Transferring device

Abstract

A transferring device including a transferring device main body; a transferring arm which is coupled with the transferring device main body to transfer a workpiece; and a supporting hand which has a plurality of engaging parts coupled with the transferring arm and forming a predetermined angle therebetween to support the workpiece based on a force applied to the workpiece according to varying rotation speeds of the transferring arm. Thus, a transferring device can stably support a workpiece.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No. 2005-0126046, filed on Dec. 20, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present general inventive concept relates to a transferring device to transfer a workpiece, and more particularly, to a transferring device which stably supports a workpiece.

2. Description of the Related Art

Generally, a transferring device is used for various purposes in various processes. There is a type of a transferring device which transfers a wafer to a processing chamber in a semiconductor manufacturing process. The transferring device is installed between a loading/unloading chamber, which accommodates a plurality of wafers, and a reaction chamber, which receives the wafers to proceed with a predetermined process, and loads/unloads the wafers for an etching process and a deposition process. Various methods are introduced to transfer the wafers precisely and quickly and to reduce the transferring time between the processes, including raising the transferring speed or stably supporting the wafers.

Korean Utility Model First Publication No. 20-173017 (Dec. 16, 1999) discloses a wafer transferring device which prevents errors and contamination while transferring wafers. US Patent First Publication No. 2003/85582 (May 8, 2003) discloses a transferring robot arm which has a projection to support a wafer. The conventional devices comprise a robot arm to support the wafer. Such a robot arm comprises a pin or a projection protruding from a plate surface to stably support the wafer.

However, the conventional device has a complex configuration to support and hold the wafer and may cause damages to the wafer when holding the wafer using an air cylinder. Also, in the case that the wafer needs be processed in a vacuum, the air cylinder or a pipe may be damaged and begin to leak, and thus the overall processes of the wafer may be affected. Further, when the conventional device rotates faster than a predetermined speed while supporting the wafer, the wafer may be separated from the robot arm.

SUMMARY OF THE INVENTION

The present general inventive concept provides a transferring device which can stably support a workpiece with a simplified method.

Additional aspects and/or utilities of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present invention.

The foregoing and/or other aspects and utilities of the present general inventive concept are achieved by providing a transferring device, comprising a transferring device main body; a transferring arm which is coupled with the transferring device main body to transfer a workpiece; and a supporting hand which has a plurality of engaging parts coupled with the transferring arm and forming a predetermined angle therebetween to support the workpiece based on a force applied to the workpiece according to varying rotation speeds of the transferring arm.

The supporting hand may comprise a coupling part which is coupled with the transferring arm and a plurality of blades which extend from the coupling part and spaced from each other.

The engaging part may comprise a first engaging part formed on the coupling part, and a plurality of second engaging parts respectively formed on the blades, and the angle between the engaging parts is defined as an angle between the second engaging parts with respect to the center of the workpiece.

The angle between the second engaging parts can be determined on the basis of a resultant force of a centrifugal force and a rotation inertial force applied to the workpiece according to the varying rotation speeds of the transferring arm.

The engaging parts can be provided in a position where the resultant force of the centrifugal force and the rotation inertial force becomes the maximum.

The engaging parts can be depressed from a planar surface of the supporting hand with a predetermined depth.

The engaging parts can form a larger diameter than the workpiece.

The supporting hand can comprise a spacer which is depressed inside the engaging parts.

The spacer can have a smaller diameter than the workpiece.

The supporting hand can comprise one of stainless steel and ceramic.

The supporting hand can comprise an inclination part which is formed along edges of the engaging parts.

The workpiece can comprise a wafer.

The foregoing and/or other aspects and utilities of the present general inventive concept are also achieved by providing a transferring device to transfer a workpiece, comprising: a body; a transferring arm to extend away from and contract toward the body; and a supporting hand to connect with the transferring arm, the supporting hand comprising: a coupling part to engage with the transferring arm, two blades extending from the coupling part and spaced from each other by a predetermined amount, a stepped engaging part having a circular stepped portion extending about a circular region crossing the coupling part and an outer portion of the two blades, the stepped engaging part stepped down from a surface of the coupling part and having a diameter wider than the workpiece, and a spacer part stepped down from the stepped engaging part in a center portion thereof.

An angle X formed at the center of the diameter of the stepped engaging part between a line extending to a center of the stepped engaging part crossing one of the blades and a line extending to a center of the stepped engaging part crossing the other one of the blades can be determined on the basis of a direction of a resultant force of a centrifugal force and a rotation inertial force applied to the workpiece according to a varying rotation speed of the transferring arm.

The foregoing and/or other aspects and utilities of the present general inventive concept are also achieved by providing a supporting hand usable with a transferring device to transfer a workpiece, comprising: a coupling part provided on a first end to couple with a transferring arm of the transfer device; a couple of blades which extend from the coupling part and are spaced apart from each other; and a stepped engaging part stepped from the surface of the coupling part and having a predetermined diameter extending across the coupling part and the coupling blades to support the workpiece thereon, the stepped engaging part having a larger diameter than the workpiece.

The foregoing and/or other aspects and utilities of the present general inventive concept are also achieved by providing a method of determining an angle between blades of a transfer device supporting hand to transfer a wafer, the method comprising: calculating an optimal rotation speed of a transferring device main body; and calculating an angle between a predetermined part of two blades with respect to a center portion of a wafer holding area of the supporting hand.

The calculating an optimal rotation speed of the transferring device may comprise calculating a rotation speed in the speed increasing region where the transferring device main body starts rotating and reaches the optimal speed, the uniform speed region where the transferring device rotates at a uniform speed, and a speed decreasing region where the rotation speed of the transferring device main body becomes 0 from the optimal speed.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 illustrates an arrangement of a transferring device according to the present general inventive concept;

FIG. 2 is a perspective view of the transferring device according to the present general inventive concept;

FIG. 3 illustrates forces which are applied to a workpiece according as the transferring device rotates, according to the present general inventive concept;

FIG. 4A is a plan view of a supporting hand according to the present general inventive concept;

FIG. 4B is a side view of the supporting hand according to the present general inventive concept;

FIGS. 5A through 5D are operational views of the transferring device according to the present general inventive concept; and

FIG. 6 is a control flowchart of a workpiece supporting process of the transferring device according to the present general inventive concept.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures.

Hereinafter, a transferring device 10 according to an exemplarity embodiment of the present general inventive concept will be described. A workpiece 15 can comprise a wafer which is used in a semiconductor manufacturing process by way of example.

As illustrated in FIGS. 1 through 3, the transferring device 10 according to the present general inventive concept can comprise a transferring device main body 20; a transferring arm 30 which is coupled with the transferring device main body 20 to transfer the workpiece 15; and a supporting hand 50 coupled with the transferring arm 30. The transferring device 10 is disposed between a loading/unloading chamber 7 which accommodates the plurality of workpieces 15 and a processing chamber 5 which receives the workpiece(s) 15 to proceed with a predetermined process, and transfers the workpiece(s) 15. The transferring device 10 may transfer the workpiece 15 under the condition of vacuum and/or a chemical reaction, such as a deposition process or an etching process.

The workpiece 15 can have a predetermined thickness and diameter according to its standard. The workpiece 15 is supported by the supporting hand 50 and transferred by the transferring device main body 20 or by the transferring arm 30. The workpiece 15 may have a round shape, or alternatively, a rectangular shape, such as a small panel.

As illustrated in FIG. 2, the transferring device main body 20 can comprise a driver (not illustrated) which is coupled with the transferring arm 30 and transfers the workpiece 15 in vertical and horizontal directions. The transferring device main body 20 may vary in optimal/fastest transferring speed to transfer the workpiece 15, according to manufacturers. The transferring device main body 20 comprises rotational regions including: a region where the rotation speed increases from a suspension state; a region where the optimal rotation speed is uniformly maintained; and a region where the optimal rotation speed decreases, while rotating.

The transferring arm 30 may comprise a driver (not illustrated) which is coupled with the transferring device main body 20 and provides a moving force to move between a loading/unloading position of loading and unloading the workpiece 15 by the supporting hand 50 and a retraction position that is retracted to be adjacent to the transferring device main body 20.

As illustrated in FIGS. 2 through 4B, the supporting hand 50 comprises a stepped engaging part 51, which is coupled with the transferring arm 30 and has a predetermined diameter to support the workpiece 15 based on a force applied to the workpiece 15 according to the varying rotation speed of the transferring arm 30. The supporting hand 50 comprises a ceramic which has high resistance to a chemical process such as a deposition process or stainless steel which has corrosion resistance or high strength, but is not limited thereto. Alternatively, the supporting hand 50 may comprise various well-known materials as necessary in order to achieve the intended purposes of the general inventive concept as described herein. The supporting hand 50 comprises a coupling part 53 which is provided on a first end thereof and couples with the transferring arm 30; and a couple of blades 55 which extend from the coupling part 53 and are spaced from each other. The supporting hand 50 further comprises a spacer 57 which is depressed from a planar surface of the stepped engaging part 51 with a predetermined depth. The supporting hand 50 further comprises an inclination part 59 which is formed along edges of the engaging part 51.

As illustrated in FIGS. 4A and 4B, the engaging part 51 is depressed from the planar surface of the supporting hand 50 and has a larger diameter than the workpiece 15. The engaging part 51 comprises a first engaging part 51a which is formed adjacent to the coupling part 53; and a couple of second engaging parts 51b which are formed adjacent to the blades 55. More specifically, each second engaging part 51b is formed adjacent to a respective one of the blades 55. An angle (2X) between the two second engaging parts 51b is determined on the basis of a direction of a resultant force of a centrifugal force and a rotation inertial force applied to the workpiece 15 according to the varying rotation speed of the transferring arm 30.

Hereinafter, a process of determining the angle (2X) between the second engaging parts 51b will be described. First, an optimal rotation speed of the transferring device main body 20 is calculated. That is, the rotation speed is calculated in the speed increasing region where the transferring device main body 20 starts rotating and reaches the optimal speed, the uniform speed region where the transferring device main body 20 rotates at an uniform speed, and a speed decreasing region where the rotation speed of the transferring device main body 20 becomes 0 from the optimal speed. The optimal rotation speed of the transferring device main body 20 may be determined from a speed range including the maximum speed, in consideration of the distance between the processes, the size of the workpiece 15 and the type of the transferring device main body 20. Then, the angle (2X) between the second engaging parts 51b may be calculated as follows, based on the optimal speed change.

First, a centrifugal force according to the varying rotation speeds in the respective processes may be calculated as follows.

F_{(centrifugal)}=mdω²  Formula 1

Here, “m” refers to the weight of the workpiece 15, “d” is distance from the rotation center of the transferring device main body 20 to the center of the workpiece 15 (see FIG. 3), and “ω” is an angular velocity (radian/sec) of the transferring device main body 20.

Then, an angular acceleration may be calculated as follows.

α=ω/t  Formula 2

Here, “t” refers to acceleration time.

The rotation inertial force according to the angular acceleration can be calculated as follows.

F_(rotation)=mdα  Formula 3

Thus, the combined force of the centrifugal force and the rotation inertial force in Formula 1 through 3 is as follows.

F=√{square root over (F^Q_centrifugal+F^Q_rotation)}  Formula 4

Here, the engaging part 51 is provided in a position where the resultant force of the centrifugal force and the rotation inertial force calculated through the Formula 4 becomes the maximum.

Here, the angle X (see, for example, FIG. 3) between the resultant force and the centrifugal force may be calculated as follows.

$\begin{array}{cc}X={\cos }^{-1}\left(\frac{F_{\mathrm{centrifugal}}}{F}\right)& \mathrm{Formula}5\end{array}$

Then, the angle 2X is the angle between the second engaging parts 51b. The engaging part 51 may vary in thickness (see FIGS. 4A and 4B) according to the size of the workpiece 15 and the optimal rotation speed.

The engaging part 51 is depressed from the plate surface of the supporting hand 50 with the predetermined depth. The depth thereof may vary according to the size and thickness of the workpiece 15. Alternatively, the engaging part 51 may protrude from the plate surface of the supporting hand 50 to a predetermined height or may be installed at a predetermined position as a plurality of pins protruding from the plate surface of the supporting hand 50, to have a predetermined inner diameter.

Thus, the engaging part 51 of the supporting hand 50 can stably support the workpiece 15 corresponding to the varying rotation speed of the workpiece 15 since the engaging part 51 is formed in consideration of the resultant force according to the optimal rotation speed. Also, the transferring device 10 can reduce the transferring time of the workpiece 15.

As illustrated in FIG. 4A, the coupling part 53 comprises at least one coupling hole 53a which is formed on a side thereof to be coupled with the transferring arm 30 by a coupling member, such as a screw.

The blades 55 are shaped like a plate and separated from each other, to thereby minimize the weight of the supporting hand 50.

the spacer 57 is depressed from the planar surface of the engaging part 51 with a predetermined depth. The spacer 57 has a smaller diameter than the workpiece 15, and thus the workpiece 15 supported by the engaging part 51 is and not in contact with the planar surface of the spacer 57. Thus, the surface of the engaging part 51 which contacts the workpiece 15 is minimized, thereby preventing contamination or damages to the workpiece 15 due to contact with the workpiece 15.

The inclination part 59, formed along the edges of the engaging part 51, allows the workpiece 15 to be stably seated by its own weight.

As described above, the workpiece 15 may comprise a wafer according to the exemplary embodiment of the present general inventive concept, but is not limited thereto. The transferring device 10 according to the present general inventive concept may be applicable to transferring various types of workpieces, such a small display panel.

With the foregoing configuration, the rotating process of the transferring device 10 according to the present general inventive concept will be described with reference to FIGS. 5A and 6.

First, a method of providing the transferring device 10 that supports the workpiece 15 will be described with reference to FIG. 6.

The transferring device main body 20 comprises a driver (not illustrated) such as a robot to transfer the workpiece 15 vertically and horizontally at a stage of constituting the transferring device main body 20 (operation S110).

The transferring arm 30 is coupled with the transferring device main body 20 to support the workpiece 15 and to transfer the workpiece 15 between the loading/unloading position and the retraction position at the operation of coupling the transferring arm 30 (operation S115).

The optimal rotation speed is calculated in the speed increasing region where the transferring device main body 20 starts rotating and reaches the optimal rotation speed, the uniform speed region where the transferring device main body 20 rotates at the uniform speed and the speed decreasing region where the rotation speed of the transferring device main body 20 is reduced to “0” from the optimal rotation speed, at the stage of determining the optimal rotation speed (operation S120). Here, the optimal rotation speed may be determined within the speed range including the maximum rotation speed of the transferring device main body 20 in consideration of the speed capability of the transferring device main body 20, the processing time and the type of the workpiece 15.

Then, the angle 2X between the two second engaging parts 51b is determined to support the workpiece 15 based on the forces applied to the workpiece 15 according to the varying rotation speeds of the transferring arm 30 (operation S125). The angle 2X is calculated based on the resultant force of the centrifugal force and the rotation inertial force applied to the workpiece 15 according to the varying rotation speeds of the transferring arm 30.

The engaging part 51 is depressed from the planar surface of the supporting hand 50 considering the angle 2X calculated at the stage of operation S125 (operation S130).

The supporting hand 50 having the engaging part 51 is coupled with the transferring arm 30 by a screw or the like (operation S135).

A process of supporting and rotating the workpiece 15 is illustrate in FIGS. 5A and 5D.

As illustrated in FIG. 5A, the transferring arm 30 is moved to the loading/unloading position to load the workpiece 15, and supports the workpiece 15. As illustrated in FIG. 5B, while the workpiece 15 is supported by the engaging part 51 of the supporting hand 50, the transferring arm 30 is moved from the loading/unloading position to the retraction position adjacent to the transferring device main body 20. Then, as illustrated in FIG. 5C, the transferring arm 30 comprises the process of increasing the speed; the process of rotating at the uniform speed; and the process of being positioned at the predetermined position according to the decrease of the rotation speed while rotating according to the varying optimal rotation speed. The centrifugal force and the rotation inertial force are applied to the workpiece 15 during the processes. The engaging part 51 is provided in the position where the resultant force of the centrifugal force and the rotation inertial force becomes the maximum. As illustrated in FIG. 5D, the transferring device main body 20 rotates to a predetermined position, and the workpiece 15 is transferred to the processing chamber (refer to FIG. 1).

As described above, the engaging part 51 is provided in a direction where the maximum force is applied to the workpiece in consideration of varying optimal rotation speeds of the transferring device main body, thereby stably supporting the workpiece and preventing damages to the workpiece. Also, the rotation speed is maximized to reduce the processing time.

As described above, a workpiece is stably supported corresponding to varying rotation speeds according to the present general inventive concept, thereby preventing damages to the workpiece and reducing the processing time according to the transfer of the workpiece.

Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A transferring device, comprising:

a transferring device main body;

a transferring arm that couples with the transferring device main body to transfer a workpiece; and

a supporting hand which has a plurality of engaging parts coupled with the transferring arm and forms a predetermined angle therebetween to support the workpiece based on a force applied to the workpiece according to varying rotation speeds of the transferring arm.

2. The transferring device according to claim 1, wherein the supporting hand comprises a coupling part which couples with the transferring arm and a plurality of blades which extend from the coupling part and are spaced apart from each other.

3. The transferring device according to claim 2, wherein the engaging part comprises a first engaging part formed on the coupling part, and a second engaging part formed on each of the blades, and the angle between the engaging parts is defined by an angle between the second engaging parts with respect to the center of the workpiece.

4. The transferring device according to claim 3, wherein the angle between the second engaging parts is determined on the basis of a resultant force of a centrifugal force and a rotation inertial force applied to the workpiece according to the varying rotation speeds of the transferring arm.

5. The transferring device according to claim 4, wherein the engaging parts is provided in a position where the resultant force of the centrifugal force and the rotation inertial force becomes the maximum.

6. The transferring device according to claim 3, wherein the engaging parts are depressed from a planar surface of the supporting hand by a predetermined depth.

7. The transferring device according to claim 3, wherein the engaging parts form a larger diameter than the workpiece.

8. The transferring device according to claim 3, wherein the supporting hand comprises a spacer which is depressed inside the engaging parts.

9. The transferring device according to claim 8, wherein the spacer has a smaller diameter than the workpiece.

10. The transferring device according to claim 3, wherein the supporting hand comprises one of stainless steel and ceramic.

11. The transferring device according to claim 3, wherein the supporting hand comprises an inclination part formed along edges of the engaging parts.

12. The transferring device according to claim 1, wherein the workpiece comprises a wafer.

13. A transferring device to transfer a workpiece, comprising:

a body;

a transferring arm to extend away from and contract toward the body; and

a supporting hand to connect with the transferring arm, the supporting hand comprising: a coupling part to engage with the transferring arm, two blades extending from the coupling part and spaced from each other by a predetermined amount, a stepped engaging part having a circular stepped portion extending about a circular region crossing the coupling part and an outer portion of the two blades, the stepped engaging part stepped down from a surface of the coupling part and having a diameter wider than the workpiece, and a spacer part stepped down from the stepped engaging part in a center portion thereof.

14. The transferring device according to claim 13, wherein an angle X formed at the center of the diameter of the stepped engaging part between a line extending to a center of the stepped engaging part crossing one of the blades and a line extending to a center of the stepped engaging part crossing the other one of the blades is determined on the basis of a direction of a resultant force of a centrifugal force and a rotation inertial force applied to the workpiece according to a varying rotation speed of the transferring arm.

15. The transferring device according to claim 14, wherein the angle X is calculated as follows: X = cos - 1  ( F centrifugal F ).

calculating a centrifugal force as F(centrifugal)=mdω2

where “m” refers to the weight of the workpiece 15, “d” is distance from the rotation center of the transferring device main body 20 to the center of the workpiece 15 (see FIG. 3), and “ω” is an angular velocity (radian/sec) of the transferring device main body,

calculating an angular acceleration α=ω/t,

where “t” refers to acceleration time,

calculating the rotation inertial force according to an angular acceleration as F(rotation)=mdα,

combining the calculated centrifugal force and the rotation inertial force as F=√{square root over (FQcentrifugal+FQrotation)},

and calculating the angle X as

16. A supporting hand usable with a transferring device to transfer a workpiece, comprising:

a coupling part provided on a first end to couple with a transferring arm of the transfer device;

a couple of blades which extend from the coupling part and are spaced apart from each other; and

a stepped engaging part stepped from the surface of the coupling part and having a predetermined diameter extending across the coupling part and the coupling blades to support the workpiece thereon, the stepped engaging part having a larger diameter than the workpiece.

17. The supporting hand according to claim 16, wherein an angle between the engaging part on the first blade and the engaging part on the second blade is determined on the basis of a direction of a resultant force of a centrifugal force and a rotation inertial force applied to the workpiece according to a varying rotation speed of the transferring arm.

18. A method of determining an angle between blades of a transfer device supporting hand to transfer a wafer, the method comprising:

calculating an optimal rotation speed of a transferring device main body; and

calculating an angle between a predetermined part of two blades with respect to a center portion of a wafer holding area of the supporting hand.

19. The method of according to claim 18, wherein the calculating an optimal rotation speed of the transferring device comprises:

calculating a rotation speed in the speed increasing region where the transferring device main body starts rotating and reaches the optimal speed, the uniform speed region where the transferring device rotates at a uniform speed, and a speed decreasing region where the rotation speed of the transferring device main body becomes 0 from the optimal speed.