JP2002110760A - Load port for open cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve worker safety of workers in a clean room. SOLUTION: This load port 1 comprises a mounting stage 7 for receiving and placing an open cassette 6 in which a wafer W is loaded, which is arranged in the clean room 2, a door 13 for opening/closing so as to separate the placement stage 7 from the clean room 2, and a down-flow supply means 14 for supplying air flow to cause it to flow down around the placement stage 7, and the door 13 is provided in an vertically openable way and a driving device 16 for the door 13 is arranged under the mounting stage 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided for receiving an open cassette provided in a clean room and conveyed in the clean room, and supplying a wafer loaded in the open cassette to a main frame. And a load port for an open cassette delivered to a manipulator.

[0002]

2. Description of the Related Art As a method of supplying a wafer to a main frame, there are a method using an open cassette and a method using a closed box type cassette. Conventionally, in Japan, a method using an open cassette has been mainly adopted as a method for supplying a 200 mm wafer to a main frame.

In this method, an open load port formed integrally with a robot room having a manipulator is used. That is, the robot room and the load port connected to the main frame via the load lock are integrally disposed in the clean room, so that the air cleanness around the wafer is kept high. When an open cassette carried by an automatic guided vehicle (hereinafter, referred to as an AGV) traveling in a clean room is delivered to a load port, a wafer is pulled out of the open cassette by the operation of the manipulator and supplied to the main frame. Was to be done.

On the other hand, the method using a box type cassette has recently become the mainstream overseas for supplying 300 mm wafers. This method accommodates a large number of wafers in a sealed box-type cassette and maintains the inside of the cassette with high cleanliness, and has become an industry standard overseas as the FOUP method.

In other words, the FOUP system uses a cassette which is kept highly clean by itself, connects the cassette to a robot room which is also kept highly air-clean, and then opens a partition between the two. This is a method in which a wafer in a cassette is taken out by a manipulator in a robot room.
According to this method, the cleanness of the air around the wafer is kept high by the sealed cassette, so that the environment for transporting the cassette does not need to be a clean room with high cleanliness. There is an advantage that an overhead traveling mechanism can be used.

[0006]

SUMMARY OF THE INVENTION However, FOU
In the P method, since the inside of the cassette needs to be kept at a high degree of cleanliness, the mechanism for opening and closing the cassette is complicated and expensive, and dust is generated when the cassette is opened and closed. Is difficult.

In the FOUP system, as described above, since wafers are transported using a sealed cassette,
It is sufficient to maintain high air cleanliness after the robot room equipped with a manipulator for handling wafers. For this purpose, the components from the main frame to the robot room are provided as one unit.

However, in a Japanese company that has conventionally adopted an open cassette for supplying 200 mm wafers, a clean room has already been set up as an environment for transferring wafers.
In some cases, it is desirable to follow the method of supplying wafers using an open cassette even for 300 mm wafers.
In this case, it is necessary that the supply method using the open cassette can be adopted for the main frame provided as a unit up to the robot room.

In the case of adopting a method of supplying an open cassette from the clean room, it is necessary for a worker in the clean room to take safety measures so as not to interfere with the manipulator in the robot room when supplying the open cassette. There is. In this case, it is possible to use an optical sensor to detect the worker's entry into the operation area of the manipulator, stop the system, or issue a warning, but it is considered that the safety is the highest. What is
The purpose is to mechanically block an operator from entering the operation area of the manipulator.

[0010] However, when a method of mechanically blocking the approach path by the door is employed, dust is generated from a mechanism for driving the door, and the dust adheres to the wafer in the open cassette.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and enables the supply of wafers using an open cassette to a main frame designed for a FOUP system, thereby enabling a worker in a clean room It is an object of the present invention to provide a load port capable of avoiding the adhesion of dust to a wafer while ensuring the safety of the wafer by mechanical means.

[0012]

In order to achieve the above object, the present invention relates to a wafer in an open cassette which is connected to a robot room having a manipulator for supplying a wafer to a main frame and has been transported in a clean room. A load port that is disposed in the clean room, receives and places an open cassette loaded with wafers, and is opened and closed so as to separate the mounting table from the clean room. A door and a downflow supply means for supplying an airflow descending around the mounting table are provided, and the door is provided so as to be openable and closable in a vertical direction, and a driving device for the door is provided below the mounting table. It proposes a load port for the placed open cassette.

In the above-described load port, the driving device may include a slider that is vertically reciprocated below the mounting table, and the door may be attached to the slider.

[0014]

According to the load port for an open cassette according to the present invention, the mounting table connected to the robot room is arranged in the clean room, and the open cassette conveyed in the clean room is mounted on the mounting table. The manipulator in the robot room can take out the wafer from the open cassette mounted on the mounting table. As a result, it is possible to supply the wafer by the open cassette to the main frame provided as one unit to the robot room.

A front door that opens and closes the mounting table so as to be separated from the clean room is provided. When the manipulator takes out the wafer, the front door is closed so that the worker can be inadvertently operated. An accident that enters the operation area of the manipulator can be reliably prevented.

Further, a downflow supply means for forming an airflow descending around the mounting table is provided, and the door driving device is disposed below the mounting table, so that dust generated by the operation of the driving device is provided. Is swept downward without being sowed above the mounting table by the descending airflow. Therefore, it is possible to avoid the problem that dust adheres to the wafer.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a load port according to the present invention will be described below with reference to the drawings. As shown in FIG. 1, the load port 1 according to this embodiment is a box-shaped device including an interface unit 5 for connecting to a robot room 4 arranged so as to open on one wall surface 3 of a clean room 2. In the vicinity of the center in the height direction, there is provided a mounting table 7 for receiving the open cassette 6 loaded with the wafer W.

The mounting table 7 is horizontally arranged and provided with positioning means (not shown) such as a projection for positioning the open cassette 6 to be mounted. Around the mounting table 7, only a rear wall portion 8 arranged on the robot room 4 side is arranged, and a wide opening 9 without a side wall is secured on the front surface and both side surfaces.

As shown in FIG. 2, on the rear wall portion 8,
A window 11 is formed which is connected to the robot chamber 4 and through which a manipulator 10 in the robot chamber 4 can take in and out the wafer W from the open cassette 6 on the mounting table 7. The window 11 is provided with a rear door 12 that is moved up and down from below the mounting table 7 to open and close the window 11. Further, the interface section 5 is provided on the back surface of the rear wall section 8.

At the upper end of the rear wall portion 8, the mounting table 7
Above the ceiling 23, a ceiling 23 arranged in parallel with the mounting table 7 with an open space for receiving the open cassette 6 is provided.
It is provided in a cantilever shape. The ceiling portion 23 is provided with a downward flow supply unit 14 for flowing a downward airflow around the mounting table 7. In the present embodiment, the descending flow supply unit 14 is, for example, a grid, which allows the descending air flow supplied from the ceiling of the clean room 2 to pass therethrough, and surrounds the open cassette 6 placed on the placing table 7. It can be supplied to. When the load port 1 is installed by the flush mount method, a fan that independently generates a downward flow and a filter disposed below the fan may be provided instead of the grid.

The mounting table 7 is moved up and down from below the mounting table 7 on the front surface and both side surfaces of the mounting table 7.
A front door 13 that opens and closes the periphery of the vehicle is provided. In the example shown in FIG. 2, the front door 13 is formed in a substantially U-shaped cross-section that opens and closes the front surface and both side surfaces simultaneously. That is, the wide opening 9 on the front surface and both side surfaces of the mounting table 7
By raising the front door 13 disposed below the mounting table 7, the front door 13 is simultaneously closed.

As shown in FIG. 3, the driving device 16 for the front door 13 includes two linear guides 17 and one ball screw 18 which are arranged on the left and right and extend vertically, and a nut for the linear guide 17 and the ball screw 18. 19, 20
, A motor 22 for rotating the ball screw 18, and a torque limiter 23 disposed between the motor 22 and the ball screw 18. All of these components are always arranged below the mounting table 7, and the lower end of the front door 13 is fixed to the slider 21. The driving device (not shown) for the rear door 12 is also disposed below the mounting table 7, similarly to the driving device 16 for the front door 13.

The front door 13 and the rear door 12 are interlocked so that they are not opened simultaneously. That is, the front door 13 is opened, and the AGV 25 or the operator
When the robot is mounted on the mounting table 7, the rear door 12 is always closed, so that the manipulator 10 in the robot chamber 4 does not move toward the mounting table 7. .

The front door 13 and the rear door 1
2 also constitutes a part of the downward flow supply means 14.
That is, by closing these doors 12 and 13, a flow path is defined around the open cassette 6 on the mounting table 7 so that the supplied downward flow is not disturbed around the open cassette 6. Can be.

Further, the load port 1 according to the present embodiment
, An optical sensor 15 (safety device) is attached to the rear door 12. The sensor 15 has a pair of light emitting units 15a and light receiving units 15b arranged so as to form a light beam A that crosses the center of the window 11 opened and closed by the rear door 12 vertically. An object that crosses the light beam A can be detected.

The operation of the thus configured load port 1 according to the present embodiment will be described below. The load port 1 according to the present embodiment, as shown in FIG.
It is arranged in the clean room 2, and thereafter connected to the robot room 4 which is opened and arranged on one wall surface 3 of the clean room 2 by using the interface 5 of the wall portion 8. Thereby, the manipulator 10 in the robot room 4 extends to the mounting table 7 of the load port 1 through the window 11 of the rear wall 8, and the open cassette 6 in the open cassette 6 mounted on the mounting table 7. The wafer W can be taken out.

In this state, the AGV 25 traveling in the clean room 2 transfers the open cassette 6 loaded with the wafer W onto the mounting table 7 of the load port 1. At this time, the front door 13 of the load port 1 is opened. Thereby, the front opening and both side surfaces of the mounting table 7 are opened, so that a wide opening 9 is secured.
The interference between the transfer arm 5 and the load port 1 is reduced. Also, at this point, by the operation of the interlock,
The rear door 12 of the window 11 of the rear wall 8 is kept closed. Therefore, it is possible to reliably prevent the transfer arm of the AGV 25 or the open cassette 6 being transferred from interfering with the manipulator 10 in the robot chamber 4.

Next, the transfer by the AGV 25 is completed,
With the transfer arm of the AGV 25 separated from the mounting table 7, the front door 13 is raised. In this case, since the front door 13 is formed in a U-shaped cross section,
The front door 13 simultaneously closes the wide openings 9 on the front surface and both side surfaces of the mounting table 7, and can reliably shut off the approach path from the clean room 2 to the mounting table 7.

That is, the ball screw 18 is rotated by the drive of the motor 22, and the slider 21 fixed to the nut 20 screwed to the ball screw 18 is moved up along the linear guide 17. These driving devices 16
Generate small dust when driven. However, all of these components are always disposed below the mounting table 7, and an air flow descending around the mounting table 7 is formed by the operation of the downflow supply means 14. The dust is swept downward by the air flow and does not soar above the mounting table 7.

Therefore, while the entrance path from the clean room 2 to the mounting table 7 is mechanically blocked by the front door 13, dust accompanying the driving of the front door 13 is reliably prevented from adhering to the wafer W. be able to.

The front door 13 has a U-shaped cross section, so that the section modulus is increased and the front door 13 is lightweight and achieves high strength. As a result, the required power of the driving device 16 can be reduced. In this embodiment, the front door 13 has a U-shaped cross section.
It also includes a cross-sectional shape such as a U-shape, a semi-circle, a semi-ellipse, etc., which can obtain the same operation and effect.

The front door 13 has a torque limiter 2
3 is attached, even if the front door 13 is accidentally closed when an operator in the clean room 2 is manually mounting the open cassette 6 on the mounting table 7. By the operation of the torque limiter 23, the blocking force of the front door 13 is limited, and it is possible to prevent the worker from being damaged.

At this point, since the rear door 12 is closed by the operation of the interlock, the worker working in the clean room 2 erroneously puts his hand on the mounting table 7 and the manipulator 10 An accident such as contact can be prevented from occurring.

When both the front door 13 and the rear door 12 are closed, the periphery of the open cassette 6 mounted on the mounting table 7 is closed over the entire circumference.
By the operation of the descending flow supply means 14, the descending flow supplied from the ceiling of the clean room 2 is supplied around the open cassette 6 on the mounting table 7, and the dust attached to the open cassette 6 is removed from the mounting table. 7 is washed down.

In this case, since the periphery of the mounting table 7 is closed by the front door 13 and the rear door 12 and a flow path is defined, the downward flow supplied by the downward flow supply means 14 is supplied to the open cassette. Disturbance around 6 is minimized. Therefore, the dust can flow below the mounting table 7 without staying around the open cassette 6.

Thereafter, by opening the rear door 12, the window 11 is opened, and the manipulator 10 in the robot room 4 can take out the wafer W from the open cassette 6. Before the rear door 12 is opened, the dust around the open cassette 6 is flowed by the downward flow, so that dust is prevented from entering the robot chamber 4.

At this time, since the front door 13 is closed by the operation of the interlock, the worker working in the clean room 2 erroneously puts his hand on the mounting table 7 and comes into contact with the manipulator 10. It is possible to prevent accidents such as accidents. Further, the rear door 12
Is provided with an optical sensor 15 for detecting an object passing through the window 11, so that when the wafer W jumps out of the open cassette 6 and crosses the window 11 for some reason, the rear door It is possible to prevent the wafer 12 from being damaged when the wafer 12 is closed. In this case, the device may be stopped and an alarm may be issued.

As described above, according to the load port 1 according to the present embodiment, the existing clean room 2 can be mounted on the main frame integrally including the robot room 4 so as to conform to the FOUP system. , The supply of the wafer W using the open cassette 6 can be enabled. Therefore, there is an advantage that the cost required for constructing new equipment in accordance with the FOUP method can be minimized.

Further, the opening / closing mechanism is complicated, cleaning is difficult, and dust is easily generated in the mechanism.
It is possible to avoid using a closed cassette which has many problems such as being expensive, and it is possible to prevent the above problems from occurring.

Further, the load port 1 according to the present embodiment
According to this, since the mounting table 7 is mechanically separated from the clean room 2 by the door, it is possible to reliably prevent the worker in the clean room 2 from handling the open cassette 6 during the removal operation of the wafer W by the manipulator 10,
Safety can be improved. Doors 12 and 13
However, in the load port 1 of the present embodiment, an air flow descending by the descending flow supply means 14 is formed around the open cassette 6 and the driving device 16 for the doors 12 and 13 is driven. Since the dust is disposed below the mounting table 7, it is possible to reliably prevent inconvenience that generated dust soars above the mounting table 7 and adheres to the wafer W in the open cassette 6.

[0041]

As described above, according to the load port of the present invention, the door driving device for separating the mounting table from the clean room is disposed below the mounting table, and
By providing a descending flow supply means for forming a descending air flow around the mounting table, the door mechanically blocks the path of entry from the clean room to the mounting table, and dust generated by the operation of the door is mounted. There is an effect that it is possible to prevent soaring onto the mounting table and to reliably avoid adhesion to the wafer.

[0042]

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view schematically showing an installation state of a load port according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the load port of FIG. 1;

FIG. 3 is a perspective view illustrating a driving device of a front door of the load port of FIG. 1;

[Explanation of symbols]

 W Wafer 1 Load port 2 Clean room 4 Robot room 6 Open cassette 7 Placement table 10 Manipulator 13 Door 14 Downflow supply means 16 Drive unit 21 Slider

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Sasaki 14-3 Shinsen, Narita-shi, Chiba Nogehira Industrial Park Inside Applied Materials Japan Co., Ltd. 3 Nogedaira Industrial Park Applied Materials Japan Co., Ltd. F-term (reference) 5F031 CA02 DA01 FA03 FA12 FA15 NA03 NA09 PA26

Claims (2)

[Claims] 1. A load port connected to a robot room having a manipulator for supplying a wafer to a main frame and transferring a wafer in an open cassette conveyed in a clean room to the manipulator, wherein the load port is disposed in the clean room. A mounting table for receiving and mounting an open cassette loaded with wafers, a door that is opened and closed so as to separate the mounting table from the clean room, and an air flow that descends around the mounting table. A load port for an open cassette, comprising: a downflow supply means; wherein the door is provided so as to be openable and closable in a vertical direction, and a drive device for the door is disposed below the mounting table. 2. The open cassette according to claim 1, wherein the driving device includes a slider that is vertically reciprocated below the mounting table, and the door is attached to the slider. For load port.