Wafer transmission device with liquid discharge function

Abstract

The invention discloses a wafer transmission device with a liquid discharge function, which comprises a robot arm, a liquid receiving device, a liquid discharge device, a controller and a collection bin, and is characterized in that the liquid receiving device is arranged below the robot arm and moves along with the robot arm to receive liquid dripping from the robot arm; the liquid discharging device comprises a liquid discharging pipeline and a control valve, the liquid discharging pipeline is connected with the liquid receiving device, and the control valve is arranged on the liquid discharging pipeline and used for controlling on-off of the liquid discharging pipeline; the controller is in communication connection with the robot arm and the control valve and used for controlling movement of the robot arm and opening and closing of the control valve. The collecting bin is located at a preset liquid discharging position. When the liquid level of the liquid in the liquid receiving device reaches a preset liquid level, the controller firstly controls the robot arm to move to a preset liquid discharging position and then controls the control valve to be opened, so that the liquid discharging pipeline discharges the liquid in the liquid receiving device to the collecting bin. Storage and discharge of liquid in the liquid receiving device can be controlled, movement of the robot arm is not limited, and therefore the normal process time of the robot arm is not affected.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a wafer transmission device with a liquid discharge function. Background Art

[0002] During the wafer transfer process, a wafer transfer robot is required to transfer wafers between various workstations. Some workstations require wafer cleaning to remove dust, residues, dirt, etc. from the wafer. A layer of liquid film is attached to the surface of the cleaned wafer. When the wafer is transferred, the liquid on the surface of the wafer will drip onto the robot, and the liquid on the robot will drip into the semiconductor equipment and cause contamination.

[0003] At present, the liquid receiving device of the robot in the semiconductor equipment is mainly used to receive the liquid dripping from the robot. A drain port and a drain pipeline are set at the bottom of the liquid receiving device, and the liquid outlet end of the drain pipeline is placed in a fixed drain tank so that the drain pipeline can continuously drain the liquid during the operation of the robot. In order to ensure the normal operation of the robot, it is necessary to ensure that the liquid in the liquid receiving device can always be discharged normally. However, in order to make the liquid outlet end of the drain pipeline always placed in the drain tank, the drain pipeline is usually set to be longer, which will have certain restrictions on the movement of the robot (such as rotation, horizontal and lifting movement). This is because during the movement of the robot (such as rotation, horizontal and lifting movement), the drain pipeline often appears to be damaged, entangled or interfered with other components, which will cause abnormal drainage of the liquid receiving device, thereby affecting the normal process of the robot. Summary of the invention

[0004] The purpose of the present invention is to solve the problem in the prior art that the liquid receiving device will restrict the movement of the robot arm and affect the normal process time of the robot arm.

[0005] In order to solve the above problems, one embodiment of the present invention provides a wafer transfer device with a liquid discharge function, comprising:

[0006] Robotic hand;

[0007] The liquid receiving device is arranged under the robot arm and moves with the robot arm, and is used to receive and store the liquid dripping from the robot arm;

[0008] The liquid discharge device comprises a liquid discharge pipeline and a control valve, wherein the liquid discharge pipeline is connected to the liquid receiving device, and the control valve is arranged on the liquid discharge pipeline to control the on-off of the liquid discharge pipeline;

[0009] A controller, which is in communication with the robot arm and the control valve, and is used to control the movement of the robot arm and the opening and closing of the control valve; and

[0010] A collection chamber located at a predetermined discharge position;

[0011] When the liquid level in the liquid receiving device reaches a preset level, the controller first controls the robot arm to move to a predetermined discharge position, and then controls the control valve to open, so that the discharge pipeline discharges the liquid in the liquid receiving device to the collection bin.

[0012] The wafer transfer device with liquid discharge function provided by the present invention includes a robot, a liquid receiving device, a liquid discharge device, a controller and a collection bin. When the robot is operating normally, the controller controls the control valve to close so that the liquid receiving device receives and stores the liquid dripping from the robot; when the liquid stored in the liquid receiving device reaches a preset liquid level, the controller first controls the robot to move to a predetermined liquid discharge position, so that the liquid discharge device approaches and aligns with the collection bin, and then controls the control valve to open, so that the liquid in the liquid receiving device is discharged from the liquid discharge pipeline to the collection bin. Because the present application controls the liquid discharge device to discharge liquid at a predetermined liquid discharge position, it is beneficial to shorten the setting length of the liquid discharge pipeline, and can avoid the liquid discharge pipeline being too long and being damaged, entangled or interfering with other surrounding components when the robot is lifted or moved horizontally. Therefore, the present application can control the storage and discharge of liquid in the liquid receiving device without restricting the movement of the robot, thereby not affecting the normal process time of the robot.

[0013] Other features and corresponding beneficial effects of the present invention are described in the latter part of the specification, and it should be understood that at least part of the beneficial effects become obvious from the description in the specification of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic front view of a wafer transfer device with a liquid discharge function provided by the present invention;

[0015] Figure 2 For along Figure 1 A schematic cross-sectional view of the middle section line UU;

[0016] Figure 3 A schematic diagram of a partial three-dimensional structure of a wafer transfer device with a liquid discharge function provided by the present invention;

[0017] Figure 4 for Figure 1 A partial schematic diagram of section F; and

[0018] Figure 5 A partial cross-sectional schematic diagram of a wafer transfer device with liquid discharge function provided by the present invention. DETAILED DESCRIPTION

[0019] The following specific embodiments illustrate the implementation of the present invention, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this implementation. On the contrary, the purpose of introducing the invention in conjunction with the implementation is to cover other options or modifications that may extend based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will include many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0020] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0021] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] The wafer transfer device with liquid discharge function of the present application can be arranged in a semiconductor device, which includes a wafer loading table and multiple process chambers. The wafer loading table is used to place a transfer box, which stores wafers to be cleaned and wafers that have been cleaned. The process chamber is used to brush away dust, residues, dirt, etc. on the wafer.

[0026] Combination Figures 1 to 3 , Figure 1 A schematic front view of a wafer transfer device with a liquid discharge function provided by the present invention; Figure 2 For along Figure 1 A schematic cross-sectional view of the middle section line UU; Figure 3 The schematic diagram of the partial three-dimensional structure of the wafer transfer device with liquid discharge function provided by the present invention. Figure 1 The coordinate axes are marked in the figure, the Y-axis direction represents the vertical movement direction H, and the X-axis direction represents the horizontal movement direction L.

[0027] like Figure 1 and Figure 2 As shown, the wafer transfer device with liquid discharge function of the present application includes a vertical guide rail 110, a horizontal guide rail 120, a mounting table 130, a robot 200, a liquid receiving device 300, a liquid discharge device 400, a collection bin 500 and a controller. The robot 200 is rotatably mounted on the mounting table 130 via a rotating shaft 210. The mounting table 130 is mounted on the vertical guide rail 110 and is used to perform lifting and lowering movements on the vertical guide rail 110 along a vertical movement direction H. A horizontal mounting portion 111 is fixedly provided on the vertical guide rail 110. The horizontal mounting portion 111 is slidably connected to the horizontal guide rail 120. The vertical guide rail 110 performs horizontal movement on the horizontal guide rail 120 along a horizontal movement direction L via the horizontal mounting portion 111. The horizontal guide rail 120 is located at a position where the coordinate on the vertical movement direction H of the robot 200 is zero. Among them, as Figure 3 As shown, the robot 200 includes a conveying arm 221 and an end effector 222. The conveying arm 221 is fixedly connected to the rotating shaft 210 and is used to rotate around the axis of the rotating shaft 210. The end effector 222 is fixed at the end of the conveying arm 221 and is used to take and place wafers from a transfer box or a process chamber.

[0028] like Figure 3As shown, the liquid receiving device 300 is arranged under the robot hand 200 and moves with the robot hand 200. The liquid receiving device 300 is used to receive and store liquid dripping from the robot hand 200 to prevent the liquid on the robot hand 200 from dripping into the semiconductor equipment and causing contamination. The liquid on the robot hand 200 mainly comes from the liquid on the wafer before or after cleaning.

[0029] The liquid discharge device 400 includes a liquid discharge pipeline 410, a control valve 420 and a mounting seat 430. The liquid discharge pipeline 410 is connected to the liquid receiving device 300, and is used to discharge the liquid in the liquid receiving device 300 to the collection bin 500. The control valve 420 is arranged on the liquid discharge pipeline 410 and fixed to the mounting seat 430, and the mounting seat 430 is fixed to the mounting platform 130. The controller is connected to the control valve 420 for communication, and is used to control the on-off of the liquid discharge pipeline 410. Among them, the control valve 420 can be a solenoid valve, and the liquid discharge pipeline 410 can be a hose.

[0030] The collecting bin 500 is fixed below the horizontal guide rail 120, and the location of the collecting bin 500 can be considered as the predetermined drainage location. A discharge outlet 510 is provided at the bottom of the collecting bin 500, and the discharge outlet 510 is used to connect to the factory wastewater treatment system. When the discharge device 400 is discharging liquid, the discharge device 400 is aligned with the collecting bin 500 to discharge liquid into the collecting bin 500.

[0031] In order to solve the problem that the continuous liquid discharge mode of the conventional liquid receiving device causes abnormal liquid discharge during the operation of the robot arm, thus affecting the normal operation of the robot arm, the overall idea of ​​the technical solution in the embodiment of the present application is as follows: when the robot arm 200 is operating normally, whether it is performing lifting movement, horizontal movement or rotation movement, the controller controls the control valve 420 to close so that the liquid receiving device 300 receives and stores the liquid dripping from the robot arm 200; when the liquid stored in the liquid receiving device 300 reaches a preset liquid level, the controller controls the robot arm 200 to move to a predetermined liquid discharge position (for example, Figure 1The control valve 420 is then controlled to open after the discharge device 400 is aligned with the collection bin 500, so that the liquid in the liquid receiving device 300 is discharged from the discharge pipe 410 to the collection bin 500. Therefore, the discharge device 400 can control the storage and discharge of the liquid in the liquid receiving device 300, without limiting the movement of the robot 200, thereby not affecting the normal process time of the robot 200. The predetermined discharge position may preferably be a position where the coordinates in the vertical movement direction H of the robot 200 are zero and the coordinates in the horizontal movement direction L of the robot 200 are zero (for example, the initial position of the robot 200), which is conducive to shortening the setting length of the discharge pipe 410. The length of the discharge pipe 410 is sufficient to discharge the liquid to the collection bin 500 normally, so as to avoid the discharge pipe 410 being too long and interfering with other surrounding components when the robot 200 is lifted or moved horizontally. It should also be noted that when the liquid receiving device 300 needs to drain, if the current process cycle has not yet ended, the controller controls the robot arm 200 to first complete the current process cycle and then move to the predetermined drain position.

[0032] When the liquid receiving device 300 needs to be drained, in order to shorten the travel of the robot 200 to move to the predetermined drain position, the collection bin 500 is set to extend along the horizontal movement direction L of the robot 200, that is, to extend along the direction of the horizontal guide rail 120. Since the collection bin 500 extends along the horizontal movement direction L of the robot 200, it can receive the liquid discharged from the drain pipe 410 when the robot 200 is at any position in the horizontal movement direction L. The predetermined drain position can be set to any coordinate position in the horizontal movement direction L of the robot 200 when the coordinate in the vertical movement direction H of the robot 200 is zero. Therefore, when the liquid in the liquid receiving device 300 needs to be discharged, the controller controls the robot 200 to complete the current process cycle first, and then return to the zero position of the vertical guide rail 110 to drain the liquid. Compared with the predetermined drain position being set only at the initial position of the robot 200, the travel of the robot 200 to move to the predetermined drain position is shortened.

[0033] In addition, when the discharge pipe 410 discharges liquid, the liquid outlet of the discharge pipe 410 is located within the opening range of the collection bin 500 so that the liquid can be discharged into the collection bin 500, thereby reducing the alignment accuracy requirements of the discharge pipe 410 and the collection bin 500.

[0034] In the present application, when the liquid in the liquid receiving device 300 needs to be discharged can be known by setting a liquid level monitor to detect the liquid level of the liquid receiving device 300. The design position and working principle of the liquid level monitor are described in detail below.

[0035] Combination Figures 3 to 5, the liquid receiving device 300 includes a residual liquid tray 310, a temporary storage tray 320 and a liquid level monitor 324. The residual liquid tray 310 is fixed on the top of the rotating shaft 210 and is arranged around the periphery of the robot 200. The residual liquid tray 310 rotates synchronously with the rotating shaft 210. The temporary storage tray 320 is located below the residual liquid tray 310 and is used to receive the liquid flowing down from the residual liquid tray 310. The temporary storage tray 320 is fixed to the mounting table 130 and is arranged with a gap from the rotating shaft 210. When the residual liquid tray 310 rotates synchronously with the rotating shaft 210, the temporary storage tray 320 does not rotate. The liquid level monitor 324 is connected to the controller for real-time monitoring of the liquid level in the temporary storage tray 320. In this example, the liquid level monitor 324 can preferably use a non-contact liquid level sensor, which is arranged at the bottom of the residual liquid tray 310, such as a laser sensor or an acoustic liquid level sensor. It can be understood that in other examples, the liquid level monitor 324 can also use a contact liquid level sensor.

[0036] Combined with reference Figure 3 The residual liquid tray 310 has a bottom wall 3101, a first side wall 3102 and a second side wall 3103. The bottom wall 3101 is fixed to the top of the rotating shaft 210, the first side wall 3102 extends obliquely upward along the outer periphery of the bottom wall 3101, and the second side wall 3103 extends upward along the upper end of the first side wall 3102 and surrounds the outer side of the robot hand 200. Figure 5 , the residual liquid tray 310 is also provided with a delivery pipe 312, which is connected to the bottom wall 3101 and is used to deliver the liquid in the residual liquid tray 310 to the temporary storage tray 320. When the liquid on the robot arm 200 drips onto the first side wall 3102, it is collected along the inclined surface of the first side wall 3102 to the bottom wall 3101 of the residual liquid tray 310, and is discharged to the temporary storage tray 320 through the delivery pipe 312 provided on the bottom wall 3101. In addition, the upper surface of the bottom wall 3101 of the residual liquid tray 310 is an inclined surface, which is inclined downward from the outer periphery of the bottom wall 3101 to the center of the bottom wall 3101, and the delivery pipe 312 is preferentially connected to the lowest point of the inclined surface, so that the liquid in the residual liquid tray 310 is collected and discharged to the delivery pipe 312.

[0037] like Figure 5 As shown, the temporary storage tray 320 has a bottom wall 3201 and a first side wall 3202, a second side wall 3203 and a first flow channel 3221 that are arranged opposite to each other. The bottom wall 3201 of the temporary storage tray 320 and the drainage pipeline 410 (combined with reference Figure 3 )connect.

[0038] The first side wall 3202 of the temporary storage tray 320 is provided with a first baffle 322, which can prevent the liquid in the temporary storage tray 320 from splashing out of the temporary storage tray 320 during the lifting or horizontal movement. There is a predetermined longitudinal distance between the first baffle 322 and the outlet of the delivery pipe 312, and the predetermined longitudinal distance is 5mm to 10mm, for example, 6mm to 8mm. The first baffle 322 extends from the first side wall 3202 to the second side wall 3203, and a first circulation channel 3221 is formed between the first baffle 322 and the second side wall 3203. When the liquid in the residual liquid tray 310 is discharged to the temporary storage tray 320 through the delivery pipe 312, the liquid in the delivery pipe 312 flows along the upper surface of the first baffle 322 and flows to the interior of the temporary storage tray 320 through the first circulation channel 3221. In other embodiments, the first circulation channel can also be a liquid outlet opened on the first baffle 322, so that the liquid on the first baffle 322 can also flow from the liquid outlet to the interior of the temporary storage tray 320. In addition, the upper surface of the first baffle 322 is an inclined surface, which is inclined downward along the first side wall 3202 toward the second side wall 3203. The liquid in the delivery pipe 312 flows through the inclined surface of the first baffle 322 to the interior of the temporary storage disk 320.

[0039] The second side wall 3203 of the temporary storage tray 320 is provided with a second baffle 323, which is used to block the liquid splashed back on the first baffle 322 or in the temporary storage tray 320. The second baffle 323 extends from the second side wall 3203 to the first side wall 3202, and forms a gap 3231 with the first side wall 3202. When the residual liquid tray 310 rotates synchronously with the rotating shaft 210, the outlet end of the delivery pipe 312 moves in the gap 3231. The second baffle 323 is arranged above the first baffle 322 at intervals, and the outlet of the delivery pipe 312 is not higher than the second baffle 323, so as to prevent the liquid delivered by the delivery pipe 312 from flying out when the residual liquid tray 310 and the delivery pipe 312 rotate.

[0040] Specifically, the upper surface of the second baffle 323 may also be a slope, which slopes downward along the second side wall 3203 toward the first side wall 3202 , so that the liquid splashed onto the upper surface of the second baffle 323 can be guided to the inside of the temporary storage disk 320 .

[0041] The following combines the above and Figures 3 to 5 The working principle of the liquid discharge device when the liquid level monitor 324 is configured is described.

[0042] When the robot 200 is operating normally, the controller controls the control valve 420 to close, and the liquid on the robot 200 drips onto the residual liquid tray 310. The liquid in the residual liquid tray 310 flows to the temporary storage tray 320 through the delivery pipe 312 at any time. When the liquid level of the liquid stored in the temporary storage tray 320 monitored by the liquid level monitor 324 is lower than the preset liquid level, the liquid level monitor 324 is not triggered, and the robot 200 can perform lifting, horizontal or rotational movements. When the liquid level of the liquid stored in the temporary storage tray 320 reaches the preset liquid level, the liquid level monitor 324 is triggered, where the preset liquid level is one quarter of the distance between the lowest point of the inclined surface of the first baffle 322 and the bottom surface of the second baffle 323. After the liquid level monitor 324 is triggered, it sends a discharge signal. After receiving the discharge signal, the controller controls the robot 200 to move to a predetermined discharge position after completing the current process cycle. Then, the controller controls the control valve 420 to open, so that the liquid in the temporary storage tray 320 is discharged into the collection bin 500 through the discharge pipeline 410. After the discharge is completed, the control valve 420 is closed, and the robot 200 can continue the next action.

[0043] In other embodiments, other methods may be used to determine when the liquid in the temporary storage tray 320 of the liquid receiving device 300 needs to be discharged. For example, when the liquid level monitor 324 is not provided, the time interval for discharging the temporary storage tray 320 may be pre-set in the process operation program, so that the temporary storage tray 320 is discharged once every predetermined period of time. When discharging, the controller controls the robot arm 200 to move to the predetermined discharge position and then controls the control valve 420 to open.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wafer transfer device with liquid discharge function, characterized in that: include: Robotic hand; A liquid receiving device, which is arranged below the robot arm and moves with the robot arm, and is used to receive and store liquid dripping from the robot arm; A liquid discharge device, comprising a liquid discharge pipeline and a control valve, wherein the liquid discharge pipeline is connected to the liquid receiving device, and the control valve is arranged on the liquid discharge pipeline to control the on-off of the liquid discharge pipeline; A controller, which is in communication with the robot arm and the control valve, and is used to control the movement of the robot arm and the opening and closing of the control valve; as well as A collection chamber located at a predetermined discharge position; When the liquid level in the liquid receiving device reaches a preset level, the controller first controls the robot arm to move to the predetermined liquid discharge position, and then controls the control valve to open, so that the liquid discharge pipeline discharges the liquid in the liquid receiving device to the collection bin.

2. The wafer transfer device with liquid discharge function according to claim 1, characterized in that: The liquid receiving device is provided with a liquid level monitor, and the liquid level monitor is communicatively connected with the controller and is used for real-time monitoring of the liquid level in the liquid receiving device.

3. The wafer transfer device with liquid discharge function according to claim 1, characterized in that: It also includes a mounting platform and a rotating shaft, and the robot arm is rotatably arranged on the mounting platform through the rotating shaft; The liquid receiving device includes a residual liquid tray and a temporary storage tray. The residual liquid tray is fixed to the rotating shaft and is arranged around the periphery of the robot arm. The temporary storage tray is arranged on the mounting table, located below the residual liquid tray, and is connected to the liquid discharge device for receiving and discharging the liquid in the residual liquid tray.

4. The wafer transfer device with liquid discharge function according to claim 3, characterized in that: The residual liquid tray also includes a delivery pipe for delivering the liquid in the residual liquid tray to the temporary storage tray.

5. The wafer transfer device with liquid discharge function according to claim 4, characterized in that: The temporary storage tray has a first side wall, a second side wall and a first flow channel opposite to each other, the first side wall is provided with a first baffle, and there is a predetermined longitudinal distance between the first baffle and the outlet of the delivery pipe; When the liquid in the residual liquid tray is discharged to the temporary storage tray through the delivery pipe, the liquid in the delivery pipe flows along the upper surface of the first baffle and flows into the temporary storage tray through the first flow channel.

6. The wafer transfer device with liquid discharge function according to claim 5, characterized in that: The predetermined longitudinal distance between the first baffle and the outlet of the delivery pipe is 5 mm to 10 mm.

7. The wafer transfer device with liquid discharge function according to claim 5, characterized in that: The first baffle extends from the first side wall to the second side wall and forms the first flow channel between the first baffle and the second side wall.

8. The wafer transfer device with liquid discharge function according to claim 7, characterized in that: The upper surface of the first baffle is an inclined surface, and the inclined surface is inclined downward along the first side wall toward the second side wall.

9. The wafer transfer device with liquid discharge function according to claim 5, characterized in that: The second side wall of the temporary storage disk is provided with a second baffle, which extends from the second side wall to the first side wall and forms a gap with the first side wall. The second baffle is spaced above the first baffle, and the outlet of the conveying pipe is not higher than the second baffle.

10. The wafer transfer device with liquid discharge function according to claim 9, characterized in that: An upper surface of the second baffle is an inclined surface, and the inclined surface is inclined downward along the second side wall toward the first side wall.

11. The wafer transfer device with liquid discharge function according to claim 1, characterized in that: Also includes: A vertical guide rail, on which the robot arm is slidably connected, so that the robot arm moves vertically along the vertical guide rail; and A horizontal guide rail is slidably connected to the vertical guide rail so that the vertical guide rail carries the robot arm to move horizontally along the horizontal guide rail.

12. The wafer transfer device with liquid discharge function according to claim 11, characterized in that: The predetermined discharge position is a position where the coordinate in the vertical movement direction of the robot arm is zero and the coordinate in the horizontal movement direction of the robot arm is zero.

13. The wafer transfer device with liquid discharge function according to claim 11, characterized in that: The predetermined discharge position is any coordinate position in the horizontal movement direction of the robot arm when the coordinate in the vertical movement direction of the robot arm is zero.

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