JPH0820431A - Pneumatic floatation type sheet conveyor system - Google Patents

Abstract

PURPOSE:To promote the compactification of a conveyor system as preventing the sticking any scratch and dust to a wafer in time of conveyance by forming each suction layer successively in space between an opposed surface continuing this surface in the conveying direction of a thin plate and the wafer, and making the wafer alone conveyable. CONSTITUTION:An opposed surface 11 is set up so as to be opposed to a top surface 3a of a wafer 3, and this opposed surface 11 is continuously installed in the conveying direction of the wafer 3. Six supply openings 12a, 12b, 12c, 12d, 12e and 12f are installed in the opposed surface 11 so as to make each suction layer be formed in space between this opposed surface 11 and the wafer 3 successively in the conveying direction of the wafer 3. Subsequently, these supply openings 12a, 12b, 12c, 12d, 12e and 12f are installed in a row at a shorter space than length in the conveying direction of the wafer 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air levitation type thin plate conveying device, and more particularly to a device for floating and conveying thin plates in a non-contact state.

[0002]

2. Description of the Related Art Generally, a transfer device for transferring a thin plate such as a wafer or a liquid crystal substrate is arranged so that the thin plate is placed on a thin belt conveyor having a contact surface with the thin plate as small as possible. I have to.

[0003]

However, since the thin plate itself is very delicate and has a large surface area in the above-described conveying device, the contact surface of the thin plate placed on the belt conveyor may be scratched, Dust may have adhered.

Therefore, the facing surface of the hand portion of the conveying device is arranged so as to face the upper surface of the thin plate, and an air outlet for blowing air is provided in the facing surface, and the air outlet is provided between the upper surface and the facing surface of the thin plate. The air blown from the outlet toward the upper surface of the thin plate is laminarly formed to form a negative pressure layer, and the negative pressure layer causes the thin plate to float in a non-contact state with respect to the facing surface.
By using a so-called Bernoulli chuck or the like, it is possible to convey the thin plate together with the hand unit to a predetermined position while floating in a non-contact state on the facing surface. However, this device requires a device such as an arm and an actuator for driving the arm in order to move the hand part (opposing surface), and has a drawback that the transport device becomes large.

The present invention has been made in view of the above points, and an object of the present invention is to provide the above-mentioned facing surface continuously in the conveying direction of the thin plate and to sequentially provide a negative electrode between the continuous facing surface and the thin plate. The pressure layer is formed so that only the thin plate can be conveyed, and scratches and adhesion of dust to the thin plate at the time of conveyance can be prevented, and the conveying device can be made compact.

[0006]

Means for Solving the Problems In order to achieve the above-mentioned object, a means for solving the problems according to the invention of claim 1 is an air levitation type thin plate conveying device, in which a facing surface is arranged so as to face the upper surface of the thin plate, A plurality of air outlets for blowing air are provided on the facing surface, and the air blown from the air outlet toward the upper surface of the thin plate is laminarly flowed between the upper surface of the thin plate and the facing surface to form a negative pressure layer. The negative pressure layer causes the thin plate to float on the facing surface in a non-contact state and be conveyed to a predetermined position. Further, the facing surface is continuously provided in the transport direction of the thin plate, and the air outlet is sequentially formed in the transport direction of the thin plate between the facing surface and the thin plate continuous in the transport direction of the thin plate. As described above, the thin plates are arranged side by side in the conveying direction at intervals shorter than the length of the thin plates in the conveying direction.

[0007] The solving means taken by the invention of claim 2 is,
In addition to the constituent features of the invention according to claim 1, a guide portion for guiding the conveyance of the thin plate is extended in the conveyance direction of the thin plate at a corresponding position of the facing surface corresponding to both left and right sides orthogonal to the conveyance direction of the thin plate. It is configured to be provided.

[0008] The solution means taken by the invention of claim 3 is,
According to the first aspect of the present invention, the facing surface is specified, and at least at the transport start position, it is formed as an inclined surface located downward in the transport direction.

[0009] The solution means taken by the invention of claim 4 is,
In addition to the constituent features of the invention according to claim 1, a plurality of outlets are provided to open the downstream ends of the outlet passages, and air is blown out from the outlets in the sheet conveying direction, The configuration is provided such that the upstream side is inclined rearward with respect to the transport direction of the thin plate.

The means for solving the problems according to the invention of claim 5 is as follows.
In addition to the constituent features of the first aspect of the present invention, a detection means for detecting the presence of a thin plate below the outlets is provided between adjacent outlets in the sheet conveying direction. Further, the control means is provided to blow out the air only from the air outlet near the thin plate detected by the detecting means.

[0011]

According to the above-mentioned structure, according to the first aspect of the present invention,
Since a plurality of air outlets that blow air toward the upper surface of the thin plate to form a negative pressure layer between the upper surface of the thin plate and the facing surface are provided side by side in the conveying direction of the thin plate with the facing surface continuous, When a force is applied to move the sheet in the conveying direction, the air blown out from the air outlet adjacent to the outlet in the sheet conveying direction causes the layer to move between the upper surface and the facing surface of the sheet moved in the conveying direction. The negative pressure layer is formed by flowing the negative pressure layer, and the air blown from the next adjacent outlet between the upper surface and the facing surface of the thin plate that has moved in the transport direction is laminarly flown so that the negative pressure layer is in the transport direction of the thin plate. Are sequentially formed, and the thin plate itself is conveyed while being floated on the facing surface in a non-contact state. As a result, only the thin plate is conveyed in a non-contact state against the facing surface, and the thin plate may be damaged,
No dust is attached. In addition, a device such as an arm and an actuator for driving the arm, which is necessary when the thin plate is conveyed together with the facing surface of the hand part in a non-contact state, is unnecessary, and the transfer device becomes compact.

Further, since the plurality of outlets are arranged side by side in the conveying direction of the facing surface at intervals shorter than the length of the thin plate in the conveying direction, the outlets on the conveying direction side adjacent to each other in the conveying direction of the thin plates. Until the negative pressure layer is formed between the upper surface and the facing surface of the thin plate by the air blown out from the thin plate, the thin plate is reliably levitationally supported by the negative pressure layer formed by the air blown from the air outlet on the side opposite to the conveyance direction. The thin plate is smoothly conveyed to the facing surface that is continuous in the conveying direction of the thin plate.

According to the second aspect of the present invention, the thin plate is smoothly guided to a predetermined position without being displaced from the conveying direction by the guide portions provided at the corresponding positions of the facing surfaces corresponding to the left and right sides orthogonal to the conveying direction. To be done.

According to the third aspect of the present invention, at least the facing surface of the carrying start position is formed as an inclined surface located downward as it goes in the carrying direction. Therefore, the sheet is carried to the thin plate by the gravity moment acting in the gravity direction of the thin plate. Since a force acts in the direction, the thin plate is conveyed without applying a force in the conveying direction to the thin plate, and it is not necessary to separately provide a device such as an actuator that applies a conveying force to the thin plate in the conveying direction. .

According to the fourth aspect of the present invention, the blowout passages each having a downstream end open to the plurality of blowout openings are provided in a state where the upstream side is inclined rearward with respect to the conveying direction of the thin plate. The air laminarly flowing between the air bearing surface and the facing surface positively flows in the transport direction to give a flow in the transport direction, and the negative pressure layer formed by this air causes the thin plate to move in the transport direction. The thin plate is conveyed without applying force, and a device such as an actuator that applies a conveying force to the thin plate is also unnecessary.

Further, in the invention according to claim 5, the detection means provided between the air outlets adjacent to each other in the conveying direction detects that the thin plate is below, and the air is emitted only from the air outlets near the thin plate. Since it is blown out, unnecessary air is prevented from being blown out from the air outlet that is unrelated to the transport of the thin plate, waste of air is prevented, and laminar flow between the thin plate and the facing surface, that is, on the transport system path. Disorder is prevented.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an air-floating thin plate carrier according to a first embodiment of the present invention. This air-floating thin plate carrier 1 is installed in a clean room 2.
The air floating type thin plate transfer device 1 is provided so as to extend from a transfer start position to an end position so as to transfer a silicon wafer 3 (thin plate) which is a substrate of an integrated circuit in the clean room 2.

The air levitation type thin plate carrier 1 is provided with a facing surface 11 facing the upper surface 3a of the wafer 3 on the lower surface side, and the facing surface 11 is provided with a recessed portion in a substantially central portion in the width direction to blow air. A substantially circular outlet 12 for opening is opened. The outlet 12 is the first outlet 12a at the wafer transfer start position.
To the second outlet 12b, the third outlet 12c, the fourth outlet 12d, the fifth outlet 12e, the sixth outlet 12f, ... A clean air passage (not shown) extending in the transfer direction of the wafer 3 is provided inside the air floating thin plate transfer device 1. The first outlet passages 13a, the second outlet passages 13b, which individually extend in the vertical direction from the clean air passages to the respective outlets 12a, ...
The downstream ends of the third outlet passage 13c, the fourth outlet passage 13d, the fifth outlet passage 13e, the sixth outlet passage 13f, ... Are connected, and the clean air (the arrow shown in the figure) from the clean air passage is blown out from each outlet. The air outlet 12 through the passages 13a, ...
are individually sent to a, ....
In this case, the amount of clean air delivered from each of the outlets 12a, ... Is set to be uniform at any of the outlets 12a ,.

The first to third outlets 12a to 12c located at the transfer start position correspond to the upper surface 3a of the wafer 3, and the transfer start position is reached from each of the outlets 12a to 12c. In the above, clean air is blown toward the upper surface 3a of the wafer 3 lifted by a lifting means (not shown) so as to face the facing surface 11, and the clean air is transferred between the upper surface 3a of the wafer 3 and the facing surface 11. A negative pressure layer is formed between the upper surface 3a of the wafer 3 and the facing surface 11 by causing a laminar flow at a wind speed of about 1 m / s or less, and the negative pressure layer causes the wafer 3 to face the facing surface 11. , About 0.1
It is floated in a non-contact state with a gap of about mm to 0.2 mm and conveyed from the conveyance start position to the end position.

The facing surface 11 is formed in a horizontal plane which continuously extends from the transfer start position to the end position of the wafer 3. In addition, the outlets 12a, 12b, 1
2c, ... Are spaced from each other by a distance (for example, 70 m) shorter than the length (for example, 200 mm) in the transfer direction of the wafer 3 on the facing surface 11 that is continuous from the transfer start position to the end position of the wafer 3.
m), the negative pressure layers are sequentially formed between the opposing surface 11 of the wafer 3 and the wafer 3 which are arranged in a line in the carrying direction and are continuous in the carrying direction, each time the wafer 3 moves in the carrying direction. I am trying to do it.

Guide portions 21, 2 for guiding the transfer of the wafer 3 are provided at both left and right ends of the facing surface 11 corresponding to the left and right sides of the wafer 3 which are orthogonal to the transfer direction.
1 projects downward and is integrally provided. Each of the guide portions 21 is provided so as to continuously extend in the transfer direction of the wafer 3. Further, at the transfer start position on the facing surface 11, a transfer force applying means 22 for applying a transfer force to the wafer 3 in the transfer direction is provided. The transfer force applying means 22 is provided at the starting end of the air levitation type thin plate transfer device 1 in the transfer direction, and has an actuator 24 having a rod 23 that can be retracted and retracted in the transfer direction of the wafer 3, and the rod 2 thereof.
An arm whose base end (upper end) is fixed to the front end of 3 and whose front end (lower end) projects below the facing surface 11 through a hole portion 25 that is open on the side opposite to the transfer direction of the wafer 3 at the transfer start position. And 26.

Therefore, in the first embodiment described above, the clean air is blown toward the upper surface 3a of the wafer 3 and the wafer 3
, Which form a negative pressure layer between the upper surface 3a of the wafer 3 and the facing surface 11 are arranged in a line in the transfer direction of the wafer 3 where the facing surface 11 is continuous, the first to the third. Wafer 3 that was levitated and supported by air outlets 12a to 12c
However, when the actuator 23 (conveyance force applying means 22) causes the arm 26 to protrude in the conveyance direction via the rod 24 and is pushed out in the conveyance direction, the arm 26 is disengaged from the first outlet 12a and is conveyed in the conveyance direction of the third outlet 12c. Adjacent 4th outlet 12
A negative pressure layer is formed between the upper surface 3a of the wafer 3 (the position indicated by the alternate long and short dash line in FIG. 1) moved in the transport direction by the clean air blown from d and the facing surface 11, and the wafer 3 further moved in the transport direction. Upper surface 3 (at the position indicated by the chain double-dashed line in FIG. 1)
A negative pressure layer is sequentially formed between a and the facing surface 11 by clean air blown from the next adjacent fifth outlet 12e, and the wafer 3 itself is floated on the facing surface 11 in a non-contact state. Transport to. As a result, only the wafer 3 is conveyed in a non-contact state with the facing surface 11, and it is possible to prevent the wafer 3 from being scratched or dust from being attached. Further, equipment such as an arm and an actuator for driving the arm, which is necessary when the wafer (thin plate) is transferred to the facing surface of the hand part without contacting the hand part, is unnecessary, and the air levitation type thin plate transfer device 1 is compact. It can be anything.

Moreover, since the air outlets 12a, ... Are provided on the facing surface 11 continuous in the carrying direction of the wafer 3 at intervals shorter than the length of the wafer 3 in the carrying direction, they are arranged in a line in the carrying direction. Until a negative pressure layer is formed between the upper surface 3a of the wafer 3 and the facing surface 11 by the clean air blown from the air outlet 12d (12e) on the transport direction side adjacent to the air outlet 12c in the transport direction, Blow-out port 1 on the opposite side
The wafer 3 is reliably floated and supported by the negative pressure layer formed by the clean air blown from 2b and 12c (12c and 12d), and the wafer 3 can be smoothly transferred to the facing surface 11 continuous in the transfer direction of the wafer 3. .

Further, the guide portions 21 and 21 provided on the left and right end portions of the facing surface 11 corresponding to the left and right side portions orthogonal to the transfer direction of the wafer 3 allow the wafer 3 to smoothly reach the end position without deviating from the transfer direction. It can be conveyed while being guided.

Furthermore, since the wafer 3 can be transferred by the blowout ports 12a, ...
The air levitation type thin plate transporting device 1 suitable for the clean room 2 which is reluctant to blow air upward is constructed, which is very advantageous for implementation.

Next, a second embodiment of the present invention will be described with reference to FIG.

In the second embodiment, the structure of the conveying force applying means is changed.

That is, in this embodiment, as shown in FIG. 3, the facing surface 11 is formed on the inclined surface 31 located downward at the carrying start position in the carrying direction. The inclined surface 31 is inclined with respect to the horizontal plane A by an inclination angle θ. In addition, each outlet passage 13 corresponding to the inclined surface 31.
.. are also inclined in directions orthogonal to the inclined surface 31. In addition, the other configuration of the conveying force applying means,
This is the same as the case of the first embodiment, and the same parts are denoted by the same reference numerals and the description thereof is omitted.

Therefore, in the second embodiment, since the facing surface 11 at the carrying start position is formed on the inclined surface 31 located downward as it goes in the carrying direction, the gravitational moment acting in the gravitational direction of the wafer 3 causes Since a force in the carrying direction acts on the wafer 3, the wafer 3 is carried in order from the solid line position to the one-dot chain line position to the two-dot chain line position without applying a force to the wafer 3 in the carrying direction. It is possible to eliminate the need for a separate conveying force applying unit such as an actuator that applies a conveying force in the conveying direction.

Next, a third embodiment of the present invention will be described with reference to FIG.

In the third embodiment, the structure of the conveying force applying means is changed.

That is, in this embodiment, as shown in FIG. 4, the blow-out passages 13a, ... The upstream side is inclined rearward with respect to the transfer direction of the wafer 3 so as to blow clean air in the direction. These outlet passages 13a, ...
It is inclined by an inclination angle α with respect to the vertical line x. The rest of the configuration of the conveying force applying means is the same as that of the first embodiment, and the same parts are designated by the same reference numerals and the description thereof is omitted.

Therefore, in the third embodiment described above, the blow-out passages 13a, ... Are provided so as to be inclined rearward with respect to the transfer direction of the wafer 3 by the inclination angle α. The clean air laminarly flowing with the facing surface 11 positively flows in the transfer direction, and a flow in the transfer direction is imparted, and the negative pressure layer formed by the clean air transfers the clean air to the wafer 3. The wafer 3 is carried in the order of the solid line position, the one-dot chain line position, and the two-dot chain line position without applying a force in the direction, and a transfer force applying unit such as an actuator for applying a transfer force to the wafer 3 in the transfer direction is also used. Can be unnecessary.

Next, a fourth embodiment of the present invention will be described with reference to FIG.

In the fourth embodiment, the structure of the conveying force applying means is changed.

That is, in the present embodiment, as shown in FIG. 5, the air outlets 12a, which are adjacent to each other in the wafer 3 transfer direction,
Between the 12b (or 12b, 12c, or 12c, 12d, or 12d, 12e), there is provided detection means 41 for detecting the presence of the wafer 3 therebelow.
The clean air is blown out only from the air outlets 12a to 12e near the wafer 3 detected by the detection means 41. In this case, a shutter valve (not shown) is provided in each of the outlet passages 13a, ... And the shutter valve is opened and closed by a control means (not shown). When the detecting means 41, ... Detects the wafer 3, the shutter valve is opened / closed by the control means which receives a signal from the detecting means 41 that has detected the wafer, and the outlets 12a to 12a near the wafer 3 are opened. The clean air is blown from only 12e. The rest of the configuration of the conveying force applying means is the same as that of the first embodiment, and the same parts are designated by the same reference numerals and the description thereof is omitted.

Therefore, in the above embodiment, the detection means 41 provided between the air outlets 12a and 12b adjacent to each other in the carrying direction detects that the wafer 3 is below, and the air outlet 12a near the wafer 3 is detected. Since clean air is blown out only from ~ 12e, the air outlets unrelated to the transfer of the wafer 3, that is, the movement of the wafer 3 causes the clean air to be blown behind the wafer 3.
(Not shown at the position of the alternate long and short dash line of the wafer 3
At the position indicated by the chain double-dashed line of the blower outlet 12a and the wafer 3, unnecessary clean air is prevented from being blown out from the first blower outlet 12a and the second blower outlet 12b) and a blower outlet not shown in the figure, thus preventing waste of clean air. In addition, it is possible to prevent turbulence of the laminar flow between the wafer 3 and the facing surface 11, that is, on the transfer system path. Moreover, it is possible to prevent unnecessary blowing of clean air and prevent dust from being wound up in the clean room 2.

The present invention is not limited to the above-mentioned embodiments, but includes various modifications. For example, in each of the above-described embodiments, the outlets 12a, ... Are provided in the widthwise central portion of the facing surface 11, but a plurality of rows are arranged in the widthwise direction of the facing surface or in a plurality of rows while being displaced in the transport direction. It may be the exit. In addition, in each of the above-described embodiments, the wafer 3 is associated with three outlets, but it may be associated with two or four or more outlets.

Further, in each of the above-mentioned embodiments, the case where the air floating thin plate carrier 1 is installed in the clean room 2 has been described, but it goes without saying that it may be installed in any other place. In the above embodiment, the wafer is used as the thin plate, but any thin material having a large surface area such as a liquid crystal substrate may be used.

Further, in each of the above-mentioned embodiments, the guide portions 21 are continuously provided in the wafer transfer direction, but the guide portions may be provided intermittently so that the wafer can be guided. Well, in this case, an escape route for clean air is secured, a laminar flow can be performed smoothly, and a negative pressure layer is effectively formed.

[0042]

As described above, according to the air levitation type thin plate conveying device of the invention of claim 1, the conveying direction of the thin plate on the facing surface which is continuous in the conveying direction is shorter than the length of the thin plate in the conveying direction. Since a plurality of outlets are arranged side by side in the sheet, a negative pressure layer is sequentially formed between the upper surface and the facing surface of the thin plate that moves in the transport direction to enable smooth transport of the thin plate itself in a non-contact state. It is possible to prevent scratches and dust from adhering to the device, and it is possible to reduce the size of the transfer device by eliminating the need for devices such as an arm and an actuator for driving the arm that are required to transfer the thin plate together with the hand part.

According to the air levitation type thin plate conveying device of the second aspect of the invention, the thin plate can be guided by the guide portion so that the thin plate can be smoothly guided to a predetermined position without being displaced from the conveying direction.

According to the air levitation type thin plate conveying device of the third aspect of the present invention, at least the facing surface at the base end position in the conveying direction is formed as an inclined surface, so that the thin plate is given a force in the conveying direction due to its gravitational moment. However, it is possible to eliminate the need for a separate conveying force applying device.

According to the air levitation type thin plate carrier of the invention as defined in claim 4, since the blowing passage is provided in a state where the upstream side is inclined rearward with respect to the carrying direction of the thin plate, the upper surface and the facing surface of the thin plate are opposed to each other. A negative pressure layer that gives a flow in the transport direction is formed between the thin plates, and the thin plates can be transported without applying a force in the transport direction to the thin plates, and a device for applying a force in the transport direction to the thin plates is also unnecessary. Can be

Further, according to the air levitation type thin plate conveying device of the fifth aspect of the invention, since the air is blown out only from the air outlet in the vicinity of the thin plate detected by the detecting means, it is possible to prevent waste of air and to convey the air. It is possible to prevent turbulence of the air flow on the system road.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view in the vicinity of a transfer start position of an air floating type thin plate transfer device according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional rear view in the vicinity of a transport start position of the air levitation type thin plate transport device.

FIG. 3 is a view corresponding to FIG. 1 according to a second embodiment.

FIG. 4 is a view corresponding to FIG. 1 according to a third embodiment.

FIG. 5 is a view corresponding to FIG. 1 according to a fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air floating type thin plate conveying apparatus 3 Wafer (thin plate) 3a Upper surface 11 Opposing surface 12a to 12f Air outlet 13a to 13f Air outlet passage 21 Guide portion 31 Sloping surface 41 Detection means

Claims (5)

[Claims] 1. A facing surface is disposed so as to face the upper surface of the thin plate, and a plurality of air outlets for blowing air are provided in the facing surface, and the air outlet is provided between the upper surface of the thin plate and the facing surface. A negative pressure layer is formed by laminarly flowing the air blown toward the upper surface of the thin plate, and the negative pressure layer causes the thin plate to float in a non-contact state with respect to the facing surface and to be conveyed to a predetermined position. The facing surface is continuously provided in the transport direction of the thin plate, and the air outlet is between the facing surface and the thin plate continuous in the transport direction of the thin plate, and the negative pressure layer is sequentially formed in the transport direction of the thin plate. The air-floating thin plate transporting device is characterized in that it is provided on the facing surface side by side in the transporting direction at intervals shorter than the length of the thin plates in the transporting direction. 2. A guide part for guiding the conveyance of the thin plate is provided at a corresponding position of the facing surface corresponding to both left and right sides orthogonal to the conveying direction of the thin plate, extending in the conveying direction of the thin plate. 1. The air levitation type thin plate carrier according to 1. 3. The air-floating thin plate carrier according to claim 1, wherein the facing surface is formed as an inclined surface located downward in the carrying direction at least at the carrying start position. 4. A downstream end of an outlet passage is opened at each of the plurality of outlets, and the outlet passage is arranged so as to blow out air from the outlets in the sheet conveying direction. The air levitation type thin plate carrier according to claim 1, wherein the upstream side is provided so as to be inclined rearward. 5. A detection means for detecting the presence of the thin plate is provided between the air outlets adjacent to each other in the conveying direction of the thin plate, and the air outlet near the thin plate detected by the detection means. The air levitation type thin plate transport device according to claim 1, further comprising a control means for blowing air from only the above.