JP2009149389A - Floating unit and device having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a floating unit and a device having the same capable of floating and conveying a workpiece such as a glass substrate without warping it. <P>SOLUTION: The floating unit has a chamber 36. A vent hole communicating with airtight space of the chamber is formed on a ceiling wall of the chamber 36. Also the floating unit has a porous plate secured to the ceiling wall at its lower side and forming a conveyance path surface F. The floating unit supplies gas to the airtight space and jets the gas from the conveyance path side through the vent hole and the gap of the porous plate. An air guide groove 75 opening at the conveyance path side and gradually extending to a center line of the conveyance path in a workpiece conveyance direction U is formed on the conveyance path surface F of the porous plate. Consequently, air in the air guide groove 75 moves in the groove and outflows in the vicinity of the center line of the conveyance path F by movement force in the conveyance direction affected by the air of the lower side of the workpiece. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a floating unit that floats a workpiece such as a liquid crystal display (LCD), a plasma display panel (PDP), and a color filter and conveys the workpiece in a non-contact manner, and an apparatus having the floating unit.

  Glass substrates used in flat panel displays (FPD) such as LCDs and PDPs tend to increase in size in response to demands for larger screens.

  In a conventional FPD manufacturing process, a glass substrate is transported by a roller. However, due to friction between the glass substrate and the roller, a problem of stress applied to the glass substrate, etc., the glass substrate is floated by compressed air and transported. Is considered.

However, as shown in FIG. 20, the levitation unit as in Patent Document 1 employs a method in which air is blown up from an air blowing hole 204 formed in the ceiling wall 202 of the levitation block 200 and the glass substrate 206 is levitated. Therefore, the glass substrate 206 is warped between the air blowing holes 204.
JP 2004-331265 A

  This invention considers the fact which concerns, and makes it a subject to provide the floating unit which can be floated and conveyed without generate | occur | producing a workpiece | work, such as a glass substrate, and an apparatus having the same.

  According to the first aspect of the present invention, a chamber in which an airtight space is formed, a fluid passage hole communicating with the airtight space is formed in the ceiling wall, a lower side is fixed to the ceiling wall, and a workpiece is provided on the upper side. A porous body forming a transport path for transport, and a fluid supply means for supplying a fluid to the airtight space and ejecting the fluid from the transport path side through the fluid passage hole and the gap of the porous body. And a fluid guide groove having at least a groove portion that opens in the conveyance path side and extends in the workpiece conveyance direction as it becomes the conveyance path center side is formed in the conveyance path of the porous body. To do.

  In the first aspect of the present invention, when a fluid is supplied to the airtight space of the chamber by the fluid supply means, the fluid is ejected from a fluid passage hole formed in the ceiling wall. Since the porous body is fixed to the ceiling wall, the fluid is ejected from the gap of the porous body.

  That is, on the upper side of the porous body, that is, on the conveyance path side, the fluid is ejected from the entire surface and the entire surface becomes the air bearing surface, so that the workpiece can be lifted and conveyed without causing warpage.

  Further, when the workpiece moves in the conveyance direction, the air under the workpiece (hereinafter referred to as “under-work air”) moves in the conveyance direction together with the workpiece due to the viscosity of the air. Therefore, a force that moves in the transport direction is exerted on the air in the fluid guide groove formed in the transport path of the porous body from the air under the work.

  Here, the fluid guide groove has at least a groove portion that opens in the conveyance path side and extends in the workpiece conveyance direction as it reaches the conveyance path center side. Therefore, the air in the groove portion moves in the groove portion toward the center of the conveyance path by the moving force exerted from the air under the workpiece in the conveying direction. Along with this, air flows into the groove from the opening on the side of the conveyance path. That is, air flows in from the opening on the side of the conveyance path in the groove, and air flows out on the conveyance path at the end of the groove on the center side of the conveyance path. Accordingly, it is possible to further generate a force for floating the workpiece.

The invention according to claim 2 is characterized in that the fluid guide groove is formed so as to be symmetric with respect to a central line of the transport path.
In the second aspect of the invention, the air flow in the fluid guide groove can be made the same on both sides of the central line of the conveyance path, and the buoyancy on both sides of the central line can be made the same. Therefore, the conveyance state of a workpiece | work can be stabilized more.

The invention according to claim 3 is characterized in that the fluid guide groove is formed in a shape extending linearly from the central line of the transport path to the side.
In the invention described in claim 3, since air flows linearly in the fluid guide groove, the flow resistance of air in the fluid guide groove is small.

According to a fourth aspect of the present invention, the fluid guide groove is formed with a groove protrusion that protrudes in the workpiece conveyance direction.
In the invention according to claim 4, a large amount of air flows out from the groove protrusion onto the conveyance path as the workpiece is conveyed. Therefore, it is easier to lift the workpiece.

According to a fifth aspect of the present invention, the fluid guide groove is formed with a reverse groove protrusion that protrudes in a direction opposite to the workpiece conveyance direction.
According to the fifth aspect of the present invention, the air on the conveyance path flows into the reverse groove protrusion as the workpiece is conveyed. Accordingly, the workpiece can be attracted to the conveyance path side, and the conveyance state of the workpiece can be further stabilized.

  The invention described in claim 6 is characterized in that a protective film is formed on the conveyance path side of the porous body.

  The method for forming the protective film is not particularly limited. For example, known methods such as painting, electroplating, electroless plating, physical vapor deposition (PVD, vacuum deposition, ion plating, sputtering, etc.), chemical vapor deposition (CVD), ion plantation, etc. By doing so, a protective film is formed.

  In the invention described in claim 6, prevention of peeling of the porous body and improvement in strength are achieved by the protective film formed on the upper side of the porous body.

The invention described in claim 7 has the levitation unit described in any one of claims 1 to 6.
Examples of the apparatus include an exposure apparatus, an inspection apparatus, a defect repair apparatus, and a coater apparatus.

According to an eighth aspect of the present invention, a part of the conveyance path is formed by the levitation unit according to any one of the first to sixth aspects, and the fluid guide groove is formed in the remainder of the conveyance path. It is characterized by being formed by no floating unit.
In the invention according to claim 8, the floating unit in which the fluid guide groove is formed and the floating unit in which the fluid guide groove is not formed can be mixed and arranged.

  Since this invention set it as the said structure, it can be floated and conveyed, without giving curvature to workpieces, such as a glass substrate.

[First Embodiment]
1 to 3 show an exposure apparatus 12 in which the floating unit according to the first embodiment is incorporated.

(Basic configuration)
The exposure apparatus 12 includes an assembly frame 18 configured in a long frame shape with rails 14 and cross members 16. The assembly frame 18 is supported above the frame-like base frame 22 by the post 20.

  A plurality of beam members 28 are bridged between the rails 14. An air supply box 29 to which negative pressure and positive pressure air is supplied from the first compressor 32 via the tube 34 is disposed on the beam member 28 on one end side of the chamber 36. On the air supply box 29, three rows of the floating units 10 according to the first embodiment are set along the rails 14. Note that what is supplied from the compressor is not limited to air, but may be an inert gas such as nitrogen, argon, or helium, or a gas such as carbon dioxide. Moreover, liquids, such as water, may be sufficient.

  The air supply box 29 may be an ejector that generates a negative pressure and a positive pressure with the pressurized air supplied from the first compressor 32.

  Further, a height adjusting member 30 for adjusting the height of the chamber 36 is disposed on the beam member 28 on which the air supply box 29 is not disposed.

  The bottom plate of the chamber 36 of the levitation unit 10 is formed with three supply ports (not shown) connected to the air supply box 29 and supplied with negative and positive pressure air.

  Further, a support plate 38 is bridged between the rails 14 on the right side of the rails 14 shown in FIG. A floating unit 40 according to a second embodiment to be described later is set on the support plate 38. From the lower surface side of the support plate 38, negative pressure and positive pressure air are supplied from the second compressor 44 through the tube 46. Then, negative pressure and positive pressure air are supplied to three supply ports (not shown) formed in the bottom plate of the chamber 80 of the levitation unit 40.

  Further, a linear transport device 50 is mounted on the rail 14 on the near side. The transfer device 50 includes a plurality of vacuum suction cups 52 and is configured to chuck the lower surface of the floated glass substrate P and transfer it in the workpiece transfer direction U. The transfer device 50 can also move in the direction opposite to the workpiece transfer direction U.

  The glass substrate P levitated above the levitation unit 10 is levitated and conveyed toward the levitation unit 40 by the conveying device 50. The glass substrate P that has been levitated and conveyed is exposed by an exposure unit (not shown) while the levitated state is maintained above the levitating unit 40, and a predetermined circuit pattern is formed.

  The chamber 36 is formed with a flow path (not shown) through which a cooling medium (for example, water) flows along the longitudinal direction. This flow path is directed downward at a position slightly downstream of the adjustment member 30 disposed on the upstream side of the workpiece conveyance of the levitation unit 10 in the conveyance direction, and a water supply port is formed at the lower end of the water supply pipe. 55 (see FIG. 1) is connected. Further, this flow path is directed downward at a position slightly upstream of the air supply box 29 disposed on the downstream side of the work transfer of the levitation unit 10, and a drain outlet is formed at the lower end. A drain pipe 57 (see FIG. 1) is connected. Thereby, the cooling effect is greater on the upstream side of the flow path in the workpiece conveyance direction than on the downstream side of the workpiece conveyance direction.

(Specific configuration)
Next, a specific configuration of the levitation unit 10 according to the first embodiment will be described.

  As shown in FIGS. 4 to 9, the chamber 36 of the levitation unit 10 is a long cylindrical body having a rectangular cross section, and the inner space is formed by two partition walls 54 provided on the inner side and has a rectangular cross section at the center. It is divided into a suction chamber 56 and ejection chambers 58 and 60 having a rectangular cross section. Then, by joining the side plate 62 to the end face of the chamber 36, the suction chamber 56 and the ejection chambers 58, 60 of the chamber 36 become an airtight space.

  As shown in FIG. 6, a pedestal portion 152 in which a screw hole 150 is formed is provided on the end surface of the chamber 36. Further, a mounting hole 154 is formed in the side plate 62. The screw hole 150 and the attachment hole 154 are formed in a positional relationship where the screw hole 150 and the attachment hole 154 face each other when the side plate 62 is overlapped on the end face of the chamber 36. Then, the screw 36 is inserted into the mounting hole 154 and the screw hole 150 with the screw hole 150 and the mounting hole 154 facing each other, whereby the chamber 36 and the side plate 62 are screwed.

  The chamber 36 and the side plate 62 can be joined by other means such as an adhesive in addition to screwing with the screw 156.

  However, when the chamber 36 and the side plate 62 are joined together by an adhesive, the curing time of the adhesive is required, so that the production efficiency cannot be improved, and it is difficult to disassemble after joining. Therefore, it is difficult to perform maintenance or replacement of parts. Therefore, it is preferable to join the chamber 36 and the side plate 62 with the screw 156 as described above.

  Negative pressure air is supplied to the suction chamber 56 from the aforementioned supply port, and positive pressure air is supplied to the ejection chambers 58 and 60.

  A long groove 64 is formed on the side surface of the chamber 36 along the longitudinal direction in order to reduce the weight.

  On the other hand, a lattice groove portion (lattice-like groove portion) 68 divided into four sections is formed on the ceiling wall 37 of the chamber 36. The reason why the lattice groove portions 68 are formed in each of the sections is that air can be uniformly supplied to the porous plate 76 joined to the ceiling wall 37. However, in the present invention, the number of compartments in which the lattice groove 68 is formed is not limited, and the chamber 36 may be configured by one compartment.

  A plurality of ventilation holes 74 that are fluid passage holes of the present invention pass through the groove bottom of the lattice groove portion 68 and are arranged in a straight line. The ventilation hole 74 communicates with the ejection chamber 60. An air intake hole 70 is formed in the groove bottom of the lattice groove portion 68 and communicates with the suction chamber 56. A ventilation hole 72 which is a fluid passage hole of the present invention is formed at the groove bottom of the lattice groove 68. The vent hole 72 communicates with the ejection chamber 58.

  A porous plate 76 processed into a plate shape is joined to the ceiling wall 37 of the chamber 36 in which the groove portion is formed in this way. The porous plate 76 can be made of, for example, porous graphite, sintered metal, porous ceramics, porous resin, or the like.

  When composed of porous graphite, it is possible to improve the weight reduction, the mechanical strength, the manufacturing cost, the surface flatness, and when the glass substrate P comes into contact with the glass substrate P, Damage can be reduced.

  In addition, the weight of the porous plate can be reduced. In addition, the function of electrostatic grounding due to the conductivity of the porous plate 76 can be added.

When the air permeability of the porous plate 76 is in the range of 0.2 to 6.0 cm ² / s, the work (glass substrate P) conveyed by the levitation unit 10 can be effectively levitated. Moreover, a workpiece | work can be levitated more effectively as the porosity of the porous board 76 is 5-25 vol%.

As shown in FIGS. 3 and 4 (see also FIGS. 5, 6, 8, and 9), an opening 75 </ b> E is formed in the transport path F (transport path surface F) of the porous plate 76 on the transport path side. Then, an air guide groove 75 that gradually extends in the workpiece conveying direction U is formed as it becomes closer to the center of the conveying path. The air guide groove 75 is symmetrical with respect to the center line FM of the conveyance path surface F, and is linear from the opening 75E to the center line FM. Accordingly, a groove protrusion 75T that protrudes in the workpiece conveyance direction U in plan view is formed on the central line FM and in the vicinity thereof.
1 and 3 show an example in which four air guide grooves 75 are formed in each porous plate 76, and in FIG. 4 and FIG. 5, five air guide grooves 75 are formed in each porous plate 76. However, in the present embodiment, the number of the air guide grooves 75 is not particularly limited.

  In a state where the chamber 36 and the porous plate 76 are joined, the suction hole 70 formed in the chamber 36 and the suction hole 78 formed in the porous plate 76 communicate with each other so as to face each other.

  As a joining method, the surface to be the air bearing surface of the porous plate 76 is placed on the surface plate, the adhesive is applied to the ceiling wall 37 of the chamber 36, and the weight is placed on the porous plate 76. An example is the method of fixing the The adhesive is preferably applied so as not to protrude into the lattice groove 68.

  Here, the lattice grooves 68 are not formed on the back surface of the porous plate 76 but formed on the ceiling wall 37 of the chamber 36, compared to the case where the groove portions are formed on the back surface of the porous plate 76. This is because the groove portion can be easily formed with high accuracy when the groove portion is formed on the ceiling portion.

  In particular, in order to reduce the variation in the flying height of the glass substrate P and stably float it, the flatness of the bearing surface of the porous plate 76 needs to be made small (more flat). If a groove is formed on the back surface of the plate, it becomes difficult to reduce the flatness of the bearing surface of the porous plate 76.

  On the other hand, in the present invention, since the groove is not formed on the back surface of the porous plate, the flatness of the bearing surface of the porous plate can be reduced. It is possible to float stably with less variation.

  Here, a mechanism in which air is ejected from the gap of the porous plate 76 to make the entire surface an air bearing surface will be briefly described.

  In the porous plate 76, a plurality of fine voids communicating with each other are formed. The air ejected from the lattice groove portion 68 passes through the air gap formed by the lattice groove portion 68 and the lower surface of the porous plate 76 and passes through the gap of the porous plate 76, and from the bearing surface of the porous plate 76 to the outside. It spouts towards. At this time, since the minute gaps communicate with each other, the fine gaps are ejected not only from above the air passage but also from the entire bearing surface.

  Next, the operation of the levitation unit 10 according to the first embodiment will be described.

  From the first compressor 32, positive pressure air (for example, 50 to 400 kPa) is supplied to the ejection chambers 58 and 60, and negative pressure air (for example, 0 to −50 kPa) is supplied to the suction chamber 56 (air is supplied from the suction chamber 56). Suction.

  The air supplied to the ejection chambers 58, 60 is ejected from the vent holes 72, 74, travels through the air passage formed by the lower surface of the porous plate 76 and the lattice grooves 68, and is evenly applied to the lower surface of the porous plate 76. And then ejected from the gap of the porous plate 76.

  That is, since air is ejected from the entire surface of the porous plate 76 and the entire surface of the porous plate 76 becomes an air bearing surface, the glass substrate P is levitated without generating warpage and is not in contact with the porous plate 76. It becomes possible to convey with. The sucker 52 chucks the floated glass substrate P, and the transport device 50 transports it in the direction of the arrow.

  The negative pressure air supplied to the suction chamber 56 generates a force for sucking the glass substrate P into the suction hole 78 formed in the porous plate 76 through the suction hole 70. The suction force generated by the intake holes 70 regulates the flying height of the glass substrate P that has been floated by the air ejected from the porous plate 76. Therefore, the flying height of the glass substrate P can be controlled by controlling the suction force.

  Moreover, when the glass substrate P moves in the workpiece conveyance direction U, a part of the air below the glass substrate (hereinafter referred to as workpiece lower air L (see FIG. 8)) is conveyed along with the glass substrate P by the viscosity of the air. Move to. Therefore, a force that moves in the workpiece conveyance direction U is exerted on the air in the air guide groove 75 from the workpiece lower air L.

Here, as described above, the air guide groove 75 opens on the conveyance path side and gradually extends in the workpiece conveyance direction U toward the conveyance path center side. Therefore, the air in the air guide groove 75 moves in the direction of the arrow S toward the center line FM by the moving force in the work conveyance direction U exerted from the work lower air L. Accordingly, air flows into the air guide groove 75 from the opening 75E. In other words, in the air guide groove 75, air flows in from the opening 75E having a low pressure, and the air flows out on the conveyance path surface F in the vicinity of the groove protrusion 75T having a high pressure.
Therefore, it is possible to further generate a force that causes the glass substrate P to float at and near the groove protrusion 75T. And since it is a low voltage | pressure in the opening 75E and its vicinity, the glass substrate P can be attracted | sucked to the conveyance path surface F side, and the glass substrate P is conveyed stably.

  In this embodiment, the air guide groove 75 is formed on all the porous plates 76. However, the present invention is not limited to this, and at least a porous plate on which the air guide groove 75 is not formed is provided. It may be arranged in part.

  For example, as shown in FIG. 10, in each of the three chambers, a porous plate 76 in which the air guide groove 75 is formed and a porous plate 77 in which the air guide groove 75 is not formed are alternately arranged. Also good. Thereby, the cost reduction as an apparatus can be aimed at.

  Furthermore, as shown in FIG. 11, the arrangement positions of the porous plates 76 in which the air guide grooves 75 are formed may be arranged in a staggered manner so as to be staggered in adjacent chambers. Even with this arrangement, the cost of the apparatus can be reduced.

[Second Embodiment]
Next, the levitation unit 40 according to the second embodiment will be described.

  Since the basic configuration of the levitation unit 40 is the same as that of the levitation unit 10 of the first embodiment, the configuration of the groove portion of the chamber 80 shown in FIGS. 12 and 13 and the configuration and shape of the porous plate 82 will be described. .

  On the ceiling wall of the chamber 80, four vertical groove portions 97 in the longitudinal direction and a plurality of horizontal groove portions 102 are formed in the width direction, and a plurality of islands 86 are formed at predetermined intervals by the vertical groove portions 97 and the horizontal groove portions 102. Has been. A vent hole 92 is formed in the groove bottom of the lateral groove portion 102. The vent hole 92 communicates with an ejection chamber (not shown). The remote island 86 has an intake hole 90 communicating with the suction chamber.

  On the other hand, a suction hole 96 is formed in the porous plate 82 at a position corresponding to the suction hole 90 when it is overlapped with the ceiling wall of the chamber 80. Further, through holes 101 are formed on both sides of the porous plate 82, and the porous plate 82 can be fixed to the chamber 80 by inserting screws into the mounting holes 94 formed in the chamber 80. Yes.

  In addition, an air guide groove 85 that gradually extends in the workpiece conveyance direction U is formed on the conveyance path surface F of the porous plate 82 so that an opening 85E is formed on the conveyance path side side and the conveyance path center side is formed. As in the first embodiment, the air guide groove 85 has a symmetrical shape with respect to the central line FM of the conveyance path surface F, and is linear from the opening 85E to the central line FM. Accordingly, a groove protrusion 85T that protrudes in the workpiece conveyance direction U in plan view is formed on the central line FM and in the vicinity thereof.

  In the floating unit 40 having the above-described configuration, the through holes 101 are formed on the surface of the porous plate 82 to enable screwing. Further, since the groove is not formed in the porous plate 82, the flatness of the porous plate 82 can be maintained. Furthermore, by arranging the intake holes at equal intervals, the flying height of the glass substrate P can be regulated in a well-balanced manner.

  Moreover, when a workpiece | work (glass substrate P) moves to the workpiece conveyance direction U, a part of workpiece | work lower air moves to the workpiece conveyance direction U with a workpiece | work by the viscosity of air. Therefore, a force that moves in the workpiece conveyance direction U is exerted on the air in the air guide groove 85 from the workpiece lower air. Accordingly, as in the first embodiment, the air in the air guide groove 85 moves in the direction of arrow S toward the center line FM in the groove as the workpiece is conveyed. As a result, air flows into the air guide groove 85 from the opening 85E. That is, air flows into the air guide groove 85 from the opening 85E having a low pressure, and the air flows out from the air guide groove 85 onto the conveyance path surface F at and near the groove protrusion 85T having a high pressure. Therefore, it is possible to further generate a force that causes the workpiece to float at and near the groove protrusion 85T. Since the pressure is low in the opening 85E and the vicinity thereof, the workpiece can be attracted to the conveyance path surface F side, and the workpiece is stably conveyed.

  In the embodiment shown in FIGS. 1 to 11, the levitation unit 10 is configured by joining four porous plates 76 to the ceiling wall of the chamber 36. In the embodiment shown in FIGS. 12 and 13, the levitating unit 40 has a single porous plate 82 joined to the ceiling wall of the chamber 80. However, in the present invention, the number of porous plates is not limited. Moreover, not only a porous board but a general porous body may be sufficient as long as a conveyance path can be formed in the upper surface side.

[Third Embodiment]
Next, a third embodiment will be described. As shown in FIG. 14, in the levitation unit according to the present embodiment, a porous plate 116 having a protective film 114 formed on the conveyance path surface side is provided instead of the porous plate 76 as compared with the first embodiment. ing.

  The upper surface side of the porous plate 116 is covered with a protective film 114 (see FIG. 6) in order to prevent peeling of the porous plate 116 and improve strength. Suitable for use in a clean room because particle generation due to peeling can be suppressed. The protective film 114 is formed so as not to block a gap opened on the upper surface of the porous plate 116. A transport path F is formed by the porous plate 116 and the protective film 114.

  The protective film 114 is made of, for example, a resin. Thereby, the weight of the protective film can be reduced and the protective film can be easily formed. In this case, the resin may be composed of at least one resin selected from an epoxy resin, a phenol resin, a furan resin, a fluororesin, and nylon.

  The protective film 114 is made of a metal or a metal compound. Thereby, the strength of the protective film 114 can be improved. Further, since the protective film 114 becomes conductive, the function of electrostatic grounding can be added to the protective film 114. In this case, the metal or metal compound may contain at least one element selected from Ni, Zn, Cr, Cu, Ag, Fe, Sn, and Mg. Further, a black plating film or a needle-like plating film may be formed as the protective film 114 by this metal or metal compound. Thereby, since the reflectance of light can be reduced, it is possible to provide a floating unit suitable for a line that requires a conveyance path having a low reflectance in the exposure process.

  Further, the protective film 114 may be made of at least one of glassy carbon and diamond-like carbon. As a result, the protective film 114 becomes conductive, thereby adding an electrostatic grounding function. Moreover, since the reflectance of light can be reduced, it is possible to provide a floating unit that is more suitable for a line that requires a low-reflectance conveyance path in the exposure process. Further, the protective film 114 may be made of a substance containing silicon dioxide such as glass. Thereby, the chemical stability of the protective film can be achieved.

[Fourth Embodiment]
Next, a fourth embodiment will be described. As shown in FIG. 15, in the levitation unit according to the present embodiment, a larger number of intake holes 70 and suction holes 78 than the first embodiment along the center line FM (for example, one between each air guide groove 75). ) Is formed. Thereby, a workpiece | work (glass substrate P) can be conveyed in the state stabilized more.
In addition, it is preferable that the positions of the air intake holes 70 are arranged at equal intervals in the workpiece conveyance direction because a negative pressure can be applied uniformly. In this case, being between the air guide grooves adjacent to each other in the workpiece conveyance direction U is more preferable from the viewpoint of conveying the workpiece in a stable state because negative pressure and positive pressure can be applied equally. .

[Fifth Embodiment]
Next, a fifth embodiment will be described. As shown in FIGS. 16 and 17, in the levitation unit according to the present embodiment, the porous plate 126 in which the suction holes 70 (see FIG. 7) and the suction holes 78 are not formed is more porous than in the first embodiment. It is provided in place of the plate 76.

  In the present embodiment, as the workpiece (glass substrate P) is transported, air flows in the direction of arrow S in the air guide groove 75 of each transport path, and air is sucked into the air guide groove 75 from the opening 75E and the transport path surface. Air is ejected from the air guide groove 75 at the center line FM of F. Therefore, since the pressure is low in the opening 75E and the vicinity thereof, the glass substrate P can be attracted to the conveyance path surface side, and the glass substrate P is stably conveyed. For this reason, it is possible to stably convey the workpiece in the workpiece conveyance direction U even if no intake hole is formed.

  With this configuration, as shown in FIG. 17, the partition wall portion 54 (see FIG. 8) can be removed, and the entire chamber can be made into the ejection chamber 58. Therefore, according to the present embodiment, a floating unit with a simple configuration can be obtained.

[Sixth Embodiment]
Next, a sixth embodiment will be described. As shown in FIG. 18, in the levitation unit according to the present embodiment, a porous plate 136 having a different shape of the air guide groove compared to the fifth embodiment is provided instead of the porous plate 126 (see FIG. 16). Yes.

The air guide groove 135 formed on the conveyance path surface side of the porous plate 136 has a W shape in plan view that is symmetrical with respect to the center line FM of the conveyance path surface F.
Therefore, on both sides of the center line FM of the air guide groove 135, groove protrusions 135TA and 135TB that protrude in the workpiece transfer direction U in plan view are formed, respectively. And the reverse direction groove | channel protrusion 135TZ which protruded in the reverse direction with respect to the workpiece conveyance direction U by planar view is formed in the center line FM and its vicinity.
With this configuration, on one side of the center line FM, an outer groove 135J that opens to the conveyance path side and extends linearly to the groove protrusion 135TA, and an inner side that extends linearly from the groove protrusion 135TA to the reverse groove protrusion 135TZ. A groove part 135 </ b> E is formed in the air guide groove 135. A similar groove shape is formed on the other side of the center line.
In the present embodiment, when the workpiece (glass substrate P) is conveyed in the workpiece conveyance direction U, air flows in the air guide groove 135 in the direction of the arrow S, and the air flows from the two groove protrusions 135TA and 135TB on the conveyance path surface. To leak. Accordingly, it is possible to further generate a force for floating the workpiece at the two groove protrusions 135TA and 135TB and in the vicinity thereof.
Thereby, a workpiece | work can be conveyed in the more stable state.

  In addition, at the reverse groove protrusion 135TZ and its vicinity, air on the conveyance path surface flows into the inner groove 135E as the workpiece is conveyed. Then, the air that has flowed out flows out of the groove protrusions 135TA and 135TB. Accordingly, the reverse groove protrusion 135TZ and the vicinity thereof have a lower pressure than the two groove protrusions 135TA and 135TB, so that the workpiece can be attracted to the conveyance road surface side, and the workpiece can be conveyed more stably.

[Seventh Embodiment]
Next, a seventh embodiment will be described. As shown in FIG. 19, in the levitation unit according to the present embodiment, a porous plate 146 having a different air guide groove shape as compared with the first embodiment is provided instead of the porous plate 76.

  The air guide groove 145 formed on the conveyance path surface side of the porous plate 146 has a groove position on both sides of the central line FM by a half of the interval between adjacent grooves in the workpiece conveyance direction U, as compared with the first embodiment. Are arranged in a staggered manner.

According to this embodiment, as the workpiece is conveyed in the workpiece conveyance direction U, air flows in the direction of the arrow S in each air guide groove 145 due to the viscosity of the air under the workpiece. That is, air flows in from the opening 145E formed on the conveyance path side, and air flows out on the conveyance path surface at the groove end 145M on the conveyance path center side, that is, in the central line FM and the vicinity thereof.
Thereby, like other embodiment, a workpiece | work can be conveyed in a more stable state.

  In the embodiment shown in FIG. 1 to FIG. 19, the floating units 10 and 40 of the present invention are incorporated in the exposure apparatus, but the present invention is not limited to this, other than the exposure apparatus, For example, it can be used for an apparatus for transporting a glass substrate, such as an inspection apparatus, a defect repair apparatus, and a coater apparatus.

  Furthermore, in embodiment shown in FIGS. 1-19, although the glass substrate was demonstrated to the example as a to-be-conveyed body conveyed by the floating units 10 and 40, this invention is not limited to this, For example, You may convey to-be-conveyed bodies other than a glass substrate, such as a resin plate and a metal plate.

It is a perspective view which shows the exposure apparatus with which the floating unit which concerns on 1st Embodiment, and the floating unit which concerns on 2nd Embodiment were assembled | attached. It is a side view which shows the exposure apparatus with which the floating unit which concerns on 1st Embodiment, and the floating unit which concerns on 2nd Embodiment were assembled | attached. It is a top view which shows the exposure apparatus with which the floating unit which concerns on 1st Embodiment, and the floating unit which concerns on 2nd Embodiment were assembled | attached. It is a perspective view of the levitation unit concerning a 1st embodiment. It is a disassembled perspective view of the levitation unit concerning a 1st embodiment. It is a perspective view which shows the attachment structure of the side plate of the floating unit which concerns on 1st Embodiment. It is an enlarged plan view of a levitation unit and a chamber according to the first embodiment. It is a sectional side view of the levitation unit concerning a 1st embodiment. It is a sectional side view of the levitation unit concerning a 1st embodiment. It is a perspective view which shows the modification of the exposure apparatus with which the floating unit which concerns on 1st Embodiment, and the floating unit which concerns on 2nd Embodiment were assembled | attached. It is a perspective view which shows the modification of the exposure apparatus with which the floating unit which concerns on 1st Embodiment, and the floating unit which concerns on 2nd Embodiment were assembled | attached. It is a top view of the chamber of the levitation unit concerning a 2nd embodiment. It is a top view of the porous board of the levitation unit concerning a 2nd embodiment. It is a perspective view which shows that the protective film is formed in the porous board with the floating unit which concerns on 3rd Embodiment. It is a top view of the porous board which constitutes the levitation unit concerning a 4th embodiment. It is a top view of the porous board which constitutes the levitation unit concerning a 5th embodiment. It is a sectional side view of the levitation unit concerning a 5th embodiment. It is a top view of the porous board which constitutes the levitation unit concerning a 6th embodiment. It is a top view of the porous board which constitutes the floating unit concerning a 7th embodiment. It is a perspective view which shows the conventional floating unit.

Explanation of symbols

10 Floating unit 32 1st compressor (gas supply means)
36 Chamber 37 Ceiling wall 40 Levitation unit 44 Second compressor (gas supply means)
72 Vent hole 74 Vent hole 75 Air guide groove (gas guide groove)
75T groove protrusion 76 porous plate (porous body)
80 Chamber 85 Air guide groove (gas guide groove)
85T groove projection 114 protective film 116 porous plate (porous body)
126 Porous plate (porous body)
135 Air guide groove (gas guide groove)
135J Outside groove (groove)
135TA groove protrusion 135TB groove protrusion 135TZ reverse groove protrusion 136 porous plate (porous body)
146 Porous plate (porous body)
145 Air guide groove (gas guide groove)
F Transport surface (transport path)
FM center line P glass substrate (work)
U Work transfer direction

Claims (8)

A chamber in which an airtight space is formed and a fluid passage hole communicating with the airtight space is formed in the ceiling wall;
A porous body having a lower side fixed to the ceiling wall and an upper side forming a conveyance path for conveying a workpiece;
Fluid supply means for supplying a fluid to the airtight space and ejecting the fluid from the transport path side through the fluid passage hole and the gap of the porous body;
Have
The floating unit is characterized in that a fluid guide groove having at least a groove portion that opens in the conveyance path side and opens in the conveyance path center side is formed in the conveyance path of the porous body. .   The levitation unit according to claim 1, wherein the fluid guide groove is formed so as to be symmetric with respect to a center line of the conveyance path.   The levitation unit according to claim 1 or 2, wherein the fluid guide groove has a shape extending linearly from a central line of the transport path to a side.   The levitation unit according to claim 3, wherein the fluid guide groove is formed with a groove protrusion that protrudes in the workpiece conveyance direction.   The levitation unit according to claim 4, wherein the fluid guide groove is formed with a reverse groove protrusion that protrudes in a direction opposite to the workpiece conveyance direction.   The levitation unit according to claim 1, wherein a protective film is formed on a conveyance path side of the porous body.   An apparatus comprising the levitation unit according to claim 1. A part of a conveyance path is formed by the levitation unit according to any one of claims 1 to 6,
8. The apparatus according to claim 7, wherein the remainder of the conveyance path is formed by a floating unit in which the fluid guide groove is not formed.

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