JP2008166348A - Substrate transfer apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a transfer mechanism to smoothly shift to levitation transfer from other than levitation transfer in the substrate transfer apparatus. <P>SOLUTION: The substrate transfer apparatus 3 is constituted with levitation plates 8A, 8B for levitating a substrate 1, a holding transfer mechanism for holding the substrate 1 to move on the levitation transfer route, and a roller transfer mechanism 9 for supporting the substrate 1 to move in the transfer direction at the time of upward movement and for saving it to the lower side of the levitation surface of the levitation plate 8A at the time of downward movement by providing a roller 9a for the levitation surface of the levitation plate 8A in one end of the levitation transfer route. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a substrate transfer apparatus. For example, the present invention relates to a substrate transport apparatus that transfers and transports a thin plate-like substrate such as a semiconductor wafer or a flat panel display (hereinafter abbreviated as FPD) glass substrate.

2. Description of the Related Art Conventionally, for example, in a production line for semiconductors, liquid crystal displays, and the like, a substrate transport apparatus is used when transporting a thin plate-shaped substrate to various manufacturing apparatuses and inspection apparatuses.
When transporting a substrate to an exposure device or inspection device that requires particularly high accuracy, the substrate flatness (( It is necessary to carry the sheet with high accuracy. On the other hand, in recent years, the size of a master glass substrate for manufacturing a liquid crystal display has been remarkably increased to 2000 mm as compared with a thickness of 0.7 mm, and such a large substrate can be stabilized horizontally without bending or vibration. It is required to be transported.
In addition, since such a large substrate has a very large area and tends to accumulate static electricity, it is desired to transport the substrate in a non-contact manner in order to prevent the discharge of the substrate due to the static electricity.
Therefore, the substrate is floated on the floating plate that discharges air from a large number of small holes to maintain flatness, and a part of the substrate is held and transported in a non-contact state where the substrate is lifted from the transport surface. A substrate transfer device is used.
For example, Patent Document 1 includes a standby carry-in process portion, a substrate cooling process portion, and a substrate carry-out portion along the substrate transfer direction as such a substrate transfer device, and the standby carry-in process portion and the substrate carry-out portion. Is a cooling device provided with an airflow levitation cooling table that blasts air from a jet port arranged at a predetermined pitch to float the substrate to cool it. The roller transport mechanism disposed on the upstream side and the downstream side of the substrate cooling process portion drives the roller shaft by a power transmission mechanism to transport the substrate.
JP 2001-358206 A (FIGS. 1 and 2)

However, the conventional substrate transfer apparatus as described above has the following problems.
In the technique described in Patent Document 1, since the airflow levitation mechanism is used for a process portion that requires flatness and non-contact holding, the requirements for flatness and non-contact holding can be satisfied. There is a problem that the conveyance is likely to become unstable at the portion to be switched to.
That is, in the roller transport mechanism on the upstream side, the roller contacts and conveys the substrate, but when this substrate is delivered to the airflow levitation table, the contact resistance between the floating substrate and the levitation conveyance surface is small, The floating substrate cannot be fixed. For this reason, the substrate may run away due to the moment of inertia at the moment of transition to the roller transport mechanism or the airflow levitation stage, and the substrate may rotate and contact the guard rail, causing damage to the substrate.
Although it is conceivable to provide a stopper for restraining the substrate immediately after the transfer to the levitation conveyance, there is a possibility that the substrate may collide with the stopper and be damaged due to the inertia of the substrate.
Also, depending on the configuration of the production line, for example, in the case of a substrate apparatus provided with a vibration isolation table, the roller conveyance unit and the floating conveyance unit that do not include the vibration isolation table cannot be formed integrally. In this case, since the height of the floating conveyance varies depending on the vibration isolation table, the conveyance height of the roller conveyance section and the conveyance height of the floating conveyance cannot be exactly matched. There is also a problem that it cannot be done.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a substrate transfer apparatus that can smoothly and surely shift from a transfer mechanism different from floating transfer to floating transfer.

  In order to solve the above-described problems, a substrate transport apparatus according to the present invention includes a levitation mechanism that floats a plate-shaped transported body, and a holding transport mechanism that holds the transported body and moves it on the levitation transport path. A substrate transport apparatus, wherein a roller is provided on one end side of the levitation transport path with respect to a floating surface of the levitation mechanism, and supports the transported body so as to be movable in the transport direction when ascending, and the levitation mechanism when descending A roller transport mechanism that retracts below the air bearing surface is provided.

  According to the substrate transfer apparatus of the present invention, the intermediate transfer mechanism is provided on one end side of the transfer path so as to be movable up and down with respect to the holding surface of the holding transfer mechanism, and above the holding surface of the holding transfer mechanism by the intermediate transfer mechanism. Since the transferred object can be moved, stopped moving, held by the holding and conveying mechanism, and lowered to the floating surface of the levitation mechanism, the transfer mechanism different from the levitation conveyance can be smoothly and reliably transferred to the levitation conveyance. There is an effect that can be done.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In all the drawings, even if the embodiments are different, the same or corresponding members are denoted by the same reference numerals, and common description is omitted.

A substrate transfer apparatus according to an embodiment of the present invention will be described.
1A and 1B are a plan view and a front view showing a schematic configuration of a substrate transfer apparatus according to an embodiment of the present invention. 2A and 2B are cross-sectional views taken along line AA of FIG. 1 when the intermediate transfer mechanism of the substrate transfer apparatus according to the embodiment of the present invention is raised and lowered.

The floating substrate transfer device 3 of the present embodiment is an inspection device that inspects a master glass substrate manufactured in a photolithography process installed in a manufacturing line, for example, as a thin plate-like substrate 1 made of a semiconductor wafer, an FPD glass substrate, or the like. Used as a transfer stage. As shown in FIGS. 1 (a) and 1 (b), this substrate transport apparatus includes at least a substrate entrance / exit 3A located at one end of the transport path, and a floating transport unit adjacent to the substrate entrance / exit 3A in the transport direction. 3B.
In addition, although the shape of the board | substrate 1 can employ | adopt suitable shapes, such as a disk shape, for example, in this Embodiment, it demonstrates with the example of the master glass board | substrate which manufactures a liquid crystal display in multiple faces.

The substrate loading / unloading portion 3A is a portion for loading or unloading the substrate 1 supplied from another transfer device into the apparatus main body of the present invention. Hereinafter, in the present embodiment, as other devices, to support the substrate 1 in the horizontal direction, the height of the conveying surface is at H _1, 1 roller conveying apparatus 2 to the roller conveyed from the left (a) to the right And the substrate transport apparatus 3 will be described with an example in which the same direction is the transport direction.
For this reason, the substrate loading / unloading section 3A is a loading section. However, if each operation is reversed, it can be used as a loading / unloading section for unloading the substrate 1 by setting the conveyance direction to the reverse direction with the same configuration.
The height H ₁ is, for example, a height measuring upward from a suitable reference surface set downward such installation surface of the apparatus main body. Hereinafter, otherwise the height otherwise shall measure from the height H ₁ identical to the reference plane.

The substrate transport device 3 is a mechanism common to the substrate loading / unloading unit 3A and the floating transport unit 3B. The substrate holding transport for forcibly transporting the floating substrate 1 while holding at least one side parallel to the transport direction of the substrate 1 A mechanism is provided. As this substrate holding and conveying mechanism, a pair of guide rails 5 extending along the substrate conveying direction on the base portion 4, and a slide portion 6 and a slide portion that move along the guide rail 5 by driving means such as a linear motor. A rectangular box-shaped support portion 7a provided on the upper and lower portions 6 and a plurality of substrate fixing portions 7b arranged on the upper surface of the support portion 7a are provided.
The substrate fixing portion 7b is provided with means capable of vacuum suction and release of negative pressure, and sucks the back surface of the substrate 1 by vacuum suction and releases suction to the substrate 1 by switching to negative pressure release. Etc. can be adopted.
Each support portion 7a has the same width in the transport direction of the substrate 1 as can be transported by sucking and holding both left and right sides with respect to the transport direction of the substrate 1. The two support portions 7a and 7a face each other in a direction orthogonal to the transport direction, and when the substrate 1 in the transport posture is disposed across the two support portions 7a and 7a, slightly inside the width of the substrate 1 in the direction orthogonal to the transport direction. They are spaced apart so as to be positioned. The two slide parts 6 are moved in synchronization with the two slide parts 6 and 6 while the two sides of the substrate 1 are attracted and held by the substrate fixing parts 7b on the support parts 7a and 7a. The floating substrate can be moved in the transport direction.
The height of the upper surface of the substrate fixing portion 7b is set to the flying height H ₂ (where H ₂ <H ₁ ) of the substrate 1 when the substrate 1 is sucked and held.
Further, the support portion 7a is lowered and waits so that the substrate fixing portion 7b does not come into contact with the back surface of the substrate 1 when the substrate 1 is loaded into and unloaded from the substrate loading / unloading portion 3A, and is fixed when the substrate 1 is transferred. The portion 7b rises to a position where it contacts the back surface of the substrate 1.

In addition to this, the substrate entrance / exit part 3 </ b> A includes an alignment mechanism including a floating plate 8 </ b> A (floating mechanism), a roller transport mechanism 9, reference pins 10 and 12, and a pressing pin 11.
Floating plate 8A is a floating mechanism for non-contact holding a substrate 1 flying at a height H _2. In the present embodiment, on the flying height of the flying plate 8A substrate than flying height H ₂ of 1 (e.g., 0.2 mm) by a low height H ₃ installed smooth foundation surface (conveying road surface), the upper It is formed in a rectangular air floating block provided with a large number of air blowing holes 8a for discharging air, and four air floating blocks are arranged in a sawtooth shape with a gap 8b in a direction perpendicular to the conveying direction.
Here, the discharge pressure of the air from the air blowing hole 8a is the clearance dimension (substrate floating amount) between the substrate 1 supported at both ends by the substrate fixing portion 7b and the base surface of the floating plate 8A (H ₂ − H ₃ ). For this reason, when the substrate 1 is placed on the substrate fixing portion 7b, the flatness of the substrate 1 is best maintained.

The roller transport mechanism 9 is for transporting the substrate 1 by the top of the roller outer peripheral surface coming into contact with the substrate 1 from the lower surface side and transmitting the rotational force of the roller 9 a to the substrate 1. A plurality of rollers 9a are arranged on the straight line along the transport direction at appropriate intervals in the transport direction so that the rotation direction in plan view coincides with the transport direction. The rotation shaft of each roller 9a is rotatably held by a roller holding portion 16. In this embodiment, the roller transport mechanism 9 is arranged so as to cover the entire area of the floating plate 8A, but it is also possible to arrange at least one line at one end on the connection side with the other transport device 2.
And such a roller 9a is each installed in the clearance gap 8b between each floating plate 8A.
As shown in FIGS. 2A and 2B, each roller transport mechanism 9 is connected to a transmission mechanism 14, and a driving force is transmitted by a driving unit 13 made of a motor or the like, and according to an appropriate control signal. Can be rotated or stopped in synchronization with each other.
The transmission mechanism 14 may have any configuration as long as the driving force from the driving unit 13 can be transmitted. For example, a mechanism such as a suction mechanism using a belt, a chain, a gear, or a magnetic material can be employed.
Further, each roller holding portion 16 and the transmission mechanism 14 are supported by an elevating mechanism 15 so as to be movable up and down. Therefore, each roller 9a can advance and retreat on the conveyance path from the gap 8b between the floating plates 8A. In other words, the gap 8b forms an elevator port through which the roller 9a moves up and down.
The up-and-down range of the upper top of each roller 9a is a standby height H ₄ slightly lower than the height H ₃ of the base surface of the floating plate 8A from the transport height H ₁ of the substrate 1 of the roller transport device 2 (however, H ₄ <H ₃ ).
In the drawing, the elevating mechanism 15 is drawn so as to integrally support each roller holding portion 16 and the transmission mechanism 14, but the transmission mechanism 14 is provided in each roller holding portion 16, and accordingly, the elevating mechanism 15 15 may be configured by a plurality of mechanisms in which the height and timing are synchronized.

The reference pins 10 and 12 and the pressing pin 11 are alignment mechanisms that align the substrate 1 transported to the substrate entrance / exit part 3A to the reference position in a state where the substrate 1 is floated on each floating plate 8A. The reference pin 10 is composed of two cylindrical pin-shaped members that are erected at a height and a position for positioning one side on the right side in the conveyance direction of the substrate 1. The reference pin 12 is a positioning member that regulates the tip of the substrate 1 conveyed to the substrate loading / unloading portion 3A to a reference position, and is provided at a boundary portion between the substrate loading / unloading portion 3A and the floating conveyance portion 3B so as to be able to advance and retreat in the vertical direction. ing.
The pressing pin 11 is used to adjust the position of the substrate 1 by pressing the end of the substrate 1 that has floated toward the reference pins 11. For example, a cylindrical pin-like shape is provided on the left side in the transport direction. A guide provided at the tip and connected to a mechanism that moves in a direction orthogonal to the transport direction via a buffering elastic member such as a spring can be employed.
In addition, a position detection sensor 17 that detects the position of the end of the substrate 1 that has been conveyed is located in the vicinity of the substrate fixing portion 7b on the right side in the conveyance direction and at the boundary between the substrate entry / exit portion 3A and the floating conveyance unit 3B. Has been placed. The position detection sensor 17 is not particularly limited as long as the position of the end of the substrate 1 can be detected. For example, a reflection type or transmission type optical sensor, a contact mechanical sensor, or the like can be used.

  The levitation conveyance unit 3B is for levitation conveyance of the substrate 1 transferred to the substrate loading / unloading unit 3A to an inspection area arranged on the downstream side. By fixing the inspection head for observing the substrate 1 and the portal post-type arm that supports the inspection head so as to be movable in the direction orthogonal to the conveyance direction to the base unit 4 across the levitation conveyance unit 3B. A board inspection apparatus can be configured. Also, in the in-line substrate manufacturing process in which the same roller transport mechanism as the substrate entrance / exit section 3A is provided upstream and downstream of the levitation transport section 3B serving as the inspection area to transport the substrate 1 from the upstream side to the downstream side. It may be arranged.

The levitation transport unit 3B includes a levitation plate 8B.
The levitation plate 8B has the same configuration as that of the levitation plate 8A, is arranged adjacent to the end of each levitation plate 8A and at the same height as it, and extends in the same conveying direction. Air floating block.
Unlike the case of the levitation plate 8A, each levitation plate 8B need not be provided with a roller 9a between them, and may be integrated, but in the present embodiment, the gap 8a of the levitation plate 8A may be integrated. They are arranged in a slat form that forms a narrower gap 8c.
In this case, the gap 8c of the floating plate 8B may be a gap that allows the air discharged from each air suction hole 8a to be exhausted. The levitation conveyance unit 3B is required to precisely control the flying height of the substrate 1 in order to inspect the substrate 1 with high accuracy. For this reason, it is preferable to employ a precision levitation block provided with an air suction hole for sucking air in addition to the air suction hole 8a in the levitation transport unit 3B.

Next, the operation of the substrate transfer apparatus 3 will be described.
The substrate 1 is transported like a substrate 1A by the rollers 2a of the roller transport device 2 from the left side of FIG. 1A toward the substrate entrance / exit part 3A on the substrate inspection device side. In this roller transport device 2, since many rollers 2a come into contact with the back surface of the substrate 1 and rotate in the same direction, the position in the direction orthogonal to the transport direction is regulated by the frictional force on the roller 2a. Yes. Therefore, the substrate 1 is conveyed at a height H ₁ toward the substrate entrance and exit part 3A.

On the other hand, the substrate entrance and exit part 3A, raises the lifting mechanism 15, it sets the roller 9a of the roller transfer mechanism 9 at the same height H ₁ and the roller 2a of the roller conveyor apparatus 2 (see FIG. 2 (a)), the driving The rotation speed of the roller 9a is set so that the rotation speed of the section 13 is adjusted to be the same as that of the roller conveyance device 2.
When the substrate 1 reaches the substrate entrance / exit part 3A, the substrate 1 moves from the front end side onto the roller 9a positioned at the same height, and proceeds straight by receiving a conveying force from both the rollers 9a and 2a.
At this time, the slide part 6 moves along the guide rail 5 to the substrate entrance / exit part 3A and stands by. The support portion 7a is lowered as the holding surface of the substrate fixing portion 7b is in a position lower than the height H ₃ of the base surface of the floating plate 8A, a substrate fixing portion 7b of the non-contact with the substrate 1 state Let me.
Further, since the height H ₁ of the roller 9a is set at a position higher than the flying height H ₂ of the substrate 1, an air discharged from the air outlet hole 8a does not reach pressures of up to float the substrate 1 . Therefore, the substrate 1 does not float further upward from the roller 9a, and the contact state with the roller 9a is maintained.
As a result, the substrate 1 is smoothly transferred from the roller 2a onto the roller 9a. On the roller 9a, the frictional force at the contact portion acts like the roller 2a, and the movement in the direction orthogonal to the conveying direction is restricted. Therefore, it does not shake or vibrate in the direction orthogonal to the transport direction.

In this way, the substrate 1 is transferred onto the substrate loading / unloading portion 3A as the rollers 2a and 9a rotate (see FIG. 1B).
When the substrate 1 reaches the position indicated by the substrate 1B in FIG. 1A and the position detection sensor 17 provided at the boundary with the levitation transport unit 3B detects the arrival of the tip of the substrate 1, the drive unit 13 The rotation of each roller 9a is stopped. At this time, when the substrate 1 is moved and stopped before the position detection sensor 17 at the boundary portion, the drive unit 13 is reversed to return the substrate 1 into the alignment region.
Then, by operating the elevating mechanism 15 is retracted downwardly to a position where the top position is a height H _4, which is lower than the height H ₃ of the base surface of the floating plate 8A of the rollers 9a (FIG. 2 (b) reference).
In this case, the substrate 1 is also descends in the same manner, but is floating held in flying height H ₂ by the air ejected from the air outlet hole 8a.
At that time, the substrate 1 is not restrained in the horizontal direction, but since the conveyance of the substrate 1 has already been stopped, the substrate 1 is still in the horizontal direction due to inertia even if it is separated from the roller 9a. There is no risk of moving.

In a state where the substrate 1 is floated, the pressing pins 11 and 11 are operated, and the substrate 1 is pressed against the reference pins 10 and 10 to perform alignment at the reference position. At this time, the reference pin 12 is advanced on the transport path so that the substrate 1 does not move in the transport direction.
As described above, the reference pins 10 and 12 and the pressing pin 11 constitute the positioning mechanism (alignment region) of the present embodiment.

When the positioning of the substrate 1 is completed, the support portion 7a is raised and the substrate 1 is sucked and fixed by each substrate fixing portion 7b. After confirming that the substrate 1 is attracted and held by the substrate holding and conveying mechanism, the pressing pins 11 are separated from the substrate 1 and the reference pins 12 are lowered to release the horizontal restraint of the substrate 1.
And each board | substrate 1 is conveyed by driving each slide part 6 to a conveyance direction. At this time, the substrate 1 is not in contact with the base surface of the levitation plate 8A, and the slide portion 6 moves on the guide rail 5, so that the levitation height H is increased by the discharge pressure of air from the air blowing holes 8a. ₂ is transported while maintaining good flatness.
When the substrate 1 reaches the levitation conveyance unit 3B, air is discharged from the levitation plate 8B, and the substrate 1 continues to be conveyed while maintaining the same floating state as the levitation plate 8A. Then, the substrate holding and transporting mechanism transports the substrate 1 that has floated on the floating transport unit 3B to a predetermined position, and inspects the substrate 1 with the inspection head.

As described above, according to the substrate transport apparatus 3 of the present embodiment, the roller 1 is lifted and lowered on the floating plate 8A that floats and transports the substrate 1, and the roller 9a is raised and lowered on the floating transport surface. When carrying in, the roller 9a protrudes from the floating plate 8A so that the substrate 1 can be drawn onto the floating plate 8A, and the substrate 1 carried in from the other roller conveyance device 2 can run smoothly without being runaway. It is possible to move reliably.
In addition, by lowering each roller 9a in a state where the substrate 1 is moved onto each roller 9a, the substrate 1 can be placed in non-contact with the floating plate 8A and positioned. High-precision positioning is easy.

In the above description, the example of using the levitation plates 8A and 8B arranged in a slat-like shape as the levitation mechanism has been described. However, these shapes can be appropriately modified.
For example, the levitation mechanism may be a common mechanism over the substrate entrance / exit part 3A and the levitation transport part 3B.
The gaps 8b and 8c may have any shape as long as each roller 9 can advance and retract on the base surface of the floating mechanism. For example, as shown in FIG. 3, a plurality of roller elevating holes 8d (elevating holes) may be provided on the floating plate 8A (8B), and the roller 9a may be advanced and retracted from each roller elevating hole 8d. In this case, the levitation mechanism can also be arranged in the conveyance direction between the rollers 9a, so that more stable levitation conveyance can be performed.
Further, the levitation mechanism may be configured as an integrated mechanism over the substrate entrance / exit part 3A and the levitation transport part 3B.
A plurality of floating mechanisms separated in the transport direction can also be employed. In this case, in order to further stabilize the levitation force, the interval in the conveyance direction is made narrower than the width of the substrate 1 in the conveyance direction, or a plurality of levitation mechanisms are arranged in a zigzag shape in plan view. It is preferable to stabilize the average levitation force over the conveying direction by adopting a configuration in which any of the levitation mechanisms are arranged in parallel along the direction.
Moreover, in all these floating mechanisms, it is preferable that a clearance is provided around the roller transport mechanism 9 to form a flow path through which air is released. In that case, there is an advantage that a stable air flow path can be formed and the holding surface height of the substrate 1 can be stabilized.

In the above description, the example of the air levitation mechanism that discharges air has been described as the levitation mechanism. However, for example, a gas levitation mechanism that discharges another gas such as nitrogen or an inert gas may be used.
Further, the levitation mechanism is not limited to such a gas levitation mechanism, and may be a levitation mechanism according to another method such as an electrostatic levitation mechanism or an ultrasonic levitation mechanism.

  In the above description, an example in which a roller transport mechanism that transports in a fixed direction is used has been described. However, the transport direction can also be changed or transported in a biaxial direction. For example, a mechanism using a spherical roller whose rotation direction can be freely changed may be employed.

  Further, in the above description, the example in which the alignment is performed by the alignment mechanism after being transferred to the floating mechanism has been described. However, an alignment device, an alignment device, and the like are provided in another place on the conveyance path. In some cases, the alignment mechanism may be omitted.

  In the above description, the holding and transport mechanism is described as an example in which the holding body is held at both ends in the transport direction of the transported body. However, if the transported body can be transported, only one side is held. Or may be held at another position, for example, at the center.

  In the above description, an example in which the conveyance direction is horizontal has been described. However, the conveyance direction is not limited to the horizontal direction.

It is the top view and front view which show schematic structure of the board | substrate conveyance apparatus which concerns on embodiment of this invention. 2 is a cross-sectional view taken along line AA of FIG. 1 when the intermediate transfer mechanism of the substrate transfer apparatus according to the embodiment of the present invention is raised and lowered. It is a fragmentary top view explaining the modification of the levitation mechanism of embodiment of this invention.

Explanation of symbols

1, 1A, 1B substrate (conveyed body)
3 Substrate conveying device 3A Substrate entry / exit part 3B Levitation conveyance part 5 Guide 6 Slide part 7 Substrate fixing part 8A, 8B Levitation plate
8a Air outlet hole 8b Clearance (elevator)
8c Clearance 8d Roller lift hole (lift hole)
9 Roller (intermediate transport mechanism)
10, 12 Reference pin (positioning mechanism)
11 Pressing pin (positioning mechanism)
15 Lifting mechanism 17 Position detection sensor

Claims (2)

A substrate transport apparatus having a floating mechanism for levitating a plate-shaped transported body and a holding transport mechanism for holding the transported body and moving it on a floating transport path,
At one end of the levitation conveyance path, a roller is provided on the air bearing surface of the levitation mechanism to support the object to be conveyed so as to move in the conveyance direction when ascending, and retract below the air bearing surface of the levitation mechanism when descending. A substrate transport device comprising a roller transport mechanism for performing the above operation. The levitation mechanism comprises a gas levitation mechanism for discharging gas,
The substrate conveyance device according to claim 1, wherein the roller conveyance mechanism raises and lowers the roller through an elevating port provided on the substrate surface.

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