport device 20. In the following description, components that are substantially the same as those of the first embodiment are described. The same reference numerals are given and the description thereof is omitted.

The non-contact conveyance device 20 according to the present embodiment is configured by using a plurality of swirl flow forming bodies 2 according to the first embodiment, and specifically, a plate having a flat surface facing the plate-like body. The base 21, the six swirling flow forming bodies 2 attached to the base 21, the centering mechanism 22 provided below the base 21, and the base 21 are fixed so that the base 21 can be moved. And a gripping portion 23 for the purpose.

The base 21 is composed of a base 211 and two arms 212 branched from the base 211 in a bifurcated manner. A protruding centering guide 213 is provided at the protruding end of each arm 212.

[0028] The six swirling flow forming bodies 2 are supported so that the closed end face side is attached to the upper surface of the base body 21, and the flat opposed faces 4 are all the same face. A fluid supply port 24 is provided on the side surface of the grip portion 23, and a fluid (not shown) that communicates the fluid supply port 24 with the fluid introduction port 8 of the swirling flow forming body 2 inside the base body 21. A passage is formed by branching from the fluid supply port 24. A centering mechanism 22 is provided below the base 21 for positioning and preventing separation of the plate-like body held in a non-contact manner. As shown in FIG. 15, the centering mechanism 22 includes a cylinder 221 provided in the gripping portion 23, one end connected to one end of the cylinder 221 and two centering guides provided to the other end. It consists of a link plate 222. When the inside of the cylinder 221 is pressurized by the fluid, the two centering guides 22 are driven toward the plate-like body via the link plate 222. As a result of the centering guide 223 moving toward the plate-like body, the plate-like body held in a non-contact manner by the non-contact conveying device 20 is moved to the centering guide 222 on the link plate 222 and the protruding end of the arm portion 212. The centering guide 213 provided on the outer periphery restricts its outer periphery and positions it. On the other hand, when the pressure in the cylinder 221 is reduced by the fluid, the two centering guides 223 are driven through the link plate 222 in a direction in which the plate-like body force is also separated. By the movement of the centering guide 223 in the direction of separating the plate-like body force, the restriction on the plate-like body is released, and the plate-like body becomes free.

In the non-contact conveyance device 20 having the above configuration, when a fluid is supplied from an air supply device (not shown) to the fluid supply port 24, the fluid passes through a fluid passage in the base body 21 (not shown). And is sent to each swirl flow forming body 2. The fluid sent to each swirling flow forming body 2 is blown into the concave cylindrical chamber 3 from the short offset nozzle 5 via the fluid introducing port 8 and the bell mouth fluid passage 6. The fluid blown into the concave cylindrical chamber 3 is rectified as a swirling flow in the internal space of the concave cylindrical chamber 3 and then flows out of the concave cylindrical chamber 3. Here, the swirling flow formed by each swirling flow forming body 2 has its swirling direction adjusted in advance so as not to rotate when the plate-like body is held in a non-contact manner. In the case of the non-contact conveyance device 20 according to the present embodiment, among the six swirl flow forming bodies 2, three swirl swirl flows clockwise, and the remaining three swirl counterclockwise. Adjusted.

When a fluid flows out from the concave cylindrical chamber 3 of each swirl flow forming body 2, if a plate-like body is disposed at a position facing the flat opposed surface 4 of each swirl flow forming body 2, the concave cylindrical chamber 3 The supply of atmospheric pressure from the outside to the inside is limited, the density of fluid molecules per unit area gradually decreases due to the entrainment effect and centrifugal force, and the pressure at the center of the swirling flow in the concave cylindrical chamber 3 decreases. Negative pressure is generated. As a result, the plate-like body is pressed by the ambient atmospheric pressure and sucked toward the flat opposed surface 4 side, while when the distance between the flat opposed surface 4 and the plate-like body approaches, the discharge from the concave cylindrical chamber 3 is performed. Since the fluid is restricted and the flow velocity of the fluid blown from the short offset nozzle 5 becomes slow, the pressure at the center of the swirl flow in the concave cylindrical chamber 3 rises and the plate-like body does not come into contact with the flat opposed surface 4 and the plate. The distance of the body is maintained. In addition, the plate-like body is stably held in a non-contact state by the air interposed between the flat opposed surface 4 and the plate-like body. When the base 21 is moved in this state, the plate-like body is moved while being guided by the centering guides 213 and 223 together with the movement.

In this non-contact conveyance device 20, since the plate-like body is sucked by the swirling flow formed by the six swirling flow forming bodies 2, the suction force can be made extremely strong. Further, in this non-contact conveyance device 20, since a swirl flow is formed at six locations, even a plate-like body having a large diameter is sucked throughout. Therefore, even if the plate-like body is warped, it is possible to correct the warp throughout. Further, since the non-contact transfer device 20 is configured in a plate shape, it can freely access even the wafers in the stacked wafer cassettes that have been difficult to access. Further, in this non-contact conveying apparatus 20, the same swirling flow as that in the non-contact conveying apparatus 1 according to the first embodiment is used. Since the formed body 2 is used, as in the non-contact transfer apparatus 1 according to the first embodiment, a great improvement in energy efficiency and energy saving can be realized.

In the above description, six swirl flow formations 2 are provided. However, it is not necessary to be limited to six, and an arbitrary number of two or more may be provided. The same applies to the centering guides 213 and 223.

Claims

The scope of the claims

[1] a substantially columnar body having a concave cylindrical chamber having an inner circumferential surface formed in a circumferential shape;

A flat end surface of the main body formed on the opening side of the concave cylindrical chamber;

A nozzle that is formed so as to face the inner peripheral surface of the concave cylindrical chamber and discharges the supply fluid into the concave cylindrical chamber;

A fluid passage communicating with the nozzle and supplying a fluid into the concave cylindrical chamber through the nozzle;

With

The non-contact transfer device, wherein the nozzle is disposed at a position farther inward than the inner circumferential surface of the concave cylindrical chamber.

2. The non-contact transfer device according to claim 1, wherein two nozzles are arranged at positions that are point-symmetric with respect to the center of the circumference of the concave cylindrical chamber.

[3] The non-contact transfer device according to claim 1 or 2, wherein the nozzle is disposed in the middle of the concave cylindrical chamber.

[4] The nozzle is provided so as to have a predetermined angle Θ with respect to a tangent that is in contact with the inner periphery at the discharge point P. The angle Θ is a line L 1 extending from the discharge point P in the fluid discharge direction. When the radius rl perpendicular to the line is drawn, the distance δ between the intersection P2 of the radius rl and the line L1 and the intersection P3 of the radius rl and the circumference of the concave cylindrical chamber is δ Zrl = 5% to 25% 4. The non-contact transfer device according to claim 1, wherein the non-contact transfer device is set so as to satisfy the above.

5. The opening edge of the concave cylindrical chamber is characterized in that the inner peripheral surface force of the concave cylindrical chamber smoothly curves and extends to the outer edge of the concave cylindrical chamber opening. Non-contact transfer device as described in No.4.